@@@ bench wip

[mLib] / test / tvec.h

/* -*-c-*-
 *
 * Test vector processing framework
 *
 * (c) 2023 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of the mLib utilities library.
 *
 * mLib is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Library General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * mLib is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with mLib.  If not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */

#ifndef MLIB_TVEC_H
#define MLIB_TVEC_H

#ifdef __cplusplus
  extern "C" {
#endif

/* Here's the overall flow for a testing session.
 *
 * @tvec_begin@
 *                      -> output @bsession@
 * @tvec_read@
 *                      -> output @bgroup@
 *                      -> env @setup@
 *   one or more tests
 *                      -> type @init@ (input and output)
 *                      -> type @parse@ (input)
 *                      -> output @btest@
 *                      -> env @before@
 *                              -> @tvec_skipgroup@
 *                                      -> output @skipgroup@
 *                      -> env @run@
 *                              -> @tvec_skip@
 *                                      -> output @skip@
 *                              -> test @fn@
 *                              -> @tvec_checkregs@
 *                                      -> type @eq@
 *                              -> @tvec_fail@
 *                                      -> output @fail@
 *                              -> @tvec_mismatch@
 *                                      -> output @dumpreg@
 *                                              -> type @dump@
 *                      -> output @etest@
 *                      -> env @after@
 *   finally
 *                      -> output @egroup@
 *                      -> env @teardown@
 *
 * @tvec_adhoc@
 *   @tvec_begingroup@
 *                      -> output @bgroup@
 *                      -> env @setup@
 *     @tvec_begintest@
 *                      -> output @btest@
 *     @tvec_skip@
 *                      -> output @skip@
 *     @tvec_claimeq@
 *                      -> @tvec_fail@
 *                              -> output @fail@
 *                      -> @tvec_mismatch@
 *                              -> output @dumpreg@
 *                              -> type @dump@
 *     @tvec_endtest@
 *                      -> output @etest@
 *     or @tvec_skipgroup@
 *                      -> output @skipgroup@
 * @tvec_endgroup@
 *                      -> output @egroup@
 *
 * @tvec_end@
 *                      -> output @esession@
 *                      -> output @destroy@
 *
 * @tvec_benchrun@
 *                      -> type @dump@ (compact style)
 *                      -> output @bbench@
 *                      -> subenv @run@
 *                              -> test @fn@
 *                      -> output @ebench@
 *                              -> @tvec_benchreport@
 *
 * The output functions @error@ and @notice@ can be called at arbitrary
 * times.
 */

/*----- Header files ------------------------------------------------------*/

#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>

#ifndef MLIB_BUF_H
#  include "buf.h"
#endif

#ifndef MLIB_CONTROL_H
#  include "control.h"
#endif

#ifndef MLIB_BUF_H
#  include "dstr.h"
#endif

#ifndef MLIB_GPRINTF_H
#  include "gprintf.h"
#endif

#ifndef MLIB_LBUF_H
#  include "lbuf.h"
#endif

#ifndef MLIB_MACROS_H
#  include "macros.h"
#endif

/*----- Miscellaneous values ----------------------------------------------*/

/* These are attached to structures which represent extension points, as a
 * way to pass an opaque parameter to whatever things are hooked onto them.
 */

#define TVEC_MISCSLOTS(_)                                               \
        _(PTR, const void *, p)         /* arbitrary pointer */         \
        _(INT, long, i)                 /* signed integer */            \
        _(UINT, unsigned long, u)       /* signed integer */            \
        _(FLT, double, f)               /* floating point */

union tvec_misc {
#define TVEC_DEFSLOT(tag, ty, slot) ty slot;
  TVEC_MISCSLOTS(TVEC_DEFSLOT)
#undef TVEC_DEFSLOT
};
enum {
#define TVEC_DEFCONST(tag, ty, slot) TVMISC_##tag,
  TVEC_MISCSLOTS(TVEC_DEFCONST)
  TVMISC_LIMIT
};

/*----- Register values ---------------------------------------------------*/

/* The framework doesn't have a preconceived idea about what's in a register
 * value: it just allocates them and accesses them through the register type
 * functions.  It doesn't even have a baked-in idea of how big a register
 * value is: instead, it gets that via the `regsz' slot in `struct
 * tvec_testinfo'.  So, as far as the framework is concerned, it's safe to
 * add new slots to this union, even if they make the overall union larger.
 * This can be done by defining the preprocessor macro `TVEC_REGSLOTS' to be
 * a `union' fragment defining any additional union members.
 *
 * This creates a distinction between code which does and doesn't know the
 * size of a register value.  Code which does, which typically means the test
 * functions, benchmarking setup and teardown functions, and tightly-bound
 * runner functions, is free to index the register vectors directly.  Code
 * which doesn't, which means the framework core itself and output formatting
 * machinery, must use the `TVEC_REG' macro (or its more general `TVEC_GREG'
 * companion) for indexing register vectors.  (In principle, register type
 * handlers also fit into this category, but they have no business peering
 * into register values other than the one's they're given.)
 */

union tvec_regval {
  /* The actual register value.  This is what the type handler sees.
   * Additional members can be added by setting `TVEC_REGSLOTS' before
   * including this file.
   *
   * A register value can be /initialized/, which simply means that its
   * contents represent a valid value according to its type -- the register
   * can be compared, dumped, serialized, parsed into, etc.  You can't do
   * anything safely to an uninitialized register value other than initialize
   * it.
   */

  long i;                               /* signed integer */
  unsigned long u;                      /* unsigned integer */
  void *p;                              /* pointer */
  double f;                             /* floating point */
  struct { unsigned char *p; size_t sz; } bytes; /* binary string of bytes */
  struct { char *p; size_t sz; } text;  /* text string */
  struct {                              /* buffer */
    unsigned char *p; size_t sz;        /* binary string */
    size_t a, m;                        /* residue and modulus */
    size_t off;                         /* offset into full buffer */
  } buf;
#ifdef TVEC_REGSLOTS
  TVEC_REGSLOTS
#endif
};

struct tvec_reg {
  /* A register.
   *
   * Note that all of the registers listed as being used by a particular test
   * group are initialized at all times[1] while that test group is being
   * processed.  (The other register slots don't even have types associated
   * with them, so there's nothing useful we could do with them.)
   *
   * The `TVRF_LIVE' flag indicates that the register was assigned a value by
   * the test vector file: it's the right thing to use to check whether an
   * optional register is actually present.  Even `dead' registers are still
   * initialized, though.
   *
   * [1] This isn't quite true.  Between individual tests, the registers are
   *     released and reinitialized in order to reset them to known values
   *     ready for the next test.  But you won't see them at this point.
   */

  unsigned f;                           /* flags */
#define TVRF_LIVE 1u                    /*   used in current test  */
  union tvec_regval v;                  /* register value */
};

struct tvec_regdef {
  /* A register definition.  Register definitions list the registers which
   * are used by a particular test group (see `struct tvec_test' below).
   *
   * A vector of register definitions is terminated by a definition whose
   * `name' slot is null.
   */

  const char *name;                     /* register name (for input files) */
  unsigned i;                           /* register index */
  const struct tvec_regty *ty;          /* register type descriptor */
  unsigned f;                           /* flags */
#define TVRF_OPT 1u                     /*   optional register */
#define TVRF_ID 2u                      /*   part of test identity  */
  union tvec_misc arg;                  /* extra detail for the type */
};
#define TVEC_ENDREGS { 0, 0, 0, 0, { 0 } }

/* @TVEC_GREG(vec, i, regsz)@
 *
 * If @vec@ is a data pointer which happens to contain the address of a
 * vector of @struct tvec_reg@ objects, @i@ is an integer, and @regsz@ is the
 * size of a @struct tvec_reg@, then this evaluates to the address of the
 * @i@th element of the vector.
 *
 * This is the general tool you need for accessing register vectors when you
 * don't have absolute knowledge of the size of a @union tvec_regval@.
 * Usually you want to access one of the register vectors in a @struct
 * tvec_state@, and @TVEC_REG@ will be more convenient.
 */
#define TVEC_GREG(vec, i, regsz)                                        \
        ((struct tvec_reg *)((unsigned char *)(vec) + (i)*(regsz)))

/*----- Register types ----------------------------------------------------*/

struct tvec_state;                      /* forward declaration */

struct tvec_regty {
  /* A register type. */

  void (*init)(union tvec_regval */*rv*/, const struct tvec_regdef */*rd*/);
    /* Initialize the value in @*rv@.  This will be called before any other
     * function acting on the value, including @release@.
     */

  void (*release)(union tvec_regval */*rv*/,
                  const struct tvec_regdef */*rd*/);
    /* Release any resources associated with the value in @*rv@. */

  int (*eq)(const union tvec_regval */*rv0*/,
            const union tvec_regval */*rv1*/,
            const struct tvec_regdef */*rd*/);
    /* Return nonzero if @*rv0@ and @*rv1@ are equal values.  Asymmetric
     * criteria are permitted: @tvec_checkregs@ calls @eq@ with the input
     * register as @rv0@ and the output as @rv1@.
     */

  int (*tobuf)(buf */*b*/, const union tvec_regval */*rv*/,
               const struct tvec_regdef */*rd*/);
    /* Serialize the value @*rv@, writing the result to @b@.  Return zero on
     * success, or %$-1$% on error.
     */

  int (*frombuf)(buf */*b*/, union tvec_regval */*rv*/,
                 const struct tvec_regdef */*rd*/);
    /* Deserialize a value from @b@, storing it in @*rv@.  Return zero on
     * success, or %$-1$% on error.
     */

  int (*parse)(union tvec_regval */*rv*/, const struct tvec_regdef */*rd*/,
               struct tvec_state */*tv*/);
    /* Parse a value from @tv->fp@, storing it in @*rv@.  Return zero on
     * success, or %$-1$% on error, having reported one or more errors via
     * @tvec_error@ or @tvec_syntax@.  A successful return should leave the
     * input position at the start of the next line; the caller will flush
     * the remainder of the line itself.
     */

  void (*dump)(const union tvec_regval */*rv*/,
               const struct tvec_regdef */*rd*/,
               unsigned /*style*/,
               const struct gprintf_ops */*gops*/, void */*go*/);
#define TVSF_COMPACT 1u
    /* Write a human-readable representation of the value @*rv@ using
     * @gprintf@ on @gops@ and @go@.  The @style@ is a collection of flags:
     * if @TVSF_COMPACT@ is set, then output should be minimal, and must fit
     * on a single line; otherwise, output may consist of multiple lines and
     * may contain redundant information if that is likely to be useful to a
     * human reader.
     */
};

/*----- Test descriptions -------------------------------------------------*/

typedef void tvec_testfn(const struct tvec_reg */*in*/,
                         struct tvec_reg */*out*/,
                         void */*ctx*/);
  /* A test function.  It should read inputs from @in@ and write outputs to
   * @out@.  The @TVRF_LIVE@ is set on inputs which are actually present, and
   * on outputs which are wanted to test.  A test function can set additional
   * `gratuitous outputs' by setting @TVRF_LIVE@ on them; clearing
   * @TVRF_LIVE@ on a wanted output causes a mismatch.
   *
   * A test function may be called zero or more times by the environment.  In
   * particular, it may be called multiple times, though usually by prior
   * arrangement with the environment.
   *
   * The @ctx@ is supplied by the environment's @run@ function (see below).
   * The default environment calls the test function once, with a null
   * @ctx@.  There is no expectation that the environment's context has
   * anything to do with the test function's context.
   */

struct tvec_env;

typedef int tvec_setvarfn(struct tvec_state */*tv*/, const char */*var*/,
                          const union tvec_regval */*rv*/, void */*ctx*/);
  /* Called after a variable is read.  Return zero on success or %$-1$% on
   * error.  This function is never called if the test group is skipped.
   */

struct tvec_vardef {
  size_t regsz;                         /* (minimum) register size */
  tvec_setvarfn *setvar;                /* function to set variable */
  struct tvec_regdef def;               /* register definition */
};

typedef void tvec_envsetupfn(struct tvec_state */*tv*/,
                             const struct tvec_env */*env*/,
                             void */*pctx*/, void */*ctx*/);
  /* Initialize the context; called at the start of a test group; @pctx@ is
   * null for environments called by the core, but may be non-null for
   * subordinate environments.  If setup fails, the function should call
   * @tvec_skipgroup@ with a suitable excuse.  The @set@, @after@, and
   * @teardown@ entry points will still be called, but @before@ and @run@
   * will not.
   */

typedef const struct tvec_vardef *tvec_envfindvarfn
  (struct tvec_state */*tv*/, const char */*name*/,
   void **/*ctx_out*/, void */*ctx*/);
  /* Called when the parser finds a %|@var|%' special variable.  If a
   * suitable variable was found, set @*ctx_out@ to a suitable context and
   * return the variable definition; the context will be passed to the
   * variable definition's @setvar@ function.  If no suitable variable was
   * found, then return null.
   */

typedef void tvec_envbeforefn(struct tvec_state */*tv*/, void */*ctx*/);
  /* Called prior to running a test.  This is the right place to act on any
   * `%|@var|%' settings.  If preparation fails, the function should call
   * @tvec_skip@ with a suitable excuse.  This function is never called if
   * the test group is skipped.  It %%\emph{is}%% called if the test will be
   * skipped due to erroneous test data.  It should check the @TVSF_ACTIVE@
   * flag if necessary.
   */

typedef void tvec_envrunfn(struct tvec_state */*tv*/,
                           tvec_testfn */*fn*/, void */*ctx*/);
  /* Run the test.  It should either call @tvec_skip@, or run @fn@ one or
   * more times.  In the latter case, it is responsible for checking the
   * outputs, and calling @tvec_fail@ as necessary; @tvec_checkregs@ will
   * check the register values against the supplied test vector, while
   * @tvec_check@ does pretty much everything necessary.  This function is
   * never called if the test group is skipped.
   */

typedef void tvec_envafterfn(struct tvec_state */*tv*/, void */*ctx*/);
  /* Called after running or skipping a test.  Typical actions involve
   * resetting whatever things were established by @set@.  This function
   * %%\emph{is}%% called if the test group is skipped or the test data is
   * erroneous, so that the test environment can reset variables set by the
   * @set@ entry point.  It should check the @TVSF_SKIP@ flag if necessary.
   */

typedef void tvec_envteardownfn(struct tvec_state */*tv*/, void */*ctx*/);
  /* Tear down the environment: called at the end of a test group. */


struct tvec_env {
  /* A test environment sets things up for and arranges to run the test.
   *
   * The caller is responsible for allocating storage for the environment's
   * context, based on the @ctxsz@ slot, and freeing it later; this space is
   * passed in as the @ctx@ parameter to the remaining functions; if @ctxsz@
   * is zero then @ctx@ is null.
   */

  size_t ctxsz;                         /* environment context size */

  tvec_envsetupfn *setup;               /* setup for group */
  tvec_envfindvarfn *findvar;           /* find variable */
  tvec_envbeforefn *before;             /* prepare for test */
  tvec_envrunfn *run;                   /* run test function */
  tvec_envafterfn *after;               /* clean up after test */
  tvec_envteardownfn *teardown;         /* tear down after group */
};

struct tvec_test {
  /* A test description. */

  const char *name;                     /* name of the test */
  const struct tvec_regdef *regs;       /* descriptions of the registers */
  const struct tvec_env *env;           /* environment to run test in */
  tvec_testfn *fn;                      /* test function */
};
#define TVEC_ENDTESTS { 0, 0, 0, 0 }

enum {
  /* Register output dispositions. */

  TVRD_INPUT,                           /* input-only register */
  TVRD_OUTPUT,                          /* output-only (input is dead) */
  TVRD_MATCH,                           /* matching (equal) registers */
  TVRD_FOUND,                           /* mismatching output register */
  TVRD_EXPECT,                          /* mismatching input register */
  TVRD_LIMIT                            /* (number of dispositions) */
};

/*----- Test state --------------------------------------------------------*/

enum {
  /* Possible test outcomes. */

  TVOUT_LOSE,                           /* test failed */
  TVOUT_SKIP,                           /* test skipped */
  TVOUT_WIN,                            /* test passed */
  TVOUT_XFAIL,                          /* test passed, but shouldn't have */
  TVOUT_LIMIT                           /* (number of possible outcomes) */
};

struct tvec_state {
  /* The primary state structure for the test vector machinery. */

  unsigned f;                           /* flags */
#define TVSF_SKIP 0x0001u               /*   skip this test group */
#define TVSF_OPEN 0x0002u               /*   test is open */
#define TVSF_ACTIVE 0x0004u             /*   test is active */
#define TVSF_ERROR 0x0008u              /*   an error occurred */
#define TVSF_OUTMASK 0x00f0u            /*   test outcome (@TVOUT_...@) */
#define TVSF_OUTSHIFT 4                 /*   shift applied to outcome */
#define TVSF_XFAIL 0x0100u              /*   test expected to fail */
#define TVSF_MUFFLE 0x0200u             /*   muffle errors */

  /* Registers.  Available to execution environments. */
  unsigned nrout, nreg;                /* number of output/total registers */
  size_t regsz;                         /* size of register entry */
  struct tvec_reg *in, *out;            /* register vectors */

  /* Test groups state.  Available to output formatters. */
  const struct tvec_test *tests, *test; /* all tests and current test */

  /* Test scoreboard.  Available to output formatters. */
  unsigned curr[TVOUT_LIMIT], all[TVOUT_LIMIT], grps[TVOUT_LIMIT];

  /* Output machinery. */
  struct tvec_output *output;           /* output formatter */

  /* Input machinery.  Available to type parsers. */
  const char *infile; unsigned lno, test_lno; /* input file name, line */
  FILE *fp;                             /* input file stream */
};

/* @TVEC_REG(tv, vec, i)@
 *
 * If @tv@ is a pointer to a @struct tvec_state@, @vec@ is either @in@ or
 * @out@, and @i@ is an integer, then this evaluates to the address of the
 * @i@th register in the selected vector.
 */
#define TVEC_REG(tv, vec, i) TVEC_GREG((tv)->vec, (i), (tv)->regsz)

struct tvec_config {
  /* An overall test configuration. */

  const struct tvec_test *tests;        /* the tests to be performed */
  unsigned nrout, nreg;                 /* number of output/total regs */
  size_t regsz;                         /* size of a register */
};

/*----- Output formatting -------------------------------------------------*/

struct tvec_output {
  /* An output formatter. */
  const struct tvec_outops *ops;        /* pointer to operations */
};

/* Benchmarking details. */
enum {
  TVBU_OP,                             /* counting operations of some kind */
  TVBU_BYTE,                            /* counting bytes (@rbuf >= 0@) */
  TVBU_LIMIT                            /* (number of units) */
};
struct bench_timing;     /* include <mLib/bench.h> for the real definition */

struct tvec_outops {
  /* Output operations. */

  void (*bsession)(struct tvec_output */*o*/, struct tvec_state */*tv*/);
    /* Begin a test session.  The output driver will probably want to
     * save @tv@, because this isn't provided to any other methods.
     */

  int (*esession)(struct tvec_output */*o*/);
    /* End a session, and return the suggested exit code. */

  void (*bgroup)(struct tvec_output */*o*/);
    /* Begin a test group.  The test group description is @tv->test@. */

  void (*skipgroup)(struct tvec_output */*o*/,
                    const char */*excuse*/, va_list */*ap*/);
    /* The group is being skipped; @excuse@ may be null or a format
     * string explaining why.  The @egroup@ method will not be called
     * separately.
     */

  void (*egroup)(struct tvec_output */*o*/);
    /* End a test group.  At least one test was attempted or @skipgroup@
     * would have been called instead.  If @tv->curr[TVOUT_LOSE]@ is nonzero
     * then the test group as a whole failed; otherwise it passed.
     */

  void (*btest)(struct tvec_output */*o*/);
    /* Begin a test case. */

  void (*skip)(struct tvec_output */*o*/,
               const char */*excuse*/, va_list */*ap*/);
    /* The test case is being skipped; @excuse@ may be null or a format
     * string explaining why.  The @etest@ function will still be called (so
     * this works differently from @skipgroup@ and @egroup@).  A test case
     * can be skipped at most once, and, if skipped, it cannot fail.
     */

  void (*fail)(struct tvec_output */*o*/,
               const char */*detail*/, va_list */*ap*/);
    /* The test case failed.
     *
     * The output driver should preferably report the filename (@infile@) and
     * line number (@test_lno@, not @lno@) for the failing test.
     *
     * The @detail@ may be null or a format string describing detail about
     * how the failing test was run which can't be determined from the
     * registers; a @detail@ is usually provided when (and only when) the
     * test environment potentially invokes the test function more than once.
     *
     * A single test case can fail multiple times!
     */

  void (*dumpreg)(struct tvec_output */*o*/,
                  unsigned /*disp*/, const union tvec_regval */*rv*/,
                  const struct tvec_regdef */*rd*/);
    /* Dump a register.  The `disposition' @disp@ explains what condition the
     * register is in; see @tvec_dumpreg@ and the @TVRD_...@ codes.  The
     * register value is at @rv@, and its definition, including its type, at
     * @rd@.  Note that this function may be called on virtual registers
     * which aren't in either of the register vectors or mentioned by the
     * test description.  It may also be called with @rv@ null, indicating
     * that the register is not live.
     */

  void (*etest)(struct tvec_output */*o*/, unsigned /*outcome*/);
    /* The test case concluded with the given @outcome@ (one of the
     * @TVOUT_...@ codes.
     */

  void (*bbench)(struct tvec_output */*o*/,
                 const char */*ident*/, unsigned /*unit*/);
    /* Begin a benchmark.  The @ident@ is a formatted string identifying the
     * benchmark based on the values of the input registered marked
     * @TVRF_ID@; the output driver is free to use this or come up with its
     * own way to identify the test, e.g., by inspecting the register values
     * for itself.  The @unit@ is one of the @TVBU_...@ constants explaining
     * what sort of thing is being measured.
     */

  void (*ebench)(struct tvec_output */*o*/,
                 const char */*ident*/, unsigned /*unit*/,
                 const struct bench_timing */*tm*/);
    /* End a benchmark.  The @ident@ and @unit@ arguments are as for
     * @bbench@.  If @tm@ is zero then the measurement failed; otherwise
     * @tm->n@ counts total number of things (operations or bytes, as
     * indicated by @unit@) processed in the indicated time.
     */

  void (*report)(struct tvec_output */*o*/, unsigned /*level*/,
                 const char */*msg*/, va_list */*ap*/);
    /* Report a message.  The driver should ideally report the filename
     * (@infile@) and line number (@lno@) prompting the error.
     */

  void (*destroy)(struct tvec_output */*o*/);
    /* Release any resources acquired by the driver. */
};

#define TVEC_LEVELS(_)                                                  \
        _(NOTE, "notice", 4)                                            \
        _(ERR, "ERROR", 8)

enum {
#define TVEC_DEFLEVEL(tag, name, val) TVLEV_##tag = val,
  TVEC_LEVELS(TVEC_DEFLEVEL)
#undef TVEC_DEFLEVEL
  TVLEV_LIMIT
};

/*----- Session lifecycle -------------------------------------------------*/

/* --- @tvec_begin@ --- *
 *
 * Arguments:   @struct tvec_state *tv_out@ = state structure to fill in
 *              @const struct tvec_config *config@ = test configuration
 *              @struct tvec_output *o@ = output driver
 *
 * Returns:     ---
 *
 * Use:         Initialize a state structure ready to do some testing.
 */

extern void tvec_begin(struct tvec_state */*tv_out*/,
                       const struct tvec_config */*config*/,
                       struct tvec_output */*o*/);

/* --- @tvec_end@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *
 * Returns:     A proposed exit code.
 *
 * Use:         Conclude testing and suggests an exit code to be returned to
 *              the calling program.  (The exit code comes from the output
 *              driver's @esession@ method.)
 */

extern int tvec_end(struct tvec_state */*tv*/);

/* --- @tvec_read@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *infile@ = the name of the input file
 *              @FILE *fp@ = stream to read from
 *
 * Returns:     Zero on success, %$-1$% on error.
 *
 * Use:         Read test vector data from @fp@ and exercise test functions.
 *              THe return code doesn't indicate test failures: it's only
 *              concerned with whether there were problems with the input
 *              file or with actually running the tests.
 */

extern int tvec_read(struct tvec_state */*tv*/,
                     const char */*infile*/, FILE */*fp*/);

/*----- Command-line interface --------------------------------------------*/

extern const struct tvec_config tvec_adhocconfig;
  /* A special @struct tvec_config@ to use for programs which perform ad-hoc
   * testing.
   */

/* --- @tvec_parseargs@ --- *
 *
 * Arguments:   @int argc@ = number of command-line arguments
 *              @char *argv[]@ = vector of argument strings
 *              @struct tvec_state *tv_out@ = test vector state to initialize
 *              @int *argpos_out@ = where to leave unread argument index
 *              @const struct tvec_config *cofig@ = test vector configuration
 *
 * Returns:     ---
 *
 * Use:         Parse arguments and set up the test vector state @*tv_out@.
 *              If errors occur, print messages to standard error and exit
 *              with status 2.
 */

extern void tvec_parseargs(int /*argc*/, char */*argv*/[],
                           struct tvec_state */*tv_out*/,
                           int */*argpos_out*/,
                           const struct tvec_config */*config*/);

/* --- @tvec_readstdin@, @tvec_readfile@, @tvec_readarg@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test vector state
 *              @const char *file@ = pathname of file to read
 *              @const char *arg@ = argument to interpret
 *
 * Returns:     Zero on success, %$-1$% on error.
 *
 * Use:         Read test vector data from stdin or a named file.  The
 *              @tvec_readarg@ function reads from stdin if @arg@ is `%|-|%',
 *              and from the named file otherwise.
 */

extern int tvec_readstdin(struct tvec_state */*tv*/);
extern int tvec_readfile(struct tvec_state */*tv*/, const char */*file*/);
extern int tvec_readarg(struct tvec_state */*tv*/, const char */*arg*/);

/* --- @tvec_readdflt@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test vector state
 *              @const char *dflt@ = defsault filename or null
 *
 * Returns:     Zero on success, %$-1$% on error.
 *
 * Use:         Reads from the default test vector data.  If @file@ is null,
 *              then read from standard input, unless that's a terminal; if
 *              @file@ is not null, then read the named file, looking in the
 *              directory named by the `%|srcdir|%' environment variable if
 *              that's set, or otherwise in the current directory.
 */

extern int tvec_readdflt(struct tvec_state */*tv*/, const char */*file*/);

/* --- @tvec_readargs@ --- *
 *
 * Arguments:   @int argc@ = number of command-line arguments
 *              @char *argv[]@ = vector of argument strings
 *              @struct tvec_state *tv@ = test vector state
 *              @int *argpos_inout@ = current argument position (updated)
 *              @const char *dflt@ = default filename or null
 *
 * Returns:     Zero on success, %$-1$% on error.
 *
 * Use:         Reads from the sources indicated by the command-line
 *              arguments, in order, interpreting each as for @tvec_readarg@;
 *              if no arguments are given then read from @dflt@ as for
 *              @tvec_readdflt@.
 */

extern int tvec_readargs(int /*argc*/, char */*argv*/[],
                         struct tvec_state */*tv*/,
                         int */*argpos_inout*/, const char */*dflt*/);

/* --- @tvec_main@ --- *
 *
 * Arguments:   @int argc@ = number of command-line arguments
 *              @char *argv[]@ = vector of argument strings
 *              @const struct tvec_config *cofig@ = test vector configuration
 *              @const char *dflt@ = default filename or null
 *
 * Returns:     Exit code.
 *
 * Use:         All-in-one test vector front-end.  Parse options from the
 *              command-line as for @tvec_parseargs@, and then process the
 *              remaining positional arguments as for @tvec_readargs@.  The
 *              function constructs and disposes of a test vector state.
 */

extern int tvec_main(int /*argc*/, char */*argv*/[],
                     const struct tvec_config */*config*/,
                     const char */*dflt*/);

/*----- Test processing ---------------------------------------------------*/

/* --- @tvec_skipgroup@, @tvec_skipgroup_v@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *excuse@, @va_list *ap@ = reason why skipped
 *
 * Returns:     ---
 *
 * Use:         Skip the current group.  This should only be called from a
 *              test environment @setup@ function; a similar effect occurs if
 *              the @setup@ function fails.
 */

extern PRINTF_LIKE(2, 3)
  void tvec_skipgroup(struct tvec_state */*tv*/,
                      const char */*excuse*/, ...);
extern void tvec_skipgroup_v(struct tvec_state */*tv*/,
                             const char */*excuse*/, va_list */*ap*/);

/* --- @tvec_skip@, @tvec_skip_v@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *excuse@, @va_list *ap@ = reason why test skipped
 *
 * Returns:     ---
 *
 * Use:         Skip the current test.  This should only be called from a
 *              test environment @run@ function; a similar effect occurs if
 *              the @before@ function fails.
 */

extern PRINTF_LIKE(2, 3)
  void tvec_skip(struct tvec_state */*tv*/, const char */*excuse*/, ...);
extern void tvec_skip_v(struct tvec_state */*tv*/,
                        const char */*excuse*/, va_list */*ap*/);

/* --- @tvec_fail@, @tvec_fail_v@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *detail@, @va_list *ap@ = description of test
 *
 * Returns:     ---
 *
 * Use:         Report the current test as a failure.  This function can be
 *              called multiple times for a single test, e.g., if the test
 *              environment's @run@ function invokes the test function
 *              repeatedly; but a single test that fails repeatedly still
 *              only counts as a single failure in the statistics.  The
 *              @detail@ string and its format parameters can be used to
 *              distinguish which of several invocations failed; it can
 *              safely be left null if the test function is run only once.
 */

extern PRINTF_LIKE(2, 3)
  void tvec_fail(struct tvec_state */*tv*/, const char */*detail*/, ...);
extern void tvec_fail_v(struct tvec_state */*tv*/,
                        const char */*detail*/, va_list */*ap*/);

/* --- @tvec_dumpreg@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @unsigned disp@ = the register disposition (@TVRD_...@)
 *              @const union tvec_regval *tv@ = register value, or null
 *              @const struct tvec_regdef *rd@ = register definition
 *
 * Returns:     ---
 *
 * Use:         Dump a register value to the output.  This is the lowest-
 *              level function for dumping registers, and calls the output
 *              formatter directly.
 *
 *              Usually @tvec_mismatch@ is much more convenient.  Low-level
 *              access is required for reporting `virtual' registers
 *              corresponding to test environment settings.
 */

extern void tvec_dumpreg(struct tvec_state */*tv*/,
                         unsigned /*disp*/, const union tvec_regval */*rv*/,
                         const struct tvec_regdef */*rd*/);

/* --- @tvec_initregs@, @tvec_releaseregs@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *
 * Returns:     ---
 *
 * Use:         Initialize or release, respectively, the registers required
 *              by the current test.  All of the registers, both input and
 *              output, are effected.  Initialized registers are not marked
 *              live.
 */

extern void tvec_initregs(struct tvec_state */*tv*/);
extern void tvec_releaseregs(struct tvec_state */*tv*/);

/* --- @tvec_resetoutputs@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *
 * Returns:     ---
 *
 * Use:         Reset (releases and reinitializes) the output registers in
 *              the test state.  This is mostly of use to test environment
 *              @run@ functions, between invocations of the test function.
 *              Output registers are marked live if and only if the
 *              corresponding input register is live.
 */

extern void tvec_resetoutputs(struct tvec_state */*tv*/);

/* --- @tvec_checkregs@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *
 * Returns:     Zero on success, %$-1$% on mismatch.
 *
 * Use:         Compare the active output registers (according to the current
 *              test group definition) with the corresponding input register
 *              values.  A mismatch occurs if the two values differ
 *              (according to the register type's @eq@ method), or if the
 *              input is live but the output is dead.
 *
 *              This function only checks for a mismatch and returns the
 *              result; it takes no other action.  In particular, it doesn't
 *              report a failure, or dump register values.
 */

extern int tvec_checkregs(struct tvec_state */*tv*/);

/* --- @tvec_mismatch@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @unsigned f@ = flags (@TVMF_...@)
 *
 * Returns:     ---
 *
 * Use:         Dumps registers suitably to report a mismatch.  The flag bits
 *              @TVMF_IN@ and @TVF_OUT@ select input-only and output
 *              registers.  If both are reset then nothing happens.
 *              Suppressing the output registers may be useful, e.g., if the
 *              test function crashed rather than returning outputs.
 */

#define TVMF_IN 1u
#define TVMF_OUT 2u
extern void tvec_mismatch(struct tvec_state */*tv*/, unsigned /*f*/);

/* --- @tvec_check@, @tvec_check_v@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *detail@, @va_list *ap@ = description of test
 *
 * Returns:     ---
 *
 * Use:         Check the register values, reporting a failure and dumping
 *              the registers in the event of a mismatch.  This just wraps up
 *              @tvec_checkregs@, @tvec_fail@ and @tvec_mismatch@ in the
 *              obvious way.
 */

extern PRINTF_LIKE(2, 3)
  void tvec_check(struct tvec_state */*tv*/, const char */*detail*/, ...);
extern void tvec_check_v(struct tvec_state */*tv*/,
                         const char */*detail*/, va_list */*ap*/);

/*----- Ad-hoc testing ----------------------------------------------------*/

/* --- @tvec_adhoc@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @struct tvec_test *t@ = space for a test definition
 *
 * Returns:     ---
 *
 * Use:         Begin ad-hoc testing, i.e., without reading a file of
 *              test-vector data.
 *
 *              The structure at @t@ will be used to record information about
 *              the tests underway, which would normally come from a static
 *              test definition.  The other functions in this section assume
 *              that @tvec_adhoc@ has been called.
 */

extern void tvec_adhoc(struct tvec_state */*tv*/, struct tvec_test */*t*/);

/* --- @tvec_begingroup@, @TVEC_BEGINGROUP@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *name@ = name for this test group
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *
 * Returns:     ---
 *
 * Use:         Begin an ad-hoc test group with the given name.  The @file@
 *              and @lno@ can be anything, but it's usually best if they
 *              refer to the source code performing the test: the macro
 *              @TVEC_BEGINGROUP@ does this automatically.
 */

extern void tvec_begingroup(struct tvec_state */*tv*/, const char */*name*/,
                            const char */*file*/, unsigned /*lno*/);
#define TVEC_BEGINGROUP(tv, name)                                       \
        do tvec_begingroup(tv, name, __FILE__, __LINE__); while (0)

/* --- @tvec_endgroup@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *
 * Returns:     ---
 *
 * Use:         End an ad-hoc test group.  The statistics are updated and the
 *              outcome is reported to the output formatter.
 */

extern void tvec_endgroup(struct tvec_state */*tv*/);

/* --- @TVEC_TESTGROUP@, @TVEC_TESTGROUP_TAG@ --- *
 *
 * Arguments:   @tag@ = label-disambiguation tag
 *              @const struct tvec_state *tv = test-vector state
 *              @const char *name@ = test-group name
 *
 * Returns:     ---
 *
 * Use:         Control-structure macro: @TVEC_TESTGROUP(tv, name) stmt@
 *              establishes a test group with the given @name@ (attributing
 *              it to the source file and lie number), executes @stmt@, and
 *              ends the test group.  If @stmt@ invokes @break@ then the test
 *              group is skipped.  @TVEC_TESTGROUP_TAG@ is the same, with an
 *              additional @tag@ argument for use in higher-level macros.
 */

#define TVEC_TESTGROUP_TAG(tag, tv, name)                               \
        MC_WRAP(tag##__around,                                          \
          { TVEC_BEGINGROUP(tv, name); },                               \
          { tvec_endgroup(tv); },                                       \
          { if (!((tv)->f&TVSF_SKIP)) tvec_skipgroup(tv, 0);            \
            tvec_endgroup(tv); })
#define TVEC_TESTGROUP(tv, name) TVEC_TESTGROUP_TAG(grp, tv, name)

/* --- @tvec_begintest@, @TVEC_BEGINTEST@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *
 * Returns:     ---
 *
 * Use:         Begin an ad-hoc test case.  The @file@ and @lno@ can be
 *              anything, but it's usually best if they refer to the source
 *              code performing the test: the macro @TVEC_BEGINGROUP@ does
 *              this automatically.
 */

extern void tvec_begintest(struct tvec_state */*tv*/,
                           const char */*file*/, unsigned /*lno*/);
#define TVEC_BEGINTEST(tv)                                              \
        do tvec_begintest(tv, __FILE__, __LINE__); while (0)

/* --- @tvec_endtest@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *
 * Returns:     ---
 *
 * Use:         End an ad-hoc test case,  The statistics are updated and the
 *              outcome is reported to the output formatter.
 */

extern void tvec_endtest(struct tvec_state */*tv*/);

/* --- @TVEC_TEST@, @TVEC_TEST_TAG@ --- *
 *
 * Arguments:   @tag@ = label-disambiguation tag
 *              @struct tvec_test *t@ = space for a test definition
 *
 * Returns:     ---
 *
 * Use:         Control-structure macro: @TVEC_TEST(tv) stmt@ begins a test
 *              case, executes @stmt@, and ends the test case.  If @stmt@
 *              invokes @break@ then the test case is skipped.
 *              @TVEC_TEST_TAG@ is the same, with an additional @tag@ argumet
 *              for use in higher-level macros.
 */

#define TVEC_TEST_TAG(tag, tv)                                          \
        MC_WRAP(tag##__around,                                          \
          { TVEC_BEGINTEST(tv); },                                      \
          { tvec_endtest(tv); },                                        \
          { if ((tv)->f&TVSF_ACTIVE) tvec_skip((tv), 0);                \
            tvec_endtest(tv); })
#define TVEC_TEST(tv) TVEC_TEST_TAG(test, tv)

/* --- @tvec_claim@, @tvec_claim_v@, @TVEC_CLAIM@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @int ok@ = a flag
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *msg@, @va_list *ap@ = message to report on
 *                      failure
 *
 * Returns:     The value @ok@.
 *
 * Use:         Check that a claimed condition holds, as (part of) a test.
 *              If no test case is underway (i.e., if @TVSF_OPEN@ is reset in
 *              @tv->f@), then a new test case is begun and ended.  The
 *              @file@ and @lno@ are passed to the output formatter to be
 *              reported in case of a failure.  If @ok@ is nonzero, then
 *              nothing else happens; so, in particular, if @tvec_claim@
 *              established a new test case, then the test case succeeds.  If
 *              @ok@ is zero, then a failure is reported, quoting @msg@.
 *
 *              The @TVEC_CLAIM@ macro is similar, only it (a) identifies the
 *              file and line number of the call site automatically, and (b)
 *              implicitly quotes the source text of the @ok@ condition in
 *              the failure message.
 */

extern PRINTF_LIKE(5, 6)
  int tvec_claim(struct tvec_state */*tv*/, int /*ok*/,
                 const char */*file*/, unsigned /*lno*/,
                 const char */*msg*/, ...);
extern int tvec_claim_v(struct tvec_state */*tv*/, int /*ok*/,
                        const char */*file*/, unsigned /*lno*/,
                        const char */*msg*/, va_list */*ap*/);
#define TVEC_CLAIM(tv, cond)                                            \
        (tvec_claim(tv, !!(cond), __FILE__, __LINE__, "%s untrue", #cond))

/* --- @tvec_claimeq@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const struct tvec_regty *ty@ = register type
 *              @const union tvec_misc *arg@ = register type argument
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if the input and output values of register 0 are
 *              equal, zero if they differ.
 *
 * Use:         Check that the input and output values of register 0 are
 *              equal (according to the register type @ty@).  As for
 *              @tvec_claim@ above, a test case is automatically begun and
 *              ended if none is already underway.  If the values are
 *              unequal, then @tvec_fail@ is called, quoting @expr@, and the
 *              mismatched values are dumped.
 *
 *              This function is not expected to be called directly, but
 *              through type-specific wrapper functions or macros such as
 *              @TVEC_CLAIMEQ_INT@.
 */

extern int tvec_claimeq(struct tvec_state */*tv*/,
                        const struct tvec_regty */*ty*/,
                        const union tvec_misc */*arg*/,
                        const char */*file*/, unsigned /*lno*/,
                        const char */*expr*/);

/*----- Benchmarking ------------------------------------------------------*/

struct tvec_benchenv {
  struct tvec_env _env;                 /* benchmarking is an environment */
  struct bench_state **bst;             /* benchmark state anchor or null */
  unsigned long niter;                  /* iterations done per unit */
  int riter, rbuf;                      /* iterations and buffer registers */
  const struct tvec_env *env;           /* subordinate environment */
};

struct tvec_benchctx {
  const struct tvec_benchenv *be;       /* environment configuration */
  struct bench_state *bst;              /* benchmark state */
  double dflt_target;                   /* default time in seconds */
  unsigned f;                           /* flags */
#define TVBF_SETTRG 1u                  /*   set `@target' */
#define TVBF_SETMASK (TVBF_SETTRG))     /*   mask of @TVBF_SET...@ */
  void *subctx;                         /* subsidiary environment context */
};

extern struct bench_state *tvec_benchstate;

/* --- Environment implementation --- *
 *
 * The following special variables are supported.
 *
 *   * %|@target|% is the (approximate) number of seconds to run the
 *     benchmark.
 *
 * Unrecognized variables are passed to the subordinate environment, if there
 * is one.  Other events are passed through to the subsidiary environment.
 */

extern tvec_envsetupfn tvec_benchsetup;
extern tvec_envfindvarfn tvec_benchfindvar;
extern tvec_envbeforefn tvec_benchbefore;
extern tvec_envrunfn tvec_benchrun;
extern tvec_envafterfn tvec_benchafter;
extern tvec_envteardownfn tvec_benchteardown;

#define TVEC_BENCHENV                                                   \
  { sizeof(struct tvec_benchctx),                                       \
    tvec_benchsetup,                                                    \
    tvec_benchfindvar,                                                  \
    tvec_benchbefore,                                                   \
    tvec_benchrun,                                                      \
    tvec_benchafter,                                                    \
    tvec_benchteardown }
#define TVEC_BENCHINIT TVEC_BENCHENV, &tvec_benchstate

/* --- @tvec_benchreport@ --- *
 *
 * Arguments:   @const struct gprintf_ops *gops@ = print operations
 *              @void *go@ = print destination
 *              @unsigned unit@ = the unit being measured (~TVBU_...@)
 *              @const struct bench_timing *tm@ = the benchmark result
 *
 * Returns:     ---
 *
 * Use:         Formats a report about the benchmark performance.  This
 *              function is intended to be called on by an output
 *              @ebench@ function.
 */

extern void tvec_benchreport
  (const struct gprintf_ops */*gops*/, void */*go*/,
   unsigned /*unit*/, const struct bench_timing */*tm*/);

/*----- Remote execution --------------------------------------------------*/

struct tvec_remotecomms {
  int infd, outfd;                      /* input and output descriptors */
  dbuf bout;                            /* output buffer */
  unsigned char *bin;                   /* input buffer */
  size_t binoff, binlen, binsz;         /* input offset, length, and size */
  size_t t;                             /* temporary offset */
  unsigned f;                           /* flags */
#define TVRF_BROKEN 0x0001u             /*   communications have failed */
};
#define TVEC_REMOTECOMMS_INIT { -1, -1, DBUF_INIT, 0, 0, 0, 0, 0, 0 }

struct tvec_remotectx {
  struct tvec_state *tv;                /* test vector state */
  struct tvec_remotecomms rc;           /* communication state */
  const struct tvec_remoteenv *re;      /* environment configuration */
  void *subctx;                         /* subenvironment context */
  struct tvec_vardef vd;                /* temporary variable definition */
  unsigned ver;                         /* protocol version */
  pid_t kid;                            /* child process id */
  int errfd;                            /* child stderr descriptor */
  lbuf errbuf;                          /* child stderr line buffer */
  dstr prgwant, progress;               /* progress: wanted/reported */
  unsigned exwant, exit;                /* exit status wanted/reported */
#define TVRF_RCNMASK 0x0300u            /*   reconnection behaviour: */
#define TVRCN_DEMAND 0x0000u            /*     connect on demand */
#define TVRCN_SKIP 0x0100u              /*     skip unless connected */
#define TVRCN_FORCE 0x0200u             /*     force reconnection */
#define TVRF_MUFFLE 0x0400u             /*   muffle child stderr */
#define TVRF_SETEXIT 0x0800u            /*   set `@exit' */
#define TVRF_SETPRG 0x1000u             /*   set `@progress' */
#define TVRF_SETRCN 0x2000u             /*   set `@reconnect' */
#define TVRF_SETMASK (TVRF_SETEXIT | TVRF_SETPRG | TVRF_SETRCN)
                                        /*   mask of @TVTF_SET...@ */
};

typedef int tvec_connectfn(pid_t */*kid_out*/, int */*infd_out*/,
                           int */*outfd_out*/, int */*errfd_out*/,
                           struct tvec_state */*tv*/,
                           const struct tvec_remoteenv */*env*/);
  /* A connection function.  On entry, @tv@ holds the test-vector state, and
   * @env@ is the test group's remote environment structure, which will
   * typically really be some subclass of @struct tvec_remoteenv@ containing
   * additional parameters for establishing the child process.
   *
   * On successful completion, the function stores input and output
   * descriptors (which need not be distinct) in @*infd_out@ and
   * @*outfd_out@, and returns zero; if it creates a child process, it should
   * additionally store the child's process-id in @*kid_out@ and store in
   * @*errfd_out@ a descriptor from which the child's error output can be
   * read.  On error, the function should report an appropriate message via
   * @tvec_error@ and return %$-1$%.
   */

struct tvec_remoteenv_slots {
  tvec_connectfn *connect;              /* connection function */
  const struct tvec_env *env;           /* subsidiary environment */
  unsigned dflt_reconn;                 /* default reconnection */
};

struct tvec_remoteenv {
  struct tvec_env _env;
  struct tvec_remoteenv_slots r;
};

struct tvec_remotefork_slots {
  const struct tvec_test *tests;        /* child tests (or null) */
};

struct tvec_remotefork {
  struct tvec_env _env;
  struct tvec_remoteenv_slots r;
  struct tvec_remotefork_slots f;
};

struct tvec_remoteexec_slots {
  const char *const *args;              /* command line to execute */
};

struct tvec_remoteexec {
  struct tvec_env _env;
  struct tvec_remoteenv_slots r;
  struct tvec_remoteexec_slots x;
};

union tvec_remoteenv_subclass_kludge {
  struct tvec_env _env;
  struct tvec_remoteenv renv;
  struct tvec_remotefork fork;
  struct tvec_remoteexec exec;
};

/* Exit status.
 *
 * We don't use the conventional encoding returned by the @wait@(2) family of
 * system calls because it's too hard for our flags type to decode.  Instead,
 * we use our own encoding.
 *
 * The exit code or signal number ends up in the `value' field in the low 12
 * bits; bit 12 is set if the value field holds a signal, and it if holds an
 * exit code.  Bits 13--15 hold a code which describes the status of a child
 * process or connection.
 */
#define TVXF_VALMASK 0x0fffu            /* value (exit code or signal) */
#define TVXF_SIG 0x1000u                /* value is signal, not exit code */
#define TVXF_CAUSEMASK 0xe000u          /* mask for cause bits */
#define TVXST_RUN 0x0000u               /*   still running */
#define TVXST_EXIT 0x2000u              /*   child exited */
#define TVXST_KILL 0x4000u              /*   child killed by signal */
#define TVXST_CONT 0x6000u              /*   child continued (?) */
#define TVXST_STOP 0x8000u              /*   child stopped (?) */
#define TVXST_DISCONN 0xa000u           /*   disconnected */
#define TVXST_UNK 0xc000u               /*   unknown */
#define TVXST_ERR 0xe000u             /*   local error prevented diagnosis */

/* Remote environment. */
extern tvec_envsetupfn tvec_remotesetup;
extern tvec_envfindvarfn tvec_remotefindvar;
extern tvec_envbeforefn tvec_remotebefore;
extern tvec_envrunfn tvec_remoterun;
extern tvec_envafterfn tvec_remoteafter;
extern tvec_envteardownfn tvec_remoteteardown;
#define TVEC_REMOTEENV                                                  \
  { sizeof(struct tvec_remotectx),                                      \
    tvec_remotesetup,                                                   \
    tvec_remotefindvar,                                                 \
    tvec_remotebefore,                                                  \
    tvec_remoterun,                                                     \
    tvec_remoteafter,                                                   \
    tvec_remoteteardown }

/* --- @tvec_setprogress@, @tvec_setprogress_v@ --- *
 *
 * Arguments:   @const char *status@ = progress status token format
 *              @va_list ap@ = argument tail
 *
 * Returns:     ---
 *
 * Use:         Reports the progress of a test execution to the client.
 *
 *              The framework makes use of tokens beginning with %|%|%:
 *
 *                * %|%IDLE|%: during the top-level server code;
 *
 *                * %|%SETUP|%: during the enclosing environment's @before@
 *                  function;
 *
 *                * %|%RUN|%: during the environment's @run@ function, or the
 *                  test function; and
 *
 *                * %|%DONE|%: during the enclosing environment's @after@
 *                  function.
 *
 *              The intent is that a test can use the progress token to check
 *              that a function which is expected to crash does so at the
 *              correct point, so it's expected that more complex test
 *              functions and/or environments will set their own progress
 *              tokens to reflect what's going on.
 */

extern PRINTF_LIKE(1, 2) int tvec_setprogress(const char */*status*/, ...);
extern int tvec_setprogress_v(const char */*status*/, va_list */*ap*/);

/* --- @tvec_remoteserver@ --- *
 *
 * Arguments:   @int infd@, @int outfd@ = input and output file descriptors
 *              @const struct tvec_config *config@ = test configuration
 *
 * Returns:     Suggested exit code.
 *
 * Use:         Run a test server, reading packets from @infd@ and writing
 *              responses and notifications to @outfd@, and invoking tests as
 *              described by @config@.
 *
 *              This function is not particularly general purpose.  It
 *              expects to `take over' the process, and makes use of private
 *              global variables.
 */

extern int tvec_remoteserver(int /*infd*/, int /*outfd*/,
                             const struct tvec_config */*config*/);

extern tvec_connectfn tvec_fork, tvec_exec;

#define TVEC_REMOTEFORK(subenv, tests)                                  \
        TVEC_REMOTEENV, { tvec_fork, subenv }, { tests }

#define TVEC_REMOTEEXEC(subenv, args)                                   \
        TVEC_REMOTEENV, { tvec_exec, subenv }, { args }

/*----- Timeouts ----------------------------------------------------------*/

struct tvec_timeoutenv {
  struct tvec_env _env;
  int timer;                    /* the timer (@ITIMER_...@) */
  double t;                             /* time to wait (in seconds) */
  const struct tvec_env *env;           /* subsidiary environment */
};

struct tvec_timeoutctx {
  const struct tvec_timeoutenv *te;     /* saved environment description */
  int timer;                            /* timer code (as overridden) */
  double t;                             /* time to wait (as overridden) */
  unsigned f;                           /* flags */
#define TVTF_SETTMO 1u                  /*   set `@timeout' */
#define TVTF_SETTMR 2u                  /*   set `@timer' */
#define TVTF_SETMASK (TVTF_SETTMO | TVTF_SETTMR)
                                        /*   mask of @TVTF_SET...@ */
  void *subctx;
};

extern tvec_envsetupfn tvec_timeoutsetup;
extern tvec_envfindvarfn tvec_timeoutfindvar;
extern tvec_envbeforefn tvec_timeoutbefore;
extern tvec_envrunfn tvec_timeoutrun;
extern tvec_envafterfn tvec_timeoutafter;
extern tvec_envteardownfn tvec_timeoutteardown;
#define TVEC_TIMEOUTENV                                                 \
        { sizeof(struct tvec_timeoutctx),                               \
          tvec_timeoutsetup,                                            \
          tvec_timeoutfindvar,                                          \
          tvec_timeoutbefore,                                           \
          tvec_timeoutrun,                                              \
          tvec_timeoutafter,                                            \
          tvec_timeoutteardown }
#define TVEC_TIMEOUTINIT(timer, t) TVEC_TIMEOUTENV, timer, t

/*----- Output functions --------------------------------------------------*/

/* --- @tvec_strlevel@ --- *
 *
 * Arguments:   @unsigned level@ = level code
 *
 * Returns:     A human-readable description.
 *
 * Use:         Converts a level code into something that you can print in a
 *              message.
 */

extern  const char *tvec_strlevel(unsigned /*level*/);

/* --- @tvec_report@, @tvec_report_v@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *msg@, @va_list ap@ = error message
 *
 * Returns:     ---
 *
 * Use:         Report an message with a given severity.  Messages with level
 *              @TVLEV_ERR@ or higher force a nonzero exit code.
 */

extern PRINTF_LIKE(3, 4)
  void tvec_report(struct tvec_state */*tv*/, unsigned /*level*/,
                   const char */*msg*/, ...);
extern void tvec_report_v(struct tvec_state */*tv*/, unsigned /*level*/,
                          const char */*msg*/, va_list */*ap*/);

/* --- @tvec_error@, @tvec_notice@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *msg@, @va_list ap@ = error message
 *
 * Returns:     The @tvec_error@ function returns %$-1$% as a trivial
 *              convenience; @tvec_notice@ does not return a value.
 *
 * Use:         Report an error or a notice.  Errors are distinct from test
 *              failures, and indicate that a problem was encountered which
 *              compromised the activity of testing.  Notices are important
 *              information which doesn't fit into any other obvious
 *              category.
 */

extern PRINTF_LIKE(2, 3)
  int tvec_error(struct tvec_state */*tv*/, const char */*msg*/, ...);
extern PRINTF_LIKE(2, 3)
  void tvec_notice(struct tvec_state */*tv*/, const char */*msg*/, ...);

/* --- @tvec_humanoutput@ --- *
 *
 * Arguments:   @FILE *fp@ = output file to write on
 *
 * Returns:     An output formatter.
 *
 * Use:         Return an output formatter which writes on @fp@ with the
 *              expectation that a human will be watching and interpreting
 *              the output.  If @fp@ denotes a terminal, the display shows a
 *              `scoreboard' indicating the outcome of each test case
 *              attempted, and may in addition use colour and other
 *              highlighting.
 */

extern struct tvec_output *tvec_humanoutput(FILE */*fp*/);

/* --- @tvec_tapoutput@ --- *
 *
 * Arguments:   @FILE *fp@ = output file to write on
 *
 * Returns:     An output formatter.
 *
 * Use:         Return an output formatter which writes on @fp@ in `TAP'
 *              (`Test Anything Protocol') format.
 *
 *              TAP comes from the Perl community, but has spread rather
 *              further.  This driver produces TAP version 14, but pretends
 *              to be version 13.  The driver produces a TAP `test point' --
 *              i.e., a result reported as `ok' or `not ok' -- for each input
 *              test group.  Failure reports and register dumps are produced
 *              as diagnostic messages before the final group result.  (TAP
 *              permits structuerd YAML data after the test-point result,
 *              which could be used to report details, but (a) postponing the
 *              details until after the report is inconvenient, and (b) there
 *              is no standardization for the YAML anyway, so in practice
 *              it's no more useful than the unstructured diagnostics.
 */

extern struct tvec_output *tvec_tapoutput(FILE */*fp*/);

/* --- @tvec_dfltoutput@ --- *
 *
 * Arguments:   @FILE *fp@ = output file to write on
 *
 * Returns:     An output formatter.
 *
 * Use:         Selects and instantiates an output formatter suitable for
 *              writing on @fp@.  The policy is subject to change, but
 *              currently the `human' output format is selected if @fp@ is
 *              interactive (i.e., if @isatty(fileno(fp))@ is true), and
 *              otherwise the `tap' format is used.
 */

extern struct tvec_output *tvec_dfltout(FILE */*fp*/);

/*------ Serialization utilities ------------------------------------------*/

/* Serialization format.
 *
 * The `candidate register definitions' are those entries @r@ in the @regs@
 * vector whose index @r.i@ is strictly less than @nr@.  The `selected
 * register definitions' are those candidate register definitions @r@ for
 * which the indicated register @rv[r.i]@ has the @TVRF_LIVE@ flag set.  The
 * serialized output begins with a header bitmap: if there are %$n$%
 * candidate register definitions then the header bitmap consists of %$\lceil
 * n/8 \rceil$% bytes.  Bits are ordered starting from the least significant
 * bit of the first byte, end ending at the most significant bit of the final
 * byte.  The bit corresponding to a candidate register definition is set if
 * and only if that register defintion is selected.  The header bitmap is
 * then followed by the serializations of the selected registers -- i.e., for
 * each selected register definition @r@, the serialized value of register
 * @rv[r.i]@ -- simply concatenated together, with no padding or alignment.
 */

/* --- @tvec_serialize@ --- *
 *
 * Arguments:   @const struct tvec_reg *rv@ = vector of registers
 *              @buf *b@ = buffer to write on
 *              @const struct tvec_regdef *regs@ = vector of register
 *                      descriptions, terminated by an entry with a null
 *                      @name@ slot
 *              @unsigned nr@ = number of entries in the @rv@ vector
 *              @size_t regsz@ = true size of each element of @rv@
 *
 * Returns:     Zero on success, %$-1$% on failure.
 *
 * Use:         Serialize a collection of register values.
 *
 *              The serialized output is written to the buffer @b@.  Failure
 *              can be caused by running out of buffer space, or a failing
 *              type handler.
 */

extern int tvec_serialize(const struct tvec_reg */*rv*/, buf */*b*/,
                          const struct tvec_regdef */*regs*/,
                          unsigned /*nr*/, size_t /*regsz*/);

/* --- @tvec_deserialize@ --- *
 *
 * Arguments:   @struct tvec_reg *rv@ = vector of registers
 *              @buf *b@ = buffer to write on
 *              @const struct tvec_regdef *regs@ = vector of register
 *                      descriptions, terminated by an entry with a null
 *                      @name@ slot
 *              @unsigned nr@ = number of entries in the @rv@ vector
 *              @size_t regsz@ = true size of each element of @rv@
 *
 * Returns:     Zero on success, %$-1$% on failure.
 *
 * Use:         Deserialize a collection of register values.
 *
 *              The size of the register vector @nr@ and the register
 *              definitions @regs@ must match those used when producing the
 *              serialization.  For each serialized register value,
 *              deserialize and store the value into the appropriate register
 *              slot, and set the @TVRF_LIVE@ flag on the register.  See
 *              @tvec_serialize@ for a description of the format.
 *
 *              Failure results only from a failing register type handler.
 */

extern int tvec_deserialize(struct tvec_reg */*rv*/, buf */*b*/,
                            const struct tvec_regdef */*regs*/,
                            unsigned /*nr*/, size_t /*regsz*/);

/*----- Input utilities ---------------------------------------------------*/

/* These are provided by the core for the benefit of type @parse@ methods,
 * and test-environment @set@ functions, which get to read from the test
 * input file.  The latter are usually best implemented by calling on the
 * former.
 *
 * The two main rules are as follows.
 *
 *   * Leave the file position at the beginning of the line following
 *     whatever it was that you read.
 *
 *   * When you read and consume a newline (which you do at least once, by
 *     the previous rule), then increment @tv->lno@ to keep track of the
 *     current line number.
 */

/* --- @tvec_syntax@, @tvec_syntax_v@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @int ch@ = the character found (in @fgetc@ format)
 *              @const char *expect@, @va_list ap@ = what was expected
 *
 * Returns:     %$-1$%.
 *
 * Use:         Report a syntax error quoting @ch@ and @expect@.  If @ch@ is
 *              a newline, then back up so that it can be read again (e.g.,
 *              by @tvec_flushtoeol@ or @tvec_nexttoken@, which will also
 *              advance the line number).
 */

extern PRINTF_LIKE(3, 4)
  int tvec_syntax(struct tvec_state */*tv*/, int /*ch*/,
                  const char */*expect*/, ...);
extern int tvec_syntax_v(struct tvec_state */*tv*/, int /*ch*/,
                         const char */*expect*/, va_list */*ap*/);

/* --- @tvec_unkreg@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *name@ = register or pseudoregister name
 *
 * Returns:     %$-1$%.
 *
 * Use:         Reports an error that the register or pseudoregister is
 *              unrecognized.
 */

extern int tvec_unkreg(struct tvec_state */*tv*/, const char */*name*/);

/* --- @tvec_dupreg@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *name@ = register or pseudoregister name
 *
 * Returns:     %$-1$%.
 *
 * Use:         Reports an error that the register or pseudoregister has been
 *              assigned already in the current test.
 */

extern int tvec_dupreg(struct tvec_state */*tv*/, const char */*name*/);

/* --- @tvec_skipspc@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *
 * Returns:     ---
 *
 * Use:         Advance over any whitespace characters other than newlines.
 *              This will stop at `;', end-of-file, or any other kind of
 *              non-whitespace; and it won't consume a newline.
 */

extern void tvec_skipspc(struct tvec_state */*tv*/);

/* --- @tvec_flushtoeol@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @unsigned f@ = flags (@TVFF_...@)
 *
 * Returns:     Zero on success, %$-1$% on error.
 *
 * Use:         Advance to the start of the next line, consuming the
 *              preceding newline.
 *
 *              A syntax error is reported if no newline character is found,
 *              i.e., the file ends in mid-line.  A syntax error is also
 *              reported if material other than whitespace or a comment is
 *              found before the end of the line end, and @TVFF_ALLOWANY@ is
 *              not set in @f@.  The line number count is updated
 *              appropriately.
 */

#define TVFF_ALLOWANY 1u
extern int tvec_flushtoeol(struct tvec_state */*tv*/, unsigned /*f*/);

/* --- @tvec_nexttoken@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *
 * Returns:     Zero if there is a next token which can be read; %$-1$% if no
 *              token is available.
 *
 * Use:         Advance to the next whitespace-separated token, which may be
 *              on the next line.
 *
 *              Tokens are separated by non-newline whitespace, comments, and
 *              newlines followed by whitespace; a newline /not/ followed by
 *              whitespace instead begins the next assignment, and two
 *              newlines separated only by whitespace terminate the data for
 *              a test.
 *
 *              If this function returns zero, then the next character in the
 *              file begins a suitable token which can be read and
 *              processed.  If it returns %$-1$% then there is no such token,
 *              and the file position is left correctly.  The line number
 *              count is updated appropriately.
 */

extern int tvec_nexttoken(struct tvec_state */*tv*/);

/* --- @tvec_readword@, @tvec_readword_v@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @dstr *d@ = string to append the word to
 *              @const char **p_inout@ = pointer into string, updated
 *              @const char *delims@ = additional delimiters to stop at
 *              @const char *expect@, @va_list ap@ = what was expected
 *
 * Returns:     Zero on success, %$-1$% on failure.
 *
 * Use:         A `word' consists of characters other than whitespace, null
 *              characters, and other than those listed in @delims@;
 *              furthermore, a word does not begin with a `;'.  (If you want
 *              reading to stop at comments not preceded by whitespace, then
 *              include `;' in @delims@.  This is a common behaviour.)
 *
 *              If there is no word beginning at the current file position,
 *              then return %$-1$%; furthermore, if @expect@ is not null,
 *              then report an appropriate error via @tvec_syntax@.
 *
 *              Otherwise, the word is accumulated in @d@ and zero is
 *              returned; if @d@ was not empty at the start of the call, the
 *              newly read word is separated from the existing material by a
 *              single space character.  Since null bytes are never valid
 *              word constituents, a null terminator is written to @d@, and
 *              it is safe to treat the string in @d@ as being null-
 *              terminated.
 *
 *              If @p_inout@ is not null, then @*p_inout@ must be a pointer
 *              into @d->buf@, which will be adjusted so that it will
 *              continue to point at the same position even if the buffer is
 *              reallocated.  As a subtle tweak, if @*p_inout@ initially
 *              points at the end of the buffer, then it will be adjusted to
 *              point at the beginning of the next word, rather than at the
 *              additional intervening space.
 */

extern PRINTF_LIKE(5, 6)
  int tvec_readword(struct tvec_state */*tv*/, dstr */*d*/,
                    const char **/*p_inout*/, const char */*delims*/,
                    const char */*expect*/, ...);
extern int tvec_readword_v(struct tvec_state */*tv*/, dstr */*d*/,
                           const char **/*p_inout*/, const char */*delims*/,
                           const char */*expect*/, va_list */*ap*/);

/*----- Integer types: signed and unsigned --------------------------------*/

/* Integers may be input in decimal, hex, binary, or octal, following
 * approximately usual conventions.
 *
 *   * Signed integers may be preceded with a `+' or `-' sign.
 *
 *   * Decimal integers are just a sequence of decimal digits `0' ... `9'.
 *
 *   * Octal integers are a sequence of digits `0' ... `7', preceded by `0o'
 *     or `0O'.
 *
 *   * Hexadecimal integers are a sequence of digits `0' ... `9', `a'
 *     ... `f', or `A' ... `F', preceded by `0x' or `0X'.
 *
 *   * Radix-B integers are a sequence of digits `0' ... `9', `a' ... `f', or
 *     `A' ... `F', each with value less than B, preceded by `Br' or `BR',
 *     where 0 < B < 36 is expressed in decimal without any leading `0' or
 *     internal underscores `_'.
 *
 *   * A digit sequence may contain internal underscore `_' separators, but
 *     not before or after all of the digits; and two consecutive `_'
 *     characters are not permitted.
 */

extern const struct tvec_regty tvty_int, tvty_uint;

/* The @arg.p@ slot may be null or a pointer to @struct tvec_irange@ or
 * @struct tvec_urange@ as appropriate.  The bounds are inclusive; use, e.g.,
 * @LONG_MAX@ explicitly if one or the other bound is logically inapplicable.
 */
struct tvec_irange { long min, max; };
struct tvec_urange { unsigned long min, max; };

/* Bounds corresponding to common integer types. */
extern const struct tvec_irange
  tvrange_schar, tvrange_short, tvrange_int, tvrange_long,
  tvrange_sbyte, tvrange_i16, tvrange_i32;
extern const struct tvec_urange
  tvrange_uchar, tvrange_ushort, tvrange_uint, tvrange_ulong, tvrange_size,
  tvrange_byte, tvrange_u16, tvrange_u32;

/* --- @tvec_claimeq_int@, @TVEC_CLAIMEQ_INT@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @long i0, i1@ = two signed integers
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if @i0@ and @i1@ are equal, otherwise zero.
 *
 * Use:         Check that values of @i0@ and @i1@ are equal.  As for
 *              @tvec_claim@ above, a test case is automatically begun and
 *              ended if none is already underway.  If the values are
 *              unequal, then @tvec_fail@ is called, quoting @expr@, and the
 *              mismatched values are dumped: @i0@ is printed as the output
 *              value and @i1@ is printed as the input reference.
 *
 *              The @TVEC_CLAIM_INT@ macro is similar, only it (a) identifies
 *              the file and line number of the call site automatically, and
 *              (b) implicitly quotes the source text of the @i0@ and @i1@
 *              arguments in the failure message.
 */

extern int tvec_claimeq_int(struct tvec_state */*tv*/,
                            long /*i0*/, long /*i1*/,
                            const char */*file*/, unsigned /*lno*/,
                            const char */*expr*/);
#define TVEC_CLAIMEQ_INT(tv, i0, i1)                                    \
        (tvec_claimeq_int(tv, i0, i1, __FILE__, __LINE__, #i0 " /= " #i1))

/* --- @tvec_claimeq_uint@, @TVEC_CLAIMEQ_UINT@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @unsigned long u0, u1@ = two unsigned integers
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if @u0@ and @u1@ are equal, otherwise zero.
 *
 * Use:         Check that values of @u0@ and @u1@ are equal.  As for
 *              @tvec_claim@ above, a test case is automatically begun and
 *              ended if none is already underway.  If the values are
 *              unequal, then @tvec_fail@ is called, quoting @expr@, and the
 *              mismatched values are dumped: @u0@ is printed as the output
 *              value and @u1@ is printed as the input reference.
 *
 *              The @TVEC_CLAIM_UINT@ macro is similar, only it (a)
 *              identifies the file and line number of the call site
 *              automatically, and (b) implicitly quotes the source text of
 *              the @u0@ and @u1@ arguments in the failure message.
 */

extern int tvec_claimeq_uint(struct tvec_state */*tv*/,
                            unsigned long /*u0*/, unsigned long /*u1*/,
                            const char */*file*/, unsigned /*lno*/,
                            const char */*expr*/);
#define TVEC_CLAIMEQ_UINT(tv, u0, u1)                                   \
        (tvec_claimeq_uint(tv, u0, u1, __FILE__, __LINE__, #u0 " /= " #u1))

/*----- Floating-point type -----------------------------------------------*/

/* Floating-point values are either NaN (%|#nan|%, if supported by the
 * platform); positive or negative infinity (%|#inf|%, %|+#inf|%, or
 * %|#+inf|% (preferring the last), and %|-#inf|% or %|#-inf|% (preferring
 * the latter), if supported by the platform); or a number in strtod(3)
 * syntax.
 *
 * The comparison rules for floating-point numbers are complex: see
 * @tvec_claimeqish_float@ for details.
 */

extern const struct tvec_regty tvty_float;

struct tvec_floatinfo {
  /* Details about acceptable floating-point values. */

  unsigned f;                           /* flags (@TVFF_...@ bits) */
#define TVFF_NOMIN 1u                   /*   ignore @min@ (allow -inf) */
#define TVFF_NOMAX 2u                   /*   ignore @max@ (allow +inf) */
#define TVFF_NANOK 4u                   /*   permit NaN */
#define TVFF_EQMASK 0xf0                /*   how to compare */
#define TVFF_EXACT 0x00                 /*     must equal exactly */
#define TVFF_ABSDELTA 0x10              /*     must be within @delta@ */
#define TVFF_RELDELTA 0x20              /*     diff < @delta@ fraction */
  double min, max;                      /* smallest/largest value allowed */
  double delta;                         /* maximum tolerable difference */
};

/* --- @tvec_claimeqish_float@, @TVEC_CLAIMEQISH_FLOAT@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @double f0, f1@ = two floating-point numbers
 *              @unsigned f@ = flags (@TVFF_...@)
 *              @double delta@ = maximum tolerable difference
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if @f0@ and @u1@ are sufficiently close, otherwise
 *              zero.
 *
 * Use:         Check that values of @f0@ and @f1@ are sufficiently close.
 *              As for @tvec_claim@ above, a test case is automatically begun
 *              and ended if none is already underway.  If the values are
 *              too far apart, then @tvec_fail@ is called, quoting @expr@,
 *              and the mismatched values are dumped: @f0@ is printed as the
 *              output value and @f1@ is printed as the input reference.
 *
 *              The details for the comparison are as follows.
 *
 *                * A NaN value matches any other NaN, and nothing else.
 *
 *                * An infinity matches another infinity of the same sign,
 *                  and nothing else.
 *
 *                * If @f&TVFF_EQMASK@ is @TVFF_EXACT@, then any
 *                  representable number matches only itself: in particular,
 *                  positive and negative zero are considered distinct.
 *                  (This allows tests to check that they land on the correct
 *                  side of branch cuts, for example.)
 *
 *                * If @f&TVFF_EQMASK@ is @TVFF_ABSDELTA@, then %$x$% matches
 *                  %$y$% when %$|x - y| < \delta$%.
 *
 *                * If @f&TVFF_EQMASK@ is @TVFF_RELDELTA@, then %$x$% matches
 *                  %$y$% when %$|1 - y/x| < \delta$%.  (Note that this
 *                  criterion is asymmetric FIXME
 *
 *              The @TVEC_CLAIM_FLOAT@ macro is similar, only it (a)
 *              identifies the file and line number of the call site
 *              automatically, and (b) implicitly quotes the source text of
 *              the @f0@ and @f1@ arguments (and @delta@) in the failure
 *              message.
 */

extern int tvec_claimeqish_float(struct tvec_state */*tv*/,
                                 double /*f0*/, double /*f1*/,
                                 unsigned /*f*/, double /*delta*/,
                                 const char */*file*/, unsigned /*lno*/,
                                 const char */*expr*/);
#define TVEC_CLAIMEQISH_FLOAT(tv, f0, f1, f, delta)                     \
        (tvec_claimeqish_float(tv, f0, f1, f, delta, , __FILE__, __LINE__, \
                               #f0 " /= " #f1 " (+/- " #delta ")"))

/* --- @tvec_claimeq_float@, @TVEC_CLAIMEQ_FLOAT@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @double f0, f1@ = two floating-point numbers
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if @f0@ and @u1@ are identical, otherwise zero.
 *
 * Use:         Check that values of @f0@ and @f1@ are identical.  The
 *              function is exactly equivalent to @tvec_claimeqish_float@
 *              with @f == TVFF_EXACT@; the macro is similarly like
 *              @TVEC_CLAIMEQISH_FLOAT@ with @f == TVFF_EXACT@, except that
 *              it doesn't bother to quote a delta.
 */

extern int tvec_claimeq_float(struct tvec_state */*tv*/,
                              double /*f0*/, double /*f1*/,
                              const char */*file*/, unsigned /*lno*/,
                              const char */*expr*/);
#define TVEC_CLAIMEQ_FLOAT(tv, f0, f1)                                  \
        (tvec_claimeq_float(tv, f0, f1, __FILE__, __LINE__, #f0 " /= " #f1))

extern const struct tvec_floatinfo tvflt_finite, tvflt_nonneg;

/*----- Durations ---------------------------------------------------------*/

/* A duration measures a time interval in seconds.  The input format consists
 * of a nonnegative decimal floating-point number in @strtod@ format followed
 * by an optional unit specification.
 *
 * No @tvec_claimeq_...@ function is provided for durations: use
 * @tvec_claimeq_float@.
 */

extern const struct tvec_regty tvty_duration;

/* --- @tvec_parsedurunit@ --- *
 *
 * Arguments:   @double *scale_out@ = where to leave the scale
 *              @const char **p_inout@ = input unit string, updated
 *
 * Returns:     Zero on success, %$-1$% on error.
 *
 * Use:         If @*p_inout@ begins with a unit string followed by the end
 *              of the string or some non-alphanumeric character, then store
 *              the corresponding scale factor in @*scale_out@, advance
 *              @*p_inout@ past the unit string, and return zero.  Otherwise,
 *              return %$-1$%.
 */

extern int tvec_parsedurunit(double */*scale_out*/,
                             const char **/*p_inout*/);

/*----- Enumerated types --------------------------------------------------*/

/* An enumeration describes a set of values of some underlying type, each of
 * which has a symbolic name.  Values outside of the defined set can occur --
 * on output, because of bugs in the tested code, or on input to test
 * handling of unexpected values.
 *
 * There is a distinct enumerated type for each of the branches of
 * @tvec_misc@.  In the following, we write @t@ for the type code, which is
 * @i@ for signed integer, @u@ for unsigned integer, @f@ for floating-point,
 * and @p@ for pointer.
 *
 * On input, an enumerated value may be given by name or as a literal value.
 * For enumerations based on numeric types, the literal values can be written
 * in the same syntax as the underlying values.  For enumerations based on
 * pointers, the only permitted literal is %|#nil|%, which denotes a null
 * pointer.  On output, names are preferred (with the underlying value given
 * in a comment).
 */

#define DEFENUMTY(tag, ty, slot)                                        \
        extern const struct tvec_regty tvty_##slot##enum;
TVEC_MISCSLOTS(DEFENUMTY)
#undef DEFENUMTY

/* A @struct tvec_tassoc@ associates a string tag with a value. */
#define DEFASSOC(tag_, ty, slot)                                        \
        struct tvec_##slot##assoc { const char *tag; ty slot; };
TVEC_MISCSLOTS(DEFASSOC)
#undef DEFASSOC

#define TVEC_ENDENUM { 0, 0 }

/* Information about an enumerated type. */
#define DEFINFO(tag, ty, slot)                                          \
        struct tvec_##slot##enuminfo {                                  \
          const char *name;             /* type name for diagnostics */ \
          const struct tvec_##slot##assoc *av; /* name/value mappings */ \
          EXTRA_##tag##_INFOSLOTS       /* type-specific extra info */  \
        };

#define EXTRA_INT_INFOSLOTS                                             \
        const struct tvec_irange *ir;   /* allowed range of raw values */

#define EXTRA_UINT_INFOSLOTS                                            \
        const struct tvec_urange *ur;   /* allowed range of raw values */

#define EXTRA_FLT_INFOSLOTS                                             \
        const struct tvec_floatinfo *fi; /* range and matching policy */

#define EXTRA_PTR_INFOSLOTS             /* (nothing) */

TVEC_MISCSLOTS(DEFINFO)

#undef EXTRA_INT_INFOSLOTS
#undef EXTRA_UINT_INFOSLOTS
#undef EXTRA_FLT_INFOSLOTS
#undef EXTRA_PTR_INFOSLOTS

#undef DEFINFO

/* Standard enumerations. */
extern const struct tvec_ienuminfo tvenum_bool;
extern const struct tvec_ienuminfo tvenum_cmp;

/* --- @tvec_claimeq_tenum@, @TVEC_CLAIMEQ_TENUM@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const struct tvec_typeenuminfo *ei@ = enumeration type info
 *              @ty t0, t1@ = two values
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if @t0@ and @t1@ are equal, otherwise zero.
 *
 * Use:         Check that values of @t0@ and @t1@ are equal.  As for
 *              @tvec_claim@ above, a test case is automatically begun and
 *              ended if none is already underway.  If the values are
 *              unequal, then @tvec_fail@ is called, quoting @expr@, and the
 *              mismatched values are dumped: @t0@ is printed as the output
 *              value and @t1@ is printed as the input reference.
 *
 *              The @TVEC_CLAIM_TENUM@ macro is similar, only it (a)
 *              identifies the file and line number of the call site
 *              automatically, and (b) implicitly quotes the source text of
 *              the @t0@ and @t1@ arguments in the failure message.
 */

#define DECLCLAIM(tag, ty, slot)                                        \
        extern int tvec_claimeq_##slot##enum                            \
          (struct tvec_state */*tv*/,                                   \
           const struct tvec_##slot##enuminfo */*ei*/,                  \
           ty /*t0*/, ty /*t1*/,                                        \
           const char */*file*/, unsigned /*lno*/, const char */*expr*/);
TVEC_MISCSLOTS(DECLCLAIM)
#undef DECLCLAIM
#define TVEC_CLAIMEQ_IENUM(tv, ei, i0, i1)                              \
        (tvec_claimeq_ienum(tv, ei, i0, i1,                             \
                            __FILE__, __LINE__, #i0 " /= " #i1))
#define TVEC_CLAIMEQ_UENUM(tv, ei, u0, u1)                              \
        (tvec_claimeq_uenum(tv, ei, u0, u1,                             \
                            __FILE__, __LINE__, #u0 " /= " #u1))
#define TVEC_CLAIMEQ_FENUM(tv, ei, f0, f1)                              \
        (tvec_claimeq_fenum(tv, ei, f0, f1,                             \
                            __FILE__, __LINE__, #f0 " /= " #f1))
#define TVEC_CLAIMEQ_PENUM(tv, ei, p0, p1)                              \
        (tvec_claimeq_penum(tv, ei, p0, p1,                             \
                            __FILE__, __LINE__, #p0 " /= " #p1))

/*----- Flags type --------------------------------------------------------*/

/* A flags value packs a number of fields into a single nonnegative integer.
 * Symbolic names are associated with the possible values of the various
 * fields; more precisely, each name is associated with a value and a
 * covering bitmask.
 *
 * The input syntax is a sequence of items separated by `%|||%' signs.  Each
 * item may be the symbolic name of a field value, or a literal unsigned
 * integer.  The masks associated with the given symbolic names must be
 * disjoint.  The resulting numerical value is simply the bitwise OR of the
 * given values.
 *
 * On output, the table of symbolic names and their associated values and
 * masks is repeatedly scanned, in order, to find disjoint matches -- i.e.,
 * entries whose value matches the target value in the bit positions
 * indicated by the mask, and whose mask doesn't overlap with any previously
 * found matches; the names are then output, separated by `%|||%'.  Any
 * remaining nonzero bits not covered by any of the matching masks are output
 * as a single literal integer, in hex.
 */

extern const struct tvec_regty tvty_flags;

struct tvec_flag {
  /* Definition of a single flag or bitfield value.
   *
   * Each named setting comes with a value @v@ and a mask @m@; the mask
   * should cover all of the value bits, i.e., @(v&~m) == 0@.
   */

  const char *tag;                      /* name */
  unsigned long m, v;                   /* mask and value */
};

#define TVEC_ENDFLAGS { 0, 0, 0 }

struct tvec_flaginfo {
  /* Information about a flags type. */

  const char *name;                     /* type name for diagnostics  */
  const struct tvec_flag *fv;           /* name/mask/value mappings */
  const struct tvec_urange *range;      /* permitted range for literals */
};

/* --- @tvec_claimeq_flags@, @TVEC_CLAIMEQ_FLAGS@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const struct tvec_flaginfo *fi@ = flags type info
 *              @unsigned long f0, f1@ = two values
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if @f0@ and @f1@ are equal, otherwise zero.
 *
 * Use:         Check that values of @f0@ and @f1@ are equal.  As for
 *              @tvec_claim@ above, a test case is automatically begun and
 *              ended if none is already underway.  If the values are
 *              unequal, then @tvec_fail@ is called, quoting @expr@, and the
 *              mismatched values are dumped: @f0@ is printed as the output
 *              value and @f1@ is printed as the input reference.
 *
 *              The @TVEC_CLAIM_FLAGS@ macro is similar, only it (a)
 *              identifies the file and line number of the call site
 *              automatically, and (b) implicitly quotes the source text of
 *              the @f0@ and @f1@ arguments in the failure message.
 */

extern int tvec_claimeq_flags(struct tvec_state */*tv*/,
                              const struct tvec_flaginfo */*fi*/,
                              unsigned long /*f0*/, unsigned long /*f1*/,
                              const char */*file*/, unsigned /*lno*/,
                              const char */*expr*/);
#define TVEC_CLAIMEQ_FLAGS(tv, fi, f0, f1)                              \
        (tvec_claimeq_flags(tv, fi, f0, f1,                             \
                            __FILE__, __LINE__, #f0 " /= " #f1))

/*----- Character type ----------------------------------------------------*/

/* A character value holds a character, as read by @fgetc@.  The special
 * @EOF@ value can also be represented.
 *
 * On input, a character value can be given by symbolic name, with a leading
 * `%|#|%'; or a character or `%|\|%'-escape sequence, optionally in single
 * quotes.
 *
 * The following escape sequences and character names are recognized.
 *
 *   * `%|#eof|%' is the special end-of-file marker.
 *
 *   * `%|#nul|%' is the NUL character, sometimes used to terminate strings.
 *
 *   * `%|bell|%', `%|bel|%', `%|ding|%', or `%|\a|%' is the BEL character
 *     used to ring the terminal bell (or do some other thing to attract the
 *     user's attention).
 *
 *   * %|#backspace|%, %|#bs|%, or %|\b|% is the backspace character, used to
 *     move the cursor backwords by one cell.
 *
 *   * %|#escape|% %|#esc|%, or%|\e|% is the escape character, used to
 *     introduce special terminal commands.
 *
 *   * %|#formfeed|%, %|#ff|%, or %|\f|% is the formfeed character, used to
 *     separate pages of text.
 *
 *   * %|#newline|%, %|#linefeed|%, %|#lf|%, %|#nl|%, or %|\n|% is the
 *     newline character, used to terminate lines of text or advance the
 *     cursor to the next line (perhaps without returning it to the start of
 *     the line).
 *
 *   * %|#return|%, %|#carriage-return|%, %|#cr|%, or %|\r|% is the
 *     carriage-return character, used to return the cursor to the start of
 *     the line.
 *
 *   * %|#tab|%, %|#horizontal-tab|%, %|#ht|%, or %|\t|% is the tab
 *     character, used to advance the cursor to the next tab stop on the
 *     current line.
 *
 *   * %|#vertical-tab|%, %|#vt|%, %|\v|% is the vertical tab character.
 *
 *   * %|#space|%, %|#spc|% is the space character.
 *
 *   * %|#delete|%, %|#del|% is the delete character, used to erase the most
 *     recent character.
 *
 *   * %|\'|% is the single-quote character.
 *
 *   * %|\\|% is the backslash character.
 *
 *   * %|\"|% is the double-quote character.
 *
 *   * %|\NNN|% or %|\{NNN}|% is the character with code NNN in octal.  The
 *     NNN may be up to three digits long.
 *
 *   * %|\xNN|% or %|\x{NN}|% is the character with code NNN in hexadecimal.
 */

extern const struct tvec_regty tvty_char;

/* --- @tvec_claimeq_char@, @TVEC_CLAIMEQ_CHAR@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @int ch0, ch1@ = two character codes
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if @ch0@ and @ch1@ are equal, otherwise zero.
 *
 * Use:         Check that values of @ch0@ and @ch1@ are equal.  As for
 *              @tvec_claim@ above, a test case is automatically begun and
 *              ended if none is already underway.  If the values are
 *              unequal, then @tvec_fail@ is called, quoting @expr@, and the
 *              mismatched values are dumped: @ch0@ is printed as the output
 *              value and @ch1@ is printed as the input reference.
 *
 *              The @TVEC_CLAIM_CHAR@ macro is similar, only it (a)
 *              identifies the file and line number of the call site
 *              automatically, and (b) implicitly quotes the source text of
 *              the @ch0@ and @ch1@ arguments in the failure message.
 */

extern int tvec_claimeq_char(struct tvec_state */*tv*/,
                             int /*ch0*/, int /*ch1*/,
                             const char */*file*/, unsigned /*lno*/,
                             const char */*expr*/);
#define TVEC_CLAIMEQ_CHAR(tv, c0, c1)                                   \
        (tvec_claimeq_char(tv, c0, c1, __FILE__, __LINE__, #c0 " /= " #c1))

/*----- Text and binary string types --------------------------------------*/

/* A string is a sequence of octets.  Text and binary strings differ
 * primarily in presentation: text strings are shown as raw characters where
 * possible; binary strings are shown as hex dumps with an auxiliary text
 * display.
 *
 * The input format for both kinds of strings is basically the same: a
 * `compound string', consisting of
 *
 *   * single-quoted strings, which are interpreted entirely literally, but
 *     can't contain single quotes or newlines;
 *
 *   * double-quoted strings, in which `%|\|%'-escapes are interpreted as for
 *     characters;
 *
 *   * character names, marked by an initial `%|#|%' sign;
 *
 *   * special tokens marked by an initial `%|!|%' sign; or
 *
 *   * barewords interpreted according to the current coding scheme.
 *
 * The special tokens are
 *
 *   * `%|!bare|%', which causes subsequent sequences of barewords to be
 *     treated as plain text;
 *
 *   * `%|!hex|%', `%|!base32|%', `%|!base64|%', which cause subsequent
 *     barewords to be decoded in the requested manner.
 *
 *   * `%|!repeat|% %$n$% %|{|% %%\textit{string}%% %|}|%', which includes
 *     %$n$% copies of the (compound) string.
 *
 * The only difference between text and binary strings is that the initial
 * coding scheme is %|bare|% for text strings and %|hex|% for binary strings.
 *
 * Either kind of string can contain internal nul characters.  A trailing nul
 * is appended -- beyond the stated input length -- to input strings as a
 * convenience to test functions.  Test functions may include such a nul
 * character on output but this is not checked by the equality test.
 *
 * A @struct tvec_urange@ may be supplied as an argument: the length of the
 * string (in bytes) will be checked against the permitted range.
 */

extern const struct tvec_regty tvty_text, tvty_bytes;

/* --- @tvec_claimeq_text@, @TVEC_CLAIMEQ_TEXT@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *p0@, @size_t sz0@ = first string with length
 *              @const char *p1@, @size_t sz1@ = second string with length
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if the strings at @p0@ and @p1@ are equal, otherwise
 *              zero.
 *
 * Use:         Check that strings at @p0@ and @p1@ are equal.  As for
 *              @tvec_claim@ above, a test case is automatically begun and
 *              ended if none is already underway.  If the values are
 *              unequal, then @tvec_fail@ is called, quoting @expr@, and the
 *              mismatched values are dumped: @p0@ is printed as the output
 *              value and @p1@ is printed as the input reference.
 *
 *              The @TVEC_CLAIM_TEXT@ macro is similar, only it (a)
 *              identifies the file and line number of the call site
 *              automatically, and (b) implicitly quotes the source text of
 *              the @ch0@ and @ch1@ arguments in the failure message.
 */

extern int tvec_claimeq_text(struct tvec_state */*tv*/,
                             const char */*p0*/, size_t /*sz0*/,
                             const char */*p1*/, size_t /*sz1*/,
                             const char */*file*/, unsigned /*lno*/,
                             const char */*expr*/);
#define TVEC_CLAIMEQ_TEXT(tv, p0, sz0, p1, sz1)                         \
        (tvec_claimeq_text(tv, p0, sz0, p1, sz1, __FILE__, __LINE__,    \
                           #p0 "[" #sz0 "] /= " #p1 "[" #sz1 "]"))

/* --- @tvec_claimeq_textz@, @TVEC_CLAIMEQ_TEXTZ@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const char *p0, *p1@ = two strings to compare
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if the strings at @p0@ and @p1@ are equal, otherwise
 *              zero.
 *
 * Use:         Check that strings at @p0@ and @p1@ are equal, as for
 *              @tvec_claimeq_string@, except that the strings are assumed
 *              null-terminated, so their lengths don't need to be supplied
 *              explicitly.  The macro is similarly like @TVEC_CLAIMEQ_TEXT@.
 */

extern int tvec_claimeq_textz(struct tvec_state */*tv*/,
                              const char */*p0*/, const char */*p1*/,
                              const char */*file*/, unsigned /*lno*/,
                              const char */*expr*/);
#define TVEC_CLAIMEQ_TEXTZ(tv, p0, p1)                                  \
        (tvec_claimeq_textz(tv, p0, p1, __FILE__, __LINE__, #p0 " /= " #p1))

/* --- @tvec_claimeq_bytes@, @TVEC_CLAIMEQ_BYTES@ --- *
 *
 * Arguments:   @struct tvec_state *tv@ = test-vector state
 *              @const void *p0@, @size_t sz0@ = first string with length
 *              @const void *p1@, @size_t sz1@ = second string with length
 *              @const char *file@, @unsigned @lno@ = calling file and line
 *              @const char *expr@ = the expression to quote on failure
 *
 * Returns:     Nonzero if the strings at @p0@ and @p1@ are equal, otherwise
 *              zero.
 *
 * Use:         Check that binary strings at @p0@ and @p1@ are equal.  As for
 *              @tvec_claim@ above, a test case is automatically begun and
 *              ended if none is already underway.  If the values are
 *              unequal, then @tvec_fail@ is called, quoting @expr@, and the
 *              mismatched values are dumped: @p0@ is printed as the output
 *              value and @p1@ is printed as the input reference.
 *
 *              The @TVEC_CLAIM_STRING@ macro is similar, only it (a)
 *              identifies the file and line number of the call site
 *              automatically, and (b) implicitly quotes the source text of
 *              the @ch0@ and @ch1@ arguments in the failure message.
 */

extern int tvec_claimeq_bytes(struct tvec_state */*tv*/,
                               const void */*p0*/, size_t /*sz0*/,
                               const void */*p1*/, size_t /*sz1*/,
                               const char */*file*/, unsigned /*lno*/,
                               const char */*expr*/);
#define TVEC_CLAIMEQ_BYTES(tv, p0, sz0, p1, sz1)                        \
        (tvec_claimeq(tv, p0, sz0, p1, sz1, __FILE__, __LINE__,         \
                      #p0 "[" #sz0 "] /= " #p1 "[" #sz1 "]"))

/* --- @tvec_alloctext@, @tvec_allocbytes@ --- *
 *
 * Arguments:   @union tvec_regval *rv@ = register value
 *              @size_t sz@ = required size
 *
 * Returns:     ---
 *
 * Use:         Allocated space in a text or binary string register.  If the
 *              current register size is sufficient, its buffer is left
 *              alone; otherwise, the old buffer, if any, is freed and a
 *              fresh buffer allocated.  These functions are not intended to
 *              be used to adjust a buffer repeatedly, e.g., while building
 *              output incrementally: (a) they will perform badly, and (b)
 *              the old buffer contents are simply discarded if reallocation
 *              is necessary.  Instead, use a @dbuf@ or @dstr@.
 *
 *              The @tvec_alloctext@ function sneakily allocates an extra
 *              byte for a terminating zero.  The @tvec_allocbytes@ function
 *              doesn't do this.
 */

extern void tvec_alloctext(union tvec_regval */*rv*/, size_t /*sz*/);
extern void tvec_allocbytes(union tvec_regval */*rv*/, size_t /*sz*/);

/*----- Buffer type -------------------------------------------------------*/

/* Buffer registers are primarily used for benchmarking.  Only a buffer's
 * allocation parameters are significant: its contents are ignored on
 * comparison and output, and unspecified on input.
 *
 * The input format gives the buffer's size, and an optional alignment
 * specification, in the form %|SZ [`@' M [`+' A]]|%.  Each of %|SZ|%, %|M|%
 * and %|A|% are sizes, as an integer, optionally suffixed with a unit `kB',
 * `MB', `GB', `TB', `PB', `EB', `ZB', `YB' (with or without the `B')
 * denoting a power of 1024.  The %|SZ|% gives the (effective) buffer size.
 * %|M|% is the `alignment quantum' and %|A|% is the `alignment offset'; both
 * default to zero, but if %|M|% is nonzero then the start of the buffer is
 * aligned such that it is %|A|% more than a multiple of %|M|% bytes.  Note
 * that %|M|% need not be a power of two, though this is common.
 *
 * Units other than `B' are used on output only when the size would be
 * expressed exactly.
 *
 * Buffers are %%\emph{not}%% allocated by default.  In benchmarks, this is
 * best done in a @before@ function.
 *
 * No @claimeq@ functions or macros are provided for buffers because they
 * don't seem very useful.
 */

extern const struct tvec_regty tvty_buffer;

/* --- @tvec_initbuffer@ --- *
 *
 * Arguments:   @union tvec_regval *rv@ = register value
 *              @const union tvec_regval *src@ = source buffer
 *              @size_t sz@ = size to allocate
 *
 * Returns:     ---
 *
 * Use:         Initialize the alignment parameters in @rv@ to match @src@,
 *              and the size to @sz@.
 */

extern void tvec_initbuffer(union tvec_regval */*rv*/,
                            const union tvec_regval */*src*/, size_t /*sz*/);

/* --- @tvec_allocbuffer@ --- *
 *
 * Arguments:   @union tvec_regval *rv@ = register value
 *
 * Returns:     ---
 *
 * Use:         Allocate @sz@ bytes to the buffer and fill the space with a
 *              distinctive pattern.
 */

extern void tvec_allocbuffer(union tvec_regval */*rv*/);

/*----- That's all, folks -------------------------------------------------*/

#ifdef __cplusplus
  }
#endif

#endif