Fix various compiler warnings and errors. In particular, my cunning

auto-type-checking DEPLANARISE and REPLANARISE macros have turned
out to only work in gcc, which is a shame.

git-svn-id: svn://svn.tartarus.org/sgt/charset@6455 cda61777-01e9-0310-a592-d414129be87e

diff --git a/iso2022.c b/iso2022.c
index 0b8ddae..73fc023 100644 (file)
--- a/iso2022.c
+++ b/iso2022.c
@@ -22,6 +22,7 @@
 #ifndef ENUM_CHARSETS
 
 #include <assert.h>
+#include <string.h>
 
 #include "charset.h"
 #include "internal.h"
@@ -51,10 +52,31 @@ static int unicode_to_null_dbcs(long int, int *, int *);
 typedef int (*to_dbcs_t)(long int, int *, int *);
 typedef int (*to_dbcs_planar_t)(long int, int *, int *, int *);
 
-/* Cast between to_dbcs_planar_t and to_dbcs_t, type-checking first */
+/*
+ * Cast between to_dbcs_planar_t and to_dbcs_t.
+ * 
+ * I (SGT) originally defined these two macros as follows:
+
 #define DEPLANARISE(x) ( (x) == (to_dbcs_planar_t)NULL, (to_dbcs_t)(x) )
 #define REPLANARISE(x) ( (x) == (to_dbcs_t)NULL, (to_dbcs_planar_t)(x) )
 
+ * When compiled with gcc, this had the effect of type-checking the
+ * input, so that DEPLANARISE would cast a to_dbcs_t to a
+ * to_dbcs_planar_t but cause a compile error if passed any other
+ * input type, and vice versa. However, MSVC felt that this was a
+ * non-constant expression and hence not legal to use in a static
+ * initialiser, and probably rightly so: I haven't had a chance to
+ * check with the C standard, but I'd be surprised if it _required_
+ * compilers to keep an open mind long enough to discover that the
+ * non-constant part of the expression has its result thrown away.
+ * 
+ * I can't think of any other means of performing this type check
+ * which doesn't have the same problem, so I'm taking the type
+ * checks out, with regret.
+ */
+#define DEPLANARISE(x) ( (to_dbcs_t)(x) )
+#define REPLANARISE(x) ( (to_dbcs_planar_t)(x) )
+
 /*
  * Values used in the `enable' field. Each of these identifies a
  * class of character sets; we then have a bitmask indicating which
@@ -169,10 +191,15 @@ const struct iso2022_subcharset {
 
 static long int null_dbcs_to_unicode(int r, int c)
 {
+    UNUSEDARG(r);
+    UNUSEDARG(c);
     return ERROR;
 }
 static int unicode_to_null_dbcs(long int unicode, int *r, int *c)
 {
+    UNUSEDARG(unicode);
+    UNUSEDARG(r);
+    UNUSEDARG(c);
     return 0;                         /* failed to convert anything */
 }
 
@@ -421,7 +448,7 @@ static void docs_ctext(long int input_chr,
        if (input_chr == 2)
            state->s0 = (state->s0 & 0xf0000000) | (i << 26) | (0xf << 22);
     } else if (n != 0xf) {
-       while (j < lenof(ctext_encodings) &&
+       while ((unsigned)j < lenof(ctext_encodings) &&
               !memcmp(ctext_encodings[j].name,
                       ctext_encodings[oi].name, n)) {
            if (ctext_encodings[j].name[n] < input_chr)
@@ -429,7 +456,7 @@ static void docs_ctext(long int input_chr,
            else
                break;
        }
-       if (i >= lenof(ctext_encodings) ||
+       if ((unsigned)i >= lenof(ctext_encodings) ||
            memcmp(ctext_encodings[i].name,
                   ctext_encodings[oi].name, n) ||
            ctext_encodings[i].name[n] != input_chr) {
@@ -453,7 +480,7 @@ static void docs_ctext(long int input_chr,
        assert(i < 4 && n < 16);
        state->s0 = (state->s0 & 0xf0000000) | (i << 26) | (n << 22);
     } else {
-       if (i >= lenof(ctext_encodings))
+       if ((unsigned)i >= lenof(ctext_encodings))
            emit(emitctx, ERROR);
        else {
            charset_state substate;
@@ -776,7 +803,7 @@ static void oselect(charset_state *state, int i, int right,
     int shift = (right ? 31-7 : 31-7-7);
     struct iso2022_subcharset const *subcs = &iso2022_subcharsets[i];
 
-    if (((state->s1 >> shift) & 0x7F) != i) {
+    if (((state->s1 >> shift) & 0x7F) != (unsigned)i) {
        state->s1 &= ~(0x7FL << shift);
        state->s1 |= (i << shift);
 
@@ -975,7 +1002,7 @@ static int write_iso2022(charset_spec const *charset, long int input_chr,
        /*
         * Start with US-ASCII in GL and also in GR.
         */
-       for (i = 0; i < lenof(iso2022_subcharsets); i++) {
+       for (i = 0; (unsigned)i < lenof(iso2022_subcharsets); i++) {
            subcs = &iso2022_subcharsets[i];
            if (subcs->type == mode->ltype &&
                subcs->i == mode->li &&
@@ -994,7 +1021,7 @@ static int write_iso2022(charset_spec const *charset, long int input_chr,
         */
        docs_char(state, emit, emitctx, -2, NULL, 0);   /* leave DOCS */
 
-       for (i = 0; i < lenof(iso2022_subcharsets); i++) {
+       for (i = 0; (unsigned)i < lenof(iso2022_subcharsets); i++) {
            subcs = &iso2022_subcharsets[i];
            if (subcs->type == mode->ltype &&
                subcs->i == mode->li &&
@@ -1021,7 +1048,7 @@ static int write_iso2022(charset_spec const *charset, long int input_chr,
      * Analyse the input character and work out which subcharset it
      * belongs to.
      */
-    for (i = 0; i < lenof(iso2022_subcharsets); i++) {
+    for (i = 0; (unsigned)i < lenof(iso2022_subcharsets); i++) {
        subcs = &iso2022_subcharsets[i];
        if (!(mode->enable_mask & (1 << subcs->enable)))
            continue;                  /* this charset is disabled */
@@ -1065,7 +1092,7 @@ static int write_iso2022(charset_spec const *charset, long int input_chr,
        }
     }
 
-    if (i < lenof(iso2022_subcharsets)) {
+    if ((unsigned)i < lenof(iso2022_subcharsets)) {
        int right;
 
        /*
@@ -1129,7 +1156,7 @@ static int write_iso2022(charset_spec const *charset, long int input_chr,
 
        cs = -2;                       /* means failure */
 
-       for (i = 0; i <= lenof(ctext_encodings); i++) {
+       for (i = 0; (unsigned)i <= lenof(ctext_encodings); i++) {
            charset_state substate;
            charset_spec const *subcs = ctext_encodings[i].subcs;
 
@@ -1140,7 +1167,7 @@ static int write_iso2022(charset_spec const *charset, long int input_chr,
            substate.s1 = substate.s0 = 0;
            p = data;
 
-           if (i < lenof(ctext_encodings)) {
+           if ((unsigned)i < lenof(ctext_encodings)) {
                if ((mode->enable_mask & (1 << ctext_encodings[i].enable)) &&
                    subcs->write(subcs, input_chr, &substate,
                                 write_to_pointer, &p)) {