Info backend now takes care to avoid magic characters in node names

[sgt/halibut] / bk_info.c

/*
 * info backend for Halibut
 * 
 * TODO:
 * 
 *  - configurable choice of how to allocate node names
 *  - might be helpful to diagnose duplicate node names!
 *  - test everything in info(1), and probably jed too
 * 
 * Later:
 * 
 *  - configurable indentation, bullets, emphasis, quotes etc?
 */

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "halibut.h"

typedef struct {
    char *filename;
    int maxfilesize;
} infoconfig;

typedef struct node_tag node;
struct node_tag {
    node *listnext;
    node *up, *prev, *next, *lastchild;
    int pos, started_menu, filenum;
    char *name;
    rdstringc text;
};

typedef struct {
    char *text;
    int nnodes, nodesize;
    node **nodes;
} info_idx;

static int info_convert(wchar_t *, char **);

static void info_heading(rdstringc *, word *, word *, int);
static void info_rule(rdstringc *, int, int);
static void info_para(rdstringc *, word *, char *, word *, keywordlist *,
                      int, int, int);
static void info_codepara(rdstringc *, word *, int, int);
static void info_versionid(rdstringc *, word *);
static void info_menu_item(rdstringc *, node *, paragraph *);
static word *info_transform_wordlist(word *, keywordlist *);
static int info_check_index(word *, node *, indexdata *);

static void info_rdaddwc(rdstringc *, word *, word *, int);

static node *info_node_new(char *name);
static char *info_node_name(paragraph *p);

static infoconfig info_configure(paragraph *source) {
    infoconfig ret;

    /*
     * Defaults.
     */
    ret.filename = dupstr("output.info");
    ret.maxfilesize = 64 << 10;

    for (; source; source = source->next) {
        if (source->type == para_Config) {
            if (!ustricmp(source->keyword, L"info-filename")) {
                sfree(ret.filename);
                ret.filename = utoa_dup(uadv(source->keyword));
            } else if (!ustricmp(source->keyword, L"info-max-file-size")) {
                ret.maxfilesize = utoi(uadv(source->keyword));
            }
        }
    }

    return ret;
}

paragraph *info_config_filename(char *filename)
{
    paragraph *p;
    wchar_t *ufilename, *up;
    int len;

    p = mknew(paragraph);
    memset(p, 0, sizeof(*p));
    p->type = para_Config;
    p->next = NULL;
    p->fpos.filename = "<command line>";
    p->fpos.line = p->fpos.col = -1;

    ufilename = ufroma_dup(filename);
    len = ustrlen(ufilename) + 2 + lenof(L"info-filename");
    p->keyword = mknewa(wchar_t, len);
    up = p->keyword;
    ustrcpy(up, L"info-filename");
    up = uadv(up);
    ustrcpy(up, ufilename);
    up = uadv(up);
    *up = L'\0';
    assert(up - p->keyword < len);
    sfree(ufilename);

    return p;
}

void info_backend(paragraph *sourceform, keywordlist *keywords,
                  indexdata *idx) {
    paragraph *p;
    infoconfig conf;
    word *prefix, *body, *wp;
    word spaceword;
    char *prefixextra;
    int nesting, nestindent;
    int indentb, indenta;
    int filepos;
    int has_index;
    rdstringc intro_text = { 0, 0, NULL };
    node *topnode, *currnode;
    word bullet;
    FILE *fp;

    /*
     * FIXME
     */
    int width = 70, listindentbefore = 1, listindentafter = 3;
    int indent_code = 2, index_width = 40;

    IGNORE(keywords);                  /* we don't happen to need this */
    IGNORE(idx);                       /* or this */

    conf = info_configure(sourceform);

    /*
     * Go through and create a node for each section.
     */
    topnode = info_node_new("Top");
    currnode = topnode;
    for (p = sourceform; p; p = p->next) switch (p->type) {
        /*
         * Chapter titles.
         */
      case para_Chapter:
      case para_Appendix:
      case para_UnnumberedChapter:
      case para_Heading:
      case para_Subsect:
        {
            node *newnode, *upnode;
            char *nodename;

            nodename = info_node_name(p);
            newnode = info_node_new(nodename);
            sfree(nodename);

            p->private_data = newnode;

            if (p->parent)
                upnode = (node *)p->parent->private_data;
            else
                upnode = topnode;
            assert(upnode);
            newnode->up = upnode;

            currnode->next = newnode;
            newnode->prev = currnode;

            currnode->listnext = newnode;
            currnode = newnode;
        }
        break;
    }

    /*
     * Set up the display form of each index entry.
     */
    {
        int i;
        indexentry *entry;

        for (i = 0; (entry = index234(idx->entries, i)) != NULL; i++) {
            info_idx *ii = mknew(info_idx);
            rdstringc rs = { 0, 0, NULL };
            char *p, *q;

            ii->nnodes = ii->nodesize = 0;
            ii->nodes = NULL;

            info_rdaddwc(&rs, entry->text, NULL, FALSE);

            /*
             * We cannot have colons in index terms, since they
             * disrupt the structure of the index menu. Remove any
             * that we find, with a warning.
             */
            p = q = rs.text;
            while (*p) {
                if (*p == ':') {
                    error(err_infoindexcolon, &entry->fpos);
                } else {
                    *q++ = *p;
                }
                p++;
            }

            ii->text = rs.text;

            entry->backend_data = ii;
        }
    }

    /*
     * An Info file begins with a piece of introductory text which
     * is apparently never shown anywhere. This seems to me to be a
     * good place to put the copyright notice and the version IDs. 
     * Also, Info directory entries are expected to go here.
     */

    rdaddsc(&intro_text,
            "This Info file generated by Halibut, ");
    rdaddsc(&intro_text, version);
    rdaddsc(&intro_text, "\n\n");

    for (p = sourceform; p; p = p->next)
        if (p->type == para_Config &&
            !ustricmp(p->keyword, L"info-dir-entry")) {
            wchar_t *section, *shortname, *longname, *kw;
            char *s;

            section = uadv(p->keyword);
            shortname = *section ? uadv(section) : NULL;
            longname = *shortname ? uadv(shortname) : NULL;
            kw = *longname ? uadv(longname) : NULL;

            if (!*longname) {
                error(err_infodirentry, &p->fpos);
                continue;
            }

            rdaddsc(&intro_text, "INFO-DIR-SECTION ");
            s = utoa_dup(section);
            rdaddsc(&intro_text, s);
            sfree(s);
            rdaddsc(&intro_text, "\nSTART-INFO-DIR-ENTRY\n* ");
            s = utoa_dup(shortname);
            rdaddsc(&intro_text, s);
            sfree(s);
            rdaddsc(&intro_text, ": (");
            s = dupstr(conf.filename);
            if (strlen(s) > 5 && !strcmp(s+strlen(s)-5, ".info"))
                s[strlen(s)-5] = '\0';
            rdaddsc(&intro_text, s);
            sfree(s);
            rdaddsc(&intro_text, ")");
            if (*kw) {
                keyword *kwl = kw_lookup(keywords, kw);
                if (kwl && kwl->para->private_data) {
                    node *n = (node *)kwl->para->private_data;
                    rdaddsc(&intro_text, n->name);
                }
            }
            rdaddsc(&intro_text, ".   ");
            s = utoa_dup(longname);
            rdaddsc(&intro_text, s);
            sfree(s);
            rdaddsc(&intro_text, "\nEND-INFO-DIR-ENTRY\n\n");
        }

    for (p = sourceform; p; p = p->next)
        if (p->type == para_Copyright)
            info_para(&intro_text, NULL, NULL, p->words, keywords,
                      0, 0, width);

    for (p = sourceform; p; p = p->next)
        if (p->type == para_VersionID)
            info_versionid(&intro_text, p->words);

    if (intro_text.text[intro_text.pos-1] != '\n')
        rdaddc(&intro_text, '\n');

    /* Do the title */
    for (p = sourceform; p; p = p->next)
        if (p->type == para_Title)
            info_heading(&topnode->text, NULL, p->words, width);

    nestindent = listindentbefore + listindentafter;
    nesting = 0;

    currnode = topnode;

    /* Do the main document */
    for (p = sourceform; p; p = p->next) switch (p->type) {

      case para_QuotePush:
        nesting += 2;
        break;
      case para_QuotePop:
        nesting -= 2;
        assert(nesting >= 0);
        break;

      case para_LcontPush:
        nesting += nestindent;
        break;
      case para_LcontPop:
        nesting -= nestindent;
        assert(nesting >= 0);
        break;

        /*
         * Things we ignore because we've already processed them or
         * aren't going to touch them in this pass.
         */
      case para_IM:
      case para_BR:
      case para_Biblio:                /* only touch BiblioCited */
      case para_VersionID:
      case para_NoCite:
      case para_Title:
        break;

        /*
         * Chapter titles.
         */
      case para_Chapter:
      case para_Appendix:
      case para_UnnumberedChapter:
      case para_Heading:
      case para_Subsect:
        currnode = p->private_data;
        assert(currnode);
        assert(currnode->up);

        if (!currnode->up->started_menu) {
            rdaddsc(&currnode->up->text, "* Menu:\n\n");
            currnode->up->started_menu = TRUE;
        }
        info_menu_item(&currnode->up->text, currnode, p);

        has_index |= info_check_index(p->words, currnode, idx);
        info_heading(&currnode->text, p->kwtext, p->words, width);
        nesting = 0;
        break;

      case para_Rule:
        info_rule(&currnode->text, nesting, width - nesting);
        break;

      case para_Normal:
      case para_Copyright:
      case para_DescribedThing:
      case para_Description:
      case para_BiblioCited:
      case para_Bullet:
      case para_NumberedList:
        has_index |= info_check_index(p->words, currnode, idx);
        if (p->type == para_Bullet) {
            bullet.next = NULL;
            bullet.alt = NULL;
            bullet.type = word_Normal;
            bullet.text = L"-";        /* FIXME: configurability */
            prefix = &bullet;
            prefixextra = NULL;
            indentb = listindentbefore;
            indenta = listindentafter;
        } else if (p->type == para_NumberedList) {
            prefix = p->kwtext;
            prefixextra = ".";         /* FIXME: configurability */
            indentb = listindentbefore;
            indenta = listindentafter;
        } else if (p->type == para_Description) {
            prefix = NULL;
            prefixextra = NULL;
            indentb = listindentbefore;
            indenta = listindentafter;
        } else {
            prefix = NULL;
            prefixextra = NULL;
            indentb = indenta = 0;
        }
        if (p->type == para_BiblioCited) {
            body = dup_word_list(p->kwtext);
            for (wp = body; wp->next; wp = wp->next);
            wp->next = &spaceword;
            spaceword.next = p->words;
            spaceword.alt = NULL;
            spaceword.type = word_WhiteSpace;
            spaceword.text = NULL;
        } else {
            wp = NULL;
            body = p->words;
        }
        info_para(&currnode->text, prefix, prefixextra, body, keywords,
                  nesting + indentb, indenta,
                  width - nesting - indentb - indenta);
        if (wp) {
            wp->next = NULL;
            free_word_list(body);
        }
        break;

      case para_Code:
        info_codepara(&currnode->text, p->words,
                      nesting + indent_code,
                      width - nesting - 2 * indent_code);
        break;
    }

    /*
     * Create an index node if required.
     */
    if (has_index) {
        node *newnode;
        int i, j, k;
        indexentry *entry;

        newnode = info_node_new("Index");
        newnode->up = topnode;

        currnode->next = newnode;
        newnode->prev = currnode;
        currnode->listnext = newnode;

        rdaddsc(&newnode->text, "Index\n-----\n\n* Menu:\n\n");

        info_menu_item(&topnode->text, newnode, NULL);

        for (i = 0; (entry = index234(idx->entries, i)) != NULL; i++) {
            info_idx *ii = (info_idx *)entry->backend_data;

            for (j = 0; j < ii->nnodes; j++) {
                int pos0 = newnode->text.pos;
                rdaddsc(&newnode->text, "* ");
                /*
                 * When we have multiple references for a single
                 * index term, we only display the actual term on
                 * the first line, to make it clear that the terms
                 * really are the same.
                 */
                if (j == 0)
                    rdaddsc(&newnode->text, ii->text);
                for (k = newnode->text.pos - pos0; k < index_width; k++)
                    rdaddc(&newnode->text, ' ');
                rdaddsc(&newnode->text, ": ");
                rdaddsc(&newnode->text, ii->nodes[j]->name);
                rdaddsc(&newnode->text, ".\n");
            }
        }
    }

    /*
     * Finalise the text of each node, by adding the ^_ delimiter
     * and the node line at the top.
     */
    for (currnode = topnode; currnode; currnode = currnode->listnext) {
        char *origtext = currnode->text.text;
        currnode->text.text = NULL;
        currnode->text.pos = currnode->text.size = 0;
        rdaddsc(&currnode->text, "\037\nFile: ");
        rdaddsc(&currnode->text, conf.filename);
        rdaddsc(&currnode->text, ",  Node: ");
        rdaddsc(&currnode->text, currnode->name);
        if (currnode->prev) {
            rdaddsc(&currnode->text, ",  Prev: ");
            rdaddsc(&currnode->text, currnode->prev->name);
        }
        rdaddsc(&currnode->text, ",  Up: ");
        rdaddsc(&currnode->text, (currnode->up ?
                                  currnode->up->name : "(dir)"));
        if (currnode->next) {
            rdaddsc(&currnode->text, ",  Next: ");
            rdaddsc(&currnode->text, currnode->next->name);
        }
        rdaddsc(&currnode->text, "\n\n");
        rdaddsc(&currnode->text, origtext);
        /*
         * Just make _absolutely_ sure we end with a newline.
         */
        if (currnode->text.text[currnode->text.pos-1] != '\n')
            rdaddc(&currnode->text, '\n');

        sfree(origtext);
    }    

    /*
     * Compute the offsets for the tag table.
     */
    filepos = intro_text.pos;
    for (currnode = topnode; currnode; currnode = currnode->listnext) {
        currnode->pos = filepos;
        filepos += currnode->text.pos;
    }

    /*
     * Split into sub-files.
     */
    if (conf.maxfilesize > 0) {
        int currfilesize = intro_text.pos, currfilenum = 1;
        for (currnode = topnode; currnode; currnode = currnode->listnext) {
            if (currfilesize > intro_text.pos &&
                currfilesize + currnode->text.pos > conf.maxfilesize) {
                currfilenum++;
                currfilesize = intro_text.pos;
            }
            currnode->filenum = currfilenum;
            currfilesize += currnode->text.pos;
        }
    }

    /*
     * Write the primary output file.
     */
    fp = fopen(conf.filename, "w");
    if (!fp) {
        error(err_cantopenw, conf.filename);
        return;
    }
    fputs(intro_text.text, fp);
    if (conf.maxfilesize == 0) {
        for (currnode = topnode; currnode; currnode = currnode->listnext)
            fputs(currnode->text.text, fp);
    } else {
        int filenum = 0;
        fprintf(fp, "\037\nIndirect:\n");
        for (currnode = topnode; currnode; currnode = currnode->listnext)
            if (filenum != currnode->filenum) {
                filenum = currnode->filenum;
                fprintf(fp, "%s-%d: %d\n", conf.filename, filenum,
                        currnode->pos);
            }
    }
    fprintf(fp, "\037\nTag Table:\n");
    if (conf.maxfilesize > 0)
        fprintf(fp, "(Indirect)\n");
    for (currnode = topnode; currnode; currnode = currnode->listnext)
        fprintf(fp, "Node: %s\177%d\n", currnode->name, currnode->pos);
    fprintf(fp, "\037\nEnd Tag Table\n");
    fclose(fp);

    /*
     * Write the subfiles.
     */
    if (conf.maxfilesize > 0) {
        int filenum = 0;
        fp = NULL;

        for (currnode = topnode; currnode; currnode = currnode->listnext) {
            if (filenum != currnode->filenum) {
                char *fname;

                filenum = currnode->filenum;

                if (fp)
                    fclose(fp);
                fname = mknewa(char, strlen(conf.filename) + 40);
                sprintf(fname, "%s-%d", conf.filename, filenum);
                fp = fopen(fname, "w");
                if (!fp) {
                    error(err_cantopenw, fname);
                    return;
                }
                sfree(fname);
                fputs(intro_text.text, fp);
            }
            fputs(currnode->text.text, fp);
        }

        if (fp)
            fclose(fp);
    }
}

static int info_check_index(word *w, node *n, indexdata *idx)
{
    int ret = 0;

    for (; w; w = w->next) {
        if (w->type == word_IndexRef) {
            indextag *tag;
            int i;

            tag = index_findtag(idx, w->text);
            if (!tag)
                break;

            for (i = 0; i < tag->nrefs; i++) {
                indexentry *entry = tag->refs[i];
                info_idx *ii = (info_idx *)entry->backend_data;

                if (ii->nnodes > 0 && ii->nodes[ii->nnodes-1] == n) {
                    /*
                     * If the same index term is indexed twice
                     * within the same section, we only want to
                     * mention it once in the index. So do nothing
                     * here.
                     */
                    continue;
                }

                if (ii->nnodes >= ii->nodesize) {
                    ii->nodesize += 32;
                    ii->nodes = resize(ii->nodes, ii->nodesize);
                }

                ii->nodes[ii->nnodes++] = n;

                ret = 1;
            }
        }
    }

    return ret;
}

/*
 * Convert a wide string into a string of chars. If `result' is
 * non-NULL, mallocs the resulting string and stores a pointer to
 * it in `*result'. If `result' is NULL, merely checks whether all
 * characters in the string are feasible for the output character
 * set.
 *
 * Return is nonzero if all characters are OK. If not all
 * characters are OK but `result' is non-NULL, a result _will_
 * still be generated!
 */
static int info_convert(wchar_t *s, char **result) {
    /*
     * FIXME. Currently this is ISO8859-1 only.
     */
    int doing = (result != 0);
    int ok = TRUE;
    char *p = NULL;
    int plen = 0, psize = 0;

    for (; *s; s++) {
        wchar_t c = *s;
        char outc;

        if ((c >= 32 && c <= 126) ||
            (c >= 160 && c <= 255)) {
            /* Char is OK. */
            outc = (char)c;
        } else {
            /* Char is not OK. */
            ok = FALSE;
            outc = 0xBF;               /* approximate the good old DEC `uh?' */
        }
        if (doing) {
            if (plen >= psize) {
                psize = plen + 256;
                p = resize(p, psize);
            }
            p[plen++] = outc;
        }
    }
    if (doing) {
        p = resize(p, plen+1);
        p[plen] = '\0';
        *result = p;
    }
    return ok;
}

static word *info_transform_wordlist(word *words, keywordlist *keywords)
{
    word *ret = dup_word_list(words);
    word *w;
    keyword *kwl;

    for (w = ret; w; w = w->next) {
        w->private_data = NULL;
        if (w->type == word_UpperXref || w->type == word_LowerXref) {
            kwl = kw_lookup(keywords, w->text);
            if (kwl) {
                if (kwl->para->type == para_NumberedList ||
                    kwl->para->type == para_BiblioCited) {
                    /*
                     * In Info, we do nothing special for xrefs to
                     * numbered list items or bibliography entries.
                     */
                    break;
                } else {
                    /*
                     * An xref to a different section has its text
                     * completely replaced.
                     */
                    word *w2, *w3, *w4;
                    w2 = w3 = w->next;
                    w4 = NULL;
                    while (w2) {
                        if (w2->type == word_XrefEnd) {
                            w4 = w2->next;
                            w2->next = NULL;
                            break;
                        }
                        w2 = w2->next;
                    }
                    free_word_list(w3);

                    /*
                     * Now w is the UpperXref / LowerXref we
                     * started with, and w4 is the next word after
                     * the corresponding XrefEnd (if any). The
                     * simplest thing is just to stick a pointer to
                     * the target node structure in the private
                     * data field of the xref word, and let
                     * info_rdaddwc and friends read the node name
                     * out from there.
                     */
                    w->next = w4;
                    w->private_data = kwl->para->private_data;
                    assert(w->private_data);
                }
            }
        }
    }

    return ret;
}

static void info_rdaddwc(rdstringc *rs, word *words, word *end, int xrefs) {
    char *c;

    for (; words && words != end; words = words->next) switch (words->type) {
      case word_HyperLink:
      case word_HyperEnd:
      case word_XrefEnd:
      case word_IndexRef:
        break;

      case word_Normal:
      case word_Emph:
      case word_Code:
      case word_WeakCode:
      case word_WhiteSpace:
      case word_EmphSpace:
      case word_CodeSpace:
      case word_WkCodeSpace:
      case word_Quote:
      case word_EmphQuote:
      case word_CodeQuote:
      case word_WkCodeQuote:
        assert(words->type != word_CodeQuote &&
               words->type != word_WkCodeQuote);
        if (towordstyle(words->type) == word_Emph &&
            (attraux(words->aux) == attr_First ||
             attraux(words->aux) == attr_Only))
            rdaddc(rs, '_');           /* FIXME: configurability */
        else if (towordstyle(words->type) == word_Code &&
                 (attraux(words->aux) == attr_First ||
                  attraux(words->aux) == attr_Only))
            rdaddc(rs, '`');           /* FIXME: configurability */
        if (removeattr(words->type) == word_Normal) {
            if (info_convert(words->text, &c))
                rdaddsc(rs, c);
            else
                info_rdaddwc(rs, words->alt, NULL, FALSE);
            sfree(c);
        } else if (removeattr(words->type) == word_WhiteSpace) {
            rdaddc(rs, ' ');
        } else if (removeattr(words->type) == word_Quote) {
            rdaddc(rs, quoteaux(words->aux) == quote_Open ? '`' : '\'');
                                       /* FIXME: configurability */
        }
        if (towordstyle(words->type) == word_Emph &&
            (attraux(words->aux) == attr_Last ||
             attraux(words->aux) == attr_Only))
            rdaddc(rs, '_');           /* FIXME: configurability */
        else if (towordstyle(words->type) == word_Code &&
                 (attraux(words->aux) == attr_Last ||
                  attraux(words->aux) == attr_Only))
            rdaddc(rs, '\'');          /* FIXME: configurability */
        break;

      case word_UpperXref:
      case word_LowerXref:
        if (xrefs && words->private_data) {
            rdaddsc(rs, "*Note ");
            rdaddsc(rs, ((node *)words->private_data)->name);
            rdaddsc(rs, "::");
        }
        break;
    }
}

static int info_width_internal(word *words, int xrefs);

static int info_width_internal_list(word *words, int xrefs) {
    int w = 0;
    while (words) {
        w += info_width_internal(words, xrefs);
        words = words->next;
    }
    return w;
}

static int info_width_internal(word *words, int xrefs) {
    switch (words->type) {
      case word_HyperLink:
      case word_HyperEnd:
      case word_XrefEnd:
      case word_IndexRef:
        return 0;

      case word_Normal:
      case word_Emph:
      case word_Code:
      case word_WeakCode:
        return (((words->type == word_Emph ||
                  words->type == word_Code)
                 ? (attraux(words->aux) == attr_Only ? 2 :
                    attraux(words->aux) == attr_Always ? 0 : 1)
                 : 0) +
                (info_convert(words->text, NULL) ?
                 ustrlen(words->text) :
                 info_width_internal_list(words->alt, xrefs)));

      case word_WhiteSpace:
      case word_EmphSpace:
      case word_CodeSpace:
      case word_WkCodeSpace:
      case word_Quote:
      case word_EmphQuote:
      case word_CodeQuote:
      case word_WkCodeQuote:
        assert(words->type != word_CodeQuote &&
               words->type != word_WkCodeQuote);
        return (((towordstyle(words->type) == word_Emph ||
                  towordstyle(words->type) == word_Code)
                 ? (attraux(words->aux) == attr_Only ? 2 :
                    attraux(words->aux) == attr_Always ? 0 : 1)
                 : 0) + 1);

      case word_UpperXref:
      case word_LowerXref:
        if (xrefs && words->private_data) {
            /* "*Note " plus "::" comes to 8 characters */
            return 8 + strlen(((node *)words->private_data)->name);
        }
        break;
    }
    return 0;                          /* should never happen */
}

static int info_width_noxrefs(word *words)
{
    return info_width_internal(words, FALSE);
}
static int info_width_xrefs(word *words)
{
    return info_width_internal(words, TRUE);
}

static void info_heading(rdstringc *text, word *tprefix,
                         word *words, int width) {
    rdstringc t = { 0, 0, NULL };
    int margin, length;
    int firstlinewidth, wrapwidth;
    int i;
    wrappedline *wrapping, *p;

    if (tprefix) {
        info_rdaddwc(&t, tprefix, NULL, FALSE);
        rdaddsc(&t, ": ");             /* FIXME: configurability */
    }
    margin = length = (t.text ? strlen(t.text) : 0);

    margin = 0;
    firstlinewidth = width - length;
    wrapwidth = width;

    wrapping = wrap_para(words, firstlinewidth, wrapwidth, info_width_noxrefs);
    for (p = wrapping; p; p = p->next) {
        info_rdaddwc(&t, p->begin, p->end, FALSE);
        length = (t.text ? strlen(t.text) : 0);
        for (i = 0; i < margin; i++)
            rdaddc(text, ' ');
        rdaddsc(text, t.text);
        rdaddc(text, '\n');
        for (i = 0; i < margin; i++)
            rdaddc(text, ' ');
        while (length--)
            rdaddc(text, '-');
        rdaddc(text, '\n');
        margin = 0;
        sfree(t.text);
        t = empty_rdstringc;
    }
    wrap_free(wrapping);
    rdaddc(text, '\n');

    sfree(t.text);
}

static void info_rule(rdstringc *text, int indent, int width) {
    while (indent--) rdaddc(text, ' ');
    while (width--) rdaddc(text, '-');
    rdaddc(text, '\n');
    rdaddc(text, '\n');
}

static void info_para(rdstringc *text, word *prefix, char *prefixextra,
                      word *input, keywordlist *keywords,
                      int indent, int extraindent, int width) {
    wrappedline *wrapping, *p;
    word *words;
    rdstringc pfx = { 0, 0, NULL };
    int e;
    int i;
    int firstlinewidth = width;

    words = info_transform_wordlist(input, keywords);

    if (prefix) {
        info_rdaddwc(&pfx, prefix, NULL, FALSE);
        if (prefixextra)
            rdaddsc(&pfx, prefixextra);
        for (i = 0; i < indent; i++)
            rdaddc(text, ' ');
        rdaddsc(text, pfx.text);
        /* If the prefix is too long, shorten the first line to fit. */
        e = extraindent - strlen(pfx.text);
        if (e < 0) {
            firstlinewidth += e;       /* this decreases it, since e < 0 */
            if (firstlinewidth < 0) {
                e = indent + extraindent;
                firstlinewidth = width;
                rdaddc(text, '\n');
            } else
                e = 0;
        }
        sfree(pfx.text);
    } else
        e = indent + extraindent;

    wrapping = wrap_para(words, firstlinewidth, width, info_width_xrefs);
    for (p = wrapping; p; p = p->next) {
        for (i = 0; i < e; i++)
            rdaddc(text, ' ');
        info_rdaddwc(text, p->begin, p->end, TRUE);
        rdaddc(text, '\n');
        e = indent + extraindent;
    }
    wrap_free(wrapping);
    rdaddc(text, '\n');

    free_word_list(words);
}

static void info_codepara(rdstringc *text, word *words,
                          int indent, int width) {
    int i;

    for (; words; words = words->next) if (words->type == word_WeakCode) {
        char *c;
        info_convert(words->text, &c);
        if (strlen(c) > (size_t)width) {
            /* FIXME: warn */
        }
        for (i = 0; i < indent; i++)
            rdaddc(text, ' ');
        rdaddsc(text, c);
        rdaddc(text, '\n');
        sfree(c);
    }

    rdaddc(text, '\n');
}

static void info_versionid(rdstringc *text, word *words) {
    rdaddc(text, '[');                 /* FIXME: configurability */
    info_rdaddwc(text, words, NULL, FALSE);
    rdaddsc(text, "]\n");
}

static node *info_node_new(char *name)
{
    node *n;

    n = mknew(node);
    n->text.text = NULL;
    n->text.pos = n->text.size = 0;
    n->up = n->next = n->prev = n->lastchild = n->listnext = NULL;
    n->name = dupstr(name);
    n->started_menu = FALSE;

    return n;
}

static char *info_node_name(paragraph *par)
{
    rdstringc rsc = { 0, 0, NULL };
    char *p, *q;
    info_rdaddwc(&rsc, par->kwtext ? par->kwtext : par->words, NULL, FALSE);

    /*
     * We cannot have commas or colons in a node name. Remove any
     * that we find, with a warning.
     */
    p = q = rsc.text;
    while (*p) {
        if (*p == ':' || *p == ',') {
            error(err_infonodechar, &par->fpos, *p);
        } else {
            *q++ = *p;
        }
        p++;
    }
    *p = '\0';

    return rsc.text;
}

static void info_menu_item(rdstringc *text, node *n, paragraph *p)
{
    /*
     * FIXME: Depending on how we're doing node names in this info
     * file, we might want to do
     * 
     *   * Node name:: Chapter title
     * 
     * _or_
     * 
     *   * Chapter number: Node name.
     * 
     * 
     */
    rdaddsc(text, "* ");
    rdaddsc(text, n->name);
    rdaddsc(text, "::");
    if (p) {
        rdaddc(text, ' ');
        info_rdaddwc(text, p->words, NULL, FALSE);
    }
    rdaddc(text, '\n');
}