Initial implementation. Has problem on x86-64 when compiled without -O2

Import files from discount-1.2.6. The library works fine compiled using the
rockspec on my 32 bit gcc 4.1.2 system. But when compiled on an x86-64 box
(gcc 4.3.1) without -O2, calling the function exported by ldiscount just
causes the program to acquire memory until it dies with a segmentation fault.
It appears to work fine when built with -O2 in the CFLAGS (as in the included
Makefile).

Makefile

@@ -0,0 +1,32 @@
+VERSION= 0.1
+
+# change these to reflect your Lua installation
+LUA= /usr
+LUAINC= $(LUA)/include
+LUALIB= $(LUA)/lib
+LUABIN= $(LUA)/bin
+
+# probably no need to change anything below here
+CC= gcc
+CFLAGS= $(INCS) $(WARN) -O2 -fPIC
+WARN= -Wall
+INCS= -I$(LUAINC)
+
+DISCOUNT_OBJS = docheader.o \
+	dumptree.o \
+	generate.o \
+	markdown.o \
+	mkdio.o \
+	resource.o
+OBJS=  $(DISCOUNT_OBJS) ldiscount.o
+SOS= discount.so
+
+all: $(SOS)
+
+$(SOS): $(OBJS)
+	$(CC) -o $@ -shared $(OBJS) $(LIBS)
+
+.PHONY: clean test distr
+clean:
+	rm -f $(OBJS) $(SOS) core core.* a.out
+

amalloc.h

@@ -0,0 +1,29 @@
+/*
+ * debugging malloc()/realloc()/calloc()/free() that attempts
+ * to keep track of just what's been allocated today.
+ */
+#ifndef AMALLOC_D
+#define AMALLOC_D
+
+#include "config.h"
+
+#ifdef USE_AMALLOC
+
+extern void *amalloc(int);
+extern void *acalloc(int,int);
+extern void *arealloc(void*,int);
+extern void afree(void*);
+extern void adump();
+
+#define malloc	amalloc
+#define	calloc	acalloc
+#define realloc	arealloc
+#define free	afree
+
+#else
+
+#define adump()	(void)1
+
+#endif
+
+#endif/*AMALLOC_D*/

config.h

@@ -0,0 +1,5 @@
+#undef USE_AMALLOC
+
+#define TABSTOP 4
+#define COINTOSS() (random()&1)
+#define INITRNG(x) srandom((unsigned int)x)

cstring.h

@@ -0,0 +1,68 @@
+/* two template types:  STRING(t) which defines a pascal-style string
+ * of element (t) [STRING(char) is the closest to the pascal string],
+ * and ANCHOR(t) which defines a baseplate that a linked list can be
+ * built up from.   [The linked list /must/ contain a ->next pointer
+ * for linking the list together with.]
+ */
+#ifndef _CSTRING_D
+#define _CSTRING_D
+
+#include <string.h>
+#include <stdlib.h>
+
+#include "amalloc.h"
+
+/* expandable Pascal-style string.
+ */
+#define STRING(type)	struct { type *text; int size, alloc; }
+
+#define CREATE(x)	T(x) = (void*)(S(x) = (x).alloc = 0)
+#define EXPAND(x)	(S(x)++)[(S(x) < (x).alloc) \
+			    ? (T(x)) \
+			    : (T(x) = T(x) ? realloc(T(x), sizeof T(x)[0] * ((x).alloc += 100)) \
+					   : malloc(sizeof T(x)[0] * ((x).alloc += 100)) )]
+
+#define DELETE(x)	(x).alloc ? (free(T(x)), S(x) = (x).alloc = 0) \
+				  : ( S(x) = 0 )
+#define CLIP(t,i,sz)	\
+	    ( ((i) >= 0) && ((sz) > 0) && (((i)+(sz)) <= S(t)) ) ? \
+	    (memmove(&T(t)[i], &T(t)[i+sz], (S(t)-(i+sz)+1)*sizeof(T(t)[0])), \
+		S(t) -= (sz)) : -1
+
+#define RESERVE(x, sz)	T(x) = ((x).alloc > S(x) + (sz) \
+			    ? T(x) \
+			    : T(x) \
+				? realloc(T(x), sizeof T(x)[0] * ((x).alloc = 100+(sz)+S(x))) \
+				: malloc(sizeof T(x)[0] * ((x).alloc = 100+(sz)+S(x))))
+#define SUFFIX(t,p,sz)	\
+	    memcpy(((S(t) += (sz)) - (sz)) + \
+		    (T(t) = T(t) ? realloc(T(t), sizeof T(t)[0] * ((t).alloc += sz)) \
+				 : malloc(sizeof T(t)[0] * ((t).alloc += sz))), \
+		    (p), sizeof(T(t)[0])*(sz))
+
+#define PREFIX(t,p,sz)	\
+	    RESERVE( (t), (sz) ); \
+	    if ( S(t) ) { memmove(T(t)+(sz), T(t), S(t)); } \
+	    memcpy( T(t), (p), (sz) ); \
+	    S(t) += (sz)
+
+/* reference-style links (and images) are stored in an array
+ */
+#define T(x)		(x).text
+#define S(x)		(x).size
+
+/* abstract anchor type that defines a list base
+ * with a function that attaches an element to
+ * the end of the list.
+ *
+ * the list base field is named .text so that the T()
+ * macro will work with it.
+ */
+#define ANCHOR(t)	struct { t *text, *end; }
+
+#define ATTACH(t, p)	( (t).text ?( ((t).end->next = (p)), ((t).end = (p)) ) \
+				   :( ((t).text = (t).end = (p)) ) )
+
+typedef STRING(char) Cstring;
+
+#endif/*_CSTRING_D*/

docheader.c

@@ -0,0 +1,43 @@
+/*
+ * docheader -- get values from the document header
+ *
+ * Copyright (C) 2007 David L Parsons.
+ * The redistribution terms are provided in the COPYRIGHT file that must
+ * be distributed with this source code.
+ */
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+#include "cstring.h"
+#include "markdown.h"
+#include "amalloc.h"
+
+#define afterdle(t)	(T((t)->text) + (t)->dle)
+
+char *
+mkd_doc_title(Document *doc)
+{
+    if ( doc && doc->headers )
+	return afterdle(doc->headers);
+    return 0;
+}
+
+
+char *
+mkd_doc_author(Document *doc)
+{
+    if ( doc && doc->headers && doc->headers->next )
+	return afterdle(doc->headers->next);
+    return 0;
+}
+
+
+char *
+mkd_doc_date(Document *doc)
+{
+    if ( doc && doc->headers && doc->headers->next && doc->headers->next->next )
+	return afterdle(doc->headers->next->next);
+    return 0;
+}

dumptree.c

@@ -0,0 +1,147 @@
+/* markdown: a C implementation of John Gruber's Markdown markup language.
+ *
+ * Copyright (C) 2007 David L Parsons.
+ * The redistribution terms are provided in the COPYRIGHT file that must
+ * be distributed with this source code.
+ */
+#include <stdio.h>
+#include "markdown.h"
+#include "cstring.h"
+#include "amalloc.h"
+
+struct frame {
+    int indent;
+    char c;
+};
+
+typedef STRING(struct frame) Stack;
+
+static char *
+Pptype(int typ)
+{
+    switch (typ) {
+    case WHITESPACE: return "whitespace";
+    case CODE      : return "code";
+    case QUOTE     : return "quote";
+    case MARKUP    : return "markup";
+    case HTML      : return "html";
+    case DL        : return "dl";
+    case UL        : return "ul";
+    case OL        : return "ol";
+    case LISTITEM  : return "item";
+    case HDR       : return "header";
+    case HR        : return "HR";
+    default        : return "mystery node!";
+    }
+}
+
+static void
+pushpfx(int indent, char c, Stack *sp)
+{
+    struct frame *q = &EXPAND(*sp);
+
+    q->indent = indent;
+    q->c = c;
+}
+
+
+static void
+poppfx(Stack *sp)
+{
+    S(*sp)--;
+}
+
+
+static void
+changepfx(Stack *sp, char c)
+{
+    char ch;
+
+    if ( !S(*sp) ) return;
+
+    ch = T(*sp)[S(*sp)-1].c;
+
+    if ( ch == '+' || ch == '|' )
+	T(*sp)[S(*sp)-1].c = c;
+}
+
+
+static void
+printpfx(Stack *sp, FILE *f)
+{
+    int i;
+    char c;
+
+    if ( !S(*sp) ) return;
+
+    c = T(*sp)[S(*sp)-1].c;
+
+    if ( c == '+' || c == '-' ) {
+	fprintf(f, "--%c", c);
+	T(*sp)[S(*sp)-1].c = (c == '-') ? ' ' : '|';
+    }
+    else
+	for ( i=0; i < S(*sp); i++ ) {
+	    if ( i )
+		fprintf(f, "  ");
+	    fprintf(f, "%*s%c", T(*sp)[i].indent + 2, " ", T(*sp)[i].c);
+	    if ( T(*sp)[i].c == '`' )
+		T(*sp)[i].c = ' ';
+	}
+    fprintf(f, "--");
+}
+
+
+static void
+dumptree(Paragraph *pp, Stack *sp, FILE *f)
+{
+    int count;
+    Line *p;
+    int d;
+    static char *Begin[] = { 0, "P", "center" };
+
+    while ( pp ) {
+	if ( !pp->next )
+	    changepfx(sp, '`');
+	printpfx(sp, f);
+
+	d = fprintf(f, "[%s", Pptype(pp->typ));
+	if ( pp->align )
+	    d += fprintf(f, ", <%s>", Begin[pp->align]);
+
+	for (count=0, p=pp->text; p; ++count, (p = p->next) )
+	    ;
+
+	if ( count )
+	    d += fprintf(f, ", %d line%s", count, (count==1)?"":"s");
+
+	d += fprintf(f, "]");
+
+	if ( pp->down ) {
+	    pushpfx(d, pp->down->next ? '+' : '-', sp);
+	    dumptree(pp->down, sp, f);
+	    poppfx(sp);
+	}
+	else fputc('\n', f);
+	pp = pp->next;
+    }
+}
+
+
+int
+mkd_dump(Document *doc, FILE *out, int flags, char *title)
+{
+    Stack stack;
+
+    if (mkd_compile(doc, flags) ) {
+
+	CREATE(stack);
+	pushpfx(fprintf(out, "%s", title), doc->code->next ? '+' : '-', &stack);
+	dumptree(doc->code, &stack, out);
+	DELETE(stack);
+
+	mkd_cleanup(doc);
+	return 0;
+    }
+    return -1;
+}