Add support C89 + misc changes0.1

3 files changed, 28 insertions, 25 deletions

diff --git a/README.md b/README.md
index c2bce0a..86e8901 100644
--- a/README.md
+++ b/README.md
@@ -1,22 +1,27 @@
 dalloc
 ======
-A simple, thread safe, drop-in memory allocation debugging lib for C
+A simple, thread safe, drop-in memory allocation debugging lib in C89
 
 Usage
 -----
 dalloc.c and dalloc.h should be dropped into an existing project and
 compiled with the `-DDALLOC` flag to define the macro that enables dalloc.
 dalloc will replace free(), malloc(), calloc(), realloc(), reallocarray(),
-strdup(), strndup(), vasprintf() and asprintf() by a more secure version that
-will check for buffer overflow and memory leak.
-It will also output a recap at the end of the program.
+strdup() and strndup() by a more secure version that will check for buffer
+overflow and memory leak.
 
-reallocarray, strdup, strndup, vasprintf and asprintf are not standard so
-you'll probably need to define `_DEFAULT_SOURCE` or include
-[ubik](https://github.com/ratakor/libre) to use them outside of dalloc.
+dalloc will also output a recap at the end of the program if the compiler
+supports the destructor attribute.
+
+vasprintf() and asprintf() are also supported when compiling for C99+.
+
+`_DEFAULT_SOURCE` or other feature test macros may be needed to use these
+functions outside of dalloc.
 
 Functions
 ---------
+All functions do nothing when DALLOC is not defined.
+
 #### dalloc_check_overflow(void)
 Output all memory overflow to stderr and return the sum of all overflow.
 
@@ -24,23 +29,21 @@ Output all memory overflow to stderr and return the sum of all overflow.
 Output all allocation that were not freed to stderr.
 
 #### dalloc_check_all(void)
-Run both dalloc_check_free() and dalloc_check_overflow() on program exit.
+Run both dalloc_check_free() and dalloc_check_overflow() on program's exit.
 
 #### dalloc_ignore(void *p)
 Ignore the pointer in argument for memory leak check. This can be useful when
 developing an application that never stop.
-When `DALLOC` is not defined this function does nothing.
 
 #### dalloc_comment(void *p, char *comment)
 Add a comment to a pointer so it is more easy to know what the pointer stands
 for just by looking at the error message from dalloc.
-When `DALLOC` is not defined this function does nothing.
 
 #### dalloc_query(void *p)
 Output informations about p to stderr.
-When `DALLOC` is not defined this function does nothing.
 
 Notes
 -----
-An error with "Unknown pointer" is either caused by a double free or when
-freeing a pointer allocated with a function not supported by dalloc.
+An error with "Unknown pointer" is may caused by a use after free or when using
+free or realloc on a pointer allocated with a function not supported by
+dalloc.
diff --git a/dalloc.c b/dalloc.c
index ccc402d..9e28c50 100644
--- a/dalloc.c
+++ b/dalloc.c
@@ -16,17 +16,13 @@
 
 #include <errno.h>
 #include <pthread.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 
 #define DALLOC_INTERNAL
 #include "dalloc.h"
 
-#define EXIT_STATUS    9
+#define EXIT_STATUS    EXIT_FAILURE
 #define OVER_ALLOC     64
-#define MAGIC_NUMBER   0x99
+#define MAGIC_NUMBER   0xdead
 
 #define x1             ((char)(MAGIC_NUMBER))
 #define x2             x1, x1
@@ -222,7 +218,7 @@ _dalloc_query(void *p, char *file, int line)
 void
 _dalloc_free(void *p, char *file, int line)
 {
-	dalloc_ptr *dp, *prev;
+	dalloc_ptr *dp, *prev = NULL; /* cc whines */
 
 	if (p == NULL)
 		return;
@@ -311,7 +307,7 @@ _dalloc_realloc(void *p, size_t siz, char *file, int line)
 		return _dalloc_malloc(siz, file, line);
 
 	if (siz == 0) {
-		_dalloc_free(p, file, line);
+		eprintf("%s:%d: dalloc: realloc with size == 0\n", file, line);
 		return NULL;
 	}
 
@@ -370,12 +366,10 @@ _dalloc_strdup(const char *s, char *file, int line)
 char *
 _dalloc_strndup(const char *s, size_t n, char *file, int line)
 {
-	const char *end;
 	char *p;
 	size_t siz;
 
-	end = memchr(s, '\0', n);
-	siz = end ? (size_t)(end - s) : n;
+	siz = strnlen(s, n);
 	p = _dalloc_malloc(siz + 1, file, line);
 	memcpy(p, s, siz);
 	p[siz] = '\0';
@@ -383,6 +377,7 @@ _dalloc_strndup(const char *s, size_t n, char *file, int line)
 	return p;
 }
 
+#if __STDC_VERSION__ >= 199901L
 int
 _dalloc_vasprintf(char **p, const char *fmt, va_list ap, char *file, int line)
 {
@@ -422,3 +417,4 @@ _dalloc_asprintf(char **p, char *file, int line, const char *fmt, ...)
 
 	return rv;
 }
+#endif /* __STDC_VERSION__ >= 199901L */
diff --git a/dalloc.h b/dalloc.h
index 0f1d74e..441137f 100644
--- a/dalloc.h
+++ b/dalloc.h
@@ -8,8 +8,8 @@
 #ifndef DALLOC_H
 #define DALLOC_H
 
-#include <stdio.h>
 #include <stdarg.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -25,8 +25,10 @@ extern "C" {
 #define reallocarray(p, n, s)  (_dalloc_reallocarray(p, n, s, __FILE__, __LINE__))
 #define strdup(s)              (_dalloc_strdup(s, __FILE__, __LINE__))
 #define strndup(s, n)          (_dalloc_strndup(s, n, __FILE__, __LINE__))
+#if __STDC_VERSION__ >= 199901L
 #define vasprintf(p, fmt, ap)  (_dalloc_vasprintf(p, fmt, ap, __FILE__, __LINE__))
 #define asprintf(p, ...)       (_dalloc_asprintf(p, __FILE__, __LINE__, __VA_ARGS__))
+#endif /* __STDC_VERSION__ >= 199901L */
 
 #define dalloc_ignore(p)       (_dalloc_ignore(p, __FILE__, __LINE__))
 #define dalloc_comment(p, str) (_dalloc_comment(p, str, __FILE__, __LINE__))
@@ -48,8 +50,10 @@ void *_dalloc_realloc(void *p, size_t siz, char *file, int line);
 void *_dalloc_reallocarray(void *p, size_t n, size_t s, char *file, int line);
 char *_dalloc_strdup(const char *s, char *file, int line);
 char *_dalloc_strndup(const char *s, size_t n, char *file, int line);
+#if __STDC_VERSION__ >= 199901L
 int _dalloc_vasprintf(char **p, const char *fmt, va_list ap, char *file, int line);
 int _dalloc_asprintf(char **p, char *file, int line, const char *fmt, ...);
+#endif /* __STDC_VERSION__ >= 199901L */
 #else
 #define dalloc_check_overflow() 0
 #define dalloc_check_free()