ref: 57fbcd2b29aa74423d47a9efd783a1508ab1bfc5
parent: 5c5c607fdb834bc73033736f5774ef53c42008aa
author: Simon Tatham <anakin@pobox.com>
date: Sat Dec 11 06:13:00 EST 2021
malloc.c: check allocation sizes against PTRDIFF_MAX. I don't expect this to actually come up in any circumstance, but it prevents a warning in some versions of gcc that would otherwise arise from the use of 'int' to compute the input size: if gcc isn't confident that the int is positive, then it complains that possible inputs to malloc might be in the region of 2^64 - (small multiple of a negative 32-bit int). I would hope malloc would fail in any case on such an input, so failing a couple of lines earlier makes no important difference. Annoyingly, stdint.h is missing in my NestedVM build setup (though it has stdbool.h - it's not _totally_ C90). So I have to check that at cmake time. Also, removed the #defines for smalloc and friends from the tree234 test mode. These were needed in the old build system, when tree234-test was built ad-hoc without being linked against malloc.c. But now tree234-test links against the same utils library as everything else, and can use the real smalloc - and doing so prevents another of these warnings when compiling with -flto.
--- a/cmake/setup.cmake
+++ b/cmake/setup.cmake
@@ -32,6 +32,12 @@
set(puzzle_names)
set(puzzle_sources)
+include(CheckIncludeFile)
+check_include_file(stdint.h HAVE_STDINT_H)
+if(NOT HAVE_STDINT_H)
+ add_compile_definitions(NO_STDINT_H)
+endif()
+
include(icons/icons.cmake)
# The main function called from the top-level CMakeLists.txt to define
--- a/malloc.c
+++ b/malloc.c
@@ -2,6 +2,9 @@
* malloc.c: safe wrappers around malloc, realloc, free, strdup
*/
+#ifndef NO_STDINT_H
+#include <stdint.h>
+#endif
#include <stdlib.h>
#include <string.h>
#include "puzzles.h"
@@ -12,6 +15,10 @@
*/
void *smalloc(size_t size) {void *p;
+#ifdef PTRDIFF_MAX
+ if (size > PTRDIFF_MAX)
+ fatal("allocation too large");+#endif
p = malloc(size);
if (!p)
fatal("out of memory");@@ -32,6 +39,10 @@
*/
void *srealloc(void *p, size_t size) {void *q;
+#ifdef PTRDIFF_MAX
+ if (size > PTRDIFF_MAX)
+ fatal("allocation too large");+#endif
if (p) {q = realloc(p, size);
} else {--- a/tree234.c
+++ b/tree234.c
@@ -43,9 +43,6 @@
va_end(ap);
}
#define LOG(x) (logprintf x)
-#define smalloc malloc
-#define srealloc realloc
-#define sfree free
#else
#define LOG(x)
#endif