Win32: use low-level memory allocation during initialization

As of d41489a6 "Add more large blob test cases", git's high-level memory
allocation functions (xmalloc, xmemdupz etc.) access the environment to
simulate limited memory in tests (see 'getenv("GIT_ALLOC_LIMIT")' in
memory_limit_check()). These functions should not be used before the
environment is fully initialized (particularly not to initialize the
environment itself).

The current solution ('environ = NULL; ALLOC_GROW(environ...)') only works
because MSVCRT's getenv() reinitializes environ when it is NULL (i.e. it
leaves us with two sets of unusabe (non-UTF-8) and unfreeable (CRT-
allocated) environments).

Add our own set of malloc-or-die functions to be used in startup code.

Also check the result of __wgetmainargs, which may fail if there's not
enough memory for wide-char arguments and environment.

This patch is in preparation of the sorted environment feature, which
completely replaces MSVCRT's getenv() implementation.

Signed-off-by: Karsten Blees <blees@dcon.de>
This commit is contained in:
Karsten Blees
2012-03-15 20:29:04 +01:00
committed by Stepan Kasal
parent 7f77021569
commit d0f63e9351

View File

@@ -2001,16 +2001,37 @@ typedef struct {
extern int __wgetmainargs(int *argc, wchar_t ***argv, wchar_t ***env, int glob,
_startupinfo *si);
static NORETURN void die_startup()
{
fputs("fatal: not enough memory for initialization", stderr);
exit(128);
}
static void *malloc_startup(size_t size)
{
void *result = malloc(size);
if (!result)
die_startup();
return result;
}
static char *wcstoutfdup_startup(char *buffer, const wchar_t *wcs, size_t len)
{
len = xwcstoutf(buffer, wcs, len) + 1;
return memcpy(malloc_startup(len), buffer, len);
}
void mingw_startup()
{
int i, len, maxlen, argc;
int i, maxlen, argc;
char *buffer;
wchar_t **wenv, **wargv;
_startupinfo si;
/* get wide char arguments and environment */
si.newmode = 0;
__wgetmainargs(&argc, &wargv, &wenv, _CRT_glob, &si);
if (__wgetmainargs(&argc, &wargv, &wenv, _CRT_glob, &si) < 0)
die_startup();
/* determine size of argv and environ conversion buffer */
maxlen = wcslen(_wpgmptr);
@@ -2019,26 +2040,25 @@ void mingw_startup()
for (i = 0; wenv[i]; i++)
maxlen = max(maxlen, wcslen(wenv[i]));
/* nedmalloc can't free CRT memory, allocate resizable environment list */
environ = NULL;
/*
* nedmalloc can't free CRT memory, allocate resizable environment
* list. Note that xmalloc / xmemdupz etc. call getenv, so we cannot
* use it while initializing the environment itself.
*/
environ_size = i + 1;
ALLOC_GROW(environ, environ_size * sizeof(char*), environ_alloc);
environ_alloc = alloc_nr(environ_size * sizeof(char*));
environ = malloc_startup(environ_alloc);
/* allocate buffer (wchar_t encodes to max 3 UTF-8 bytes) */
maxlen = 3 * maxlen + 1;
buffer = xmalloc(maxlen);
buffer = malloc_startup(maxlen);
/* convert command line arguments and environment to UTF-8 */
len = xwcstoutf(buffer, _wpgmptr, maxlen);
__argv[0] = xmemdupz(buffer, len);
for (i = 1; i < argc; i++) {
len = xwcstoutf(buffer, wargv[i], maxlen);
__argv[i] = xmemdupz(buffer, len);
}
for (i = 0; wenv[i]; i++) {
len = xwcstoutf(buffer, wenv[i], maxlen);
environ[i] = xmemdupz(buffer, len);
}
__argv[0] = wcstoutfdup_startup(buffer, _wpgmptr, maxlen);
for (i = 1; i < argc; i++)
__argv[i] = wcstoutfdup_startup(buffer, wargv[i], maxlen);
for (i = 0; wenv[i]; i++)
environ[i] = wcstoutfdup_startup(buffer, wenv[i], maxlen);
environ[i] = NULL;
free(buffer);