Hello
Here is a patch allowing to compute correctly the md5 of a file sequence
even with the bug rapported here:
http://gcc.gnu.org/ml/gcc-patches/2011-09/msg00963.html.
The function will work with both gcc 4.6 without the patch and a gcc
with the patch applied.
The problem cames from the fact that we were calling md5_process_bytes
several times with a buffer of a size which was not a multiple of 64.
Doing so, the next buffer was modified to take those data in account and
doing so, we had not always an aligned pointer.
We now concatenate file stream and so we can have a buffer with a
multiple of 64 size, so we can call md5_process_block. We only call
md5_process_bytes for the last data.
Thanks!
Pierre Vittet
2011-09-19 Pierre Vittet <pier...@pvittet.com>
* melt-runtime.c (meltgc_string_hex_md5sum_file_sequence): Concatenate
files stream to call md5_process_block, we only call md5_process_bytes
for the last datas.
Index: gcc/melt-runtime.c
===================================================================
--- gcc/melt-runtime.c (révision 178881)
+++ gcc/melt-runtime.c (copie de travail)
@@ -5374,7 +5374,11 @@ melt_compile_source (const char *srcbase, const ch
}
/* compute the hexadecimal encoded md5sum string of a tuple of file
- paths, or NULL on failure */
+ paths, or NULL on failure.
+ When we finish to proceed a file, we immediatly add the beginning of the
+ following file to bufblock to keep a size of a multiple of 64. This permit
+ to call md5_process_block. We only call md5_process_bytes for the last
+ data. */
melt_ptr_t
meltgc_string_hex_md5sum_file_sequence (melt_ptr_t pathtup_p)
{
@@ -5385,6 +5389,7 @@ melt_compile_source (const char *srcbase, const ch
FILE *fil = NULL;
int nbtup = 0;
int cnt = 0;
+ int new_file_cnt = 0;
struct md5_ctx ctx;
MELT_ENTERFRAME(3, NULL);
#define resv meltfram__.mcfr_varptr[0]
@@ -5394,12 +5399,12 @@ melt_compile_source (const char *srcbase, const ch
memset (&ctx, 0, sizeof(ctx));
memset (md5srctab, 0, sizeof (md5srctab));
memset (md5hex, 0, sizeof (md5hex));
- memset (bufblock, 0, sizeof (bufblock));
if (melt_magic_discr ((melt_ptr_t)pathtupv) != MELTOBMAG_MULTIPLE)
goto end;
md5_init_ctx (&ctx);
nbtup = melt_multiple_length ((melt_ptr_t)pathtupv);
/* this loop does not garbage collect! */
+ memset (bufblock, 0, sizeof (bufblock));
for (ix=0; ix < nbtup; ix++)
{
const char *curpath = NULL;
@@ -5414,22 +5419,33 @@ melt_compile_source (const char *srcbase, const ch
goto end;
while (!feof (fil))
{
- memset (bufblock, 0, sizeof (bufblock));
- cnt = fread (bufblock, 1, sizeof(bufblock), fil);
+ if (cnt != 0) /*means that we havent process bufblock from previous
+ file.*/
+ {
+ new_file_cnt =fread (bufblock+cnt,
sizeof(char),sizeof(bufblock)-cnt, fil);
+ cnt = cnt + new_file_cnt;
+
+ }
+ else
+ {
+ cnt = fread (bufblock, sizeof(char), sizeof(bufblock), fil);
+ }
if (cnt ==sizeof(bufblock))
{
/* an entire block has been read. */
- md5_process_bytes (bufblock, sizeof(bufblock), &ctx);
+ md5_process_block (bufblock, sizeof(bufblock), &ctx);
+ memset (bufblock, '\0', sizeof (bufblock));
+ cnt = 0;
}
- else
- {
- md5_process_bytes (bufblock, (size_t) cnt, &ctx);
- }
}
fclose (fil);
fil = NULL;
curpath = NULL;
}
+ if (cnt !=0) /*We still have some data in the buffer*/
+ {
+ md5_process_bytes (bufblock, (size_t) cnt, &ctx);
+ }
md5_finish_ctx (&ctx, md5srctab);
memset (md5hex, 0, sizeof(md5hex));
for (ix=0; ix<16; ix++) {
