kernel/git - git - PowerEL Git System

Author	SHA1	Message	Date
Jeff King	cf82bff73f	obstack: avoid computing offsets from NULL pointer As with the previous two commits, UBSan with clang-11 complains about computing offsets from a NULL pointer. The failures in t4013 (and elsewhere) look like this: kwset.c:102:23: runtime error: applying non-zero offset 107820859019600 to null pointer ... not ok 79 - git log -SF master # magic is (not used) That line is not enlightening: ... = obstack_alloc(&kwset->obstack, sizeof (struct trie)); because obstack is implemented almost entirely in macros, and the actual problem is five macros deep (I temporarily converted them to inline functions to get better compiler errors, which was tedious but worked reasonably well). The actual problem is in these pointer-alignment macros: /* If B is the base of an object addressed by P, return the result of aligning P to the next multiple of A + 1. B and P must be of type char . A + 1 must be a power of 2. / #define __BPTR_ALIGN(B, P, A) ((B) + (((P) - (B) + (A)) & ~(A))) /* Similar to _BPTR_ALIGN (B, P, A), except optimize the common case where pointers can be converted to integers, aligned as integers, and converted back again. If PTR_INT_TYPE is narrower than a pointer (e.g., the AS/400), play it safe and compute the alignment relative to B. Otherwise, use the faster strategy of computing the alignment relative to 0. / #define __PTR_ALIGN(B, P, A) \ __BPTR_ALIGN (sizeof (PTR_INT_TYPE) < sizeof (void ) ? (B) : (char *) 0, \ P, A) If we have a sufficiently-large integer pointer type, then we do the computation using a NULL pointer constant. That turns __BPTR_ALIGN() into something like: NULL + (P - NULL + A) & ~A and UBSan is complaining about adding the full value of P to that initial NULL. We can fix this by doing our math as an integer type, and then casting the result back to a pointer. The problem case only happens when we know that the integer type is large enough, so there should be no issue with truncation. Another option would be just simplify out all the 0's from __BPTR_ALIGN() for the NULL-pointer case. That probably wouldn't work for a platform where the NULL pointer isn't all-zeroes, but Git already wouldn't work on such a platform (due to our use of memset to set pointers in structs to NULL). But I tried here to keep as close to the original as possible. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Elijah Newren	03670c8b23	Fix spelling errors in no-longer-updated-from-upstream modules We have several modules originally taken from some upstream source, and which as far as I can tell we no longer update from the upstream anymore. As such, I have not submitted these spelling fixes to any external projects but just include them directly here. Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	5 years ago
Johannes Schindelin	96a0679441	obstack: fix compiler warning MS Visual C suggests that the construct condition ? (int) i : (ptrdiff_t) d is incorrect. Let's fix this by casting to ptrdiff_t also for the positive arm of the conditional. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>	6 years ago
SZEDER Gábor	764473d257	compat/obstack: fix -Wcast-function-type warnings GCC 8 introduced the new -Wcast-function-type warning, which is implied by -Wextra (which, in turn is enabled in our DEVELOPER flags). When building Git with GCC 8 and this warning enabled on a non-glibc platform [1], one is greeted with a screenful of compiler warnings/errors: compat/obstack.c: In function '_obstack_begin': compat/obstack.c:162:17: error: cast between incompatible function types from 'void * ()(long int)' to 'struct _obstack_chunk ()(void , long int)' [-Werror=cast-function-type] h->chunkfun = (struct _obstack_chunk * ()(void , long)) chunkfun; ^ compat/obstack.c:163:16: error: cast between incompatible function types from 'void ()(void )' to 'void ()(void , struct _obstack_chunk )' [-Werror=cast-function-type] h->freefun = (void () (void , struct _obstack_chunk )) freefun; ^ compat/obstack.c:116:8: error: cast between incompatible function types from 'struct _obstack_chunk * ()(void , long int)' to 'struct _obstack_chunk * ()(long int)' [-Werror=cast-function-type] : ((struct _obstack_chunk () (long)) (h)->chunkfun) ((size))) ^ compat/obstack.c:168:22: note: in expansion of macro 'CALL_CHUNKFUN' chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); ^~~~~~~~~~~~~ <snip> 'struct obstack' stores pointers to two functions to allocate and free "chunks", and depending on how obstack is used, these functions take either one parameter (like standard malloc() and free() do; this is how we use it in 'kwset.c') or two parameters. Presumably to reduce memory footprint, a single field is used to store the function pointer for both signatures, and then it's casted to the appropriate signature when the function pointer is accessed. These casts between function pointers with different number of parameters are what trigger those compiler errors. Modify 'struct obstack' to use unions to store function pointers with different signatures, and then use the union member with the appropriate signature when accessing these function pointers. This eliminates the need for those casts, and thus avoids this compiler error. [1] Compiling 'compat/obstack.c' on a platform with glibc is sort of a noop, see the comment before '# define ELIDE_CODE', so this is not an issue on common Linux distros. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	6 years ago
Todd Zullinger	484257925f	Replace Free Software Foundation address in license notices The mailing address for the FSF has changed over the years. Rather than updating the address across all files, refer readers to gnu.org, as the GNU GPL documentation now suggests for license notices. The mailing address is retained in the full license files (COPYING and LGPL-2.1). The old address is still present in t/diff-lib/COPYING. This is intentional, as the file is used in tests and the contents are not expected to change. Signed-off-by: Todd Zullinger <tmz@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	7 years ago
Stefano Lattarini	7323513d28	obstack: fix spelling of similar Noticed using Lucas De Marchi's codespell tool. Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Acked-by: Matthieu Moy <Matthieu.Moy@imag.fr> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Fredrik Kuivinen	d190a0875f	obstack: Fix portability issues i686-apple-darwin10-gcc-4.2.1 (GCC) 4.2.1, SunOS 5.10, and possibly others do not have exit.h and exitfail.h. Remove the use of these in obstack.c. The __block variable was renamed to block to avoid a gcc error: compat/obstack.h:190: error: __block attribute can be specified on variables only Initial-patch-by: David Aguilar <davvid@gmail.com> Reported-by: Brian Gernhardt <brian@gernhardtsoftware.com> Signed-off-by: Fredrik Kuivinen <frekui@gmail.com> Acked-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	14 years ago
Fredrik Kuivinen	e831171d67	Add obstack.[ch] from EGLIBC 2.10 Signed-off-by: Fredrik Kuivinen <frekui@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	14 years ago