Commit Graph

6 Commits

Author SHA1 Message Date
Aaron Ballman 7068aa9841 Strengthen -Wint-conversion to default to an error
Clang has traditionally allowed C programs to implicitly convert
integers to pointers and pointers to integers, despite it not being
valid to do so except under special circumstances (like converting the
integer 0, which is the null pointer constant, to a pointer). In C89,
this would result in undefined behavior per 3.3.4, and in C99 this rule
was strengthened to be a constraint violation instead. Constraint
violations are most often handled as an error.

This patch changes the warning to default to an error in all C modes
(it is already an error in C++). This gives us better security posture
by calling out potential programmer mistakes in code but still allows
users who need this behavior to use -Wno-error=int-conversion to retain
the warning behavior, or -Wno-int-conversion to silence the diagnostic
entirely.

Differential Revision: https://reviews.llvm.org/D129881
2022-07-22 15:24:54 -04:00
Zi Xuan Wu 632cfbc9f9 [NFC][test] Fix the line num of expected-error for CSKY at builtin-alloca-with-align.c 2022-05-20 16:54:23 +08:00
Zi Xuan Wu (Zeson) dca37af061 [NFC][Clang] Modify expect of fail test or XFAIL because CSKY align is different
CSKY is always in 4-byte align, no matter it's long long type.
For global aggregate variable, it's 4-byte align if its size is bigger than or equal to 4 bytes.

Differential Revision: https://reviews.llvm.org/D124977
2022-05-18 10:53:30 +08:00
Aaron Ballman 8c5edb59cf Use functions with prototypes when appropriate; NFC
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,

  void func();

becomes

  void func(void);

This is the second batch of tests being updated (there are a significant
number of other tests left to be updated).
2022-02-04 15:20:36 -05:00
David Majnemer 86b1bfad05 [Sema] Warn when alignof is used with __builtin_alloca_with_align
The second argument to __builtin_alloca_with_align is supposed to be in
bits, not bytes.  Using alignof there would be indicative of a bug.

llvm-svn: 285609
2016-10-31 18:07:57 +00:00
David Majnemer 5116993f8e Add support for __builtin_alloca_with_align
__builtin_alloca always uses __BIGGEST_ALIGNMENT__ for the alignment of
the allocation.  __builtin_alloca_with_align allows the programmer to
specify the alignment of the allocation.

This fixes PR30658.

llvm-svn: 285544
2016-10-31 05:37:48 +00:00