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| author | Manuel López-Ibáñez <manu@gcc.gnu.org> | 2008-08-21 19:05:46 +0000 |
|---|---|---|
| committer | Manuel López-Ibáñez <manu@gcc.gnu.org> | 2008-08-21 19:05:46 +0000 |
| commit | 2985f531b7834837d02a8d2745fdd8ec82b04acb (patch) | |
| tree | 66df13a772649e0dbf3e19930affd1570d2d47fd /gcc/builtins.c | |
| parent | 3d10ed6cbc7248d756077c1e7dc3533257c44a4f (diff) | |
| download | gcc-2985f531b7834837d02a8d2745fdd8ec82b04acb.zip gcc-2985f531b7834837d02a8d2745fdd8ec82b04acb.tar.gz gcc-2985f531b7834837d02a8d2745fdd8ec82b04acb.tar.bz2 | |
re PR c/30457 (Please warn about va_start(ap, invalid))
2008-08-21 Manuel Lopez-Ibanez <manu@gcc.gnu.org>
PR 30457
* builtins.c (fold_builtin_next_arg): Add warning about undefined
behaviour.
testsuite/
* gcc.dg/pr30457.c: New.
From-SVN: r139406
Diffstat (limited to 'gcc/builtins.c')
| -rw-r--r-- | gcc/builtins.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/gcc/builtins.c b/gcc/builtins.c index 6695672..59e4119 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -11586,6 +11586,17 @@ fold_builtin_next_arg (tree exp, bool va_start_p) it. */ warning (0, "second parameter of %<va_start%> not last named argument"); } + + /* Undefined by C99 7.15.1.4p4 (va_start): + "If the parameter parmN is declared with the register storage + class, with a function or array type, or with a type that is + not compatible with the type that results after application of + the default argument promotions, the behavior is undefined." + */ + else if (DECL_REGISTER (arg)) + warning (0, "undefined behaviour when second parameter of " + "%<va_start%> is declared with %<register%> storage"); + /* We want to verify the second parameter just once before the tree optimizers are run and then avoid keeping it in the tree, as otherwise we could warn even for correct code like: |