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| author | Joseph Myers <joseph@codesourcery.com> | 2005-04-27 22:41:15 +0100 |
|---|---|---|
| committer | Joseph Myers <jsm28@gcc.gnu.org> | 2005-04-27 22:41:15 +0100 |
| commit | 47aecf47d196c05b7b388e4fefbdce2f075bd4b0 (patch) | |
| tree | ce276778b8df2b8bd816052b690271a7aecc28d3 /gcc | |
| parent | c7466deed4c713f843bf5256ffddbeca135d1371 (diff) | |
| download | gcc-47aecf47d196c05b7b388e4fefbdce2f075bd4b0.zip gcc-47aecf47d196c05b7b388e4fefbdce2f075bd4b0.tar.gz gcc-47aecf47d196c05b7b388e4fefbdce2f075bd4b0.tar.bz2 | |
re PR c/21159 ("no effect" warning despite cast to void*)
PR c/21159
* c-typeck.c (build_compound_expr): Don't warn for left-hand side
being a compound expression whose right-hand side is cast to void.
testsuite:
* gcc.dg/void-cast-1.c: New test.
From-SVN: r98886
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/c-typeck.c | 13 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/void-cast-1.c | 11 |
4 files changed, 32 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 947e032..b5ba524 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-04-27 Joseph S. Myers <joseph@codesourcery.com> + + PR c/21159 + * c-typeck.c (build_compound_expr): Don't warn for left-hand side + being a compound expression whose right-hand side is cast to void. + 2005-04-27 Caroline Tice <ctice@apple.com> * bb-reorder.c (find_rarely_executed_basic_blocks_and_crossing_edges): diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c index cde90a7..281d2b0 100644 --- a/gcc/c-typeck.c +++ b/gcc/c-typeck.c @@ -3109,9 +3109,16 @@ build_compound_expr (tree expr1, tree expr2) statement: with -Wextra or -Wunused, we should warn if it doesn't have any side-effects, unless it was explicitly cast to (void). */ if (warn_unused_value - && !(TREE_CODE (expr1) == CONVERT_EXPR - && VOID_TYPE_P (TREE_TYPE (expr1)))) - warning (0, "left-hand operand of comma expression has no effect"); + && !VOID_TYPE_P (TREE_TYPE (expr1))) + { + if (TREE_CODE (expr1) == CONVERT_EXPR) + ; /* (void) a, b */ + else if (TREE_CODE (expr1) == COMPOUND_EXPR + && TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR) + ; /* (void) a, (void) b, c */ + else + warning (0, "left-hand operand of comma expression has no effect"); + } } /* With -Wunused, we should also warn if the left-hand operand does have diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 0febe06..b16bf69 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2005-04-27 Joseph S. Myers <joseph@codesourcery.com> + + PR c/21159 + * gcc.dg/void-cast-1.c: New test. + 2005-04-27 Paolo Bonzini <bonzini@gnu.org> * gcc.dg/tree-ssa/gen-vect-25.c: Make more portable. diff --git a/gcc/testsuite/gcc.dg/void-cast-1.c b/gcc/testsuite/gcc.dg/void-cast-1.c new file mode 100644 index 0000000..bd4e7b3 --- /dev/null +++ b/gcc/testsuite/gcc.dg/void-cast-1.c @@ -0,0 +1,11 @@ +/* Don't warn where the left-hand side of a comma expression is a + comma expression whose right-hand side is cast to void. Bug + 21159. */ +/* Origin: Joseph Myers <joseph@codesourcery.com> */ +/* { dg-do compile } */ +/* { dg-options "-Wall" } */ + +int a, b, c, d; +int e(void) { return (void)a, b; } +int f(void) { return (void)a, (void)b, c; } +int g(void) { return (void)a, (void)b, (void)c, d; } |