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| author | Martin Uecker <muecker@gwdg.de> | 2020-12-16 23:43:42 +0100 |
|---|---|---|
| committer | Martin Uecker <muecker@gwdg.de> | 2020-12-16 23:43:42 +0100 |
| commit | ec13758ed41936bf803640f0dd8c259c034fe4b9 (patch) | |
| tree | 2cd876d31542cee9d6818f0151887fd3f6aea753 /gcc | |
| parent | 64a54505ec8249178b9767d1420354f8eb55de50 (diff) | |
| download | gcc-ec13758ed41936bf803640f0dd8c259c034fe4b9.zip gcc-ec13758ed41936bf803640f0dd8c259c034fe4b9.tar.gz gcc-ec13758ed41936bf803640f0dd8c259c034fe4b9.tar.bz2 | |
C: Avoid incorrect warning for volatile in compound expressions [PR98260]
2020-12-16 Martin Uecker <muecker@gwdg.de>
gcc/c/
PR c/98260
* c-parser.c (c_parser_expression): Look into
nop expression when marking expressions as read.
gcc/testsuite/
PR c/98260
* gcc.dg/unused-9.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/c/c-parser.c | 10 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/unused-9.c | 13 |
2 files changed, 21 insertions, 2 deletions
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c index 69ecdb5..b9fdc90 100644 --- a/gcc/c/c-parser.c +++ b/gcc/c/c-parser.c @@ -10615,8 +10615,14 @@ c_parser_expression (c_parser *parser) c_parser_consume_token (parser); expr_loc = c_parser_peek_token (parser)->location; lhsval = expr.value; - while (TREE_CODE (lhsval) == COMPOUND_EXPR) - lhsval = TREE_OPERAND (lhsval, 1); + while (TREE_CODE (lhsval) == COMPOUND_EXPR + || TREE_CODE (lhsval) == NOP_EXPR) + { + if (TREE_CODE (lhsval) == COMPOUND_EXPR) + lhsval = TREE_OPERAND (lhsval, 1); + else + lhsval = TREE_OPERAND (lhsval, 0); + } if (DECL_P (lhsval) || handled_component_p (lhsval)) mark_exp_read (lhsval); next = c_parser_expr_no_commas (parser, NULL); diff --git a/gcc/testsuite/gcc.dg/unused-9.c b/gcc/testsuite/gcc.dg/unused-9.c new file mode 100644 index 0000000..bdf36e1 --- /dev/null +++ b/gcc/testsuite/gcc.dg/unused-9.c @@ -0,0 +1,13 @@ +/* PR c/98260 */ +/* { dg-do compile } */ +/* { dg-options "-Wunused" } */ + + +void g(void) +{ + int i = 0; + volatile int x; + (x, i++); /* { dg-bogus "set but not used" } */ +} + + |