diff options
| -rw-r--r-- | gcc/c/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/c/c-typeck.c | 23 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr68412-2.c | 15 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr68412.c | 41 |
5 files changed, 90 insertions, 1 deletions
diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog index b561fa0..a0cab87 100644 --- a/gcc/c/ChangeLog +++ b/gcc/c/ChangeLog @@ -1,3 +1,9 @@ +2015-11-19 Marek Polacek <polacek@redhat.com> + + PR c/68412 + * c-typeck.c (parser_build_binary_op): Properly handle + C_MAYBE_CONST_EXPR before calling warn_tautological_cmp. + 2015-11-17 David Malcolm <dmalcolm@redhat.com> * c-parser.c (set_c_expr_source_range): Bulletproof both diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c index c18c307..5cb0f7e 100644 --- a/gcc/c/c-typeck.c +++ b/gcc/c/c-typeck.c @@ -3512,7 +3512,28 @@ parser_build_binary_op (location_t location, enum tree_code code, code1, arg1.value, code2, arg2.value); if (warn_tautological_compare) - warn_tautological_cmp (location, code, arg1.value, arg2.value); + { + tree lhs = arg1.value; + tree rhs = arg2.value; + if (TREE_CODE (lhs) == C_MAYBE_CONST_EXPR) + { + if (C_MAYBE_CONST_EXPR_PRE (lhs) != NULL_TREE + && TREE_SIDE_EFFECTS (C_MAYBE_CONST_EXPR_PRE (lhs))) + lhs = NULL_TREE; + else + lhs = C_MAYBE_CONST_EXPR_EXPR (lhs); + } + if (TREE_CODE (rhs) == C_MAYBE_CONST_EXPR) + { + if (C_MAYBE_CONST_EXPR_PRE (rhs) != NULL_TREE + && TREE_SIDE_EFFECTS (C_MAYBE_CONST_EXPR_PRE (rhs))) + rhs = NULL_TREE; + else + rhs = C_MAYBE_CONST_EXPR_EXPR (rhs); + } + if (lhs != NULL_TREE && rhs != NULL_TREE) + warn_tautological_cmp (location, code, lhs, rhs); + } if (warn_logical_not_paren && TREE_CODE_CLASS (code) == tcc_comparison diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 4a4c4ce..16a6167 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2015-11-19 Marek Polacek <polacek@redhat.com> + + PR c/68412 + * gcc.dg/pr68412-2.c: New test. + * gcc.dg/pr68412.c: New test. + 2015-11-19 Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com> * gcc.dg/tree-ssa/vrp98.c: New testcase. diff --git a/gcc/testsuite/gcc.dg/pr68412-2.c b/gcc/testsuite/gcc.dg/pr68412-2.c new file mode 100644 index 0000000..be1dcfa --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr68412-2.c @@ -0,0 +1,15 @@ +/* PR c/68412 */ +/* { dg-do compile } */ +/* { dg-options "-Wall -Wextra" } */ + +int +fn1 (int i) +{ + return ({ i; }) == ({ i; }); /* { dg-warning "self-comparison always evaluates to true" } */ +} + +int +fn2 (int i) +{ + return ({ i + 1; }) != ({ i + 1; }); /* { dg-warning "self-comparison always evaluates to false" } */ +} diff --git a/gcc/testsuite/gcc.dg/pr68412.c b/gcc/testsuite/gcc.dg/pr68412.c new file mode 100644 index 0000000..825eb63 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr68412.c @@ -0,0 +1,41 @@ +/* PR c/68412 */ +/* { dg-do compile } */ +/* { dg-options "-Wall -Wextra" } */ + +#define M (sizeof (int) * __CHAR_BIT__) + +int +fn1 (int i) +{ + return i == (-1 << 8); /* { dg-warning "left shift of negative value" } */ +} + +int +fn2 (int i) +{ + return i == (1 << M); /* { dg-warning "left shift count" } */ +} + +int +fn3 (int i) +{ + return i == 10 << (M - 1); /* { dg-warning "requires" } */ +} + +int +fn4 (int i) +{ + return i == 1 << -1; /* { dg-warning "left shift count" } */ +} + +int +fn5 (int i) +{ + return i == 1 >> M; /* { dg-warning "right shift count" } */ +} + +int +fn6 (int i) +{ + return i == 1 >> -1; /* { dg-warning "right shift count" } */ +} |