diff options
| author | Jason Merrill <jason@redhat.com> | 2020-01-23 10:37:18 -0500 |
|---|---|---|
| committer | Jason Merrill <jason@redhat.com> | 2020-01-23 11:13:48 -0500 |
| commit | 6d00f052ef209bacdd93f503b0c5fb428cc6c434 (patch) | |
| tree | 8cb9fb9702cb52b019574cf007b9d8da7ad48c20 /gcc | |
| parent | 54b3d52c3cca836c7c4c08cc9c02eda6c096372a (diff) | |
| download | gcc-6d00f052ef209bacdd93f503b0c5fb428cc6c434.zip gcc-6d00f052ef209bacdd93f503b0c5fb428cc6c434.tar.gz gcc-6d00f052ef209bacdd93f503b0c5fb428cc6c434.tar.bz2 | |
c-family: One more 40752 tweak for unsigned char.
My last patch didn't fix all the failures on unsignd char targets. We were
missing one warning because by suppressing -Wsign-conversion for the second
operand of + we missed an overflow that we want to warn about, and we
properly don't warn about unsigned / or %.
PR testsuite/93391 - PR 40752 test fails with unsigned plain char.
* c-warn.c (conversion_warning): Change -Wsign-conversion handling.
* lib/target-supports.exp (check_effective_target_unsigned_char):
New.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/c-family/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/c-family/c-warn.c | 10 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/c-c++-common/Wconversion-pr40752a.c | 5 | ||||
| -rw-r--r-- | gcc/testsuite/lib/target-supports.exp | 8 |
5 files changed, 27 insertions, 5 deletions
diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index 0b9c604..023e49a 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,7 @@ +2020-01-23 Jason Merrill <jason@redhat.com> + + * c-warn.c (conversion_warning): Change -Wsign-conversion handling. + 2020-01-23 Martin Sebor <msebor@redhat.com> PR c/84919 diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c index 6c73317..9315cac 100644 --- a/gcc/c-family/c-warn.c +++ b/gcc/c-family/c-warn.c @@ -1315,10 +1315,14 @@ conversion_warning (location_t loc, tree type, tree expr, tree result) for (int i = 0; i < arith_ops; ++i) { tree op = TREE_OPERAND (expr, i); - tree opr = convert (type, op); /* Avoid -Wsign-conversion for (unsigned)(x + (-1)). */ - bool minus = TREE_CODE (expr) == PLUS_EXPR && i == 1; - if (unsafe_conversion_p (type, op, opr, !minus)) + if (TREE_CODE (expr) == PLUS_EXPR && i == 1 + && INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type) + && TREE_CODE (op) == INTEGER_CST + && tree_int_cst_sgn (op) < 0) + op = fold_build1 (NEGATE_EXPR, TREE_TYPE (op), op); + tree opr = convert (type, op); + if (unsafe_conversion_p (type, op, opr, true)) goto op_unsafe; } /* The operands seem safe, we might still want to warn if diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index fef5951..5c390ba 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-01-23 Jason Merrill <jason@redhat.com> + + * lib/target-supports.exp (check_effective_target_unsigned_char): + New. + 2020-01-23 Jakub Jelinek <jakub@redhat.com> PR target/93376 diff --git a/gcc/testsuite/c-c++-common/Wconversion-pr40752a.c b/gcc/testsuite/c-c++-common/Wconversion-pr40752a.c index cd70e34..8e3ffae 100644 --- a/gcc/testsuite/c-c++-common/Wconversion-pr40752a.c +++ b/gcc/testsuite/c-c++-common/Wconversion-pr40752a.c @@ -14,9 +14,10 @@ void foo(char c, char c2) c *= 2; /* { dg-warning "conversion" } */ c *= c2; /* { dg-warning "conversion" } */ c /= 2; - c /= c2; /* { dg-warning "conversion" } */ + /* If char is unsigned we avoid promoting to int. */ + c /= c2; /* { dg-warning "conversion" "" { target { ! unsigned_char } } } */ c %= 2; - c %= c2; /* { dg-warning "conversion" } */ + c %= c2; /* { dg-warning "conversion" "" { target { ! unsigned_char } } } */ c = -c2; /* { dg-warning "conversion" } */ c = ~c2; /* { dg-warning "conversion" } */ c = c2++; diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp index f65a810..3ca3dd3 100644 --- a/gcc/testsuite/lib/target-supports.exp +++ b/gcc/testsuite/lib/target-supports.exp @@ -3115,6 +3115,14 @@ proc check_effective_target_dfprt { } { }] } +# Return 1 iff target has unsigned plain 'char' by default. + +proc check_effective_target_unsigned_char {} { + return [check_no_compiler_messages unsigned_char assembly { + char ar[(char)-1]; + }] +} + proc check_effective_target_powerpc_popcntb_ok { } { return [check_cached_effective_target powerpc_popcntb_ok { |