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| author | Marek Polacek <polacek@redhat.com> | 2015-01-07 08:21:50 +0000 |
|---|---|---|
| committer | Marek Polacek <mpolacek@gcc.gnu.org> | 2015-01-07 08:21:50 +0000 |
| commit | 4a9a42abc4f30bd63ef666e972dcbce0f05f0d0d (patch) | |
| tree | d0f2a4cd5014273666c800236267295be4add8a2 | |
| parent | 2cc901dcb29e15e06bfeab82a9834b6254b4ae0f (diff) | |
| download | gcc-4a9a42abc4f30bd63ef666e972dcbce0f05f0d0d.zip gcc-4a9a42abc4f30bd63ef666e972dcbce0f05f0d0d.tar.gz gcc-4a9a42abc4f30bd63ef666e972dcbce0f05f0d0d.tar.bz2 | |
re PR c/64440 (-Wdiv-by-zero false negative on const variables)
PR c/64440
* c-common.c (c_fully_fold_internal): Warn for division and modulo
if orig_op1 isn't INTEGER_CST, op1 is INTEGER_CST and is zero.
* gcc.dg/pr64440.c: New test.
* c-c++-common/pr56607.c: Don't limit dg-warnings to C++.
From-SVN: r219279
| -rw-r--r-- | gcc/c-family/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/c-family/c-common.c | 11 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/c-c++-common/pr56607.c | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr64440.c | 15 |
5 files changed, 40 insertions, 2 deletions
diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index 4c86fa5..4bcff01 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,9 @@ +2015-01-07 Marek Polacek <polacek@redhat.com> + + PR c/64440 + * c-common.c (c_fully_fold_internal): Warn for division and modulo + if orig_op1 isn't INTEGER_CST, op1 is INTEGER_CST and is zero. + 2015-01-05 Trevor Saunders <tsaunders@mozilla.com> PR c++/31397 diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index 4d9dd4d..df4fddd 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -1364,6 +1364,17 @@ c_fully_fold_internal (tree expr, bool in_init, bool *maybe_const_operands, ? G_("left shift count >= width of type") : G_("right shift count >= width of type"))); } + if ((code == TRUNC_DIV_EXPR + || code == CEIL_DIV_EXPR + || code == FLOOR_DIV_EXPR + || code == EXACT_DIV_EXPR + || code == TRUNC_MOD_EXPR) + && TREE_CODE (orig_op1) != INTEGER_CST + && TREE_CODE (op1) == INTEGER_CST + && (TREE_CODE (TREE_TYPE (orig_op0)) == INTEGER_TYPE + || TREE_CODE (TREE_TYPE (orig_op0)) == FIXED_POINT_TYPE) + && TREE_CODE (TREE_TYPE (orig_op1)) == INTEGER_TYPE) + warn_for_div_by_zero (loc, op1); goto out; case INDIRECT_REF: diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 214cfd6..259d87f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,11 @@ 2015-01-07 Marek Polacek <polacek@redhat.com> + PR c/64440 + * gcc.dg/pr64440.c: New test. + * c-c++-common/pr56607.c: Don't limit dg-warnings to C++. + +2015-01-07 Marek Polacek <polacek@redhat.com> + PR c/64417 * gcc.c-torture/compile/pr28865.c: Add dg-errors. * gcc.dg/pr64417.c: New test. diff --git a/gcc/testsuite/c-c++-common/pr56607.c b/gcc/testsuite/c-c++-common/pr56607.c index d7faa81..ba13956 100644 --- a/gcc/testsuite/c-c++-common/pr56607.c +++ b/gcc/testsuite/c-c++-common/pr56607.c @@ -12,7 +12,7 @@ int f2 (void) { const int x = sizeof (char) - 1; - return 1 / x; /* { dg-warning "division by zero" "" { target c++ } } */ + return 1 / x; /* { dg-warning "division by zero" } */ } int @@ -25,5 +25,5 @@ int f4 (void) { const int x = sizeof (int) / 3 - 1; - return 1 / x; /* { dg-warning "division by zero" "" { target c++ } } */ + return 1 / x; /* { dg-warning "division by zero" } */ } diff --git a/gcc/testsuite/gcc.dg/pr64440.c b/gcc/testsuite/gcc.dg/pr64440.c new file mode 100644 index 0000000..f9cc46d --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr64440.c @@ -0,0 +1,15 @@ +/* PR c/64440 */ +/* { dg-do compile } */ +/* { dg-options "-Wall -O2" } */ + +int +foo (int x) +{ + const int y = 0; + int r = 0; + r += x / y; /* { dg-warning "division by zero" } */ + r += x / 0; /* { dg-warning "division by zero" } */ + r += x % y; /* { dg-warning "division by zero" } */ + r += x % 0; /* { dg-warning "division by zero" } */ + return r; +} |