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| author | Marek Polacek <polacek@redhat.com> | 2024-08-29 10:40:50 -0400 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2024-09-17 16:59:09 -0400 |
| commit | 7ca486889b1b1c7e7bcbbca3b6caa103294ec07d (patch) | |
| tree | 04bd06fd4b9c5d2e48c18c82751caa0383dbac6c | |
| parent | dfe0d4389a3ce43179563a63046ad3e74d615a08 (diff) | |
| download | gcc-7ca486889b1b1c7e7bcbbca3b6caa103294ec07d.zip gcc-7ca486889b1b1c7e7bcbbca3b6caa103294ec07d.tar.gz gcc-7ca486889b1b1c7e7bcbbca3b6caa103294ec07d.tar.bz2 | |
c++: ICE with -Wtautological-compare in template [PR116534]
Pre r14-4793, we'd call warn_tautological_cmp -> operand_equal_p
with operands wrapped in NON_DEPENDENT_EXPR, which works, since
o_e_p bails for codes it doesn't know. But now we pass operands
not encapsulated in NON_DEPENDENT_EXPR, and crash, because the
template tree for &a[x] has null DECL_FIELD_OFFSET.
This patch extends r12-7797 to cover the case when DECL_FIELD_OFFSET
is null.
PR c++/116534
gcc/ChangeLog:
* fold-const.cc (operand_compare::operand_equal_p): If either
field's DECL_FIELD_OFFSET is null, compare the fields with ==.
gcc/testsuite/ChangeLog:
* g++.dg/warn/Wtautological-compare4.C: New test.
Reviewed-by: Jason Merrill <jason@redhat.com>
| -rw-r--r-- | gcc/fold-const.cc | 12 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/warn/Wtautological-compare4.C | 21 |
2 files changed, 30 insertions, 3 deletions
diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc index 70db167..0578f42 100644 --- a/gcc/fold-const.cc +++ b/gcc/fold-const.cc @@ -3601,9 +3601,15 @@ operand_compare::operand_equal_p (const_tree arg0, const_tree arg1, /* Non-FIELD_DECL operands can appear in C++ templates. */ if (TREE_CODE (field0) != FIELD_DECL - || TREE_CODE (field1) != FIELD_DECL - || !operand_equal_p (DECL_FIELD_OFFSET (field0), - DECL_FIELD_OFFSET (field1), flags) + || TREE_CODE (field1) != FIELD_DECL) + return false; + + if (!DECL_FIELD_OFFSET (field0) + || !DECL_FIELD_OFFSET (field1)) + return field0 == field1; + + if (!operand_equal_p (DECL_FIELD_OFFSET (field0), + DECL_FIELD_OFFSET (field1), flags) || !operand_equal_p (DECL_FIELD_BIT_OFFSET (field0), DECL_FIELD_BIT_OFFSET (field1), flags)) diff --git a/gcc/testsuite/g++.dg/warn/Wtautological-compare4.C b/gcc/testsuite/g++.dg/warn/Wtautological-compare4.C new file mode 100644 index 0000000..96308f4 --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wtautological-compare4.C @@ -0,0 +1,21 @@ +// PR c++/116534 +// { dg-do compile } +// { dg-options "-Wall" } + +template <class A> +struct Test { + bool foo(unsigned x, unsigned y) { + bool test = &a[x] == &b[y]; + return test; + } + unsigned *a; + unsigned *b; +}; + +void +g () +{ + Test<int> t; + t.foo (0u, 1u); + t.foo (0u, 0u); +} |