On 5/6/20 4:31 PM, Marek Polacek wrote:
Since r10-6527 fold_for_warn calls maybe_constant_value, which means it can fold more than it previously could. In this testcase it means that cp_build_binary_op/RSHIFT_EXPR set short_shift because now we were able to fold op1 to an INTEGER_CST. But then when actually performing the shortening we crashed because cp_fold_rvalue wasn't able to fold as much as f_f_w and so tree_int_cst_sgn crashed on a NOP_EXPR. Therefore the calls should probably match.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk/10.2?
OK.
PR c++/94955 * typeck.c (cp_build_binary_op): Use fold_for_warn instead of cp_fold_rvalue. * g++.dg/cpp0x/constexpr-shift2.C: New test. --- gcc/cp/typeck.c | 4 +++- gcc/testsuite/g++.dg/cpp0x/constexpr-shift2.C | 12 ++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-shift2.C diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c index 8e3188a415d..b468e92896a 100644 --- a/gcc/cp/typeck.c +++ b/gcc/cp/typeck.c @@ -5606,7 +5606,9 @@ cp_build_binary_op (const op_location_t &location, { int unsigned_arg; tree arg0 = get_narrower (op0, &unsigned_arg); - tree const_op1 = cp_fold_rvalue (op1); + /* We're not really warning here but when we set short_shift we + used fold_for_warn to fold the operand. */ + tree const_op1 = fold_for_warn (op1);final_type = result_type; diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-shift2.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-shift2.Cnew file mode 100644 index 00000000000..9b3490a66a7 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-shift2.C @@ -0,0 +1,12 @@ +// PR c++/94955 +// { dg-do compile { target c++11 } } + +struct S { + static constexpr char foo() { return 10; } +}; + +short int +fn (short int e) +{ + return e >> S::foo(); +} base-commit: 319eafce3e54c8cb10e3fddce6823a6a558fca8b
