From 2d4e1e144c25e526e4f668be5a0bc10d0c1c738c Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Wed, 6 May 2020 15:53:33 -0400 Subject: [PATCH] c++: ICE when shortening right shift [PR94955] 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. 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/ChangeLog | 6 ++++++ gcc/cp/typeck.c | 4 +++- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/g++.dg/cpp0x/constexpr-shift2.C | 12 ++++++++++++ 4 files changed, 26 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-shift2.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 605cdf33ae4..4e446585aa4 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2020-05-18 Marek Polacek + + PR c++/94955 + * typeck.c (cp_build_binary_op): Use fold_for_warn instead of + cp_fold_rvalue. + 2020-05-18 Marek Polacek PR c++/94937 diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c index 768c62281f4..d2e6c907622 100644 --- a/gcc/cp/typeck.c +++ b/gcc/cp/typeck.c @@ -5633,7 +5633,9 @@ 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/ChangeLog b/gcc/testsuite/ChangeLog index 67f2c550ff0..02de8028552 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-05-18 Marek Polacek + + PR c++/94955 + * g++.dg/cpp0x/constexpr-shift2.C: New test. + 2020-05-18 Marek Polacek PR c++/94937 diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-shift2.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-shift2.C new 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(); +} -- 2.30.2