The following invalid code snippet (compiled with "-std=c++11") triggers an ICE since GCC 4.8.0: ====================================================== typedef int T __attribute__((vector_size(8))); T foo(const T& a, const T& b) { constexpr T c = a < b; return c ? a : b; } ====================================================== bug.cc: In function 'T foo(const T&, const T&)': bug.cc:5:23: error: 'a' is not a constant expression constexpr T c = a < b; ^ bug.cc:6:18: internal compiler error: tree check: expected vector_type, have error_mark in build_conditional_expr_1, at cp/call.c:4495 return c ? a : b; ^ 0xd8f084 tree_check_failed(tree_node const*, char const*, int, char const*, ...) ../../gcc/gcc/tree.c:9192 0x58441c tree_check ../../gcc/gcc/tree.h:2707 0x58441c build_conditional_expr_1 ../../gcc/gcc/cp/call.c:4495 0x5844bc build_conditional_expr(unsigned int, tree_node*, tree_node*, tree_node*, int) ../../gcc/gcc/cp/call.c:4931 0x6a8e53 build_x_conditional_expr(unsigned int, tree_node*, tree_node*, tree_node*, int) ../../gcc/gcc/cp/typeck.c:6017 0x682b2c cp_parser_question_colon_clause ../../gcc/gcc/cp/parser.c:8080 0x682b2c cp_parser_assignment_expression ../../gcc/gcc/cp/parser.c:8116 0x6847b4 cp_parser_expression ../../gcc/gcc/cp/parser.c:8274 0x67af3a cp_parser_expression ../../gcc/gcc/cp/parser.c:8313 0x67af3a cp_parser_jump_statement ../../gcc/gcc/cp/parser.c:10677 0x67af3a cp_parser_statement ../../gcc/gcc/cp/parser.c:9370 0x67b5c9 cp_parser_statement_seq_opt ../../gcc/gcc/cp/parser.c:9740 0x67b73e cp_parser_compound_statement ../../gcc/gcc/cp/parser.c:9694 0x68f15b cp_parser_function_body ../../gcc/gcc/cp/parser.c:18610 0x68f15b cp_parser_ctor_initializer_opt_and_function_body ../../gcc/gcc/cp/parser.c:18646 0x6934fe cp_parser_function_definition_after_declarator ../../gcc/gcc/cp/parser.c:22678 0x694394 cp_parser_function_definition_from_specifiers_and_declarator ../../gcc/gcc/cp/parser.c:22590 0x694394 cp_parser_init_declarator ../../gcc/gcc/cp/parser.c:16588 0x69562f cp_parser_simple_declaration ../../gcc/gcc/cp/parser.c:11200 0x679003 cp_parser_block_declaration ../../gcc/gcc/cp/parser.c:11081 Please submit a full bug report, [etc.] Marc, vector arithmetic looks like your domain, would you mind having a look?
In build_conditional_expr_1, we check error_operand_p (arg1) on the original arguments, but we don't check it again after force_rvalue, which we probably should do.
Author: glisse Date: Thu Jan 2 22:43:24 2014 New Revision: 206303 URL: http://gcc.gnu.org/viewcvs?rev=206303&root=gcc&view=rev Log: 2014-01-02 Marc Glisse <marc.glisse@inria.fr> PR c++/59641 gcc/cp/ * call.c (build_conditional_expr_1): Check the return value of force_rvalue. gcc/testsuite/ * g++.dg/cpp0x/pr59641.C: New file. Added: trunk/gcc/testsuite/g++.dg/cpp0x/pr59641.C (with props) Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/call.c trunk/gcc/testsuite/ChangeLog Propchange: trunk/gcc/testsuite/g++.dg/cpp0x/pr59641.C ('svn:eol-style' added) Propchange: trunk/gcc/testsuite/g++.dg/cpp0x/pr59641.C ('svn:keywords' added)
Fixed on trunk, not worth backporting.