https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84138
Bug ID: 84138
Summary: [8 Regression] ICE folding broken constant
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Keywords: error-recovery, ice-on-invalid-code
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: reichelt at gcc dot gnu.org
CC: mpolacek at gcc dot gnu.org
Target Milestone: ---
The following invalid code snippet triggers an ICE on trunk:
==============================
char foo()
{
const int i = 0 = 0;
return 1 ? 0 : (char)i;
}
==============================
bug.cc: In function 'char foo()':
bug.cc:3:21: error: lvalue required as left operand of assignment
const int i = 0 = 0;
^
bug.cc:4:24: internal compiler error: tree check: expected class 'type', have
'exceptional' (error_mark) in useless_type_conversion_p, at gimple-expr.c:86
return 1 ? 0 : (char)i;
^
0x788ca8 tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
../../gcc/gcc/tree.c:9375
0x6cb04c tree_class_check(tree_node*, tree_code_class, char const*, int, char
const*)
../../gcc/gcc/tree.h:3255
0x6cb04c useless_type_conversion_p(tree_node*, tree_node*)
../../gcc/gcc/gimple-expr.c:86
0x865fb4 cp_fold
../../gcc/gcc/cp/cp-gimplify.c:2359
0x8671cc cp_fold_maybe_rvalue
../../gcc/gcc/cp/cp-gimplify.c:2006
0x865872 cp_fold_maybe_rvalue
../../gcc/gcc/cp/cp-gimplify.c:2137
0x865872 cp_fold
../../gcc/gcc/cp/cp-gimplify.c:2137
0x8671cc cp_fold_maybe_rvalue
../../gcc/gcc/cp/cp-gimplify.c:2006
0x9e2202 maybe_warn_about_returning_address_of_local
../../gcc/gcc/cp/typeck.c:8995
0x9e2202 check_return_expr(tree_node*, bool*)
../../gcc/gcc/cp/typeck.c:9385
0x99cdfe finish_return_stmt(tree_node*)
../../gcc/gcc/cp/semantics.c:890
0x919fa4 cp_parser_jump_statement
../../gcc/gcc/cp/parser.c:12368
0x919fa4 cp_parser_statement
../../gcc/gcc/cp/parser.c:10773
0x91ad20 cp_parser_statement_seq_opt
../../gcc/gcc/cp/parser.c:11218
0x91adf7 cp_parser_compound_statement
../../gcc/gcc/cp/parser.c:11172
0x931580 cp_parser_function_body
../../gcc/gcc/cp/parser.c:21710
0x931580 cp_parser_ctor_initializer_opt_and_function_body
../../gcc/gcc/cp/parser.c:21747
0x931e30 cp_parser_function_definition_after_declarator
../../gcc/gcc/cp/parser.c:26648
0x932b47 cp_parser_function_definition_from_specifiers_and_declarator
../../gcc/gcc/cp/parser.c:26564
0x932b47 cp_parser_init_declarator
../../gcc/gcc/cp/parser.c:19436
Please submit a full bug report, [etc.]
The regression was introduced between 2017-07-31 and 2017-08-09.
Marek, I suspect that your patch
> 2017-08-08 Marek Polacek <pola...@redhat.com>
>
> PR c++/81607
> * cp-gimplify.c (cp_fold): If folding exposed a branch of
> a COND_EXPR, convert it to the original type of the COND_EXPR, if
> they differ.
might be responsible. Would you mind having a look?
