https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127533
Bug ID: 127533
Summary: [GIMPLE FE] malformed __PHI (missing/mismatched
arguments) crashes in find_edge /
walk_stmt_load_store_addr_ops
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Keywords: ice-on-invalid-code
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: captainnemo9292 at gmail dot com
Target Milestone: ---
Target: x86_64-linux-gnu
__PHI arguments are not checked against the predecessors of the block, so a
PHI with the wrong number of arguments, or an argument without a __BBn: edge
label, produces a phi node whose edges cannot be resolved.
Argument without an edge label in a block with no predecessors:
void __GIMPLE (ssa) a() {
int p;
__BB(2):
p_1 = __PHI (6);
}
$ gcc -fgimple -c t.c
t.c:5:1: internal compiler error: Segmentation fault
find_edge(basic_block_def*, basic_block_def*)
c_parser_parse_gimple_body
https://godbolt.org/z/bvMGd5TfK
Empty __PHI ():
void __GIMPLE (ssa) a() {
int context;
__BB(3):
context_448 = __PHI ();
if (0) goto __BB999; else goto __BB7;
__BB(7):
__BB(999):
}
-O2: Segmentation fault in walk_stmt_load_store_addr_ops <-
cgraph_edge::rebuild_edges
https://godbolt.org/z/rfze87zbs
Fewer arguments than predecessors, undeclared operands:
void __GIMPLE (ssa) a() {
int p;
__BB(2):
p_5 = __PHI (c);
if (b) goto __BB4; else goto __BB5;
__BB(4):
__BB(5):
}
internal compiler error: tree check: expected integer_cst, have error_mark in
c_parser_parse_gimple_body, at c/gimple-parser.cc:374
https://godbolt.org/z/czndnxsx5
gcc trunk 17.0.0 20260920.
