https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90949
Bug ID: 90949
Summary: [9/10 Regression] null pointer check removed
Product: gcc
Version: 9.1.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
CC: law at gcc dot gnu.org
Target Milestone: ---
From
https://stackoverflow.com/questions/56655137/undefined-behaviour-or-gcc-optimization-bug
int puts(const char*);
void free(void*);
void* malloc(unsigned long);
#define NULL 0
struct Node
{
struct Node* child;
};
void walk(struct Node* module, int cleanup)
{
if (module == NULL) {
return;
}
if (!cleanup) {
puts("No cleanup");
}
walk(module->child, cleanup);
if (cleanup) {
free(module);
}
}
int main()
{
struct Node* node = malloc(sizeof(struct Node));
node->child = NULL;
walk(node, 1);
}
This crashes when compiled with -O1 -foptimize-sibling-calls -ftree-vrp since
r270574
PR tree-optimization/90037
* Makefile.in (OBJS): Remove tree-ssa-phionlycprop.c
* passes.def: Replace all instance of phi-only cprop with the
lattice propagator. Move propagation pass from after erroneous
path isolation to before erroneous path isolation.
* tree-ssa-phionlycprop.c: Remove.
* gcc.dg/tree-ssa/20030710-1.c: Update dump file to scan.
* gcc.dg/isolate-2.c: Likewise.
* gcc.dg/isolate-4.c: Likewise.
* gcc.dg/pr19431.c: Accept either ordering of PHI args.
* gcc.dg/pr90037.c: New test.
