On 11/14/21 14:15, Aldy Hernandez wrote:
The code computing ranges in PHIs in the path solver reuses the
temporary ssa_global_cache by calling its clear method. Calling it on
an empty cache causes us to call memset with NULL.
[The testcase doesn't fail without the patch. I suppose it needs some
usbsan magic, or to live somewhere else?]
Well, the actual test-case is the compiler itself as the source code.
Anyway, the UBSAN error happens for thousands of test-cases when run
during bootstrap-ubsan.mk config file. That said, I would remove
the added test-case.
Cheers,
Martin
Tested on x86-64 Linux.
gcc/ChangeLog:
PR tree-optimization/103229
* gimple-range-cache.cc (ssa_global_cache::clear): Do not pass
null value to memset.
gcc/testsuite/ChangeLog:
* gcc.dg/pr103229.c: New test.
---
gcc/gimple-range-cache.cc | 3 ++-
gcc/testsuite/gcc.dg/pr103229.c | 10 ++++++++++
2 files changed, 12 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/pr103229.c
diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc
index a63e20e7e49..b347edeb474 100644
--- a/gcc/gimple-range-cache.cc
+++ b/gcc/gimple-range-cache.cc
@@ -651,7 +651,8 @@ ssa_global_cache::clear_global_range (tree name)
void
ssa_global_cache::clear ()
{
- memset (m_tab.address(), 0, m_tab.length () * sizeof (irange *));
+ if (m_tab.address ())
+ memset (m_tab.address(), 0, m_tab.length () * sizeof (irange *));
}
// Dump the contents of the global cache to F.
diff --git a/gcc/testsuite/gcc.dg/pr103229.c b/gcc/testsuite/gcc.dg/pr103229.c
new file mode 100644
index 00000000000..96ef9aff67c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr103229.c
@@ -0,0 +1,10 @@
+// { dg-do compile }
+// { dg-options "-O -w" }
+
+int main() {
+ int i;
+ for (; i;)
+ ;
+
+ return 0;
+}
