public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r12-9218] c-family: avoid compile-time-hog in c_genericize [PR108880]
@ 2023-03-04 18:02 Marek Polacek
0 siblings, 0 replies; only message in thread
From: Marek Polacek @ 2023-03-04 18:02 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:6ab4c8759754f34f5285924652238c829960cd4c
commit r12-9218-g6ab4c8759754f34f5285924652238c829960cd4c
Author: Marek Polacek <polacek@redhat.com>
Date: Wed Feb 22 15:17:03 2023 -0500
c-family: avoid compile-time-hog in c_genericize [PR108880]
This fixes a compile-time hog with UBSan. This only happened in cc1 but
not cc1plus. The problem is ultimately that c_genericize_control_stmt/
STATEMENT_LIST -> walk_tree_1 doesn't use a hash_set to remember visited
nodes, so it kept on recursing for a long time. We should be able to
use the pset that c_genericize created. We just need to use walk_tree
instead of walk_tree_w_d so that the pset is explicit.
PR c/108880
gcc/c-family/ChangeLog:
* c-gimplify.cc (c_genericize_control_stmt) <case STATEMENT_LIST>: Pass
pset to walk_tree_1.
(c_genericize): Call walk_tree with an explicit pset.
gcc/testsuite/ChangeLog:
* c-c++-common/ubsan/pr108880.c: New test.
(cherry picked from commit 1370014f2ea02ec185cf1199027575916f79fe63)
Diff:
---
gcc/c-family/c-gimplify.cc | 10 +++++++---
gcc/testsuite/c-c++-common/ubsan/pr108880.c | 13 +++++++++++++
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/gcc/c-family/c-gimplify.cc b/gcc/c-family/c-gimplify.cc
index 7e55fd73f81..5ec1dc5754f 100644
--- a/gcc/c-family/c-gimplify.cc
+++ b/gcc/c-family/c-gimplify.cc
@@ -510,12 +510,15 @@ c_genericize_control_stmt (tree *stmt_p, int *walk_subtrees, void *data,
STATEMENT_LIST wouldn't be present at all the resulting
expression wouldn't have TREE_SIDE_EFFECTS set, so make sure
to clear it even on the STATEMENT_LIST in such cases. */
+ hash_set<tree> *pset = (c_dialect_cxx ()
+ ? nullptr
+ : static_cast<hash_set<tree> *>(data));
for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i))
{
tree t = tsi_stmt (i);
if (TREE_CODE (t) != DEBUG_BEGIN_STMT && nondebug_stmts < 2)
nondebug_stmts++;
- walk_tree_1 (tsi_stmt_ptr (i), func, data, NULL, lh);
+ walk_tree_1 (tsi_stmt_ptr (i), func, data, pset, lh);
if (TREE_CODE (t) != DEBUG_BEGIN_STMT
&& (nondebug_stmts > 1 || TREE_SIDE_EFFECTS (tsi_stmt (i))))
clear_side_effects = false;
@@ -570,8 +573,9 @@ c_genericize (tree fndecl)
bc_state_t save_state;
push_cfun (DECL_STRUCT_FUNCTION (fndecl));
save_bc_state (&save_state);
- walk_tree_without_duplicates (&DECL_SAVED_TREE (fndecl),
- c_genericize_control_r, NULL);
+ hash_set<tree> pset;
+ walk_tree (&DECL_SAVED_TREE (fndecl), c_genericize_control_r, &pset,
+ &pset);
restore_bc_state (&save_state);
pop_cfun ();
}
diff --git a/gcc/testsuite/c-c++-common/ubsan/pr108880.c b/gcc/testsuite/c-c++-common/ubsan/pr108880.c
new file mode 100644
index 00000000000..7d589edcd12
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/ubsan/pr108880.c
@@ -0,0 +1,13 @@
+/* PR c/108880 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=undefined" } */
+
+long a;
+short b, e;
+char c;
+int d, f, g;
+void h() {
+ int i;
+ f &= i ^= (((g &= 0 / d / d % 8 << 0 << 2) % a >> e) / c >> b) / 1 % 8 << 3;
+}
+int main() {}
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2023-03-04 18:02 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-03-04 18:02 [gcc r12-9218] c-family: avoid compile-time-hog in c_genericize [PR108880] Marek Polacek
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).