From 28c5df79300ab354cbc381aab200f7c2bd0331ad Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Mon, 28 Mar 2022 14:55:49 +0200
Subject: [PATCH] tree-optimization/105080 - make sure SCEV is available for
ranger
When doing format diagnostics at -O0 we should make sure to make
SCEV available to avoid false positives due to ranges we otherwise
can trivially compute.
2022-03-28 Richard Biener <rguenther@suse.de>
PR tree-optimization/105080
* tree-ssa-strlen.cc (printf_strlen_execute): Always init
loops and SCEV.
* gcc.dg/pr105080.c: New testcase.
---
gcc/testsuite/gcc.dg/pr105080.c | 11 +++++++++++
gcc/tree-ssa-strlen.cc | 16 ++++------------
2 files changed, 15 insertions(+), 12 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/pr105080.c
diff --git a/gcc/testsuite/gcc.dg/pr105080.c b/gcc/testsuite/gcc.dg/pr105080.c
new file mode 100644
index 000000000000..77ee7eeb396e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr105080.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O0 -Wall" } */
+
+int main()
+{
+ char foo[3];
+ int i;
+
+ for (i = 0; i < 16; i++)
+ __builtin_snprintf(foo, sizeof(foo), "%d", i); /* { dg-bogus "truncated" } */
+}
diff --git a/gcc/tree-ssa-strlen.cc b/gcc/tree-ssa-strlen.cc
index 112f0dce8749..b25563662148 100644
--- a/gcc/tree-ssa-strlen.cc
+++ b/gcc/tree-ssa-strlen.cc
@@ -5858,13 +5858,8 @@ printf_strlen_execute (function *fun, bool warn_only)
strlen_optimize = !warn_only;
calculate_dominance_info (CDI_DOMINATORS);
-
- bool use_scev = optimize > 0 && flag_printf_return_value;
- if (use_scev)
- {
- loop_optimizer_init (LOOPS_NORMAL);
- scev_initialize ();
- }
+ loop_optimizer_init (LOOPS_NORMAL);
+ scev_initialize ();
gcc_assert (!strlen_to_stridx);
if (warn_stringop_overflow || warn_stringop_truncation)
@@ -5902,11 +5897,8 @@ printf_strlen_execute (function *fun, bool warn_only)
strlen_to_stridx = NULL;
}
- if (use_scev)
- {
- scev_finalize ();
- loop_optimizer_finalize ();
- }
+ scev_finalize ();
+ loop_optimizer_finalize ();
return walker.m_cleanup_cfg ? TODO_cleanup_cfg : 0;
}
--
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