From 639ece7abfa3688008cb791aec4c7a1a4f76e59f Mon Sep 17 00:00:00 2001
From: Martin Sebor <msebor@redhat.com>
Date: Wed, 15 Dec 2021 08:43:02 -0700
Subject: [PATCH] Add new test [PR78969].
gcc/testsuite/ChangeLog:
PR tree-optimization/78969
* gcc.dg/tree-ssa/builtin-snprintf-warn-6.c: New test.
---
.../gcc.dg/tree-ssa/builtin-snprintf-warn-6.c | 47 +++++++++++++++++++
1 file changed, 47 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/builtin-snprintf-warn-6.c
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/builtin-snprintf-warn-6.c b/gcc/testsuite/gcc.dg/tree-ssa/builtin-snprintf-warn-6.c
new file mode 100644
index 000000000000..2857e83369f6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/builtin-snprintf-warn-6.c
@@ -0,0 +1,47 @@
+/* PR tree-optimization/78969 - bogus snprintf truncation warning due to
+ missing range info
+ { dg-do compile }
+ { dg-options "-O2 -Wall -Wformat-truncation=2" } */
+
+typedef __SIZE_TYPE__ size_t;
+
+extern int snprintf (char*, size_t, const char*, ...);
+
+
+void f (unsigned j, char *p)
+{
+ if (j > 999)
+ j = 0;
+
+ snprintf (p, 4, "%3u", j);
+}
+
+void g (unsigned j, char *p)
+{
+ if (j > 999)
+ return;
+
+ snprintf (p, 4, "%3u", j); // { dg-bogus "-Wformat-truncation" }
+}
+
+
+void pr78969_c4 (char * p /* NNN\0" */)
+{
+ for (int idx = 0; idx < 1000; idx++) {
+ // guaranteed to be in [0-999] range
+ snprintf (p, 4, "%d", idx); // { dg-bogus "-Wformat-truncation" }
+ }
+}
+
+
+void sink (int, ...);
+
+char d[4];
+
+void pr78969_c12 (unsigned i)
+{
+ if (i >= 1000 && i < 10000)
+ snprintf (d, 4, "%3d", i / 10); // { dg-bogus "-Wformat-truncation" }
+ else
+ sink (i / 10 % 10);
+}
--
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