From 1e6294bb15d2169147c7838f89a9168980b94b47 Mon Sep 17 00:00:00 2001 From: Martin Sebor Date: Fri, 14 Jan 2022 09:59:53 -0700 Subject: [PATCH] Test to verify -Wformat-overflow uses context-sensitive ranges. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/builtin-sprintf-warn-28.c: New test. --- .../gcc.dg/tree-ssa/builtin-sprintf-warn-28.c | 21 +++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-28.c diff --git a/gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-28.c b/gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-28.c new file mode 100644 index 00000000000..d58d9808279 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-28.c @@ -0,0 +1,21 @@ +/* Verify that -Wformat-overflow uses context-sensitive ranges even + at -O0 to avoid both false positives and negatives. + { dg-do compile } + { dg-options "-O0 -Wall" } */ + +extern int sprintf (char*, const char*, ...); + +extern char a[4]; + +void test_context_range (int c) +{ + int i = 998; + + /* Prior to the switch to Ranger in GCC 12 -Wformat-overflow triggers + for both calls because EVRP doesn't expose the accurate range of + the argument. */ + if (c) + sprintf (a, "%i", i + 2); // { dg-warning "writing a terminating nul past the end of the destination" } + else + sprintf (a, "%i", i + 1); // { dg-bogus "-Wformat-overflow" } +}