[analyzer] CStringChecker: Remember to highlight the argument expression range.

When emitting a bug report, it is important to highlight which argument of the
call-expression is causing the problem.

Before:
warning: Null pointer argument in call to string comparison function
  strcmp(a, b);
  ^~~~~~~~~~~~

After:
warning: Null pointer argument in call to string comparison function
  strcmp(a, b);
  ^      ~

Affects other output modes as well, not just text.

Differential Revision: https://reviews.llvm.org/D50028

llvm-svn: 338333

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/test/Analysis/cstring-ranges.c b/clang/test/Analysis/cstring-ranges.c
new file mode 100644
index 00000000000..4fcd7eaa8be
--- /dev/null
+++ b/clang/test/Analysis/cstring-ranges.c
@@ -0,0 +1,15 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=unix.cstring -analyzer-output=text %s 2>&1 | FileCheck %s
+
+// This test verifies argument source range highlighting.
+// Otherwise we've no idea which of the arguments is null.
+
+char *strcpy(char *, const char *);
+
+void foo() {
+  char *a = 0, *b = 0;
+  strcpy(a, b);
+}
+
+// CHECK: warning: Null pointer argument in call to string copy function
+// CHECK-NEXT: strcpy(a, b);
+// CHECK-NEXT: ^      ~