Support the 'a' scanf length modifier as an extension in C++.

It should not be supported in C++11, since that uses the C99 standard
library, in which 'a' is a format specifier.

llvm-svn: 147310

3 files changed, 29 insertions, 1 deletions

diff --git a/clang/lib/Analysis/FormatString.cpp b/clang/lib/Analysis/FormatString.cpp
index bbc6f07b36d..8e295aa2be1 100644
--- a/clang/lib/Analysis/FormatString.cpp
+++ b/clang/lib/Analysis/FormatString.cpp
@@ -200,7 +200,7 @@ clang::analyze_format_string::ParseLengthModifier(FormatSpecifier &FS,
     case 'L': lmKind = LengthModifier::AsLongDouble; ++I; break;
     case 'q': lmKind = LengthModifier::AsLongLong;   ++I; break;
     case 'a':
-      if (IsScanf && !LO.C99 && !LO.CPlusPlus) {
+      if (IsScanf && !LO.C99 && !LO.CPlusPlus0x) {
         // For scanf in C90, look at the next character to see if this should
         // be parsed as the GNU extension 'a' length modifier. If not, this
         // will be parsed as a conversion specifier.
diff --git a/clang/test/SemaCXX/format-strings-0x.cpp b/clang/test/SemaCXX/format-strings-0x.cpp
new file mode 100644
index 00000000000..61bdbe188de
--- /dev/null
+++ b/clang/test/SemaCXX/format-strings-0x.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -pedantic -std=c++11 %s
+
+extern "C" {
+extern int scanf(const char *restrict, ...);
+extern int printf(const char *restrict, ...);
+}
+
+void f(char **sp, float *fp) {
+  scanf("%as", sp); // expected-warning{{conversion specifies type 'float *' but the argument has type 'char **'}}
+
+  printf("%a", 1.0);
+  scanf("%afoobar", fp);
+}
diff --git a/clang/test/SemaCXX/format-strings.cpp b/clang/test/SemaCXX/format-strings.cpp
new file mode 100644
index 00000000000..2011a71b481
--- /dev/null
+++ b/clang/test/SemaCXX/format-strings.cpp
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -pedantic %s
+
+extern "C" {
+extern int scanf(const char *restrict, ...);
+extern int printf(const char *restrict, ...);
+}
+
+void f(char **sp, float *fp) {
+  // TODO: Warn that the 'a' length modifier is an extension.
+  scanf("%as", sp);
+
+  // TODO: Warn that the 'a' conversion specifier is a C++11 feature.
+  printf("%a", 1.0);
+  scanf("%afoobar", fp);
+}