-Wformat: Don't check format strings in uninstantiated templates.

Also applies to -Wnonnull, -Wtype-safety, and -Wnon-pod-varargs.
All of these can be better checked at instantiation time.

This change does not actually affect regular CallExpr function calls,
since the checks there only happen after overload resolution.
However, it will affect Objective-C method calls.

<rdar://problem/12373934>

llvm-svn: 164984

3 files changed, 142 insertions, 4 deletions

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index ebb6cd10652..7498d348920 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -495,9 +495,8 @@ void Sema::checkCall(NamedDecl *FDecl, Expr **Args,
                      SourceLocation Loc,
                      SourceRange Range,
                      VariadicCallType CallType) {
-  // FIXME: This mechanism should be abstracted to be less fragile and
-  // more efficient. For example, just map function ids to custom
-  // handlers.
+  if (CurContext->isDependentContext())
+    return;
 
   // Printf and scanf checking.
   bool HandledFormatString = false;
diff --git a/clang/test/SemaCXX/format-strings.cpp b/clang/test/SemaCXX/format-strings.cpp
index 6b0df293537..299aa81bb16 100644
--- a/clang/test/SemaCXX/format-strings.cpp
+++ b/clang/test/SemaCXX/format-strings.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral -pedantic %s
+// RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral -pedantic -fblocks %s
 
 #include <stdarg.h>
 
@@ -75,3 +75,61 @@ int Foo::printf2(const char *fmt, ...) {
 
   return 0;
 }
+
+
+namespace Templates {
+  template<typename T>
+  void my_uninstantiated_print(const T &arg) {
+    printf("%d", arg); // no-warning
+  }
+
+  template<typename T>
+  void my_print(const T &arg) {
+    printf("%d", arg); // expected-warning {{format specifies type 'int' but the argument has type 'const char *'}}
+  }
+
+  void use_my_print() {
+    my_print("abc"); // expected-note {{requested here}}
+  }
+
+
+  template<typename T>
+  class UninstantiatedPrinter {
+  public:
+    static void print(const T &arg) {
+      printf("%d", arg); // no-warning
+    }
+  };
+
+  template<typename T>
+  class Printer {
+    void format(const char *fmt, ...) __attribute__((format(printf,2,3)));
+  public:
+
+    void print(const T &arg) {
+      format("%d", arg); // expected-warning {{format specifies type 'int' but the argument has type 'const char *'}}
+    }
+  };
+
+  void use_class(Printer<const char *> &p) {
+    p.print("abc"); // expected-note {{requested here}}
+  }
+
+  
+  extern void (^block_print)(const char * format, ...) __attribute__((format(printf, 1, 2)));
+
+  template<typename T>
+  void uninstantiated_call_block_print(const T &arg) {
+    block_print("%d", arg); // no-warning
+  }
+
+  template<typename T>
+  void call_block_print(const T &arg) {
+    block_print("%d", arg); // expected-warning {{format specifies type 'int' but the argument has type 'const char *'}}
+  }
+
+  void use_block_print() {
+    call_block_print("abc"); // expected-note {{requested here}}
+  }
+}
+
diff --git a/clang/test/SemaObjCXX/format-strings.mm b/clang/test/SemaObjCXX/format-strings.mm
new file mode 100644
index 00000000000..2fb92e27560
--- /dev/null
+++ b/clang/test/SemaObjCXX/format-strings.mm
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral -pedantic %s
+
+#include <stdarg.h>
+
+extern "C" {
+extern int scanf(const char *restrict, ...);
+extern int printf(const char *restrict, ...);
+extern int vprintf(const char *restrict, va_list);
+}
+
+@class NSString;
+
+@interface Format
++ (void)print:(NSString *)format, ... __attribute__((format(NSString, 1, 2)));
+@end
+
+
+namespace Templates {
+  template<typename T>
+  void my_uninstantiated_print(const T &arg) {
+    [Format print:@"%d", arg];
+  }
+
+  template<typename T>
+  void my_print(const T &arg) {
+    [Format print:@"%d", arg]; // expected-warning {{format specifies type 'int' but the argument has type 'const char *'}}
+  }
+
+  void use_my_print() {
+    my_print("abc"); // expected-note {{requested here}}
+  }
+
+
+  template<typename T>
+  class UninstantiatedPrinter {
+  public:
+    static void print(const T &arg) {
+      [Format print:@"%d", arg]; // no-warning
+    }
+  };
+
+  template<typename T>
+  class Printer {
+  public:
+    void print(const T &arg) {
+      [Format print:@"%d", arg]; // expected-warning {{format specifies type 'int' but the argument has type 'const char *'}}
+    }
+  };
+
+  void use_class(Printer<const char *> &p) {
+    p.print("abc"); // expected-note {{requested here}}
+  }
+
+
+  template<typename T>
+  class UninstantiatedWrapper {
+  public:
+    class Printer {
+    public:
+      void print(const T &arg) {
+        [Format print:@"%d", arg]; // no-warning
+      }
+    };
+  };
+
+  template<typename T>
+  class Wrapper {
+  public:
+    class Printer {
+    public:
+      void print(const T &arg) {
+        [Format print:@"%d", arg]; // expected-warning {{format specifies type 'int' but the argument has type 'const char *'}}
+      }
+    };
+  };
+
+  void use_class(Wrapper<const char *>::Printer &p) {
+    p.print("abc"); // expected-note {{requested here}}
+  }
+}
+