Teach printf/scanf about enums with fixed underlying types.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@157961 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 92 insertions, 0 deletions

diff --git a/test/Sema/format-strings-enum-fixed-type.cpp b/test/Sema/format-strings-enum-fixed-type.cpp
new file mode 100644
index 0000000000..8b6b237645
--- /dev/null
+++ b/test/Sema/format-strings-enum-fixed-type.cpp
@@ -0,0 +1,92 @@
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -x c++ -std=c++11 -verify %s
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -x objective-c -verify %s
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -x objective-c++ -verify %s
+
+#ifdef __cplusplus
+# define EXTERN_C extern "C"
+#else
+# define EXTERN_C extern
+#endif
+
+EXTERN_C int printf(const char *,...);
+
+typedef enum : short { Constant = 0 } TestEnum;
+// Note that in C (and Objective-C), the type of 'Constant' is 'short'.
+// In C++ (and Objective-C++) it is 'TestEnum'.
+// This is why we don't check for that in the expected output.
+
+void test(TestEnum input) {
+  printf("%hhd", input); // expected-warning{{format specifies type 'char' but the argument has type 'TestEnum'}}
+  printf("%hhd", Constant); // expected-warning{{format specifies type 'char'}}
+  
+  printf("%hd", input); // no-warning
+  printf("%hd", Constant); // no-warning
+
+  // While these are less correct, they are still safe.
+  printf("%d", input); // no-warning
+  printf("%d", Constant); // no-warning
+  
+  printf("%lld", input); // expected-warning{{format specifies type 'long long' but the argument has type 'TestEnum'}}
+  printf("%lld", Constant); // expected-warning{{format specifies type 'long long'}}
+}
+
+
+typedef enum : unsigned long { LongConstant = ~0UL } LongEnum;
+
+void testLong(LongEnum input) {
+  printf("%u", input); // expected-warning{{format specifies type 'unsigned int' but the argument has type 'LongEnum'}}
+  printf("%u", LongConstant); // expected-warning{{format specifies type 'unsigned int'}}
+  
+  printf("%lu", input);
+  printf("%lu", LongConstant);
+}
+
+
+typedef short short_t;
+typedef enum : short_t { ShortConstant = 0 } ShortEnum;
+
+void testUnderlyingTypedef(ShortEnum input) {
+  printf("%hhd", input); // expected-warning{{format specifies type 'char' but the argument has type 'ShortEnum'}}
+  printf("%hhd", ShortConstant); // expected-warning{{format specifies type 'char'}}
+  
+  printf("%hd", input); // no-warning
+  printf("%hd", ShortConstant); // no-warning
+  
+  // While these are less correct, they are still safe.
+  printf("%d", input); // no-warning
+  printf("%d", ShortConstant); // no-warning
+  
+  printf("%lld", input); // expected-warning{{format specifies type 'long long' but the argument has type 'ShortEnum'}}
+  printf("%lld", ShortConstant); // expected-warning{{format specifies type 'long long'}}
+}
+
+
+typedef ShortEnum ShortEnum2;
+
+void testTypedefChain(ShortEnum2 input) {
+  printf("%hhd", input); // expected-warning{{format specifies type 'char' but the argument has type 'ShortEnum2' (aka 'ShortEnum')}}
+  printf("%hd", input); // no-warning
+  printf("%d", input); // no-warning
+  printf("%lld", input); // expected-warning{{format specifies type 'long long' but the argument has type 'ShortEnum2' (aka 'ShortEnum')}}
+}
+
+
+typedef enum : char { CharConstant = 'a' } CharEnum;
+
+// %hhd is deliberately not required to be signed, because 'char' isn't either.
+// This is a separate code path in FormatString.cpp.
+void testChar(CharEnum input) {
+  printf("%hhd", input); // no-warning
+  printf("%hhd", CharConstant); // no-warning
+
+  // This is not correct but it is safe. We warn because '%hd' shows intent.
+  printf("%hd", input); // expected-warning{{format specifies type 'short' but the argument has type 'CharEnum'}}
+  printf("%hd", CharConstant); // expected-warning{{format specifies type 'short'}}
+  
+  // This is not correct but it matches the promotion rules (and is safe).
+  printf("%d", input); // no-warning
+  printf("%d", CharConstant); // no-warning
+  
+  printf("%lld", input); // expected-warning{{format specifies type 'long long' but the argument has type 'CharEnum'}}
+  printf("%lld", CharConstant); // expected-warning{{format specifies type 'long long'}}
+}