[PATCH] D29685: Lit C++11 Compatibility - Function Attributes

[Charles Li via Phabricator via cfe-commits]

tigerleapgorge created this revision.

I am continuing to make Lit tests C++11 compatible.
This patch contains 3 tests, previously in review https://reviews.llvm.org/D21626.
First two tests involve printf format attributes.
The third test involve thread safety attribute.
Here are the descriptions for each test.

test/SemaCXX/format-strings.cpp

  This test verifies format specifiers.
  This test contains 2 parts.
  
  Part 1.
  C++11 added Scanf floating-point format specifier “a”.
  http://en.cppreference.com/w/c/io/fscanf
  The Scanf format specifier “%as” expects type “float *”. However, the actual argument is type “char **”.
  Change in diagnostics.
    C++98: warning: 'a' length modifier is not supported by ISO C [-Wformat-non-iso]
    C++11: warning: format specifies type 'float *' but the argument has type 'char **' [-Wformat]
  
  Part 2.
  Function test_null_format() expects a const char * as its first formal argument, 
  but is instead given a Boolean literal as its first actual argument.
  Type conversion from const bool to const char * is a Warning in C++98, but an Error in C++11.
  Change in diagnostics.
    C++98: warning: initialization of pointer of type 'const char *' to null from a constant boolean expression [-Wbool-conversion]
    C++11: error: no matching function for call to 'test_null_format'
           note: candidate function not viable: no known conversion from 'bool' to 'const char *' for 1st argument

test/SemaCXX/printf-cstr.cpp

  This tests verifies type mismatches between printf format specifiers and the type of the actual arguments.
  This test contains 3 types of diagnostic changes.
  
  Diagnostics changed for mismatch between “%s” and actual arguments of non-POD class instance.
  In C++98, non-POD objects are not allowed as variadic arguments.
  In C++11, non-POD is allowed (5.2.2/7). 
            However, since the format specifier %s expects a char pointer not an object, Clang will issue a Warning on that.
            If the class has a c_str() method, Clang will issue a accompanying Note to prompt the use to invoke it.
  
  Type 1:
  A class object that has a c_str() method is passed in. 
  In C++98, Clang issues a Warning and an accompanying Note.
  In C++11, Clang issues a Warning.
  Expect the following change in diagnostics. (3 instances)
    C++98: warning: cannot pass non-POD object of type 'HasCStr' to variadic constructor; expected type from format string was 'char *' [-Wnon-pod-varargs]
           note: did you mean to call the c_str() method?
    C++11: warning: format specifies type 'char *' but the argument has type 'HasCStr' [-Wformat]
  
  Type 2:
  A class object that does not have a c_str() method is passed in.
  The accompanying note prompting the user to use the c_str() has no reason be there.
  Change in Warning diagnostics. (1 instance)
    C++98: warning: cannot pass non-POD object of type 'HasNoCStr' to variadic function; expected type from format string was 'char *' [-Wnon-pod-varargs]
    C++11: warning: format specifies type 'char *' but the argument has type 'HasNoCStr' [-Wformat]
  
  Type 3:
  printf format string is passed in as a pointer instead of a string literal.
  In both C++98 and C++11, Clang is unable to determine type mismatch at compile type.
  However, in C++98, non-POD type is not allowed inside variadic arguments. (3 instances)
    C++98: warning: cannot pass object of non-POD type 'HasCStr' through variadic function; call will abort at runtime [-Wnon-pod-varargs]
    C++11: (None)

test/SemaCXX/warn-thread-safety-parsing.cpp

  In C++11, does not issue Errors for thread safety attributes applied to static members.
  http://clang.llvm.org/docs/ThreadSafetyAnalysis.html
  This may be a side effect of C++11’s relaxation on in-class member initializers.
  http://www.stroustrup.com/C++11FAQ.html#member-init
  
  Restrict the following diagnostics to C++98. (2 instances each)
    C++98: error: invalid use of non-static data member 'mu' 
    C++98: error: invalid use of member 'mu' in static member function


https://reviews.llvm.org/D29685

Files:
  test/SemaCXX/format-strings.cpp
  test/SemaCXX/printf-cstr.cpp
  test/SemaCXX/warn-thread-safety-parsing.cpp

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