Fix strict aliasing violation from conditional typedef of wchar_t by …

…building entire project as C++ for Unix (#6801)

Enable building CoreCLR as C++ project on Unix

This series of patches fixes the strict aliasing violation from
the conditional typedef of wchar_t in src/pal/inc/pal_char16.h:40

* rename c files to cpp
* modify all cmake files to change .c files to .cpp
* apply c++ linkage to templates

src/ilasm/CMakeLists.txt

@@ -22,25 +22,23 @@ set(ILASM_SOURCES
   asmman.cpp
   main.cpp
   assembler.cpp
-  prebuilt/asmparse.c
+  prebuilt/asmparse.cpp
 )
 if(WIN32)
   set(ILASM_RESOURCES Native.rc)
   add_definitions(-DFX_VER_INTERNALNAME_STR=ilasm.exe)
 endif(WIN32)
 
-set_source_files_properties( prebuilt/asmparse.c PROPERTIES LANGUAGE CXX )
 
 if(CLR_CMAKE_PLATFORM_UNIX)
-  add_compile_options(-x c++)
-  # Need generate a right form of asmparse.c to avoid the following options.
+  # Need generate a right form of asmparse.cpp to avoid the following options.
   # Clang also produces a bad-codegen on this prebuilt file with optimization.
   # https://github.com/dotnet/coreclr/issues/2305
   add_compile_options(-Wno-delete-non-virtual-dtor)
   add_compile_options(-Wno-deprecated-register)
   add_compile_options(-Wno-array-bounds)
   add_compile_options(-Wno-unused-label)
-  set_source_files_properties( prebuilt/asmparse.c PROPERTIES COMPILE_FLAGS -O0 )
+  set_source_files_properties( prebuilt/asmparse.cpp PROPERTIES COMPILE_FLAGS "-O0" )
 endif(CLR_CMAKE_PLATFORM_UNIX)
 
 _add_executable(ilasm
@@ -82,4 +80,5 @@ else()
   )
 endif(CLR_CMAKE_PLATFORM_UNIX)
 
-install_clr(ilasm)
+install_clr(ilasm)
+

src/inc/CMakeLists.txt

@@ -50,23 +50,22 @@ add_compile_options(/TC)
 
 else()
 
-#The MIDL tool exists for Windows only, so for other systems, we have the prebuilt xxx_i.c files checked in
+#The MIDL tool exists for Windows only, so for other systems, we have the prebuilt xxx_i.cpp files checked in
 
 # The prebuilt files contain extra '!_MIDL_USE_GUIDDEF_' after the #endif, but not in the comment.
 # In order to not to have to modify these prebuilt files, we disable the extra tokens warning.
 add_compile_options(-Wno-extra-tokens)
-
+add_compile_options(-D_MIDL_USE_GUIDDEF_)
 foreach(IDL_SOURCE IN LISTS CORGUIDS_IDL_SOURCES)
    get_filename_component(IDLNAME ${IDL_SOURCE} NAME_WE)
-   set(C_SOURCE ../pal/prebuilt/idl/${IDLNAME}_i.c)
+   set(C_SOURCE ../pal/prebuilt/idl/${IDLNAME}_i.cpp)
    list(APPEND CORGUIDS_SOURCES ${C_SOURCE})
 endforeach(IDL_SOURCE)
 
 add_compile_options(-fPIC)
-
 endif(WIN32)
 
-# Compile *_i.c to lib
+# Compile *_i.cpp to lib
 _add_library(corguids ${CORGUIDS_SOURCES})
 
 # Binplace the inc files for packaging later.

src/pal/inc/mbusafecrt.h

@@ -65,7 +65,7 @@ extern WCHAR* wcstok_s( WCHAR* inString, const WCHAR* inControl, WCHAR** ioConte
 
 // strnlen is not required unless the source string is completely untrusted (e.g. anonymous input on a website)
 #ifndef SUPPRESS_STRNLEN
-    extern size_t strnlen( const char* inString, size_t inMaxSize );
+    extern size_t PAL_strnlen( const char* inString, size_t inMaxSize );
     extern size_t wcsnlen( const WCHAR* inString, size_t inMaxSize );
 #endif
 

src/pal/inc/pal.h

@@ -5802,6 +5802,7 @@ CoCreateGuid(OUT GUID * pguid);
 #define _wcstoui64    PAL__wcstoui64
 #define _flushall     PAL__flushall
 #define _vsnprintf    PAL__vsnprintf
+#define strnlen       PAL_strnlen
 
 #ifdef _AMD64_ 
 #define _mm_getcsr    PAL__mm_getcsr

src/pal/inc/pal_char16.h

@@ -37,7 +37,8 @@ This file is used to define the wchar_t type as a 16-bit type on Unix.
 // Set up the wchar_t type (which got preprocessed to __wchar_16_cpp__).
 // In C++11, the standard gives us char16_t, which is what we want (and matches types with u"")
 // In C, this doesn't exist, so use unsigned short.
-
+// **** WARNING: Linking C and C++ objects will break with -fstrict-aliasing with GCC/Clang
+//               due to conditional typedef
 #if !defined(_WCHAR_T_DEFINED) || !defined(_MSC_VER)
 #if defined (PLATFORM_UNIX)
 #if defined(__cplusplus)

src/pal/inc/pal_mstypes.h

@@ -215,6 +215,9 @@ extern "C" {
 // Defined in gnu's types.h. For non PAL_IMPLEMENTATION system
 // includes are not included, so we need to define them.
 #ifndef PAL_IMPLEMENTATION
+
+// OS X already defines these types in 64 bit
+#if !defined(_TARGET_MAC64)
 typedef __int64 int64_t;
 typedef unsigned __int64 uint64_t;
 typedef __int32 int32_t;
@@ -223,6 +226,8 @@ typedef __int16 int16_t;
 typedef unsigned __int16 uint16_t;
 typedef __int8 int8_t;
 typedef unsigned __int8 uint8_t;
+#endif
+
 #endif // PAL_IMPLEMENTATION
 
 #ifndef _MSC_VER

src/pal/inc/rt/palrt.h

@@ -1076,6 +1076,7 @@ _SAFECRT__EXTERN_C
 errno_t __cdecl _itow_s(int _Value, WCHAR *_Dst, size_t _SizeInWords, int _Radix);
 
 #if defined(__cplusplus) && _SAFECRT_USE_CPP_OVERLOADS
+extern "C++"
 template <size_t _SizeInWords>
 inline
 errno_t __cdecl _itow_s(int _Value, WCHAR (&_Dst)[_SizeInWords], int _Radix)
@@ -1104,6 +1105,7 @@ _SAFECRT__EXTERN_C
 errno_t __cdecl _i64tow_s(__int64 _Value, WCHAR *_Dst, size_t _SizeInWords, int _Radix);
 
 #if defined(__cplusplus) && _SAFECRT_USE_CPP_OVERLOADS
+extern "C++"
 template <size_t _SizeInWords>
 inline
 errno_t __cdecl _i64tow_s(__int64 _Value, WCHAR (&_Dst)[_SizeInWords], int _Radix)
@@ -1135,6 +1137,7 @@ _SAFECRT__EXTERN_C
 errno_t __cdecl getenv_s(size_t *_ReturnValue, char *_Dst, size_t _SizeInWords, const char *_Name);
 
 #if defined(__cplusplus) && _SAFECRT_USE_CPP_OVERLOADS
+extern "C++"
 template <size_t _SizeInWords>
 inline
 errno_t __cdecl getenv_s(size_t *_ReturnValue, char *_Dst, size_t _SizeInWords, const char *_Name)
@@ -1247,6 +1250,7 @@ namespace std
     typedef decltype(nullptr) nullptr_t;
 }
 
+extern "C++"
 template< class T >
 typename std::remove_reference<T>::type&& move( T&& t );
 #endif // __cplusplus

src/pal/prebuilt/idl/sospriv_i.c → src/pal/prebuilt/idl/sospriv_i.cpp

@@ -20,15 +20,13 @@
 
 #pragma warning( disable: 4049 )  /* more than 64k source lines */
 
+#include <rpc.h>
+#include <rpcndr.h>
 
 #ifdef __cplusplus
 extern "C"{
 #endif 
 
-
-#include <rpc.h>
-#include <rpcndr.h>
-
 #ifdef _MIDL_USE_GUIDDEF_
 
 #ifndef INITGUID

src/pal/src/CMakeLists.txt

@@ -160,37 +160,37 @@ set(SOURCES
   objmgr/palobjbase.cpp
   objmgr/shmobject.cpp
   objmgr/shmobjectmanager.cpp
-  safecrt/makepath_s.c
-  safecrt/memcpy_s.c
-  safecrt/memmove_s.c
-  safecrt/mbusafecrt.c
-  safecrt/safecrt_input_s.c
-  safecrt/safecrt_output_l.c
-  safecrt/safecrt_output_s.c
-  safecrt/safecrt_winput_s.c
-  safecrt/safecrt_woutput_s.c
-  safecrt/splitpath_s.c
-  safecrt/sprintf.c
-  safecrt/sscanf.c
-  safecrt/strcat_s.c
-  safecrt/strcpy_s.c
-  safecrt/strlen_s.c
-  safecrt/strncat_s.c
-  safecrt/strncpy_s.c
-  safecrt/strtok_s.c
-  safecrt/swprintf.c
-  safecrt/vsprintf.c
-  safecrt/vswprint.c
-  safecrt/wcscat_s.c
-  safecrt/wcscpy_s.c
-  safecrt/wcslen_s.c
-  safecrt/wcsncat_s.c
-  safecrt/wcsncpy_s.c
-  safecrt/wcstok_s.c
-  safecrt/wmakepath_s.c
-  safecrt/wsplitpath_s.c
-  safecrt/xtoa_s.c
-  safecrt/xtow_s.c
+  safecrt/makepath_s.cpp
+  safecrt/memcpy_s.cpp
+  safecrt/memmove_s.cpp
+  safecrt/mbusafecrt.cpp
+  safecrt/safecrt_input_s.cpp
+  safecrt/safecrt_output_l.cpp
+  safecrt/safecrt_output_s.cpp
+  safecrt/safecrt_winput_s.cpp
+  safecrt/safecrt_woutput_s.cpp
+  safecrt/splitpath_s.cpp
+  safecrt/sprintf.cpp
+  safecrt/sscanf.cpp
+  safecrt/strcat_s.cpp
+  safecrt/strcpy_s.cpp
+  safecrt/strlen_s.cpp
+  safecrt/strncat_s.cpp
+  safecrt/strncpy_s.cpp
+  safecrt/strtok_s.cpp
+  safecrt/swprintf.cpp
+  safecrt/vsprintf.cpp
+  safecrt/vswprint.cpp
+  safecrt/wcscat_s.cpp
+  safecrt/wcscpy_s.cpp
+  safecrt/wcslen_s.cpp
+  safecrt/wcsncat_s.cpp
+  safecrt/wcsncpy_s.cpp
+  safecrt/wcstok_s.cpp
+  safecrt/wmakepath_s.cpp
+  safecrt/wsplitpath_s.cpp
+  safecrt/xtoa_s.cpp
+  safecrt/xtow_s.cpp
   sharedmemory/sharedmemory.cpp
   shmemory/shmemory.cpp
   sync/cs.cpp

src/pal/src/examples/CMakeLists.txt

@@ -4,7 +4,7 @@ project(palexmpl)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  example1.c
+  example1.cpp
 )
 
 add_executable(palexmpl

src/pal/src/include/pal/palinternal.h

@@ -169,7 +169,6 @@ function_name() to call the system's implementation
 #define memmove DUMMY_memmove 
 #define memchr DUMMY_memchr
 #define strlen DUMMY_strlen
-#define strnlen DUMMY_strnlen
 #define stricmp DUMMY_stricmp 
 #define strstr DUMMY_strstr 
 #define strcmp DUMMY_strcmp 

src/pal/src/safecrt/sscanf.c → src/pal/src/safecrt/sscanf.cpp

@@ -20,7 +20,7 @@
 #include "mbusafecrt_internal.h"
 
 typedef int (*INPUTFN)(miniFILE *, const unsigned char*, va_list);
-typedef int (*WINPUTFN)(miniFILE *, const unsigned short*, va_list);
+typedef int (*WINPUTFN)(miniFILE *, const wchar_t*, va_list);
 
 
 /***

src/pal/src/safecrt/strlen_s.c → src/pal/src/safecrt/strlen_s.cpp

@@ -42,7 +42,7 @@
 *
 *******************************************************************************/
 
-size_t __cdecl strnlen(const char *str, size_t maxsize)
+size_t __cdecl PAL_strnlen(const char *str, size_t maxsize)
 {
     size_t n;
 

src/pal/tests/CMakeLists.txt

@@ -26,7 +26,12 @@ else()
   message(FATAL_ERROR "Only ARM, ARM64 and AMD64 is supported")
 endif()
 
+# C++ emits errors and warnings for c-string literal fed into char* parameter
+# this is just to take care of the warnings
+add_compile_options(-Wno-writable-strings)
+
 add_compile_options(-Wno-empty-body)
 
 add_subdirectory(palsuite)
 
+

src/pal/tests/palsuite/c_runtime/__iscsym/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  __iscsym.c
+  __iscsym.cpp
 )
 
 add_executable(paltest_iscsym_test1

src/pal/tests/palsuite/c_runtime/_alloca/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_alloca_test1

src/pal/tests/palsuite/c_runtime/_ecvt/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_ecvt_test1

src/pal/tests/palsuite/c_runtime/_fdopen/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_fdopen_test1

src/pal/tests/palsuite/c_runtime/_finite/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_finite_test1

src/pal/tests/palsuite/c_runtime/_fullpath/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_fullpath_test1

src/pal/tests/palsuite/c_runtime/_gcvt/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  _gcvt.c
+  _gcvt.cpp
 )
 
 add_executable(paltest_gcvt_test1

src/pal/tests/palsuite/c_runtime/_gcvt/test2/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test2.c
+  test2.cpp
 )
 
 add_executable(paltest_gcvt_test2

src/pal/tests/palsuite/c_runtime/_getw/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_getw_test1

src/pal/tests/palsuite/c_runtime/_isnan/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_isnan_test1

src/pal/tests/palsuite/c_runtime/_itow/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_itow_test1

src/pal/tests/palsuite/c_runtime/_makepath/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_makepath_test1

src/pal/tests/palsuite/c_runtime/_mbsdec/test1/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 set(SOURCES
-  test1.c
+  test1.cpp
 )
 
 add_executable(paltest_mbsdec_test1