QNX: Introduce QCC compiler id for that QNX platform compiler.

Introduce policy CMP0047 to control resetting the id for
compatibility.

De-duplicate content in the QNX platform file by including the GNU
one. QNX is a form of GNU platform.

Do not clear CMAKE_SHARED_LIBRARY_${lang}_FLAGS variables.  They
are populated again later by the Compiler/GNU.cmake file anyway.

Modify the CMAKE_CXX_COMPILE_OBJECT variable only when the QCC
compiler id is in use, and the language is CXX.  Use the QNX
recommended flag for QCC instead of the gcc compatible -x flag.

Populate new module files to handle system includes and depfiles
when using the QCC compiler.

Remove code which unsets the system include and depfiles related
variables.  When a GNU driver is used instead of the QCC one, the
appropriate flags will be used.  These variables were previously
cleared for lowest-common-denominator compatibility with both
drivers.

Help/manual/cmake-policies.7.rst

@@ -98,3 +98,4 @@ All Policies
    /policy/CMP0044
    /policy/CMP0045
    /policy/CMP0046
+   /policy/CMP0047

Help/policy/CMP0047.rst

@@ -0,0 +1,16 @@
+CMP0047
+-------
+
+Use QCC compiler id for the qcc drivers on QNX.
+
+CMake 2.8.12 and lower assigned the QNX qcc and QCC compiler drivers the "GNU"
+compiler id.
+
+The OLD behavior for this policy is to use the "GNU" compiler id for the qcc
+and QCC compiler drivers. The NEW behavior for this policy is to use the "QCC"
+compiler id for those drivers.
+
+This policy was introduced in CMake version 3.0.0.
+CMake version |release| warns when the policy is not set and uses
+OLD behavior.  Use the cmake_policy command to set it to OLD or
+NEW explicitly.

Modules/CMakeCCompilerId.c.in

@@ -227,6 +227,10 @@ char const* info_compiler = "INFO" ":" "compiler[" COMPILER_ID "]";
 char const* info_simulate = "INFO" ":" "simulate[" SIMULATE_ID "]";
 #endif
 
+#ifdef __QNXNTO__
+char const* qnxnto = "INFO" ":" "qnxnto";
+#endif
+
 @CMAKE_C_COMPILER_ID_PLATFORM_CONTENT@
 @CMAKE_C_COMPILER_ID_ERROR_FOR_TEST@
 

Modules/CMakeCXXCompilerId.cpp.in

@@ -220,6 +220,10 @@ char const* info_compiler = "INFO" ":" "compiler[" COMPILER_ID "]";
 char const* info_simulate = "INFO" ":" "simulate[" SIMULATE_ID "]";
 #endif
 
+#ifdef __QNXNTO__
+char const* qnxnto = "INFO" ":" "qnxnto";
+#endif
+
 @CMAKE_CXX_COMPILER_ID_PLATFORM_CONTENT@
 @CMAKE_CXX_COMPILER_ID_ERROR_FOR_TEST@
 

Modules/CMakeDetermineCompilerId.cmake

@@ -48,6 +48,21 @@ function(CMAKE_DETERMINE_COMPILER_ID lang flagvar src)
     CMAKE_DETERMINE_COMPILER_ID_VENDOR(${lang})
   endif()
 
+  if (COMPILER_QNXNTO AND CMAKE_${lang}_COMPILER_ID STREQUAL GNU)
+    execute_process(
+      COMMAND "${CMAKE_${lang}_COMPILER}"
+      -V
+      OUTPUT_VARIABLE output ERROR_VARIABLE output
+      RESULT_VARIABLE result
+      TIMEOUT 10
+      )
+    if (output MATCHES "targets available")
+      set(CMAKE_${lang}_COMPILER_ID QCC)
+      # http://community.qnx.com/sf/discussion/do/listPosts/projects.community/discussion.qnx_momentics_community_support.topc3555?_pagenum=2
+      # The qcc driver does not itself have a version.
+    endif()
+  endif()
+
   # if the format is unknown after all files have been checked, put "Unknown" in the cache
   if(NOT CMAKE_EXECUTABLE_FORMAT)
     set(CMAKE_EXECUTABLE_FORMAT "Unknown" CACHE INTERNAL "Executable file format")
@@ -369,6 +384,9 @@ function(CMAKE_DETERMINE_COMPILER_ID_CHECK lang file)
         string(REGEX REPLACE "^0+([0-9])" "\\1" SIMULATE_VERSION "${SIMULATE_VERSION}")
         string(REGEX REPLACE "\\.0+([0-9])" ".\\1" SIMULATE_VERSION "${SIMULATE_VERSION}")
       endif()
+      if("${info}" MATCHES ".*INFO:qnxnto")
+        set(COMPILER_QNXNTO 1)
+      endif()
     endforeach()
 
     # Detect the exact architecture from the PE header.
@@ -459,6 +477,7 @@ function(CMAKE_DETERMINE_COMPILER_ID_CHECK lang file)
   set(CMAKE_${lang}_SIMULATE_ID "${CMAKE_${lang}_SIMULATE_ID}" PARENT_SCOPE)
   set(CMAKE_${lang}_SIMULATE_VERSION "${CMAKE_${lang}_SIMULATE_VERSION}" PARENT_SCOPE)
   set(CMAKE_EXECUTABLE_FORMAT "${CMAKE_EXECUTABLE_FORMAT}" PARENT_SCOPE)
+  set(COMPILER_QNXNTO "${COMPILER_QNXNTO}" PARENT_SCOPE)
 endfunction()
 
 #-----------------------------------------------------------------------------

Modules/Platform/QNX-QCC-C.cmake

@@ -0,0 +1,4 @@
+
+include(Platform/QNX)
+
+__compiler_qcc(C)

Modules/Platform/QNX-QCC-CXX.cmake

@@ -0,0 +1,4 @@
+
+include(Platform/QNX)
+
+__compiler_qcc(CXX)

Modules/Platform/QNX.cmake

@@ -1,24 +1,6 @@
 set(QNXNTO 1)
 
-# The QNX GCC does not seem to have -isystem so remove the flag.
-set(CMAKE_INCLUDE_SYSTEM_FLAG_C)
-set(CMAKE_INCLUDE_SYSTEM_FLAG_CXX)
-# ... Nor does the driver support appropriate flags to create depfiles.
-set(CMAKE_DEPFILE_FLAGS_C)
-set(CMAKE_DEPFILE_FLAGS_CXX)
-
 set(CMAKE_DL_LIBS "")
-set(CMAKE_SHARED_LIBRARY_C_FLAGS "")
-set(CMAKE_SHARED_LIBRARY_CXX_FLAGS "")
-set(CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS "-shared")
-set(CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG "-Wl,-rpath,")
-set(CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG_SEP ":")
-set(CMAKE_SHARED_LIBRARY_RPATH_LINK_C_FLAG "-Wl,-rpath-link,")
-set(CMAKE_SHARED_LIBRARY_SONAME_C_FLAG "-Wl,-soname,")
-set(CMAKE_EXE_EXPORTS_C_FLAG "-Wl,--export-dynamic")
-# http://www.qnx.com/developers/docs/6.4.0/neutrino/utilities/q/qcc.html#examples
-set(CMAKE_C_COMPILE_OPTIONS_TARGET "-V")
-set(CMAKE_CXX_COMPILE_OPTIONS_TARGET "-V")
 
 # Shared libraries with no builtin soname may not be linked safely by
 # specifying the file path.
@@ -32,8 +14,22 @@ foreach(type SHARED_LIBRARY SHARED_MODULE EXE)
   set(CMAKE_${type}_LINK_STATIC_C_FLAGS "-Wl,-Bstatic")
   set(CMAKE_${type}_LINK_DYNAMIC_C_FLAGS "-Wl,-Bdynamic")
 endforeach()
-# force the language to be c++ since qnx only has gcc and not g++ and c++?
-set(CMAKE_CXX_COMPILE_OBJECT
-  "<CMAKE_CXX_COMPILER> -x c++ <DEFINES> <FLAGS> -o <OBJECT> -c <SOURCE>")
 
-include(Platform/UnixPaths)
+include(Platform/GNU)
+unset(CMAKE_LIBRARY_ARCHITECTURE_REGEX)
+
+macro(__compiler_qcc lang)
+  # http://www.qnx.com/developers/docs/6.4.0/neutrino/utilities/q/qcc.html#examples
+  set(CMAKE_${lang}_COMPILE_OPTIONS_TARGET "-V")
+
+  set(CMAKE_INCLUDE_SYSTEM_FLAG_${lang} "-Wp,-isystem,")
+  set(CMAKE_DEPFILE_FLAGS_${lang} "-Wc,-MMD,<DEPFILE>,-MT,<OBJECT>,-MF,<DEPFILE>")
+
+  if (lang STREQUAL CXX)
+    # If the toolchain uses qcc for CMAKE_CXX_COMPILER instead of QCC, the
+    # default for the driver is not c++.
+    set(CMAKE_CXX_COMPILE_OBJECT
+    "<CMAKE_CXX_COMPILER> -lang-c++ <DEFINES> <FLAGS> -o <OBJECT> -c <SOURCE>")
+  endif()
+
+endmacro()

Source/cmGlobalGenerator.cxx

@@ -748,7 +748,12 @@ void cmGlobalGenerator::CheckCompilerIdCompatibility(cmMakefile* mf,
 {
   std::string compilerIdVar = "CMAKE_" + lang + "_COMPILER_ID";
   const char* compilerId = mf->GetDefinition(compilerIdVar.c_str());
-  if(compilerId && strcmp(compilerId, "AppleClang") == 0)
+  if(!compilerId)
+    {
+    return;
+    }
+
+  if(strcmp(compilerId, "AppleClang") == 0)
     {
     cmPolicies* policies = this->CMakeInstance->GetPolicies();
     switch(mf->GetPolicyStatus(cmPolicies::CMP0025))
@@ -778,6 +783,37 @@ void cmGlobalGenerator::CheckCompilerIdCompatibility(cmMakefile* mf,
         break;
       }
     }
+
+  if(strcmp(compilerId, "QCC") == 0)
+    {
+    cmPolicies* policies = this->CMakeInstance->GetPolicies();
+    switch(mf->GetPolicyStatus(cmPolicies::CMP0047))
+      {
+      case cmPolicies::WARN:
+        if(!this->CMakeInstance->GetIsInTryCompile())
+          {
+          cmOStringStream w;
+          w << policies->GetPolicyWarning(cmPolicies::CMP0047) << "\n"
+            "Converting " << lang <<
+            " compiler id \"QCC\" to \"GNU\" for compatibility."
+            ;
+          mf->IssueMessage(cmake::AUTHOR_WARNING, w.str());
+          }
+      case cmPolicies::OLD:
+        // OLD behavior is to convert QCC to GNU.
+        mf->AddDefinition(compilerIdVar.c_str(), "GNU");
+        break;
+      case cmPolicies::REQUIRED_IF_USED:
+      case cmPolicies::REQUIRED_ALWAYS:
+        mf->IssueMessage(
+          cmake::FATAL_ERROR,
+          policies->GetRequiredPolicyError(cmPolicies::CMP0047)
+          );
+      case cmPolicies::NEW:
+        // NEW behavior is to keep QCC.
+        break;
+      }
+    }
 }
 
 //----------------------------------------------------------------------------

Source/cmPolicies.cxx

@@ -336,6 +336,11 @@ cmPolicies::cmPolicies()
     CMP0046, "CMP0046",
     "Error on non-existent dependency in add_dependencies.",
     3,0,0,0, cmPolicies::WARN);
+
+  this->DefinePolicy(
+    CMP0047, "CMP0047",
+    "Use QCC compiler id for the qcc drivers on QNX.",
+    3,0,0,0, cmPolicies::WARN);
 }
 
 cmPolicies::~cmPolicies()

Source/cmPolicies.h

@@ -100,6 +100,7 @@ public:
     CMP0044, ///< Case sensitive <LANG>_COMPILER_ID generator expressions
     CMP0045, ///< Error on non-existent target in get_target_property
     CMP0046, ///< Error on non-existent dependency in add_dependencies
+    CMP0047, ///< Use QCC compiler id for the qcc drivers on QNX.
 
     /** \brief Always the last entry.
      *