GHS: Support ARM, PPC, 86 architectures

-- Update -A option to choose target architecture.
-- Update commentary about which variables are used to control toolset and target settings
-- Remove setting CMAKE_SYSTEM_PROCESSOR because the value is overwritten to be "" by subsequent CMAKE processing

Help/generator/Green Hills MULTI.rst

@@ -3,6 +3,12 @@ Green Hills MULTI
 
 Generates Green Hills MULTI project files (experimental, work-in-progress).
 
+Customizations that are used to pick toolset and target system:
+
+The ``-A <arch>`` can be supplied for setting the target architecture.
+``<arch>`` usually is one of "arm", "ppc", "86", etcetera.  If the target architecture
+is not specified then the default architecture of "arm" will be used.
+
 Customizations are available through the following cache variables:
 
 * ``GHS_BSP_NAME``

Help/variable/CMAKE_GENERATOR_PLATFORM.rst

@@ -19,6 +19,8 @@ Platform specification is supported only on specific generators:
 * For :ref:`Visual Studio Generators` with VS 2005 and above this
   specifies the target architecture.
 
+* For :generator:`Green Hills MULTI` this specifies the target architecture.
+
 See native build system documentation for allowed platform names.
 
 Visual Studio Platform Selection

Help/variable/CMAKE_SYSTEM_PROCESSOR.rst

@@ -6,5 +6,3 @@ The name of the CPU CMake is building for.
 This variable is the same as :variable:`CMAKE_HOST_SYSTEM_PROCESSOR` if
 you build for the host system instead of the target system when
 cross compiling.
-
-* The :generator:`Green Hills MULTI` generator sets this to ``ARM`` by default.

Source/cmGlobalGhsMultiGenerator.cxx

@@ -41,11 +41,29 @@ void cmGlobalGhsMultiGenerator::GetDocumentation(cmDocumentationEntry& entry)
     "Generates Green Hills MULTI files (experimental, work-in-progress).";
 }
 
+bool cmGlobalGhsMultiGenerator::SetGeneratorPlatform(std::string const& p,
+                                                     cmMakefile* mf)
+{
+  if (p == "") {
+    cmSystemTools::Message(
+      "Green Hills MULTI: -A <arch> not specified; defaulting to \"arm\"");
+    std::string arch = "arm";
+
+    /* store the platform name for later use
+     * -- already done if -A<arch> was specified
+     */
+    mf->AddCacheDefinition("CMAKE_GENERATOR_PLATFORM", arch.c_str(),
+                           "Name of generator platform.",
+                           cmStateEnums::INTERNAL);
+  }
+
+  return true;
+}
+
 void cmGlobalGhsMultiGenerator::EnableLanguage(
   std::vector<std::string> const& l, cmMakefile* mf, bool optional)
 {
   mf->AddDefinition("CMAKE_SYSTEM_NAME", "GHS-MULTI");
-  mf->AddDefinition("CMAKE_SYSTEM_PROCESSOR", "ARM");
 
   const std::string ghsCompRoot(GetCompRoot());
   mf->AddDefinition("GHS_COMP_ROOT", ghsCompRoot.c_str());

Source/cmGlobalGhsMultiGenerator.h

@@ -40,13 +40,16 @@ public:
    * Utilized by the generator factory to determine if this generator
    * supports toolsets.
    */
-  static bool SupportsToolset() { return false; }
+  static bool SupportsToolset() { return true; }
 
   /**
    * Utilized by the generator factory to determine if this generator
    * supports platforms.
    */
-  static bool SupportsPlatform() { return false; }
+  static bool SupportsPlatform() { return true; }
+
+  // Toolset / Platform Support
+  virtual bool SetGeneratorPlatform(std::string const& p, cmMakefile* mf);
 
   /**
    * Try to determine system information such as shared library