VS: Teach VS 2019 generator to select host tools matching host arch

This generator is new so we can introduce the long-desired behavior
of selecting ``host=x64`` tools by default on x64 hosts.

3 files changed, 38 insertions, 2 deletions

diff --git a/Source/cmGlobalVisualStudio10Generator.cxx b/Source/cmGlobalVisualStudio10Generator.cxx
index 4dae479..99e9173 100644
--- a/Source/cmGlobalVisualStudio10Generator.cxx
+++ b/Source/cmGlobalVisualStudio10Generator.cxx
@@ -607,10 +607,26 @@ cmGlobalVisualStudio10Generator::GetPlatformToolsetVersionString() const
 const char*
 cmGlobalVisualStudio10Generator::GetPlatformToolsetHostArchitecture() const
 {
+  std::string const& hostArch =
+    this->GetPlatformToolsetHostArchitectureString();
+  if (hostArch.empty()) {
+    return nullptr;
+  }
+  return hostArch.c_str();
+}
+
+std::string const&
+cmGlobalVisualStudio10Generator::GetPlatformToolsetHostArchitectureString()
+  const
+{
   if (!this->GeneratorToolsetHostArchitecture.empty()) {
-    return this->GeneratorToolsetHostArchitecture.c_str();
+    return this->GeneratorToolsetHostArchitecture;
   }
-  return nullptr;
+  if (!this->DefaultPlatformToolsetHostArchitecture.empty()) {
+    return this->DefaultPlatformToolsetHostArchitecture;
+  }
+  static std::string const empty;
+  return empty;
 }
 
 const char* cmGlobalVisualStudio10Generator::GetPlatformToolsetCuda() const
diff --git a/Source/cmGlobalVisualStudio10Generator.h b/Source/cmGlobalVisualStudio10Generator.h
index 7c8918a..f496357 100644
--- a/Source/cmGlobalVisualStudio10Generator.h
+++ b/Source/cmGlobalVisualStudio10Generator.h
@@ -58,6 +58,7 @@ public:
 
   /** The toolset host architecture name (e.g. x64 for 64-bit host tools).  */
   const char* GetPlatformToolsetHostArchitecture() const;
+  std::string const& GetPlatformToolsetHostArchitectureString() const;
 
   /** The cuda toolset version.  */
   const char* GetPlatformToolsetCuda() const;
@@ -152,6 +153,7 @@ protected:
   std::string GeneratorToolsetHostArchitecture;
   std::string GeneratorToolsetCuda;
   std::string DefaultPlatformToolset;
+  std::string DefaultPlatformToolsetHostArchitecture;
   std::string WindowsTargetPlatformVersion;
   std::string SystemName;
   std::string SystemVersion;
diff --git a/Source/cmGlobalVisualStudioVersionedGenerator.cxx b/Source/cmGlobalVisualStudioVersionedGenerator.cxx
index b019f39..bc6b453 100644
--- a/Source/cmGlobalVisualStudioVersionedGenerator.cxx
+++ b/Source/cmGlobalVisualStudioVersionedGenerator.cxx
@@ -11,10 +11,13 @@
 
 #if defined(_M_ARM64)
 #  define HOST_PLATFORM_NAME "ARM64"
+#  define HOST_TOOLS_ARCH ""
 #elif defined(_M_ARM)
 #  define HOST_PLATFORM_NAME "ARM"
+#  define HOST_TOOLS_ARCH ""
 #elif defined(_M_IA64)
 #  define HOST_PLATFORM_NAME "Itanium"
+#  define HOST_TOOLS_ARCH ""
 #else
 #  include "cmsys/SystemInformation.hxx"
 #endif
@@ -33,6 +36,20 @@ static std::string VSHostPlatformName()
 #endif
 }
 
+static std::string VSHostArchitecture()
+{
+#ifdef HOST_TOOLS_ARCH
+  return HOST_TOOLS_ARCH;
+#else
+  cmsys::SystemInformation info;
+  if (info.Is64Bits()) {
+    return "x64";
+  } else {
+    return "x86";
+  }
+#endif
+}
+
 static unsigned int VSVersionToMajor(
   cmGlobalVisualStudioGenerator::VSVersion v)
 {
@@ -262,6 +279,7 @@ cmGlobalVisualStudioVersionedGenerator::cmGlobalVisualStudioVersionedGenerator(
   this->DefaultLinkFlagTableName = VSVersionToToolset(this->Version);
   if (this->Version >= cmGlobalVisualStudioGenerator::VS16) {
     this->DefaultPlatformName = VSHostPlatformName();
+    this->DefaultPlatformToolsetHostArchitecture = VSHostArchitecture();
   }
 }