VS: Provide an option to use x64 host tools

Visual Studio provides toolchains that are themselves built for 32-bit
or 64-bit host architectures.  By default it uses the 32-bit tools, but
it can be told to prefer the 64-bit tools on 64-bit hosts.  Extend the
`CMAKE_GENERATOR_TOOLSET` specification to provide a way to request
use of the 64-bit host tools.

Closes: #15622

1 files changed, 36 insertions, 1 deletions

diff --git a/Source/cmGlobalVisualStudio10Generator.cxx b/Source/cmGlobalVisualStudio10Generator.cxx
index caaac87..02ffa41 100644
--- a/Source/cmGlobalVisualStudio10Generator.cxx
+++ b/Source/cmGlobalVisualStudio10Generator.cxx
@@ -145,10 +145,36 @@ bool cmGlobalVisualStudio10Generator::SetGeneratorToolset(
     return false;
   }
 
-  this->GeneratorToolset = ts;
+  if (!this->ParseGeneratorToolset(ts, mf)) {
+    return false;
+  }
   if (const char* toolset = this->GetPlatformToolset()) {
     mf->AddDefinition("CMAKE_VS_PLATFORM_TOOLSET", toolset);
   }
+  if (const char* hostArch = this->GetPlatformToolsetHostArchitecture()) {
+    mf->AddDefinition("CMAKE_VS_PLATFORM_TOOLSET_HOST_ARCHITECTURE", hostArch);
+  }
+  return true;
+}
+
+bool cmGlobalVisualStudio10Generator::ParseGeneratorToolset(
+  std::string const& ts, cmMakefile* mf)
+{
+  if (ts.find_first_of(",=") != ts.npos) {
+    std::ostringstream e;
+    /* clang-format off */
+    e <<
+      "Generator\n"
+      "  " << this->GetName() << "\n"
+      "does not recognize the toolset\n"
+      "  " << ts << "\n"
+      "that was specified.";
+    /* clang-format on */
+    mf->IssueMessage(cmake::FATAL_ERROR, e.str());
+    return false;
+  }
+
+  this->GeneratorToolset = ts;
   return true;
 }
 
@@ -322,6 +348,15 @@ const char* cmGlobalVisualStudio10Generator::GetPlatformToolset() const
   return 0;
 }
 
+const char*
+cmGlobalVisualStudio10Generator::GetPlatformToolsetHostArchitecture() const
+{
+  if (!this->GeneratorToolsetHostArchitecture.empty()) {
+    return this->GeneratorToolsetHostArchitecture.c_str();
+  }
+  return CM_NULLPTR;
+}
+
 void cmGlobalVisualStudio10Generator::FindMakeProgram(cmMakefile* mf)
 {
   this->cmGlobalVisualStudio8Generator::FindMakeProgram(mf);