cmGlobalGenerator: Add method to check if object file location is known

Add a `HasKnownObjectFileLocation` method returning whether we know the
exact location of object files produced by the native build system.
This is true everywhere except on Xcode when an architecture placeholder
is used.

3 files changed, 19 insertions, 0 deletions

diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index 4200b21..aa2dd22 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -331,6 +331,11 @@ public:
       i.e. "Can I build Debug and Release in the same tree?" */
   virtual bool IsMultiConfig() const { return false; }
 
+  /** Return true if we know the exact location of object files.
+      If false, store the reason in the given string.
+      This is meaningful only after EnableLanguage has been called.  */
+  virtual bool HasKnownObjectFileLocation(std::string*) const { return true; }
+
   virtual bool UseFolderProperty() const;
 
   virtual bool IsIPOSupported() const { return false; }
diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index ecc3e31..8c1c0e7 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -3720,6 +3720,18 @@ bool cmGlobalXCodeGenerator::IsMultiConfig() const
   return true;
 }
 
+bool cmGlobalXCodeGenerator::HasKnownObjectFileLocation(
+  std::string* reason) const
+{
+  if (this->ObjectDirArch.find('$') != std::string::npos) {
+    if (reason != CM_NULLPTR) {
+      *reason = " under Xcode with multiple architectures";
+    }
+    return false;
+  }
+  return true;
+}
+
 bool cmGlobalXCodeGenerator::UseEffectivePlatformName(cmMakefile* mf) const
 {
   const char* epnValue =
diff --git a/Source/cmGlobalXCodeGenerator.h b/Source/cmGlobalXCodeGenerator.h
index 982dabd..a733d5c 100644
--- a/Source/cmGlobalXCodeGenerator.h
+++ b/Source/cmGlobalXCodeGenerator.h
@@ -87,6 +87,8 @@ public:
       i.e. "Can I build Debug and Release in the same tree?" */
   bool IsMultiConfig() const CM_OVERRIDE;
 
+  bool HasKnownObjectFileLocation(std::string* reason) const CM_OVERRIDE;
+
   bool UseEffectivePlatformName(cmMakefile* mf) const CM_OVERRIDE;
 
   bool ShouldStripResourcePath(cmMakefile*) const CM_OVERRIDE;