ENH: Enforce unique binary directories

The second argument of add_subdirectory must name a unique binary
directory or the build files will clobber each other.  This enforces
uniqueness with an error message.

1 files changed, 9 insertions, 0 deletions

diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index 02e2396..2d8ffb6 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -253,6 +253,12 @@ public:
   void AddRuleHash(const std::vector<std::string>& outputs,
                    std::string const& content);
 
+  /** Return whether the given binary directory is unused.  */
+  bool BinaryDirectoryIsNew(const char* dir)
+    {
+    return this->BinaryDirectories.insert(dir).second;
+    }
+
 protected:
   // for a project collect all its targets by following depend
   // information, and also collect all the targets
@@ -350,6 +356,9 @@ private:
       derived(dc), LoadedFromDisk(dc.LoadedFromDisk) {}
   };
   std::map<cmStdString, DirectoryContent> DirectoryContentMap;
+
+  // Set of binary directories on disk.
+  std::set<cmStdString> BinaryDirectories;
 };
 
 #endif