From f59e87792943904dcb11e16380883e87395d115f Mon Sep 17 00:00:00 2001
From: Stephen Kelly <steveire@gmail.com>
Date: Thu, 6 Oct 2016 18:01:36 +0200
Subject: [PATCH] cmGlobalGenerator: Add API to get settings from top-level
 cmMakefile

At generate-time, definitions are sometimes read from a nearby cmMakefile,
making the value directory-specific because they are read once per
directory.  Often however, the intention is more
often to create a 'global' setting, such that the user writes for
example:

 set(CMAKE_IMPORT_LIBRARY_SUFFIX something)

once at the top level of their project.

Many of these are also set by internal platform files, such as
CMAKE_EXTRA_LINK_EXTENSIONS.

The set() definitions are not really suitable for 'global' settings
because they can be different for each directory, and code consuming the
settings must assume they are different for each directory, and read it
freshly each time with new allocations.

CMake has other variable types which are global in scope, such as global
properties, and cache variables.  These are less convenient to populate
for users, so establish a convention and API using the value as it is at
the end of the top-level CMakeLists file.
---
 Source/cmGlobalGenerator.cxx | 19 +++++++++++++++++++
 Source/cmGlobalGenerator.h   |  4 ++++
 2 files changed, 23 insertions(+)

diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index a446862c9..7132ade19 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -1007,6 +1007,25 @@ void cmGlobalGenerator::FillExtensionToLanguageMap(const std::string& l,
   }
 }
 
+const char* cmGlobalGenerator::GetGlobalSetting(std::string const& name) const
+{
+  assert(!this->Makefiles.empty());
+  return this->Makefiles[0]->GetDefinition(name);
+}
+
+bool cmGlobalGenerator::GlobalSettingIsOn(std::string const& name) const
+{
+  assert(!this->Makefiles.empty());
+  return this->Makefiles[0]->IsOn(name);
+}
+
+const char* cmGlobalGenerator::GetSafeGlobalSetting(
+  std::string const& name) const
+{
+  assert(!this->Makefiles.empty());
+  return this->Makefiles[0]->GetSafeDefinition(name);
+}
+
 bool cmGlobalGenerator::IgnoreFile(const char* ext) const
 {
   if (!this->GetLanguageFromExtension(ext).empty()) {
diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index 4120b52ea..add2b92a0 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -194,6 +194,10 @@ public:
 
   cmExportSetMap& GetExportSets() { return this->ExportSets; }
 
+  const char* GetGlobalSetting(std::string const& name) const;
+  bool GlobalSettingIsOn(std::string const& name) const;
+  const char* GetSafeGlobalSetting(std::string const& name) const;
+
   /** Add a file to the manifest of generated targets for a configuration.  */
   void AddToManifest(std::string const& f);