Implement interprocedural optimization for GNU compilers

Honor the `INTERPROCEDURAL_OPTIMIZATION` target property for GNU
compilers by activating their link-time-optimization (LTO) flags.

1 files changed, 14 insertions, 7 deletions

diff --git a/Source/cmMakefileLibraryTargetGenerator.cxx b/Source/cmMakefileLibraryTargetGenerator.cxx
index 9ce13ec6be..cc8a6b3f06 100644
--- a/Source/cmMakefileLibraryTargetGenerator.cxx
+++ b/Source/cmMakefileLibraryTargetGenerator.cxx
@@ -129,14 +129,9 @@ void cmMakefileLibraryTargetGenerator::WriteStaticLibraryRules()
 {
   std::string linkLanguage =
     this->GeneratorTarget->GetLinkerLanguage(this->ConfigName);
-  std::string linkRuleVar = "CMAKE_";
-  linkRuleVar += linkLanguage;
-  linkRuleVar += "_CREATE_STATIC_LIBRARY";
 
-  if (this->GeneratorTarget->IsIPOEnabled(this->ConfigName) &&
-      this->Makefile->GetDefinition(linkRuleVar + "_IPO")) {
-    linkRuleVar += "_IPO";
-  }
+  std::string linkRuleVar = this->GeneratorTarget->GetCreateRuleVariable(
+    linkLanguage, this->ConfigName);
 
   std::string extraFlags;
   this->LocalGenerator->GetStaticLibraryFlags(
@@ -676,18 +671,30 @@ void cmMakefileLibraryTargetGenerator::WriteLibraryRules(
     std::string arCreateVar = "CMAKE_";
     arCreateVar += linkLanguage;
     arCreateVar += "_ARCHIVE_CREATE";
+
+    arCreateVar = this->GeneratorTarget->GetFeatureSpecificLinkRuleVariable(
+      arCreateVar, this->ConfigName);
+
     if (const char* rule = this->Makefile->GetDefinition(arCreateVar)) {
       cmSystemTools::ExpandListArgument(rule, archiveCreateCommands);
     }
     std::string arAppendVar = "CMAKE_";
     arAppendVar += linkLanguage;
     arAppendVar += "_ARCHIVE_APPEND";
+
+    arAppendVar = this->GeneratorTarget->GetFeatureSpecificLinkRuleVariable(
+      arAppendVar, this->ConfigName);
+
     if (const char* rule = this->Makefile->GetDefinition(arAppendVar)) {
       cmSystemTools::ExpandListArgument(rule, archiveAppendCommands);
     }
     std::string arFinishVar = "CMAKE_";
     arFinishVar += linkLanguage;
     arFinishVar += "_ARCHIVE_FINISH";
+
+    arFinishVar = this->GeneratorTarget->GetFeatureSpecificLinkRuleVariable(
+      arFinishVar, this->ConfigName);
+
     if (const char* rule = this->Makefile->GetDefinition(arFinishVar)) {
       cmSystemTools::ExpandListArgument(rule, archiveFinishCommands);
     }