Merge topic 'ipo-policy-CMP0069'

dfa8263f Implement interprocedural optimization for GNU compilers
1588a577 Add policy CMP0069 to enforce INTERPROCEDURAL_OPTIMIZATION
a7575700 Refactoring: s,GetFeatureAsBool,IsIPOEnabled,
e05835c3 CheckIPOSupported: Visual Studio and Xcode generators do not support IPO

Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: Brad King <brad.king@kitware.com>
Reviewed-by: Nils Gladitz <nilsgladitz@gmail.com>
Merge-request: !568

1 files changed, 75 insertions, 10 deletions

diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index f78a933..73d2009 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -286,6 +286,7 @@ cmGeneratorTarget::cmGeneratorTarget(cmTarget* t, cmLocalGenerator* lg)
   , FortranModuleDirectoryCreated(false)
   , SourceFileFlagsConstructed(false)
   , PolicyWarnedCMP0022(false)
+  , PolicyReportedCMP0069(false)
   , DebugIncludesDone(false)
   , DebugCompileOptionsDone(false)
   , DebugCompileFeaturesDone(false)
@@ -656,10 +657,65 @@ const char* cmGeneratorTarget::GetFeature(const std::string& feature,
   return this->LocalGenerator->GetFeature(feature, config);
 }
 
-bool cmGeneratorTarget::GetFeatureAsBool(const std::string& feature,
-                                         const std::string& config) const
+bool cmGeneratorTarget::IsIPOEnabled(const std::string& config) const
 {
-  return cmSystemTools::IsOn(this->GetFeature(feature, config));
+  const char* feature = "INTERPROCEDURAL_OPTIMIZATION";
+  const bool result = cmSystemTools::IsOn(this->GetFeature(feature, config));
+
+  if (!result) {
+    // 'INTERPROCEDURAL_OPTIMIZATION' is off, no need to check policies
+    return false;
+  }
+
+  cmPolicies::PolicyStatus cmp0069 = this->GetPolicyStatusCMP0069();
+
+  if (cmp0069 == cmPolicies::OLD || cmp0069 == cmPolicies::WARN) {
+    if (this->Makefile->IsOn("_CMAKE_IPO_LEGACY_BEHAVIOR")) {
+      return true;
+    }
+    if (this->PolicyReportedCMP0069) {
+      // problem is already reported, no need to issue a message
+      return false;
+    }
+    if (cmp0069 == cmPolicies::WARN) {
+      std::ostringstream w;
+      w << cmPolicies::GetPolicyWarning(cmPolicies::CMP0069) << "\n";
+      w << "INTERPROCEDURAL_OPTIMIZATION property will be ignored for target "
+        << "'" << this->GetName() << "'.";
+      this->LocalGenerator->GetCMakeInstance()->IssueMessage(
+        cmake::AUTHOR_WARNING, w.str(), this->GetBacktrace());
+
+      this->PolicyReportedCMP0069 = true;
+    }
+    return false;
+  }
+
+  // Note: check consistency with messages from CheckIPOSupported
+  const char* message = CM_NULLPTR;
+  if (!this->Makefile->IsOn("_CMAKE_IPO_SUPPORTED_BY_CMAKE")) {
+    message = "CMake doesn't support IPO for current compiler";
+  } else if (!this->Makefile->IsOn(
+               "_CMAKE_IPO_MAY_BE_SUPPORTED_BY_COMPILER")) {
+    message = "Compiler doesn't support IPO";
+  } else if (!this->GlobalGenerator->IsIPOSupported()) {
+    message = "CMake doesn't support IPO for current generator";
+  }
+
+  if (!message) {
+    // No error/warning messages
+    return true;
+  }
+
+  if (this->PolicyReportedCMP0069) {
+    // problem is already reported, no need to issue a message
+    return false;
+  }
+
+  this->PolicyReportedCMP0069 = true;
+
+  this->LocalGenerator->GetCMakeInstance()->IssueMessage(
+    cmake::FATAL_ERROR, message, this->GetBacktrace());
+  return false;
 }
 
 const std::string& cmGeneratorTarget::GetObjectName(cmSourceFile const* file)
@@ -2410,19 +2466,28 @@ void cmGeneratorTarget::GetAppleArchs(const std::string& config,
   }
 }
 
+//----------------------------------------------------------------------------
+std::string cmGeneratorTarget::GetFeatureSpecificLinkRuleVariable(
+  std::string const& var, std::string const& config) const
+{
+  if (this->IsIPOEnabled(config)) {
+    std::string varIPO = var + "_IPO";
+    if (this->Makefile->IsDefinitionSet(varIPO)) {
+      return varIPO;
+    }
+  }
+
+  return var;
+}
+
+//----------------------------------------------------------------------------
 std::string cmGeneratorTarget::GetCreateRuleVariable(
   std::string const& lang, std::string const& config) const
 {
   switch (this->GetType()) {
     case cmStateEnums::STATIC_LIBRARY: {
       std::string var = "CMAKE_" + lang + "_CREATE_STATIC_LIBRARY";
-      if (this->GetFeatureAsBool("INTERPROCEDURAL_OPTIMIZATION", config)) {
-        std::string varIPO = var + "_IPO";
-        if (this->Makefile->GetDefinition(varIPO)) {
-          return varIPO;
-        }
-      }
-      return var;
+      return this->GetFeatureSpecificLinkRuleVariable(var, config);
     }
     case cmStateEnums::SHARED_LIBRARY:
       return "CMAKE_" + lang + "_CREATE_SHARED_LIBRARY";