Merge topic 'INTERFACE_POSITION_INDEPENDENT_CODE'

3581b96 Process the INTERFACE_PIC property from linked dependencies
042ecf0 Add API to calculate link-interface-dependent bool properties or error.
bf5ece5 Keep track of properties used to determine linker libraries.

Source/cmGeneratorExpression.cxx

@@ -94,7 +94,15 @@ const char *cmCompiledGeneratorExpression::Evaluate(
 
   for ( ; it != end; ++it)
     {
-    this->Output += (*it)->Evaluate(&context, dagChecker);
+    const std::string result = (*it)->Evaluate(&context, dagChecker);
+    this->Output += result;
+
+    for(std::set<cmStdString>::const_iterator
+          p = context.SeenTargetProperties.begin();
+          p != context.SeenTargetProperties.end(); ++p)
+      {
+      this->SeenTargetProperties[*p] += result + ";";
+      }
     if (context.HadError)
       {
       this->Output = "";

Source/cmGeneratorExpression.h

@@ -83,6 +83,9 @@ public:
   std::set<cmTarget*> const& GetTargets() const
     { return this->Targets; }
 
+  std::map<cmStdString, cmStdString> const& GetSeenTargetProperties() const
+    { return this->SeenTargetProperties; }
+
   ~cmCompiledGeneratorExpression();
 
   std::string GetInput() const
@@ -110,6 +113,7 @@ private:
   bool NeedsParsing;
 
   mutable std::set<cmTarget*> Targets;
+  mutable std::map<cmStdString, cmStdString> SeenTargetProperties;
   mutable std::string Output;
 };
 

Source/cmGeneratorExpressionEvaluator.cxx

@@ -380,6 +380,14 @@ static const struct TargetPropertyNode : public cmGeneratorExpressionNode
         }
       }
 
+    if (target == context->HeadTarget)
+      {
+      // Keep track of the properties seen while processing.
+      // The evaluation of the LINK_LIBRARIES generator expressions
+      // will check this to ensure that properties form a DAG.
+      context->SeenTargetProperties.insert(propertyName);
+      }
+
     if (propertyName.empty())
       {
       reportError(context, content->GetOriginalExpression(),

Source/cmGeneratorExpressionEvaluator.h

@@ -24,6 +24,7 @@ struct cmGeneratorExpressionContext
 {
   cmListFileBacktrace Backtrace;
   std::set<cmTarget*> Targets;
+  std::set<cmStdString> SeenTargetProperties;
   cmMakefile *Makefile;
   const char *Config;
   cmTarget *HeadTarget; // The target whose property is being evaluated.

Source/cmGlobalXCodeGenerator.cxx

@@ -1639,14 +1639,16 @@ void cmGlobalXCodeGenerator::CreateBuildSettings(cmTarget& target,
     if(strcmp(lang, "CXX") == 0)
       {
       this->CurrentLocalGenerator->AddLanguageFlags(cflags, "C", configName);
-      this->CurrentLocalGenerator->AddCMP0018Flags(cflags, &target, "C");
+      this->CurrentLocalGenerator->AddCMP0018Flags(cflags, &target,
+                                                   "C", configName);
       }
 
     // Add language-specific flags.
     this->CurrentLocalGenerator->AddLanguageFlags(flags, lang, configName);
 
     // Add shared-library flags if needed.
-    this->CurrentLocalGenerator->AddCMP0018Flags(flags, &target, lang);
+    this->CurrentLocalGenerator->AddCMP0018Flags(flags, &target,
+                                                 lang, configName);
     }
   else if(binary)
   {

Source/cmLocalGenerator.cxx

@@ -1984,7 +1984,8 @@ void cmLocalGenerator::AddSharedFlags(std::string& flags,
 
 //----------------------------------------------------------------------------
 void cmLocalGenerator::AddCMP0018Flags(std::string &flags, cmTarget* target,
-                                       std::string const& lang)
+                                       std::string const& lang,
+                                       const char *config)
 {
   int targetType = target->GetType();
 
@@ -1997,11 +1998,21 @@ void cmLocalGenerator::AddCMP0018Flags(std::string &flags, cmTarget* target,
     }
   else
     {
-    // Add position independendent flags, if needed.
+    if (target->GetType() == cmTarget::OBJECT_LIBRARY)
+    {
       if (target->GetPropertyAsBool("POSITION_INDEPENDENT_CODE"))
         {
         this->AddPositionIndependentFlags(flags, lang, targetType);
         }
+      return;
+    }
+
+    if (target->GetLinkInterfaceDependentBoolProperty(
+                                                "POSITION_INDEPENDENT_CODE",
+                                                config))
+      {
+      this->AddPositionIndependentFlags(flags, lang, targetType);
+      }
     if (shared)
       {
       this->AppendFeatureOptions(flags, lang.c_str(), "DLL");

Source/cmLocalGenerator.h

@@ -142,7 +142,7 @@ public:
   void AddLanguageFlags(std::string& flags, const char* lang,
                         const char* config);
   void AddCMP0018Flags(std::string &flags, cmTarget* target,
-                       std::string const& lang);
+                       std::string const& lang, const char *config);
   void AddConfigVariableFlags(std::string& flags, const char* var,
                               const char* config);
   ///! Append flags to a string.

Source/cmMakefileTargetGenerator.cxx

@@ -268,7 +268,8 @@ std::string cmMakefileTargetGenerator::GetFlags(const std::string &l)
       this->AddFortranFlags(flags);
       }
 
-    this->LocalGenerator->AddCMP0018Flags(flags, this->Target, lang);
+    this->LocalGenerator->AddCMP0018Flags(flags, this->Target,
+                                          lang, this->ConfigName);
 
     // Add include directory flags.
     this->AddIncludeFlags(flags, lang);

Source/cmNinjaTargetGenerator.cxx

@@ -147,7 +147,8 @@ cmNinjaTargetGenerator::ComputeFlagsForObject(cmSourceFile *source,
 
   // Add shared-library flags if needed.
   this->LocalGenerator->AddCMP0018Flags(flags, this->Target,
-                                        language.c_str());
+                                        language.c_str(),
+                                        this->GetConfigName());
 
   // Add include directory flags.
   {

Source/cmTarget.cxx

@@ -877,6 +877,20 @@ void cmTarget::DefineProperties(cmake *cm)
      "CMAKE_POSITION_INDEPENDENT_CODE if it is set when a target is "
      "created.");
 
+  cm->DefineProperty
+    ("INTERFACE_POSITION_INDEPENDENT_CODE", cmProperty::TARGET,
+     "Whether consumers need to create a position-independent target",
+     "The INTERFACE_POSITION_INDEPENDENT_CODE property informs consumers of "
+     "this target whether they must set their POSITION_INDEPENDENT_CODE "
+     "property to ON.  If this property is set to ON, then the "
+     "POSITION_INDEPENDENT_CODE property on all consumers will be set to "
+     "ON.  Similarly, if this property is set to OFF, then the "
+     "POSITION_INDEPENDENT_CODE property on all consumers will be set to "
+     "OFF.  If this property is undefined, then consumers will determine "
+     "their POSITION_INDEPENDENT_CODE property by other means.  Consumers "
+     "must ensure that the targets that they link to have a consistent "
+     "requirement for their INTERFACE_POSITION_INDEPENDENT_CODE property.");
+
   cm->DefineProperty
     ("POST_INSTALL_SCRIPT", cmProperty::TARGET,
      "Deprecated install support.",
@@ -2164,16 +2178,19 @@ void cmTarget::GetDirectLinkLibraries(const char *config,
     {
     cmListFileBacktrace lfbt;
     cmGeneratorExpression ge(lfbt);
+    const cmsys::auto_ptr<cmCompiledGeneratorExpression> cge = ge.Parse(prop);
 
     cmGeneratorExpressionDAGChecker dagChecker(lfbt,
                                         this->GetName(),
                                         "LINK_LIBRARIES", 0, 0);
-    cmSystemTools::ExpandListArgument(ge.Parse(prop)->Evaluate(this->Makefile,
+    cmSystemTools::ExpandListArgument(cge->Evaluate(this->Makefile,
                                         config,
                                         false,
                                         head,
                                         &dagChecker),
                                       libs);
+
+    this->AddLinkDependentTargetsForProperties(cge->GetSeenTargetProperties());
     }
 }
 
@@ -4376,6 +4393,171 @@ const char* cmTarget::GetExportMacro()
     }
 }
 
+//----------------------------------------------------------------------------
+void cmTarget::GetLinkDependentTargetsForProperty(const std::string &p,
+                                          std::set<std::string> &targets)
+{
+  const std::map<cmStdString, std::set<std::string> >::const_iterator findIt
+                                  = this->LinkDependentProperties.find(p);
+  if (findIt != this->LinkDependentProperties.end())
+    {
+    targets = findIt->second;
+    }
+}
+
+//----------------------------------------------------------------------------
+bool cmTarget::IsNullImpliedByLinkLibraries(const std::string &p)
+{
+  return this->LinkImplicitNullProperties.find(p)
+      != this->LinkImplicitNullProperties.end();
+}
+
+//----------------------------------------------------------------------------
+void cmTarget::AddLinkDependentTargetsForProperties(
+                              const std::map<cmStdString, cmStdString> &map)
+{
+  for (std::map<cmStdString, cmStdString>::const_iterator it = map.begin();
+       it != map.end(); ++it)
+    {
+    std::vector<std::string> targets;
+    cmSystemTools::ExpandListArgument(it->second.c_str(), targets);
+    this->LinkDependentProperties[it->first].insert(targets.begin(),
+                                                    targets.end());
+    if (!this->GetProperty(it->first.c_str()))
+      {
+      this->LinkImplicitNullProperties.insert(it->first);
+      }
+    }
+}
+
+//----------------------------------------------------------------------------
+bool cmTarget::GetLinkInterfaceDependentBoolProperty(const std::string &p,
+                                                     const char *config)
+{
+  bool propContent = this->GetPropertyAsBool(p.c_str());
+  const bool explicitlySet = this->GetProperties()
+                                  .find(p.c_str())
+                                  != this->GetProperties().end();
+  std::set<std::string> dependentTargets;
+  this->GetLinkDependentTargetsForProperty(p,
+                                          dependentTargets);
+  const bool impliedByUse =
+          this->IsNullImpliedByLinkLibraries(p);
+  assert((impliedByUse ^ explicitlySet)
+      || (!impliedByUse && !explicitlySet));
+
+  cmComputeLinkInformation *info = this->GetLinkInformation(config);
+  const cmComputeLinkInformation::ItemVector &deps = info->GetItems();
+  bool propInitialized = explicitlySet;
+
+  for(cmComputeLinkInformation::ItemVector::const_iterator li =
+      deps.begin();
+      li != deps.end(); ++li)
+    {
+    // An error should be reported if one dependency
+    // has INTERFACE_POSITION_INDEPENDENT_CODE ON and the other
+    // has INTERFACE_POSITION_INDEPENDENT_CODE OFF, or if the
+    // target itself has a POSITION_INDEPENDENT_CODE which disagrees
+    // with a dependency.
+
+    if (!li->Target)
+      {
+      continue;
+      }
+
+    const bool ifaceIsSet = li->Target->GetProperties()
+                            .find("INTERFACE_" + p)
+                            != li->Target->GetProperties().end();
+    const bool ifacePropContent = li->Target->GetPropertyAsBool(
+                              ("INTERFACE_" + p).c_str());
+    if (explicitlySet)
+      {
+      if (ifaceIsSet)
+        {
+        if (propContent != ifacePropContent)
+          {
+          cmOStringStream e;
+          e << "Property " << p << " on target \""
+            << this->GetName() << "\" does\nnot match the "
+            "INTERFACE_" << p << " property requirement\nof "
+            "dependency \"" << li->Target->GetName() << "\".\n";
+          cmSystemTools::Error(e.str().c_str());
+          }
+        else
+          {
+          // Agree
+          continue;
+          }
+        }
+      else
+        {
+        // Explicitly set on target and not set in iface. Can't disagree.
+        continue;
+        }
+      }
+    else if (impliedByUse)
+      {
+      if (ifaceIsSet)
+        {
+        if (propContent != ifacePropContent)
+          {
+          cmOStringStream e;
+          e << "Property " << p << " on target \""
+            << this->GetName() << "\" is\nimplied to be FALSE because it "
+            "was used to determine the link libraries\nalready. The "
+            "INTERFACE_" << p << " property on\ndependency \""
+            << li->Target->GetName() << "\" is in conflict.\n";
+          cmSystemTools::Error(e.str().c_str());
+          }
+        else
+          {
+          // Agree
+          continue;
+          }
+        }
+      else
+        {
+        // Implicitly set on target and not set in iface. Can't disagree.
+        continue;
+        }
+      }
+    else
+      {
+      if (ifaceIsSet)
+        {
+        if (propInitialized)
+          {
+          if (propContent != ifacePropContent)
+            {
+            cmOStringStream e;
+            e << "The INTERFACE_" << p << " property of \""
+              << li->Target->GetName() << "\" does\nnot agree with the value "
+                "of " << p << " already determined\nfor \""
+              << this->GetName() << "\".\n";
+            cmSystemTools::Error(e.str().c_str());
+            }
+          else
+            {
+            // Agree.
+            continue;
+            }
+          }
+        else
+          {
+          propContent = ifacePropContent;
+          propInitialized = true;
+          }
+        }
+      else
+        {
+        // Not set. Nothing to agree on.
+        continue;
+        }
+      }
+    }
+  return propContent;
+}
+
 //----------------------------------------------------------------------------
 void cmTarget::GetLanguages(std::set<cmStdString>& languages) const
 {

Source/cmTarget.h

@@ -487,6 +487,16 @@ public:
   std::vector<std::string> GetIncludeDirectories(const char *config);
   void InsertInclude(const cmMakefileIncludeDirectoriesEntry &entry,
                      bool before = false);
+
+  void GetLinkDependentTargetsForProperty(const std::string &p,
+                                       std::set<std::string> &targets);
+  bool IsNullImpliedByLinkLibraries(const std::string &p);
+
+  void AddLinkDependentTargetsForProperties(
+          const std::map<cmStdString, cmStdString> &map);
+
+  bool GetLinkInterfaceDependentBoolProperty(const std::string &p,
+                                             const char *config);
 private:
   /**
    * A list of direct dependencies. Use in conjunction with DependencyMap.
@@ -596,6 +606,9 @@ private:
   bool DLLPlatform;
   bool IsApple;
   bool IsImportedTarget;
+  mutable std::map<cmStdString, std::set<std::string> >
+                                                      LinkDependentProperties;
+  mutable std::set<std::string> LinkImplicitNullProperties;
 
   // Cache target output paths for each configuration.
   struct OutputInfo;

Tests/RunCMake/CMakeLists.txt

@@ -50,6 +50,9 @@ add_RunCMake_test(GeneratorExpression)
 add_RunCMake_test(TargetPropertyGeneratorExpressions)
 add_RunCMake_test(Languages)
 add_RunCMake_test(ObjectLibrary)
+if(NOT WIN32)
+  add_RunCMake_test(PositionIndependentCode)
+endif()
 
 add_RunCMake_test(build_command)
 add_RunCMake_test(find_package)

Tests/RunCMake/PositionIndependentCode/CMakeLists.txt

@@ -0,0 +1,8 @@
+
+cmake_minimum_required(VERSION 2.8)
+project(${RunCMake_TEST} CXX)
+
+# MSVC creates extra targets which pollute the stderr unless we set this.
+set(CMAKE_SUPPRESS_REGENERATION TRUE)
+
+include(${RunCMake_TEST}.cmake)

Tests/RunCMake/PositionIndependentCode/Conflict1-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/PositionIndependentCode/Conflict1-stderr.txt

@@ -0,0 +1,3 @@
+CMake Error: Property POSITION_INDEPENDENT_CODE on target "conflict" does
+not match the INTERFACE_POSITION_INDEPENDENT_CODE property requirement
+of dependency "piciface".

Tests/RunCMake/PositionIndependentCode/Conflict1.cmake

@@ -0,0 +1,7 @@
+
+add_library(piciface UNKNOWN IMPORTED)
+set_property(TARGET piciface PROPERTY INTERFACE_POSITION_INDEPENDENT_CODE ON)
+
+add_executable(conflict "main.cpp")
+set_property(TARGET conflict PROPERTY POSITION_INDEPENDENT_CODE OFF)
+target_link_libraries(conflict piciface)

Tests/RunCMake/PositionIndependentCode/Conflict2-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/PositionIndependentCode/Conflict2-stderr.txt

@@ -0,0 +1,3 @@
+CMake Error: The INTERFACE_POSITION_INDEPENDENT_CODE property of "picoff" does
+not agree with the value of POSITION_INDEPENDENT_CODE already determined
+for "conflict".

Tests/RunCMake/PositionIndependentCode/Conflict2.cmake

@@ -0,0 +1,9 @@
+
+add_library(picon UNKNOWN IMPORTED)
+set_property(TARGET picon PROPERTY INTERFACE_POSITION_INDEPENDENT_CODE ON)
+
+add_library(picoff UNKNOWN IMPORTED)
+set_property(TARGET picoff PROPERTY INTERFACE_POSITION_INDEPENDENT_CODE OFF)
+
+add_executable(conflict "main.cpp")
+target_link_libraries(conflict picon picoff)

Tests/RunCMake/PositionIndependentCode/Conflict3-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/PositionIndependentCode/Conflict3-stderr.txt

@@ -0,0 +1,4 @@
+Property POSITION_INDEPENDENT_CODE on target "conflict" is
+implied to be FALSE because it was used to determine the link libraries
+already. The INTERFACE_POSITION_INDEPENDENT_CODE property on
+dependency "picon" is in conflict.

Tests/RunCMake/PositionIndependentCode/Conflict3.cmake

@@ -0,0 +1,12 @@
+
+add_library(picoff UNKNOWN IMPORTED)
+
+add_library(picon UNKNOWN IMPORTED)
+set_property(TARGET picon PROPERTY INTERFACE_POSITION_INDEPENDENT_CODE ON)
+
+add_executable(conflict "main.cpp")
+target_link_libraries(conflict picon)
+set_property(TARGET conflict APPEND PROPERTY
+  LINK_LIBRARIES
+    $<$<NOT:$<BOOL:$<TARGET_PROPERTY:POSITION_INDEPENDENT_CODE>>>:picoff>
+)

Tests/RunCMake/PositionIndependentCode/RunCMakeTest.cmake

@@ -0,0 +1,5 @@
+include(RunCMake)
+
+run_cmake(Conflict1)
+run_cmake(Conflict2)
+run_cmake(Conflict3)

Tests/RunCMake/PositionIndependentCode/main.cpp

@@ -0,0 +1,5 @@
+
+int main(int,char**)
+{
+  return 0;
+}