1 files changed, 155 insertions, 2 deletions

diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 3048c5f..cc37232 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -21,6 +21,7 @@
 #include "cmCustomCommand.h"
 #include "cmCustomCommandGenerator.h"
 #include "cmCustomCommandLines.h"
+#include "cmGeneratedFileStream.h"
 #include "cmGeneratorExpression.h"
 #include "cmGeneratorExpressionContext.h"
 #include "cmGeneratorExpressionDAGChecker.h"
@@ -278,6 +279,7 @@ cmGeneratorTarget::cmGeneratorTarget(cmTarget* t, cmLocalGenerator* lg)
   , DebugCompileDefinitionsDone(false)
   , DebugLinkOptionsDone(false)
   , DebugLinkDirectoriesDone(false)
+  , DebugPrecompileHeadersDone(false)
   , DebugSourcesDone(false)
   , LinkImplementationLanguageIsContextDependent(true)
   , UtilityItemsDone(false)
@@ -312,6 +314,10 @@ cmGeneratorTarget::cmGeneratorTarget(cmTarget* t, cmLocalGenerator* lg)
                                      t->GetLinkDirectoriesBacktraces(),
                                      this->LinkDirectoriesEntries);
 
+  CreatePropertyGeneratorExpressions(t->GetPrecompileHeadersEntries(),
+                                     t->GetPrecompileHeadersBacktraces(),
+                                     this->PrecompileHeadersEntries);
+
   CreatePropertyGeneratorExpressions(t->GetSourceEntries(),
                                      t->GetSourceBacktraces(),
                                      this->SourceEntries, true);
@@ -327,6 +333,7 @@ cmGeneratorTarget::~cmGeneratorTarget()
   cmDeleteAll(this->CompileDefinitionsEntries);
   cmDeleteAll(this->LinkOptionsEntries);
   cmDeleteAll(this->LinkDirectoriesEntries);
+  cmDeleteAll(this->PrecompileHeadersEntries);
   cmDeleteAll(this->SourceEntries);
   cmDeleteAll(this->LinkInformation);
 }
@@ -1593,7 +1600,7 @@ void cmGeneratorTarget::ComputeKindedSources(KindedSources& files,
       kind = SourceKindHeader;
     } else if (sf->GetPropertyAsBool("EXTERNAL_OBJECT")) {
       kind = SourceKindExternalObject;
-    } else if (!sf->GetLanguage().empty()) {
+    } else if (!sf->GetOrDetermineLanguage().empty()) {
       kind = SourceKindObjectSource;
     } else if (ext == "def") {
       kind = SourceKindModuleDefinition;
@@ -3312,6 +3319,152 @@ std::vector<BT<std::string>> cmGeneratorTarget::GetCompileDefinitions(
   return list;
 }
 
+std::vector<BT<std::string>> cmGeneratorTarget::GetPrecompileHeaders(
+  const std::string& config, const std::string& language) const
+{
+  std::unordered_set<std::string> uniqueOptions;
+
+  cmGeneratorExpressionDAGChecker dagChecker(this, "PRECOMPILE_HEADERS",
+                                             nullptr, nullptr);
+
+  std::vector<std::string> debugProperties;
+  const char* debugProp =
+    this->Makefile->GetDefinition("CMAKE_DEBUG_TARGET_PROPERTIES");
+  if (debugProp) {
+    cmExpandList(debugProp, debugProperties);
+  }
+
+  bool debugDefines = !this->DebugPrecompileHeadersDone &&
+    std::find(debugProperties.begin(), debugProperties.end(),
+              "PRECOMPILE_HEADERS") != debugProperties.end();
+
+  if (this->GlobalGenerator->GetConfigureDoneCMP0026()) {
+    this->DebugPrecompileHeadersDone = true;
+  }
+
+  std::vector<EvaluatedTargetPropertyEntry> entries =
+    EvaluateTargetPropertyEntries(this, config, language, &dagChecker,
+                                  this->PrecompileHeadersEntries);
+
+  AddInterfaceEntries(this, config, "INTERFACE_PRECOMPILE_HEADERS", language,
+                      &dagChecker, entries);
+
+  std::vector<BT<std::string>> list;
+  processOptions(this, entries, list, uniqueOptions, debugDefines,
+                 "precompile headers", OptionsParse::None);
+
+  return list;
+}
+
+std::string cmGeneratorTarget::GetPchHeader(const std::string& config,
+                                            const std::string& language) const
+{
+  if (language != "C" && language != "CXX") {
+    return std::string();
+  }
+  if (this->GetPropertyAsBool("DISABLE_PRECOMPILE_HEADERS")) {
+    return std::string();
+  }
+  const auto inserted =
+    this->PchHeaders.insert(std::make_pair(language + config, ""));
+  if (inserted.second) {
+    const std::vector<BT<std::string>> headers =
+      this->GetPrecompileHeaders(config, language);
+    if (headers.empty()) {
+      return std::string();
+    }
+    std::string& filename = inserted.first->second;
+
+    if (this->GetGlobalGenerator()->IsMultiConfig()) {
+      filename =
+        cmStrCat(this->LocalGenerator->GetCurrentBinaryDirectory(), "/");
+    } else {
+      // For GCC we need to have the header file .h[xx]
+      // next to the .h[xx].gch file
+      filename = this->ObjectDirectory;
+    }
+
+    filename = cmStrCat(filename, "CMakeFiles/", this->GetName(),
+                        ".dir/cmake_pch", ((language == "C") ? ".h" : ".hxx"));
+
+    const std::string filename_tmp = cmStrCat(filename, ".tmp");
+    {
+      auto pchPrologue = this->Makefile->GetDefinition("CMAKE_PCH_PROLOGUE");
+      auto pchEpilogue = this->Makefile->GetDefinition("CMAKE_PCH_EPILOGUE");
+
+      cmGeneratedFileStream file(
+        filename_tmp, false,
+        this->GetGlobalGenerator()->GetMakefileEncoding());
+      file << "/* generated by CMake */\n\n";
+      if (pchPrologue) {
+        file << pchPrologue << "\n";
+      }
+      if (this->GetGlobalGenerator()->IsXcode()) {
+        file << "#ifndef CMAKE_SKIP_PRECOMPILE_HEADERS\n";
+      }
+      if (language == "CXX") {
+        file << "#ifdef __cplusplus\n";
+      }
+      for (auto const& header_bt : headers) {
+        if (header_bt.Value.empty()) {
+          continue;
+        }
+        if (header_bt.Value[0] == '<' || header_bt.Value[0] == '"') {
+          file << "#include " << header_bt.Value << "\n";
+        } else {
+          file << "#include \"" << header_bt.Value << "\"\n";
+        }
+      }
+      if (language == "CXX") {
+        file << "#endif // __cplusplus\n";
+      }
+      if (this->GetGlobalGenerator()->IsXcode()) {
+        file << "#endif // CMAKE_SKIP_PRECOMPILE_HEADERS\n";
+      }
+      if (pchEpilogue) {
+        file << pchEpilogue << "\n";
+      }
+    }
+    cmSystemTools::CopyFileIfDifferent(filename_tmp, filename);
+    cmSystemTools::RemoveFile(filename_tmp);
+  }
+  return inserted.first->second;
+}
+
+std::string cmGeneratorTarget::GetPchSource(const std::string& config,
+                                            const std::string& language) const
+{
+  if (language != "C" && language != "CXX") {
+    return std::string();
+  }
+  const auto inserted =
+    this->PchSources.insert(std::make_pair(language + config, ""));
+  if (inserted.second) {
+    const std::string pchHeader = this->GetPchHeader(config, language);
+    if (pchHeader.empty()) {
+      return std::string();
+    }
+    std::string& filename = inserted.first->second;
+    filename = cmStrCat(this->LocalGenerator->GetCurrentBinaryDirectory(),
+                        "/CMakeFiles/", this->GetName(), ".dir/cmake_pch");
+
+    // For GCC the source extension will be tranformed into .h[xx].gch
+    if (!this->Makefile->IsOn("CMAKE_LINK_PCH")) {
+      filename += ((language == "C") ? ".h.c" : ".hxx.cxx");
+    } else {
+      filename += ((language == "C") ? ".c" : ".cxx");
+    }
+    const std::string filename_tmp = cmStrCat(filename, ".tmp");
+    {
+      cmGeneratedFileStream file(filename_tmp);
+      file << "/* generated by CMake */\n";
+    }
+    cmSystemTools::CopyFileIfDifferent(filename_tmp, filename);
+    cmSystemTools::RemoveFile(filename_tmp);
+  }
+  return inserted.first->second;
+}
+
 void cmGeneratorTarget::GetLinkOptions(std::vector<std::string>& result,
                                        const std::string& config,
                                        const std::string& language) const
@@ -6055,7 +6208,7 @@ void cmGeneratorTarget::GetLanguages(std::set<std::string>& languages,
   std::vector<cmSourceFile*> sourceFiles;
   this->GetSourceFiles(sourceFiles, config);
   for (cmSourceFile* src : sourceFiles) {
-    const std::string& lang = src->GetLanguage();
+    const std::string& lang = src->GetOrDetermineLanguage();
     if (!lang.empty()) {
       languages.insert(lang);
     }