1 files changed, 90 insertions, 41 deletions

diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 2ca5706..3a321c5 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -35,6 +35,7 @@
 #include "cmRange.h"
 #include "cmSourceFile.h"
 #include "cmSourceFileLocation.h"
+#include "cmSourceFileLocationKind.h"
 #include "cmState.h"
 #include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
@@ -3371,57 +3372,67 @@ std::string cmGeneratorTarget::GetPchHeader(const std::string& config,
     }
     std::string& filename = inserted.first->second;
 
+    const cmGeneratorTarget* generatorTarget = this;
+    const char* pchReuseFrom =
+      generatorTarget->GetProperty("PRECOMPILE_HEADERS_REUSE_FROM");
+    if (pchReuseFrom) {
+      generatorTarget =
+        this->GetGlobalGenerator()->FindGeneratorTarget(pchReuseFrom);
+    }
+
     if (this->GetGlobalGenerator()->IsMultiConfig()) {
-      filename =
-        cmStrCat(this->LocalGenerator->GetCurrentBinaryDirectory(), "/");
+      filename = cmStrCat(
+        generatorTarget->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 = generatorTarget->ObjectDirectory;
     }
 
-    filename = cmStrCat(filename, "CMakeFiles/", this->GetName(),
+    filename = cmStrCat(filename, "CMakeFiles/", generatorTarget->GetName(),
                         ".dir/cmake_pch", ((language == "C") ? ".h" : ".hxx"));
 
     const std::string filename_tmp = cmStrCat(filename, ".tmp");
-    {
+    if (!pchReuseFrom) {
       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;
+      {
+        cmGeneratedFileStream file(
+          filename_tmp, false,
+          this->GetGlobalGenerator()->GetMakefileEncoding());
+        file << "/* generated by CMake */\n\n";
+        if (pchPrologue) {
+          file << pchPrologue << "\n";
         }
-        if (header_bt.Value[0] == '<' || header_bt.Value[0] == '"') {
-          file << "#include " << header_bt.Value << "\n";
-        } else {
-          file << "#include \"" << header_bt.Value << "\"\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";
         }
       }
-      if (language == "CXX") {
-        file << "#endif // __cplusplus\n";
-      }
-      if (this->GetGlobalGenerator()->IsXcode()) {
-        file << "#endif // CMAKE_SKIP_PRECOMPILE_HEADERS\n";
-      }
-      if (pchEpilogue) {
-        file << pchEpilogue << "\n";
-      }
+      cmSystemTools::MoveFileIfDifferent(filename_tmp, filename);
     }
-    cmSystemTools::MoveFileIfDifferent(filename_tmp, filename);
   }
   return inserted.first->second;
 }
@@ -3440,8 +3451,18 @@ std::string cmGeneratorTarget::GetPchSource(const std::string& config,
       return std::string();
     }
     std::string& filename = inserted.first->second;
-    filename = cmStrCat(this->LocalGenerator->GetCurrentBinaryDirectory(),
-                        "/CMakeFiles/", this->GetName(), ".dir/cmake_pch");
+
+    const cmGeneratorTarget* generatorTarget = this;
+    const char* pchReuseFrom =
+      generatorTarget->GetProperty("PRECOMPILE_HEADERS_REUSE_FROM");
+    if (pchReuseFrom) {
+      generatorTarget =
+        this->GetGlobalGenerator()->FindGeneratorTarget(pchReuseFrom);
+    }
+
+    filename =
+      cmStrCat(generatorTarget->LocalGenerator->GetCurrentBinaryDirectory(),
+               "/CMakeFiles/", generatorTarget->GetName(), ".dir/cmake_pch");
 
     // For GCC the source extension will be tranformed into .h[xx].gch
     if (!this->Makefile->IsOn("CMAKE_LINK_PCH")) {
@@ -3449,12 +3470,40 @@ std::string cmGeneratorTarget::GetPchSource(const std::string& config,
     } else {
       filename += ((language == "C") ? ".c" : ".cxx");
     }
+
     const std::string filename_tmp = cmStrCat(filename, ".tmp");
-    {
-      cmGeneratedFileStream file(filename_tmp);
-      file << "/* generated by CMake */\n";
+    if (!pchReuseFrom) {
+      {
+        cmGeneratedFileStream file(filename_tmp);
+        file << "/* generated by CMake */\n";
+      }
+      cmSystemTools::MoveFileIfDifferent(filename_tmp, filename);
     }
-    cmSystemTools::MoveFileIfDifferent(filename_tmp, filename);
+  }
+  return inserted.first->second;
+}
+
+std::string cmGeneratorTarget::GetPchFileObject(const std::string& config,
+                                                const std::string& language)
+{
+  if (language != "C" && language != "CXX") {
+    return std::string();
+  }
+  const auto inserted =
+    this->PchObjectFiles.insert(std::make_pair(language + config, ""));
+  if (inserted.second) {
+    const std::string pchSource = this->GetPchSource(config, language);
+    if (pchSource.empty()) {
+      return std::string();
+    }
+    std::string& filename = inserted.first->second;
+
+    this->AddSource(pchSource, true);
+
+    auto pchSf = this->Makefile->GetOrCreateSource(
+      pchSource, false, cmSourceFileLocationKind::Known);
+
+    filename = cmStrCat(this->ObjectDirectory, this->GetObjectName(pchSf));
   }
   return inserted.first->second;
 }