Merge topic 'unity_explicit_groups'

9f4eb352fe Unity Builds: Support explicit specification of sources to groups
b00585adcc Unity: Refactor implementation to make it easier to extend

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !4716

2 files changed, 135 insertions, 44 deletions

diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 9aca775fd5..f29c682f80 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -2758,6 +2758,120 @@ void cmLocalGenerator::AddPchDependencies(cmGeneratorTarget* target)
   }
 }
 
+namespace {
+
+inline void RegisterUnitySources(cmGeneratorTarget* target, cmSourceFile* sf,
+                                 std::string const& filename)
+{
+  target->AddSourceFileToUnityBatch(sf->ResolveFullPath());
+  sf->SetProperty("UNITY_SOURCE_FILE", filename.c_str());
+}
+
+inline void IncludeFileInUnitySources(cmGeneratedFileStream& unity_file,
+                                      std::string const& sf_full_path,
+                                      cmProp beforeInclude,
+                                      cmProp afterInclude)
+{
+  if (beforeInclude) {
+    unity_file << *beforeInclude << "\n";
+  }
+
+  unity_file << "#include \"" << sf_full_path << "\"\n";
+
+  if (afterInclude) {
+    unity_file << *afterInclude << "\n";
+  }
+}
+
+std::vector<std::string> AddUnityFilesModeAuto(
+  cmGeneratorTarget* target, std::string const& lang,
+  std::vector<cmSourceFile*> const& filtered_sources, cmProp beforeInclude,
+  cmProp afterInclude, std::string const& filename_base, size_t batchSize)
+{
+  if (batchSize == 0) {
+    batchSize = filtered_sources.size();
+  }
+
+  std::vector<std::string> unity_files;
+  for (size_t itemsLeft = filtered_sources.size(), chunk, batch = 0;
+       itemsLeft > 0; itemsLeft -= chunk, ++batch) {
+
+    chunk = std::min(itemsLeft, batchSize);
+
+    std::string filename = cmStrCat(filename_base, "unity_", batch,
+                                    (lang == "C") ? "_c.c" : "_cxx.cxx");
+
+    const std::string filename_tmp = cmStrCat(filename, ".tmp");
+    {
+      size_t begin = batch * batchSize;
+      size_t end = begin + chunk;
+
+      cmGeneratedFileStream file(
+        filename_tmp, false,
+        target->GetGlobalGenerator()->GetMakefileEncoding());
+      file << "/* generated by CMake */\n\n";
+
+      for (; begin != end; ++begin) {
+        cmSourceFile* sf = filtered_sources[begin];
+        RegisterUnitySources(target, sf, filename);
+        IncludeFileInUnitySources(file, sf->ResolveFullPath(), beforeInclude,
+                                  afterInclude);
+      }
+    }
+    cmSystemTools::MoveFileIfDifferent(filename_tmp, filename);
+    unity_files.emplace_back(std::move(filename));
+  }
+  return unity_files;
+}
+
+std::vector<std::string> AddUnityFilesModeGroup(
+  cmGeneratorTarget* target, std::string const& lang,
+  std::vector<cmSourceFile*> const& filtered_sources, cmProp beforeInclude,
+  cmProp afterInclude, std::string const& filename_base)
+{
+  std::vector<std::string> unity_files;
+
+  // sources organized by group name. Drop any source
+  // without a group
+  std::unordered_map<std::string, std::vector<cmSourceFile*>> explicit_mapping;
+  for (cmSourceFile* sf : filtered_sources) {
+    if (cmProp value = sf->GetProperty("UNITY_GROUP")) {
+      auto i = explicit_mapping.find(*value);
+      if (i == explicit_mapping.end()) {
+        std::vector<cmSourceFile*> sources{ sf };
+        explicit_mapping.emplace(*value, sources);
+      } else {
+        i->second.emplace_back(sf);
+      }
+    }
+  }
+
+  for (auto const& item : explicit_mapping) {
+    auto const& name = item.first;
+    std::string filename = cmStrCat(filename_base, "unity_", name,
+                                    (lang == "C") ? "_c.c" : "_cxx.cxx");
+
+    const std::string filename_tmp = cmStrCat(filename, ".tmp");
+    {
+      cmGeneratedFileStream file(
+        filename_tmp, false,
+        target->GetGlobalGenerator()->GetMakefileEncoding());
+      file << "/* generated by CMake */\n\n";
+
+      for (cmSourceFile* sf : item.second) {
+        RegisterUnitySources(target, sf, filename);
+        IncludeFileInUnitySources(file, sf->ResolveFullPath(), beforeInclude,
+                                  afterInclude);
+      }
+    }
+    cmSystemTools::MoveFileIfDifferent(filename_tmp, filename);
+    unity_files.emplace_back(std::move(filename));
+  }
+
+  return unity_files;
+}
+}
+
 void cmLocalGenerator::AddUnityBuild(cmGeneratorTarget* target)
 {
   if (!target->GetPropertyAsBool("UNITY_BUILD")) {
@@ -2786,6 +2900,7 @@ void cmLocalGenerator::AddUnityBuild(cmGeneratorTarget* target)
   cmProp beforeInclude =
     target->GetProperty("UNITY_BUILD_CODE_BEFORE_INCLUDE");
   cmProp afterInclude = target->GetProperty("UNITY_BUILD_CODE_AFTER_INCLUDE");
+  cmProp unityMode = target->GetProperty("UNITY_BUILD_MODE");
 
   for (std::string lang : { "C", "CXX" }) {
     std::vector<cmSourceFile*> filtered_sources;
@@ -2800,53 +2915,28 @@ void cmLocalGenerator::AddUnityBuild(cmGeneratorTarget* target)
                      !sf->GetProperty("INCLUDE_DIRECTORIES");
                  });
 
-    size_t batchSize = unityBatchSize;
-    if (unityBatchSize == 0) {
-      batchSize = filtered_sources.size();
+    std::vector<std::string> unity_files;
+    if (!unityMode || *unityMode == "BATCH") {
+      unity_files =
+        AddUnityFilesModeAuto(target, lang, filtered_sources, beforeInclude,
+                              afterInclude, filename_base, unityBatchSize);
+    } else if (unityMode && *unityMode == "GROUP") {
+      unity_files =
+        AddUnityFilesModeGroup(target, lang, filtered_sources, beforeInclude,
+                               afterInclude, filename_base);
+    } else {
+      // unity mode is set to an unsupported value
+      std::string e("Invalid UNITY_BUILD_MODE value of " + *unityMode +
+                    " assigned to target " + target->GetName() +
+                    ". Acceptable values are BATCH and GROUP.");
+      this->IssueMessage(MessageType::FATAL_ERROR, e);
     }
 
-    for (size_t itemsLeft = filtered_sources.size(), chunk, batch = 0;
-         itemsLeft > 0; itemsLeft -= chunk, ++batch) {
-
-      chunk = std::min(itemsLeft, batchSize);
-
-      std::string filename = cmStrCat(filename_base, "unity_", batch,
-                                      (lang == "C") ? "_c.c" : "_cxx.cxx");
-
-      const std::string filename_tmp = cmStrCat(filename, ".tmp");
-      {
-        size_t begin = batch * batchSize;
-        size_t end = begin + chunk;
-
-        cmGeneratedFileStream file(
-          filename_tmp, false,
-          this->GetGlobalGenerator()->GetMakefileEncoding());
-        file << "/* generated by CMake */\n\n";
-
-        for (; begin != end; ++begin) {
-          cmSourceFile* sf = filtered_sources[begin];
-
-          target->AddSourceFileToUnityBatch(sf->ResolveFullPath());
-          sf->SetProperty("UNITY_SOURCE_FILE", filename.c_str());
-
-          if (beforeInclude) {
-            file << *beforeInclude << "\n";
-          }
-
-          file << "#include \"" << sf->ResolveFullPath() << "\"\n";
-
-          if (afterInclude) {
-            file << *afterInclude << "\n";
-          }
-        }
-      }
-      cmSystemTools::MoveFileIfDifferent(filename_tmp, filename);
-
-      target->AddSource(filename, true);
-
-      auto unity = this->Makefile->GetOrCreateSource(filename);
+    for (auto const& file : unity_files) {
+      auto unity = this->GetMakefile()->GetOrCreateSource(file);
+      target->AddSource(file, true);
       unity->SetProperty("SKIP_UNITY_BUILD_INCLUSION", "ON");
-      unity->SetProperty("UNITY_SOURCE_FILE", filename.c_str());
+      unity->SetProperty("UNITY_SOURCE_FILE", file.c_str());
     }
   }
 }
diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index a776398857..d43fbe5c03 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -372,6 +372,7 @@ cmTarget::cmTarget(std::string const& name, cmStateEnums::TargetType type,
     initProp("DISABLE_PRECOMPILE_HEADERS");
     initProp("UNITY_BUILD");
     initPropValue("UNITY_BUILD_BATCH_SIZE", "8");
+    initPropValue("UNITY_BUILD_MODE", "BATCH");
     initPropValue("PCH_WARN_INVALID", "ON");
 #ifdef __APPLE__
     if (this->GetGlobalGenerator()->IsXcode()) {