[clang] [C++20] [Modules] Embed all source files for C++20 Modules (PR #102444)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-modules

Author: Chuanqi Xu (ChuanqiXu9)

<details>
<summary>Changes</summary>

Close https://github.com/llvm/llvm-project/issues/72383

The implementation rationale is, I don't want to pass `-fmodules-embed-all-files` all the time since we can't test it in lit tests (we're using `clang_cc1`). So I tried to set it in FrontendActions for modules.

---
Full diff: https://github.com/llvm/llvm-project/pull/102444.diff


5 Files Affected:

- (modified) clang/include/clang/CodeGen/CodeGenAction.h (+1-1) 
- (modified) clang/include/clang/Frontend/FrontendActions.h (+3-1) 
- (modified) clang/include/clang/Serialization/ModuleFile.h (+5-5) 
- (modified) clang/lib/CodeGen/CodeGenAction.cpp (+3-2) 
- (modified) clang/lib/Frontend/FrontendActions.cpp (+12-3) 


``````````diff
diff --git a/clang/include/clang/CodeGen/CodeGenAction.h b/clang/include/clang/CodeGen/CodeGenAction.h
index 186dbb43f01ef..461450d875ec5 100644
--- a/clang/include/clang/CodeGen/CodeGenAction.h
+++ b/clang/include/clang/CodeGen/CodeGenAction.h
@@ -57,7 +57,7 @@ class CodeGenAction : public ASTFrontendAction {
   bool loadLinkModules(CompilerInstance &CI);
 
 protected:
-  bool BeginSourceFileAction(CompilerInstance &CI) override;
+  bool BeginInvocation(CompilerInstance &CI) override;
 
   /// Create a new code generation action.  If the optional \p _VMContext
   /// parameter is supplied, the action uses it without taking ownership,
diff --git a/clang/include/clang/Frontend/FrontendActions.h b/clang/include/clang/Frontend/FrontendActions.h
index a620ddfc40447..e82f15f89b643 100644
--- a/clang/include/clang/Frontend/FrontendActions.h
+++ b/clang/include/clang/Frontend/FrontendActions.h
@@ -152,11 +152,13 @@ class GenerateModuleFromModuleMapAction : public GenerateModuleAction {
   CreateOutputFile(CompilerInstance &CI, StringRef InFile) override;
 };
 
+bool BeginInvocationForModules(CompilerInstance &CI);
+
 /// Generates full BMI (which contains full information to generate the object
 /// files) for C++20 Named Modules.
 class GenerateModuleInterfaceAction : public GenerateModuleAction {
 protected:
-  bool BeginSourceFileAction(CompilerInstance &CI) override;
+  bool BeginInvocation(CompilerInstance &CI) override;
 
   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
                                                  StringRef InFile) override;
diff --git a/clang/include/clang/Serialization/ModuleFile.h b/clang/include/clang/Serialization/ModuleFile.h
index 3e920c0f68360..30e7f6b3e57bd 100644
--- a/clang/include/clang/Serialization/ModuleFile.h
+++ b/clang/include/clang/Serialization/ModuleFile.h
@@ -88,13 +88,13 @@ class InputFile {
 
   InputFile(FileEntryRef File, bool isOverridden = false,
             bool isOutOfDate = false) {
-    assert(!(isOverridden && isOutOfDate) &&
-           "an overridden cannot be out-of-date");
     unsigned intVal = 0;
-    if (isOverridden)
-      intVal = Overridden;
-    else if (isOutOfDate)
+    // Make isOutOfDate with higher priority than isOverridden.
+    // It is possible if the recorded hash value mismatches.
+    if (isOutOfDate)
       intVal = OutOfDate;
+    else if (isOverridden)
+      intVal = Overridden;
     Val.setPointerAndInt(&File.getMapEntry(), intVal);
   }
 
diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
index e87226e60297c..8900faf07eeaf 100644
--- a/clang/lib/CodeGen/CodeGenAction.cpp
+++ b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -969,9 +969,10 @@ CodeGenerator *CodeGenAction::getCodeGenerator() const {
   return BEConsumer->getCodeGenerator();
 }
 
-bool CodeGenAction::BeginSourceFileAction(CompilerInstance &CI) {
+bool CodeGenAction::BeginInvocation(CompilerInstance &CI) {
   if (CI.getFrontendOpts().GenReducedBMI)
-    CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleInterface);
+    return BeginInvocationForModules(CI);
+
   return true;
 }
 
diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index e70210d55fe28..7758746f9a483 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -262,11 +262,20 @@ GenerateModuleFromModuleMapAction::CreateOutputFile(CompilerInstance &CI,
                                     /*ForceUseTemporary=*/true);
 }
 
-bool GenerateModuleInterfaceAction::BeginSourceFileAction(
-    CompilerInstance &CI) {
+bool clang::BeginInvocationForModules(CompilerInstance &CI) {
+  // Embed all module files for named modules.
+  // See https://github.com/llvm/llvm-project/issues/72383 for discussion.
+  CI.getFrontendOpts().ModulesEmbedAllFiles = true;
   CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleInterface);
+  return true;
+}
 
-  return GenerateModuleAction::BeginSourceFileAction(CI);
+bool GenerateModuleInterfaceAction::BeginInvocation(
+    CompilerInstance &CI) {
+  if (!BeginInvocationForModules(CI))
+    return false;
+
+  return GenerateModuleAction::BeginInvocation(CI);
 }
 
 std::unique_ptr<ASTConsumer>

``````````

</details>


https://github.com/llvm/llvm-project/pull/102444