[clang][modules] Allow not forcing validation of user headers

clang/include/clang/Driver/Options.td

@@ -3244,6 +3244,13 @@ def fmodules_disable_diagnostic_validation : Flag<["-"], "fmodules-disable-diagn
   Group<i_Group>, Visibility<[ClangOption, CC1Option]>,
   HelpText<"Disable validation of the diagnostic options when loading the module">,
   MarshallingInfoNegativeFlag<HeaderSearchOpts<"ModulesValidateDiagnosticOptions">>;
+defm modules_force_validate_user_headers : BoolOption<"f", "modules-force-validate-user-headers",
+  HeaderSearchOpts<"ModulesForceValidateUserHeaders">, DefaultTrue,
+  PosFlag<SetTrue, [], [], "Force">,
+  NegFlag<SetFalse, [], [CC1Option], "Do not force">,
+  BothFlags<[], [ClangOption],
+            " validation of user headers when repeatedly loading a module file within single build session">>,
+  Group<i_Group>;
 defm modules_validate_system_headers : BoolOption<"f", "modules-validate-system-headers",
   HeaderSearchOpts<"ModulesValidateSystemHeaders">, DefaultFalse,
   PosFlag<SetTrue, [], [ClangOption, CC1Option],

clang/include/clang/Lex/HeaderSearchOptions.h

@@ -217,6 +217,11 @@ class HeaderSearchOptions {
   LLVM_PREFERRED_TYPE(bool)
   unsigned ModulesValidateSystemHeaders : 1;
 
+  /// Whether to force the validation of user input files when a module is
+  /// loaded (even despite the build session saying that is not necessary).
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned ModulesForceValidateUserHeaders : 1;
+
   // Whether the content of input files should be hashed and used to
   // validate consistency.
   LLVM_PREFERRED_TYPE(bool)
@@ -286,6 +291,7 @@ class HeaderSearchOptions {
         UseStandardCXXIncludes(true), UseLibcxx(false), Verbose(false),
         ModulesValidateOncePerBuildSession(false),
         ModulesValidateSystemHeaders(false),
+        ModulesForceValidateUserHeaders(true),
         ValidateASTInputFilesContent(false),
         ForceCheckCXX20ModulesInputFiles(false), UseDebugInfo(false),
         ModulesValidateDiagnosticOptions(true),

clang/include/clang/Serialization/ASTReader.h

@@ -1091,9 +1091,12 @@ class ASTReader
   /// from the current compiler instance.
   bool AllowConfigurationMismatch;
 
-  /// Whether validate system input files.
+  /// Whether to validate system input files.
   bool ValidateSystemInputs;
 
+  /// Whether to force the validation of user input files.
+  bool ForceValidateUserInputs;
+
   /// Whether validate headers and module maps using hash based on contents.
   bool ValidateASTInputFilesContent;
 
@@ -1767,6 +1770,7 @@ class ASTReader
             bool AllowASTWithCompilerErrors = false,
             bool AllowConfigurationMismatch = false,
             bool ValidateSystemInputs = false,
+            bool ForceValidateUserInputs = true,
             bool ValidateASTInputFilesContent = false,
             bool UseGlobalIndex = true,
             std::unique_ptr<llvm::Timer> ReadTimer = {});

clang/lib/Frontend/CompilerInstance.cpp

@@ -638,8 +638,9 @@ IntrusiveRefCntPtr<ASTReader> CompilerInstance::createPCHExternalASTSource(
       PP, ModCache, &Context, PCHContainerRdr, Extensions,
       Sysroot.empty() ? "" : Sysroot.data(), DisableValidation,
       AllowPCHWithCompilerErrors, /*AllowConfigurationMismatch*/ false,
-      HSOpts.ModulesValidateSystemHeaders, HSOpts.ValidateASTInputFilesContent,
-      UseGlobalModuleIndex));
+      HSOpts.ModulesValidateSystemHeaders,
+      HSOpts.ModulesForceValidateUserHeaders,
+      HSOpts.ValidateASTInputFilesContent, UseGlobalModuleIndex));
 
   // We need the external source to be set up before we read the AST, because
   // eagerly-deserialized declarations may use it.
@@ -1752,6 +1753,7 @@ void CompilerInstance::createASTReader() {
       PPOpts.DisablePCHOrModuleValidation,
       /*AllowASTWithCompilerErrors=*/FEOpts.AllowPCMWithCompilerErrors,
       /*AllowConfigurationMismatch=*/false, HSOpts.ModulesValidateSystemHeaders,
+      HSOpts.ModulesForceValidateUserHeaders,
       HSOpts.ValidateASTInputFilesContent,
       getFrontendOpts().UseGlobalModuleIndex, std::move(ReadTimer));
   if (hasASTConsumer()) {

clang/lib/Frontend/FrontendActions.cpp

@@ -364,7 +364,7 @@ void VerifyPCHAction::ExecuteAction() {
       DisableValidationForModuleKind::None,
       /*AllowASTWithCompilerErrors*/ false,
       /*AllowConfigurationMismatch*/ true,
-      /*ValidateSystemInputs*/ true));
+      /*ValidateSystemInputs*/ true, /*ForceValidateUserInputs*/ true));
 
   Reader->ReadAST(getCurrentFile(),
                   Preamble ? serialization::MK_Preamble

clang/lib/Serialization/ASTReader.cpp

@@ -3105,7 +3105,7 @@ ASTReader::ReadControlBlock(ModuleFile &F,
         if (HSOpts.ModulesValidateOncePerBuildSession &&
             F.InputFilesValidationTimestamp > HSOpts.BuildSessionTimestamp &&
             F.Kind == MK_ImplicitModule)
-          N = NumUserInputs;
+          N = ForceValidateUserInputs ? NumUserInputs : 0;
 
         for (unsigned I = 0; I < N; ++I) {
           InputFile IF = getInputFile(F, I+1, Complain);
@@ -10974,6 +10974,7 @@ ASTReader::ASTReader(Preprocessor &PP, ModuleCache &ModCache,
                      DisableValidationForModuleKind DisableValidationKind,
                      bool AllowASTWithCompilerErrors,
                      bool AllowConfigurationMismatch, bool ValidateSystemInputs,
+                     bool ForceValidateUserInputs,
                      bool ValidateASTInputFilesContent, bool UseGlobalIndex,
                      std::unique_ptr<llvm::Timer> ReadTimer)
     : Listener(bool(DisableValidationKind & DisableValidationForModuleKind::PCH)
@@ -10989,6 +10990,7 @@ ASTReader::ASTReader(Preprocessor &PP, ModuleCache &ModCache,
       AllowASTWithCompilerErrors(AllowASTWithCompilerErrors),
       AllowConfigurationMismatch(AllowConfigurationMismatch),
       ValidateSystemInputs(ValidateSystemInputs),
+      ForceValidateUserInputs(ForceValidateUserInputs),
       ValidateASTInputFilesContent(ValidateASTInputFilesContent),
       UseGlobalIndex(UseGlobalIndex), CurrSwitchCaseStmts(&SwitchCaseStmts) {
   SourceMgr.setExternalSLocEntrySource(this);

clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp

@@ -530,6 +530,7 @@ class DependencyScanningAction : public tooling::ToolAction {
     ScanInstance.getHeaderSearchOpts().ModulesSkipHeaderSearchPaths = true;
     ScanInstance.getHeaderSearchOpts().ModulesSkipPragmaDiagnosticMappings =
         true;
+    ScanInstance.getHeaderSearchOpts().ModulesForceValidateUserHeaders = false;
 
     // Avoid some checks and module map parsing when loading PCM files.
     ScanInstance.getPreprocessorOpts().ModulesCheckRelocated = false;

clang/test/Modules/fmodules-validate-once-per-build-session.c

@@ -19,32 +19,44 @@
 // Compile the module.
 // RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache -fsyntax-only -isystem %t/Inputs -fmodules-validate-system-headers -fbuild-session-timestamp=1390000000 -fmodules-validate-once-per-build-session %s
 // RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache-user -fsyntax-only -I %t/Inputs -fmodules-validate-system-headers -fbuild-session-timestamp=1390000000 -fmodules-validate-once-per-build-session %s
+// RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache-user-no-force -fsyntax-only -I %t/Inputs -fno-modules-force-validate-user-headers -fmodules-validate-system-headers -fbuild-session-timestamp=1390000000 -fmodules-validate-once-per-build-session %s
 // RUN: ls -R %t/modules-cache | grep Foo.pcm.timestamp
 // RUN: ls -R %t/modules-cache | grep Bar.pcm.timestamp
 // RUN: ls -R %t/modules-cache-user | grep Foo.pcm.timestamp
 // RUN: ls -R %t/modules-cache-user | grep Bar.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user-no-force | grep Foo.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user-no-force | grep Bar.pcm.timestamp
 // RUN: cp %t/modules-cache/Foo.pcm %t/modules-to-compare/Foo-before.pcm
 // RUN: cp %t/modules-cache/Bar.pcm %t/modules-to-compare/Bar-before.pcm
 // RUN: cp %t/modules-cache-user/Foo.pcm %t/modules-to-compare/Foo-before-user.pcm
 // RUN: cp %t/modules-cache-user/Bar.pcm %t/modules-to-compare/Bar-before-user.pcm
+// RUN: cp %t/modules-cache-user-no-force/Foo.pcm %t/modules-to-compare/Foo-before-user-no-force.pcm
+// RUN: cp %t/modules-cache-user-no-force/Bar.pcm %t/modules-to-compare/Bar-before-user-no-force.pcm
 
 // ===
 // Use it, and make sure that we did not recompile it.
 // RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache -fsyntax-only -isystem %t/Inputs -fmodules-validate-system-headers -fbuild-session-timestamp=1390000000 -fmodules-validate-once-per-build-session %s
 // RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache-user -fsyntax-only -I %t/Inputs -fmodules-validate-system-headers -fbuild-session-timestamp=1390000000 -fmodules-validate-once-per-build-session %s
+// RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache-use-no-force -fsyntax-only -I %t/Inputs -fno-modules-force-validate-user-headers -fmodules-validate-system-headers -fbuild-session-timestamp=1390000000 -fmodules-validate-once-per-build-session %s
 // RUN: ls -R %t/modules-cache | grep Foo.pcm.timestamp
 // RUN: ls -R %t/modules-cache | grep Bar.pcm.timestamp
 // RUN: ls -R %t/modules-cache-user | grep Foo.pcm.timestamp
 // RUN: ls -R %t/modules-cache-user | grep Bar.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user-no-force | grep Foo.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user-no-force | grep Bar.pcm.timestamp
 // RUN: cp %t/modules-cache/Foo.pcm %t/modules-to-compare/Foo-after.pcm
 // RUN: cp %t/modules-cache/Bar.pcm %t/modules-to-compare/Bar-after.pcm
 // RUN: cp %t/modules-cache-user/Foo.pcm %t/modules-to-compare/Foo-after-user.pcm
 // RUN: cp %t/modules-cache-user/Bar.pcm %t/modules-to-compare/Bar-after-user.pcm
+// RUN: cp %t/modules-cache-user-no-force/Foo.pcm %t/modules-to-compare/Foo-after-user-no-force.pcm
+// RUN: cp %t/modules-cache-user-no-force/Bar.pcm %t/modules-to-compare/Bar-after-user-no-force.pcm
 
 // RUN: diff %t/modules-to-compare/Foo-before.pcm %t/modules-to-compare/Foo-after.pcm
 // RUN: diff %t/modules-to-compare/Bar-before.pcm %t/modules-to-compare/Bar-after.pcm
 // RUN: diff %t/modules-to-compare/Foo-before-user.pcm %t/modules-to-compare/Foo-after-user.pcm
 // RUN: diff %t/modules-to-compare/Bar-before-user.pcm %t/modules-to-compare/Bar-after-user.pcm
+// RUN: diff %t/modules-to-compare/Foo-before-user-no-force.pcm %t/modules-to-compare/Foo-after-user-no-force.pcm
+// RUN: diff %t/modules-to-compare/Bar-before-user-no-force.pcm %t/modules-to-compare/Bar-after-user-no-force.pcm
 
 // ===
 // Change the sources.
@@ -53,31 +65,54 @@
 
 // ===
 // Use the module, and make sure that we did not recompile it if foo.h or
-// module.modulemap are system files, even though the sources changed.
+// module.modulemap are system files or user files with force validation disabled,
+// even though the sources changed.
 // RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache -fsyntax-only -isystem %t/Inputs -fmodules-validate-system-headers -fbuild-session-timestamp=1390000000 -fmodules-validate-once-per-build-session %s
 // RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache-user -fsyntax-only -I %t/Inputs -fmodules-validate-system-headers -fbuild-session-timestamp=1390000000 -fmodules-validate-once-per-build-session %s
+// RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache-user-no-force -fsyntax-only -I %t/Inputs -fno-modules-force-validate-user-headers -fmodules-validate-system-headers -fbuild-session-timestamp=1390000000 -fmodules-validate-once-per-build-session %s
 // RUN: ls -R %t/modules-cache | grep Foo.pcm.timestamp
 // RUN: ls -R %t/modules-cache | grep Bar.pcm.timestamp
 // RUN: ls -R %t/modules-cache-user | grep Foo.pcm.timestamp
 // RUN: ls -R %t/modules-cache-user | grep Bar.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user-no-force | grep Foo.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user-no-force | grep Bar.pcm.timestamp
 // RUN: cp %t/modules-cache/Foo.pcm %t/modules-to-compare/Foo-after.pcm
 // RUN: cp %t/modules-cache/Bar.pcm %t/modules-to-compare/Bar-after.pcm
 // RUN: cp %t/modules-cache-user/Foo.pcm %t/modules-to-compare/Foo-after-user.pcm
 // RUN: cp %t/modules-cache-user/Bar.pcm %t/modules-to-compare/Bar-after-user.pcm
+// RUN: cp %t/modules-cache-user-no-force/Foo.pcm %t/modules-to-compare/Foo-after-user-no-force.pcm
+// RUN: cp %t/modules-cache-user-no-force/Bar.pcm %t/modules-to-compare/Bar-after-user-no-force.pcm
 
 // RUN: diff %t/modules-to-compare/Foo-before.pcm %t/modules-to-compare/Foo-after.pcm
 // RUN: diff %t/modules-to-compare/Bar-before.pcm %t/modules-to-compare/Bar-after.pcm
-// When foo.h is a user header, we will always validate it.
+// When foo.h is an user header, we will validate it by default.
 // RUN: not diff %t/modules-to-compare/Foo-before-user.pcm %t/modules-to-compare/Foo-after-user.pcm
 // RUN: not diff %t/modules-to-compare/Bar-before-user.pcm %t/modules-to-compare/Bar-after-user.pcm
+// When foo.h is an user header, we will not validate it if force validation is turned off.
+// RUN: diff %t/modules-to-compare/Foo-before-user-no-force.pcm %t/modules-to-compare/Foo-after-user-no-force.pcm
+// RUN: diff %t/modules-to-compare/Bar-before-user-no-force.pcm %t/modules-to-compare/Bar-after-user-no-force.pcm
 
 // ===
 // Recompile the module if the today's date is before 01 January 2100.
 // RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache -fsyntax-only -isystem %t/Inputs -fmodules-validate-system-headers -fbuild-session-timestamp=4102441200 -fmodules-validate-once-per-build-session %s
+// RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache-user -fsyntax-only -I %t/Inputs -fno-modules-force-validate-user-headers -fmodules-validate-system-headers -fbuild-session-timestamp=4102441200 -fmodules-validate-once-per-build-session %s
+// RUN: %clang_cc1 -cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t/modules-cache-user-no-force -fsyntax-only -I %t/Inputs -fno-modules-force-validate-user-headers -fmodules-validate-system-headers -fbuild-session-timestamp=4102441200 -fmodules-validate-once-per-build-session %s
 // RUN: ls -R %t/modules-cache | grep Foo.pcm.timestamp
 // RUN: ls -R %t/modules-cache | grep Bar.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user | grep Foo.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user | grep Bar.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user-no-force | grep Foo.pcm.timestamp
+// RUN: ls -R %t/modules-cache-user-no-force | grep Bar.pcm.timestamp
 // RUN: cp %t/modules-cache/Foo.pcm %t/modules-to-compare/Foo-after.pcm
 // RUN: cp %t/modules-cache/Bar.pcm %t/modules-to-compare/Bar-after.pcm
+// RUN: cp %t/modules-cache-user/Foo.pcm %t/modules-to-compare/Foo-after-user.pcm
+// RUN: cp %t/modules-cache-user/Bar.pcm %t/modules-to-compare/Bar-after-user.pcm
+// RUN: cp %t/modules-cache-user-no-force/Foo.pcm %t/modules-to-compare/Foo-after-user-no-force.pcm
+// RUN: cp %t/modules-cache-user-no-force/Bar.pcm %t/modules-to-compare/Bar-after-user-no-force.pcm
 
 // RUN: not diff %t/modules-to-compare/Foo-before.pcm %t/modules-to-compare/Foo-after.pcm
 // RUN: not diff %t/modules-to-compare/Bar-before.pcm %t/modules-to-compare/Bar-after.pcm
+// RUN: not diff %t/modules-to-compare/Foo-before-user.pcm %t/modules-to-compare/Foo-after-user.pcm
+// RUN: not diff %t/modules-to-compare/Bar-before-user.pcm %t/modules-to-compare/Bar-after-user.pcm
+// RUN: not diff %t/modules-to-compare/Foo-before-user-no-force.pcm %t/modules-to-compare/Foo-after-user-no-force.pcm
+// RUN: not diff %t/modules-to-compare/Bar-before-user-no-force.pcm %t/modules-to-compare/Bar-after-user-no-force.pcm