[clang] 9223209 - [clang][deps] Handle precompiled headers' AST files
Jan Svoboda via cfe-commits
cfe-commits at lists.llvm.org
Mon Jun 14 02:28:59 PDT 2021
Author: Jan Svoboda
Date: 2021-06-14T11:28:39+02:00
New Revision: 9223209be11e93c1b701054c6fff88d46ee54658
URL: https://github.com/llvm/llvm-project/commit/9223209be11e93c1b701054c6fff88d46ee54658
DIFF: https://github.com/llvm/llvm-project/commit/9223209be11e93c1b701054c6fff88d46ee54658.diff
LOG: [clang][deps] Handle precompiled headers' AST files
The `PreprocessOnlyAction` doesn't support loading the AST file of a precompiled header. This is problematic for dependency scanning, since the `#include` manufactured for the PCH is treated as textual. This means the PCH contents get scanned with each TU, which is redundant. Moreover, dependencies of the PCH end up being considered dependency of the TU.
To handle AST file of PCH properly, this patch creates new `FrontendAction` that behaves the same way `PreprocessorOnlyAction` does, but treats the manufactured PCH `#include` as a normal compilation would (by not claiming it only uses a preprocessor and creating the default AST consumer).
The AST file is now reported as a file dependency of the TU.
Depends on D103519.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D103524
Added:
Modified:
clang/include/clang/Frontend/FrontendActions.h
clang/lib/Frontend/FrontendActions.cpp
clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
clang/test/ClangScanDeps/modules-pch.c
Removed:
################################################################################
diff --git a/clang/include/clang/Frontend/FrontendActions.h b/clang/include/clang/Frontend/FrontendActions.h
index 25ca95980806..ff8d4417eaa4 100644
--- a/clang/include/clang/Frontend/FrontendActions.h
+++ b/clang/include/clang/Frontend/FrontendActions.h
@@ -34,6 +34,17 @@ class InitOnlyAction : public FrontendAction {
bool usesPreprocessorOnly() const override { return false; }
};
+/// Preprocessor-based frontend action that also loads PCH files.
+class ReadPCHAndPreprocessAction : public FrontendAction {
+ void ExecuteAction() override;
+
+ std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
+ StringRef InFile) override;
+
+public:
+ bool usesPreprocessorOnly() const override { return false; }
+};
+
class DumpCompilerOptionsAction : public FrontendAction {
std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
StringRef InFile) override {
diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index b3f6cfcf57e3..6df57cbb45ae 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -62,6 +62,27 @@ InitOnlyAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
void InitOnlyAction::ExecuteAction() {
}
+// Basically PreprocessOnlyAction::ExecuteAction.
+void ReadPCHAndPreprocessAction::ExecuteAction() {
+ Preprocessor &PP = getCompilerInstance().getPreprocessor();
+
+ // Ignore unknown pragmas.
+ PP.IgnorePragmas();
+
+ Token Tok;
+ // Start parsing the specified input file.
+ PP.EnterMainSourceFile();
+ do {
+ PP.Lex(Tok);
+ } while (Tok.isNot(tok::eof));
+}
+
+std::unique_ptr<ASTConsumer>
+ReadPCHAndPreprocessAction::CreateASTConsumer(CompilerInstance &CI,
+ StringRef InFile) {
+ return std::make_unique<ASTConsumer>();
+}
+
//===----------------------------------------------------------------------===//
// AST Consumer Actions
//===----------------------------------------------------------------------===//
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
index ecaeeed1a061..0df515a4c99f 100644
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
@@ -73,6 +73,8 @@ class DependencyScanningAction : public tooling::ToolAction {
if (!Compiler.hasDiagnostics())
return false;
+ Compiler.getPreprocessorOpts().AllowPCHWithDifferentModulesCachePath = true;
+
// Use the dependency scanning optimized file system if we can.
if (DepFS) {
const CompilerInvocation &CI = Compiler.getInvocation();
@@ -133,7 +135,7 @@ class DependencyScanningAction : public tooling::ToolAction {
// the impact of strict context hashing.
Compiler.getHeaderSearchOpts().ModulesStrictContextHash = true;
- auto Action = std::make_unique<PreprocessOnlyAction>();
+ auto Action = std::make_unique<ReadPCHAndPreprocessAction>();
const bool Result = Compiler.ExecuteAction(*Action);
if (!DepFS)
FileMgr->clearStatCache();
diff --git a/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp b/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
index dfd853822327..3271075d9281 100644
--- a/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
+++ b/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
@@ -156,6 +156,9 @@ void ModuleDepCollectorPP::EndOfMainFile() {
MDC.MainFile = std::string(
Instance.getSourceManager().getFileEntryForID(MainFileID)->getName());
+ if (!Instance.getPreprocessorOpts().ImplicitPCHInclude.empty())
+ MDC.FileDeps.push_back(Instance.getPreprocessorOpts().ImplicitPCHInclude);
+
for (const Module *M : DirectModularDeps)
handleTopLevelModule(M);
diff --git a/clang/test/ClangScanDeps/modules-pch.c b/clang/test/ClangScanDeps/modules-pch.c
index ddb6949f5e6f..020818f74ed6 100644
--- a/clang/test/ClangScanDeps/modules-pch.c
+++ b/clang/test/ClangScanDeps/modules-pch.c
@@ -9,5 +9,52 @@
// Scan dependencies of the TU:
//
// RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch/cdb_tu.json > %t/cdb.json
+// RUN: echo -%t > %t/result_tu.json
+// FIXME: Make this work with '-mode preprocess-minimized-sources'.
// RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full \
-// RUN: -generate-modules-path-args -module-files-dir %t/build
+// RUN: -generate-modules-path-args -module-files-dir %t/build -mode preprocess >> %t/result_tu.json
+// RUN: cat %t/result_tu.json | sed 's:\\\\\?:/:g' | FileCheck %s -check-prefix=CHECK-TU
+//
+// CHECK-TU: -[[PREFIX:.*]]
+// CHECK-TU-NEXT: {
+// CHECK-TU-NEXT: "modules": [
+// CHECK-TU-NEXT: {
+// CHECK-TU-NEXT: "clang-module-deps": [],
+// CHECK-TU-NEXT: "clang-modulemap-file": "[[PREFIX]]/module.modulemap",
+// CHECK-TU-NEXT: "command-line": [
+// CHECK-TU-NEXT: "-cc1",
+// CHECK-TU: "-emit-module",
+// CHECK-TU: "-fmodule-name=ModTU",
+// CHECK-TU: "-fno-implicit-modules",
+// CHECK-TU: ],
+// CHECK-TU-NEXT: "context-hash": "[[HASH_MOD_TU:.*]]",
+// CHECK-TU-NEXT: "file-deps": [
+// CHECK-TU-NEXT: "[[PREFIX]]/mod_tu.h",
+// CHECK-TU-NEXT: "[[PREFIX]]/module.modulemap"
+// CHECK-TU-NEXT: ],
+// CHECK-TU-NEXT: "name": "ModTU"
+// CHECK-TU-NEXT: }
+// CHECK-TU-NEXT: ],
+// CHECK-TU-NEXT: "translation-units": [
+// CHECK-TU-NEXT: {
+// CHECK-TU-NEXT: "clang-context-hash": "[[HASH_TU:.*]]",
+// CHECK-TU-NEXT: "clang-module-deps": [
+// CHECK-TU-NEXT: {
+// CHECK-TU-NEXT: "context-hash": "[[HASH_MOD_TU]]",
+// CHECK-TU-NEXT: "module-name": "ModTU"
+// CHECK-TU-NEXT: }
+// CHECK-TU-NEXT: ],
+// CHECK-TU-NEXT: "command-line": [
+// CHECK-TU-NEXT: "-fno-implicit-modules",
+// CHECK-TU-NEXT: "-fno-implicit-module-maps",
+// CHECK-TU-NEXT: "-fmodule-file=[[PREFIX]]/build/[[HASH_MOD_TU]]/ModTU-{{.*}}.pcm",
+// CHECK-TU-NEXT: "-fmodule-map-file=[[PREFIX]]/module.modulemap"
+// CHECK-TU-NEXT: ],
+// CHECK-TU-NEXT: "file-deps": [
+// CHECK-TU-NEXT: "[[PREFIX]]/tu.c",
+// CHECK-TU-NEXT: "[[PREFIX]]/pch.h.gch"
+// CHECK-TU-NEXT: ],
+// CHECK-TU-NEXT: "input-file": "[[PREFIX]]/tu.c"
+// CHECK-TU-NEXT: }
+// CHECK-TU-NEXT: ]
+// CHECK-TU-NEXT: }
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