[clang] 227f719 - [clang][modules][deps] Avoid checks for relocated modules
Jan Svoboda via cfe-commits
cfe-commits at lists.llvm.org
Mon Jul 17 13:51:44 PDT 2023
Author: Jan Svoboda
Date: 2023-07-17T13:50:24-07:00
New Revision: 227f71995804fa5df3f917ae3a7b1499cd24726c
URL: https://github.com/llvm/llvm-project/commit/227f71995804fa5df3f917ae3a7b1499cd24726c
DIFF: https://github.com/llvm/llvm-project/commit/227f71995804fa5df3f917ae3a7b1499cd24726c.diff
LOG: [clang][modules][deps] Avoid checks for relocated modules
Currently, `ASTReader` performs some checks to diagnose relocated modules. This can add quite a bit of overhead to the scanner: it requires looking up, parsing and resolving module maps for all transitively loaded module files (and all the module maps encountered in the search paths on the way). Most of those checks are not really useful in the scanner anyway, since it uses strict context hash and immutable filesystem, which prevent those scenarios in the first place.
This can speed up scanning by up to 30%.
Depends on D150292.
Reviewed By: benlangmuir
Differential Revision: https://reviews.llvm.org/D150320
Added:
Modified:
clang/include/clang/Lex/PreprocessorOptions.h
clang/lib/Serialization/ASTReader.cpp
clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
clang/test/ClangScanDeps/header-search-pruning-transitive.c
Removed:
################################################################################
diff --git a/clang/include/clang/Lex/PreprocessorOptions.h b/clang/include/clang/Lex/PreprocessorOptions.h
index 432f5dfa9bce95..058194bcde72e5 100644
--- a/clang/include/clang/Lex/PreprocessorOptions.h
+++ b/clang/include/clang/Lex/PreprocessorOptions.h
@@ -69,6 +69,9 @@ class PreprocessorOptions {
std::vector<std::string> Includes;
std::vector<std::string> MacroIncludes;
+ /// Perform extra checks when loading PCM files for mutable file systems.
+ bool ModulesCheckRelocated = true;
+
/// Initialize the preprocessor with the compiler and target specific
/// predefines.
bool UsePredefines = true;
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 0671f791530dd4..5f756961c6e1d0 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -2990,6 +2990,9 @@ ASTReader::ReadControlBlock(ModuleFile &F,
BaseDirectoryAsWritten = Blob;
assert(!F.ModuleName.empty() &&
"MODULE_DIRECTORY found before MODULE_NAME");
+ F.BaseDirectory = std::string(Blob);
+ if (!PP.getPreprocessorOpts().ModulesCheckRelocated)
+ break;
// If we've already loaded a module map file covering this module, we may
// have a better path for it (relative to the current build).
Module *M = PP.getHeaderSearchInfo().lookupModule(
@@ -3011,8 +3014,6 @@ ASTReader::ReadControlBlock(ModuleFile &F,
}
}
F.BaseDirectory = std::string(M->Directory->getName());
- } else {
- F.BaseDirectory = std::string(Blob);
}
break;
}
@@ -3990,7 +3991,8 @@ ASTReader::ReadModuleMapFileBlock(RecordData &Record, ModuleFile &F,
// usable header search context.
assert(!F.ModuleName.empty() &&
"MODULE_NAME should come before MODULE_MAP_FILE");
- if (F.Kind == MK_ImplicitModule && ModuleMgr.begin()->Kind != MK_MainFile) {
+ if (PP.getPreprocessorOpts().ModulesCheckRelocated &&
+ F.Kind == MK_ImplicitModule && ModuleMgr.begin()->Kind != MK_MainFile) {
// An implicitly-loaded module file should have its module listed in some
// module map file that we've already loaded.
Module *M =
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
index baf76f01cfb54c..28206dceadd972 100644
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
@@ -253,6 +253,9 @@ class DependencyScanningAction : public tooling::ToolAction {
// context hashing.
ScanInstance.getHeaderSearchOpts().ModulesStrictContextHash = true;
+ // Avoid some checks and module map parsing when loading PCM files.
+ ScanInstance.getPreprocessorOpts().ModulesCheckRelocated = false;
+
std::unique_ptr<FrontendAction> Action;
if (ModuleName)
diff --git a/clang/test/ClangScanDeps/header-search-pruning-transitive.c b/clang/test/ClangScanDeps/header-search-pruning-transitive.c
index 512bf5ec5cc6fb..b56e10cac1eeb5 100644
--- a/clang/test/ClangScanDeps/header-search-pruning-transitive.c
+++ b/clang/test/ClangScanDeps/header-search-pruning-transitive.c
@@ -72,8 +72,8 @@ module X { header "X.h" }
// CHECK: ],
// CHECK-NEXT: "context-hash": "[[HASH_X:.*]]",
// CHECK-NEXT: "file-deps": [
-// CHECK-NEXT: "[[PREFIX]]/./X.h",
-// CHECK-NEXT: "[[PREFIX]]/./module.modulemap"
+// CHECK-NEXT: "[[PREFIX]]/X.h",
+// CHECK-NEXT: "[[PREFIX]]/module.modulemap"
// CHECK-NEXT: ],
// CHECK-NEXT: "name": "X"
// CHECK-NEXT: },
@@ -84,11 +84,11 @@ module X { header "X.h" }
// CHECK: ],
// CHECK-NEXT: "context-hash": "[[HASH_Y_WITH_A]]",
// CHECK-NEXT: "file-deps": [
-// CHECK-NEXT: "[[PREFIX]]/./Y.h",
-// CHECK-NEXT: "[[PREFIX]]/./a/a.h",
-// CHECK-NEXT: "[[PREFIX]]/./begin/begin.h",
-// CHECK-NEXT: "[[PREFIX]]/./end/end.h",
-// CHECK-NEXT: "[[PREFIX]]/./module.modulemap"
+// CHECK-NEXT: "[[PREFIX]]/Y.h",
+// CHECK-NEXT: "[[PREFIX]]/a/a.h",
+// CHECK-NEXT: "[[PREFIX]]/begin/begin.h",
+// CHECK-NEXT: "[[PREFIX]]/end/end.h",
+// CHECK-NEXT: "[[PREFIX]]/module.modulemap"
// CHECK-NEXT: ],
// CHECK-NEXT: "name": "Y"
// CHECK-NEXT: }
@@ -126,8 +126,8 @@ module X { header "X.h" }
// also has a
diff erent context hash from the first version of module X.
// CHECK-NOT: "context-hash": "[[HASH_X]]",
// CHECK: "file-deps": [
-// CHECK-NEXT: "[[PREFIX]]/./X.h",
-// CHECK-NEXT: "[[PREFIX]]/./module.modulemap"
+// CHECK-NEXT: "[[PREFIX]]/X.h",
+// CHECK-NEXT: "[[PREFIX]]/module.modulemap"
// CHECK-NEXT: ],
// CHECK-NEXT: "name": "X"
// CHECK-NEXT: },
@@ -138,10 +138,10 @@ module X { header "X.h" }
// CHECK: ],
// CHECK-NEXT: "context-hash": "[[HASH_Y_WITHOUT_A]]",
// CHECK-NEXT: "file-deps": [
-// CHECK-NEXT: "[[PREFIX]]/./Y.h",
-// CHECK-NEXT: "[[PREFIX]]/./begin/begin.h",
-// CHECK-NEXT: "[[PREFIX]]/./end/end.h",
-// CHECK-NEXT: "[[PREFIX]]/./module.modulemap"
+// CHECK-NEXT: "[[PREFIX]]/Y.h",
+// CHECK-NEXT: "[[PREFIX]]/begin/begin.h",
+// CHECK-NEXT: "[[PREFIX]]/end/end.h",
+// CHECK-NEXT: "[[PREFIX]]/module.modulemap"
// CHECK-NEXT: ],
// CHECK-NEXT: "name": "Y"
// CHECK-NEXT: }
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