[libclang] Allow skipping function bodies in preamble only

As an addition to CXTranslationUnit_SkipFunctionBodies, provide the
new option CXTranslationUnit_LimitSkipFunctionBodiesToPreamble,
which constraints the skipping of functions bodies to the preamble
only. Function bodies in the main file are not affected if this
option is set.

Skipping function bodies only in the preamble is what clangd already
does and the introduced flag implements it for libclang clients.

Patch by Nikolai Kosjar.

Differential Revision: https://reviews.llvm.org/D45815

llvm-svn: 332578

1 files changed, 47 insertions, 36 deletions

diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 9b672d97551..0ce7adb620e 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -1268,13 +1268,13 @@ makeStandaloneDiagnostic(const LangOptions &LangOpts,
 /// \returns If the precompiled preamble can be used, returns a newly-allocated
 /// buffer that should be used in place of the main file when doing so.
 /// Otherwise, returns a NULL pointer.
-std::unique_ptr<llvm::MemoryBuffer>
-ASTUnit::getMainBufferWithPrecompiledPreamble(
-    std::shared_ptr<PCHContainerOperations> PCHContainerOps,
-    const CompilerInvocation &PreambleInvocationIn,
-    IntrusiveRefCntPtr<vfs::FileSystem> VFS, bool AllowRebuild,
-    unsigned MaxLines) {
-  auto MainFilePath =
+std::unique_ptr<llvm::MemoryBuffer>

+ASTUnit::getMainBufferWithPrecompiledPreamble(

+    std::shared_ptr<PCHContainerOperations> PCHContainerOps,

+    CompilerInvocation &PreambleInvocationIn,

+    IntrusiveRefCntPtr<vfs::FileSystem> VFS, bool AllowRebuild,

+    unsigned MaxLines) {

+  auto MainFilePath =

       PreambleInvocationIn.getFrontendOpts().Inputs[0].getFile();
   std::unique_ptr<llvm::MemoryBuffer> MainFileBuffer =
       getBufferForFileHandlingRemapping(PreambleInvocationIn, VFS.get(),
@@ -1335,15 +1335,24 @@ ASTUnit::getMainBufferWithPrecompiledPreamble(
                       &NewPreambleDiagsStandalone);
 
     // We did not previously compute a preamble, or it can't be reused anyway.
-    SimpleTimer PreambleTimer(WantTiming);
-    PreambleTimer.setOutput("Precompiling preamble");
-
-    llvm::ErrorOr<PrecompiledPreamble> NewPreamble = PrecompiledPreamble::Build(
-        PreambleInvocationIn, MainFileBuffer.get(), Bounds, *Diagnostics, VFS,
-        PCHContainerOps, /*StoreInMemory=*/false, Callbacks);
-    if (NewPreamble) {
-      Preamble = std::move(*NewPreamble);
-      PreambleRebuildCounter = 1;
+    SimpleTimer PreambleTimer(WantTiming);

+    PreambleTimer.setOutput("Precompiling preamble");

+

+    const bool PreviousSkipFunctionBodies =

+        PreambleInvocationIn.getFrontendOpts().SkipFunctionBodies;

+    if (SkipFunctionBodies == SkipFunctionBodiesScope::Preamble)

+      PreambleInvocationIn.getFrontendOpts().SkipFunctionBodies = true;

+

+    llvm::ErrorOr<PrecompiledPreamble> NewPreamble = PrecompiledPreamble::Build(

+        PreambleInvocationIn, MainFileBuffer.get(), Bounds, *Diagnostics, VFS,

+        PCHContainerOps, /*StoreInMemory=*/false, Callbacks);

+

+    PreambleInvocationIn.getFrontendOpts().SkipFunctionBodies =

+        PreviousSkipFunctionBodies;

+

+    if (NewPreamble) {

+      Preamble = std::move(*NewPreamble);

+      PreambleRebuildCounter = 1;

     } else {
       switch (static_cast<BuildPreambleError>(NewPreamble.getError().value())) {
       case BuildPreambleError::CouldntCreateTempFile:
@@ -1688,13 +1697,13 @@ ASTUnit *ASTUnit::LoadFromCommandLine(
     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
     IntrusiveRefCntPtr<DiagnosticsEngine> Diags, StringRef ResourceFilesPath,
     bool OnlyLocalDecls, bool CaptureDiagnostics,
-    ArrayRef<RemappedFile> RemappedFiles, bool RemappedFilesKeepOriginalName,
-    unsigned PrecompilePreambleAfterNParses, TranslationUnitKind TUKind,
-    bool CacheCodeCompletionResults, bool IncludeBriefCommentsInCodeCompletion,
-    bool AllowPCHWithCompilerErrors, bool SkipFunctionBodies,
-    bool SingleFileParse, bool UserFilesAreVolatile, bool ForSerialization,
-    llvm::Optional<StringRef> ModuleFormat, std::unique_ptr<ASTUnit> *ErrAST,
-    IntrusiveRefCntPtr<vfs::FileSystem> VFS) {
+    ArrayRef<RemappedFile> RemappedFiles, bool RemappedFilesKeepOriginalName,

+    unsigned PrecompilePreambleAfterNParses, TranslationUnitKind TUKind,

+    bool CacheCodeCompletionResults, bool IncludeBriefCommentsInCodeCompletion,

+    bool AllowPCHWithCompilerErrors, SkipFunctionBodiesScope SkipFunctionBodies,

+    bool SingleFileParse, bool UserFilesAreVolatile, bool ForSerialization,

+    llvm::Optional<StringRef> ModuleFormat, std::unique_ptr<ASTUnit> *ErrAST,

+    IntrusiveRefCntPtr<vfs::FileSystem> VFS) {

   assert(Diags.get() && "no DiagnosticsEngine was provided");
 
   SmallVector<StoredDiagnostic, 4> StoredDiagnostics;
@@ -1721,13 +1730,14 @@ ASTUnit *ASTUnit::LoadFromCommandLine(
   PPOpts.AllowPCHWithCompilerErrors = AllowPCHWithCompilerErrors;
   PPOpts.SingleFileParseMode = SingleFileParse;
 
-  // Override the resources path.
-  CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;
-
-  CI->getFrontendOpts().SkipFunctionBodies = SkipFunctionBodies;
-
-  if (ModuleFormat)
-    CI->getHeaderSearchOpts().ModuleFormat = ModuleFormat.getValue();
+  // Override the resources path.

+  CI->getHeaderSearchOpts().ResourceDir = ResourceFilesPath;

+

+  CI->getFrontendOpts().SkipFunctionBodies =

+      SkipFunctionBodies == SkipFunctionBodiesScope::PreambleAndMainFile;

+

+  if (ModuleFormat)

+    CI->getHeaderSearchOpts().ModuleFormat = ModuleFormat.getValue();

 
   // Create the AST unit.
   std::unique_ptr<ASTUnit> AST;
@@ -1747,12 +1757,13 @@ ASTUnit *ASTUnit::LoadFromCommandLine(
   AST->TUKind = TUKind;
   AST->ShouldCacheCodeCompletionResults = CacheCodeCompletionResults;
   AST->IncludeBriefCommentsInCodeCompletion
-    = IncludeBriefCommentsInCodeCompletion;
-  AST->UserFilesAreVolatile = UserFilesAreVolatile;
-  AST->Invocation = CI;
-  if (ForSerialization)
-    AST->WriterData.reset(new ASTWriterData(*AST->PCMCache));
-  // Zero out now to ease cleanup during crash recovery.
+    = IncludeBriefCommentsInCodeCompletion;

+  AST->UserFilesAreVolatile = UserFilesAreVolatile;

+  AST->Invocation = CI;

+  AST->SkipFunctionBodies = SkipFunctionBodies;

+  if (ForSerialization)

+    AST->WriterData.reset(new ASTWriterData(*AST->PCMCache));

+  // Zero out now to ease cleanup during crash recovery.

   CI = nullptr;
   Diags = nullptr;