r312917 - [PCH] Allow VFS to be used for tests that generate PCH files
Cameron Desrochers via cfe-commits
cfe-commits at lists.llvm.org
Mon Sep 11 08:03:23 PDT 2017
Author: cameron314
Date: Mon Sep 11 08:03:23 2017
New Revision: 312917
URL: http://llvm.org/viewvc/llvm-project?rev=312917&view=rev
Log:
[PCH] Allow VFS to be used for tests that generate PCH files
When using a virtual file-system (VFS) and a preamble file (PCH) is generated,
it is generated on-disk in the real file-system instead of in the VFS (which
makes sense, since the VFS is read-only). However, when subsequently reading
the generated PCH, the frontend passes through the VFS it has been given --
resulting in an error and a failed parse (since the VFS doesn't contain the
PCH; the real filesystem does).
This patch fixes that by detecting when a VFS is being used for a parse that
needs to work with a PCH file, and creating an overlay VFS that includes the
PCH file from the real file-system.
This allows tests to be written which make use of both PCH files and a VFS.
Differential Revision: https://reviews.llvm.org/D37474
Added:
cfe/trunk/unittests/Frontend/PCHPreambleTest.cpp (with props)
Modified:
cfe/trunk/include/clang/Frontend/PrecompiledPreamble.h
cfe/trunk/lib/Frontend/ASTUnit.cpp
cfe/trunk/unittests/Frontend/CMakeLists.txt
Modified: cfe/trunk/include/clang/Frontend/PrecompiledPreamble.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Frontend/PrecompiledPreamble.h?rev=312917&r1=312916&r2=312917&view=diff
==============================================================================
--- cfe/trunk/include/clang/Frontend/PrecompiledPreamble.h (original)
+++ cfe/trunk/include/clang/Frontend/PrecompiledPreamble.h Mon Sep 11 08:03:23 2017
@@ -97,9 +97,12 @@ public:
PrecompiledPreamble(PrecompiledPreamble &&) = default;
PrecompiledPreamble &operator=(PrecompiledPreamble &&) = default;
- /// PreambleBounds used to build the preamble
+ /// PreambleBounds used to build the preamble.
PreambleBounds getBounds() const;
+ /// The temporary file path at which the preamble PCH was placed.
+ StringRef GetPCHPath() const { return PCHFile.getFilePath(); }
+
/// Check whether PrecompiledPreamble can be reused for the new contents(\p
/// MainFileBuffer) of the main file.
bool CanReuse(const CompilerInvocation &Invocation,
Modified: cfe/trunk/lib/Frontend/ASTUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/ASTUnit.cpp?rev=312917&r1=312916&r2=312917&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/ASTUnit.cpp (original)
+++ cfe/trunk/lib/Frontend/ASTUnit.cpp Mon Sep 11 08:03:23 2017
@@ -1009,6 +1009,24 @@ static void checkAndSanitizeDiags(SmallV
}
}
+static IntrusiveRefCntPtr<vfs::FileSystem> createVFSOverlayForPreamblePCH(
+ StringRef PCHFilename,
+ IntrusiveRefCntPtr<vfs::FileSystem> RealFS,
+ IntrusiveRefCntPtr<vfs::FileSystem> VFS) {
+ // We want only the PCH file from the real filesystem to be available,
+ // so we create an in-memory VFS with just that and overlay it on top.
+ auto Buf = RealFS->getBufferForFile(PCHFilename);
+ if (!Buf)
+ return VFS;
+ IntrusiveRefCntPtr<vfs::InMemoryFileSystem>
+ PCHFS(new vfs::InMemoryFileSystem());
+ PCHFS->addFile(PCHFilename, 0, std::move(*Buf));
+ IntrusiveRefCntPtr<vfs::OverlayFileSystem>
+ Overlay(new vfs::OverlayFileSystem(VFS));
+ Overlay->pushOverlay(PCHFS);
+ return Overlay;
+}
+
/// Parse the source file into a translation unit using the given compiler
/// invocation, replacing the current translation unit.
///
@@ -1030,6 +1048,24 @@ bool ASTUnit::Parse(std::shared_ptr<PCHC
Clang->setVirtualFileSystem(VFS);
}
+ // Make sure we can access the PCH file even if we're using a VFS
+ if (!VFS && FileMgr)
+ VFS = FileMgr->getVirtualFileSystem();
+ IntrusiveRefCntPtr<vfs::FileSystem> RealFS = vfs::getRealFileSystem();
+ if (OverrideMainBuffer && VFS && RealFS && VFS != RealFS &&
+ !VFS->exists(Preamble->GetPCHPath())) {
+ // We have a slight inconsistency here -- we're using the VFS to
+ // read files, but the PCH was generated in the real file system.
+ VFS = createVFSOverlayForPreamblePCH(Preamble->GetPCHPath(), RealFS, VFS);
+ if (FileMgr) {
+ FileMgr = new FileManager(FileMgr->getFileSystemOpts(), VFS);
+ Clang->setFileManager(FileMgr.get());
+ }
+ else {
+ Clang->setVirtualFileSystem(VFS);
+ }
+ }
+
// Recover resources if we crash before exiting this method.
llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
CICleanup(Clang.get());
Modified: cfe/trunk/unittests/Frontend/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Frontend/CMakeLists.txt?rev=312917&r1=312916&r2=312917&view=diff
==============================================================================
--- cfe/trunk/unittests/Frontend/CMakeLists.txt (original)
+++ cfe/trunk/unittests/Frontend/CMakeLists.txt Mon Sep 11 08:03:23 2017
@@ -6,6 +6,7 @@ add_clang_unittest(FrontendTests
ASTUnitTest.cpp
FrontendActionTest.cpp
CodeGenActionTest.cpp
+ PCHPreambleTest.cpp
)
target_link_libraries(FrontendTests
clangAST
Added: cfe/trunk/unittests/Frontend/PCHPreambleTest.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Frontend/PCHPreambleTest.cpp?rev=312917&view=auto
==============================================================================
--- cfe/trunk/unittests/Frontend/PCHPreambleTest.cpp (added)
+++ cfe/trunk/unittests/Frontend/PCHPreambleTest.cpp Mon Sep 11 08:03:23 2017
@@ -0,0 +1,156 @@
+//====-- unittests/Frontend/PCHPreambleTest.cpp - FrontendAction tests ---====//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/Frontend/FrontendOptions.h"
+#include "clang/Lex/PreprocessorOptions.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/FileManager.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+class ReadCountingInMemoryFileSystem : public vfs::InMemoryFileSystem
+{
+ std::map<std::string, unsigned> ReadCounts;
+
+public:
+ ErrorOr<std::unique_ptr<vfs::File>> openFileForRead(const Twine &Path) override
+ {
+ SmallVector<char, 128> PathVec;
+ Path.toVector(PathVec);
+ llvm::sys::path::remove_dots(PathVec, true);
+ ++ReadCounts[std::string(PathVec.begin(), PathVec.end())];
+ return InMemoryFileSystem::openFileForRead(Path);
+ }
+
+ unsigned GetReadCount(const Twine &Path) const
+ {
+ auto it = ReadCounts.find(Path.str());
+ return it == ReadCounts.end() ? 0 : it->second;
+ }
+};
+
+class PCHPreambleTest : public ::testing::Test {
+ IntrusiveRefCntPtr<ReadCountingInMemoryFileSystem> VFS;
+ StringMap<std::string> RemappedFiles;
+ std::shared_ptr<PCHContainerOperations> PCHContainerOpts;
+ FileSystemOptions FSOpts;
+
+public:
+ void SetUp() override {
+ VFS = new ReadCountingInMemoryFileSystem();
+ // We need the working directory to be set to something absolute,
+ // otherwise it ends up being inadvertently set to the current
+ // working directory in the real file system due to a series of
+ // unfortunate conditions interacting badly.
+ // What's more, this path *must* be absolute on all (real)
+ // filesystems, so just '/' won't work (e.g. on Win32).
+ VFS->setCurrentWorkingDirectory("//./");
+ }
+
+ void TearDown() override {
+ }
+
+ void AddFile(const std::string &Filename, const std::string &Contents) {
+ ::time_t now;
+ ::time(&now);
+ VFS->addFile(Filename, now, MemoryBuffer::getMemBufferCopy(Contents, Filename));
+ }
+
+ void RemapFile(const std::string &Filename, const std::string &Contents) {
+ RemappedFiles[Filename] = Contents;
+ }
+
+ std::unique_ptr<ASTUnit> ParseAST(const std::string &EntryFile) {
+ PCHContainerOpts = std::make_shared<PCHContainerOperations>();
+ std::shared_ptr<CompilerInvocation> CI(new CompilerInvocation);
+ CI->getFrontendOpts().Inputs.push_back(
+ FrontendInputFile(EntryFile, FrontendOptions::getInputKindForExtension(
+ llvm::sys::path::extension(EntryFile).substr(1))));
+
+ CI->getTargetOpts().Triple = "i386-unknown-linux-gnu";
+
+ CI->getPreprocessorOpts().RemappedFileBuffers = GetRemappedFiles();
+
+ PreprocessorOptions &PPOpts = CI->getPreprocessorOpts();
+ PPOpts.RemappedFilesKeepOriginalName = true;
+
+ IntrusiveRefCntPtr<DiagnosticsEngine>
+ Diags(CompilerInstance::createDiagnostics(new DiagnosticOptions, new DiagnosticConsumer));
+
+ FileManager *FileMgr = new FileManager(FSOpts, VFS);
+
+ std::unique_ptr<ASTUnit> AST = ASTUnit::LoadFromCompilerInvocation(
+ CI, PCHContainerOpts, Diags, FileMgr, false, false,
+ /*PrecompilePreambleAfterNParses=*/1);
+ return AST;
+ }
+
+ bool ReparseAST(const std::unique_ptr<ASTUnit> &AST) {
+ bool reparseFailed = AST->Reparse(PCHContainerOpts, GetRemappedFiles(), VFS);
+ return !reparseFailed;
+ }
+
+ unsigned GetFileReadCount(const std::string &Filename) const {
+ return VFS->GetReadCount(Filename);
+ }
+
+private:
+ std::vector<std::pair<std::string, llvm::MemoryBuffer *>>
+ GetRemappedFiles() const {
+ std::vector<std::pair<std::string, llvm::MemoryBuffer *>> Remapped;
+ for (const auto &RemappedFile : RemappedFiles) {
+ std::unique_ptr<MemoryBuffer> buf = MemoryBuffer::getMemBufferCopy(
+ RemappedFile.second, RemappedFile.first());
+ Remapped.emplace_back(RemappedFile.first(), buf.release());
+ }
+ return Remapped;
+ }
+};
+
+TEST_F(PCHPreambleTest, ReparseWithOverriddenFileDoesNotInvalidatePreamble) {
+ std::string Header1 = "//./header1.h";
+ std::string Header2 = "//./header2.h";
+ std::string MainName = "//./main.cpp";
+ AddFile(Header1, "");
+ AddFile(Header2, "#pragma once");
+ AddFile(MainName,
+ "#include \"//./foo/../header1.h\"\n"
+ "#include \"//./foo/../header2.h\"\n"
+ "int main() { return ZERO; }");
+ RemapFile(Header1, "static const int ZERO = 0;\n");
+
+ std::unique_ptr<ASTUnit> AST(ParseAST(MainName));
+ ASSERT_TRUE(AST.get());
+ ASSERT_FALSE(AST->getDiagnostics().hasErrorOccurred());
+
+ unsigned initialCounts[] = {
+ GetFileReadCount(MainName),
+ GetFileReadCount(Header1),
+ GetFileReadCount(Header2)
+ };
+
+ ASSERT_TRUE(ReparseAST(AST));
+
+ ASSERT_NE(initialCounts[0], GetFileReadCount(MainName));
+ ASSERT_EQ(initialCounts[1], GetFileReadCount(Header1));
+ ASSERT_EQ(initialCounts[2], GetFileReadCount(Header2));
+}
+
+} // anonymous namespace
Propchange: cfe/trunk/unittests/Frontend/PCHPreambleTest.cpp
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