versioner: cache -cc1 flags generated by the clang Driver.
Profiling showed that majority of time spent by versioner was being
spent in the x86 and x86_64 driver statting random files in /usr/lib,
looking for a toolchain. Hardcode a list of per-target flags which
correspond to a subset of the ones generated by clang, and use those
instead of calling out to Driver.
This changes the result of `time versioner` from:
versioner 156.57s user 1180.08s system 4109% cpu 32.525 total
to:
versioner 109.12s user 17.43s system 2433% cpu 5.201 total
Bug: http://b/32748936
Test: python run_tests.py
Change-Id: I7d254a105bf1a283cbba0546321b04e308e703d1
diff --git a/tools/versioner/src/Driver.cpp b/tools/versioner/src/Driver.cpp
new file mode 100644
index 0000000..dad8a1e
--- /dev/null
+++ b/tools/versioner/src/Driver.cpp
@@ -0,0 +1,251 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Driver.h"
+
+#include <err.h>
+#include <string.h>
+
+#include <chrono>
+#include <mutex>
+#include <string>
+#include <thread>
+#include <unordered_map>
+#include <vector>
+
+#include <clang/AST/ASTConsumer.h>
+#include <clang/Basic/Diagnostic.h>
+#include <clang/Basic/TargetInfo.h>
+#include <clang/Driver/Compilation.h>
+#include <clang/Driver/Driver.h>
+#include <clang/Frontend/CompilerInstance.h>
+#include <clang/Frontend/CompilerInvocation.h>
+#include <clang/Frontend/FrontendAction.h>
+#include <clang/Frontend/FrontendActions.h>
+#include <clang/Frontend/TextDiagnosticPrinter.h>
+#include <clang/Frontend/Utils.h>
+#include <clang/FrontendTool/Utils.h>
+#include <llvm/ADT/IntrusiveRefCntPtr.h>
+#include <llvm/ADT/SmallVector.h>
+#include <llvm/ADT/StringRef.h>
+
+#include "Arch.h"
+#include "DeclarationDatabase.h"
+#include "versioner.h"
+
+using namespace std::chrono_literals;
+using namespace std::string_literals;
+
+using namespace clang;
+
+class VersionerASTConsumer : public clang::ASTConsumer {
+ public:
+ HeaderDatabase* header_database;
+ CompilationType type;
+
+ VersionerASTConsumer(HeaderDatabase* header_database, CompilationType type)
+ : header_database(header_database), type(type) {
+ }
+
+ virtual void HandleTranslationUnit(ASTContext& ctx) override {
+ header_database->parseAST(type, ctx);
+ }
+};
+
+class VersionerASTAction : public clang::ASTFrontendAction {
+ public:
+ HeaderDatabase* header_database;
+ CompilationType type;
+
+ VersionerASTAction(HeaderDatabase* header_database, CompilationType type)
+ : header_database(header_database), type(type) {
+ }
+
+ std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance&, llvm::StringRef) override {
+ return std::make_unique<VersionerASTConsumer>(header_database, type);
+ }
+};
+
+static IntrusiveRefCntPtr<DiagnosticsEngine> constructDiags() {
+ IntrusiveRefCntPtr<DiagnosticOptions> diag_opts(new DiagnosticOptions());
+ auto diag_printer = std::make_unique<TextDiagnosticPrinter>(llvm::errs(), diag_opts.get());
+ IntrusiveRefCntPtr<DiagnosticIDs> diag_ids(new DiagnosticIDs());
+ IntrusiveRefCntPtr<DiagnosticsEngine> diags(
+ new DiagnosticsEngine(diag_ids.get(), diag_opts.get(), diag_printer.release()));
+ return diags;
+}
+
+// clang's driver is slow compared to the work it performs to compile our headers.
+// Run it once to generate flags for each target, and memoize the results.
+static std::unordered_map<CompilationType, std::vector<std::string>> cc1_flags;
+static const char* filename_placeholder = "__VERSIONER_PLACEHOLDER__";
+static void generateTargetCC1Flags(CompilationType type,
+ const std::vector<std::string>& include_dirs) {
+ std::vector<std::string> cmd = { "versioner" };
+ cmd.push_back("-std=c11");
+ cmd.push_back("-x");
+ cmd.push_back("c-header");
+ cmd.push_back("-fsyntax-only");
+
+ cmd.push_back("-Wall");
+ cmd.push_back("-Wextra");
+ cmd.push_back("-Werror");
+ cmd.push_back("-Wundef");
+ cmd.push_back("-Wno-unused-macros");
+ cmd.push_back("-Wno-unused-function");
+ cmd.push_back("-Wno-unused-variable");
+ cmd.push_back("-Wno-unknown-attributes");
+ cmd.push_back("-Wno-pragma-once-outside-header");
+
+ cmd.push_back("-target");
+ cmd.push_back(arch_targets[type.arch]);
+
+ cmd.push_back("-DANDROID");
+ cmd.push_back("-D__ANDROID_API__="s + std::to_string(type.api_level));
+ cmd.push_back("-D_FORTIFY_SOURCE=2");
+ cmd.push_back("-D_GNU_SOURCE");
+ cmd.push_back("-D_FILE_OFFSET_BITS="s + std::to_string(type.file_offset_bits));
+
+ cmd.push_back("-nostdinc");
+
+ if (add_include) {
+ const char* top = getenv("ANDROID_BUILD_TOP");
+ if (!top) {
+ errx(1, "-i passed, but ANDROID_BUILD_TOP is unset");
+ }
+ cmd.push_back("-include");
+ cmd.push_back(to_string(top) + "/bionic/libc/include/android/versioning.h");
+ }
+
+ for (const auto& dir : include_dirs) {
+ cmd.push_back("-isystem");
+ cmd.push_back(dir);
+ }
+
+ cmd.push_back(filename_placeholder);
+
+ auto diags = constructDiags();
+ driver::Driver driver("versioner", llvm::sys::getDefaultTargetTriple(), *diags);
+ driver.setCheckInputsExist(false);
+
+ llvm::SmallVector<const char*, 32> driver_args;
+ for (const std::string& str : cmd) {
+ driver_args.push_back(str.c_str());
+ }
+
+ std::unique_ptr<driver::Compilation> Compilation(driver.BuildCompilation(driver_args));
+ const driver::JobList& jobs = Compilation->getJobs();
+ if (jobs.size() != 1) {
+ errx(1, "driver returned %zu jobs for %s", jobs.size(), to_string(type).c_str());
+ }
+
+ const driver::Command& driver_cmd = llvm::cast<driver::Command>(*jobs.begin());
+ const driver::ArgStringList& cc_args = driver_cmd.getArguments();
+
+ if (cc_args.size() == 0) {
+ errx(1, "driver returned empty command for %s", to_string(type).c_str());
+ }
+
+ std::vector<std::string> result(cc_args.begin(), cc_args.end());
+
+ {
+ static std::mutex cc1_init_mutex;
+ std::unique_lock<std::mutex> lock(cc1_init_mutex);
+ if (cc1_flags.count(type) > 0) {
+ errx(1, "attemped to generate cc1 flags for existing CompilationType %s",
+ to_string(type).c_str());
+ }
+
+ cc1_flags.emplace(std::make_pair(type, std::move(result)));
+ }
+}
+
+static std::vector<const char*> getCC1Command(CompilationType type, const std::string& filename) {
+ const auto& target_flag_it = cc1_flags.find(type);
+ if (target_flag_it == cc1_flags.end()) {
+ errx(1, "failed to find target flags for CompilationType %s", to_string(type).c_str());
+ }
+
+ std::vector<const char*> result;
+ for (const std::string& flag : target_flag_it->second) {
+ if (flag == "-disable-free") {
+ continue;
+ } else if (flag == filename_placeholder) {
+ result.push_back(filename.c_str());
+ } else {
+ result.push_back(flag.c_str());
+ }
+ }
+ return result;
+}
+
+void initializeTargetCC1FlagCache(const std::set<CompilationType>& types,
+ const std::unordered_map<Arch, CompilationRequirements>& reqs) {
+ if (!cc1_flags.empty()) {
+ errx(1, "reinitializing target CC1 flag cache?");
+ }
+
+ auto start = std::chrono::high_resolution_clock::now();
+ std::vector<std::thread> threads;
+ for (const CompilationType type : types) {
+ threads.emplace_back([type, &reqs]() {
+ const auto& arch_req_it = reqs.find(type.arch);
+ if (arch_req_it == reqs.end()) {
+ errx(1, "CompilationRequirement map missing entry for CompilationType %s",
+ to_string(type).c_str());
+ }
+
+ generateTargetCC1Flags(type, arch_req_it->second.dependencies);
+ });
+ }
+ for (auto& thread : threads) {
+ thread.join();
+ }
+ auto end = std::chrono::high_resolution_clock::now();
+
+ if (verbose) {
+ auto diff = (end - start) / 1.0ms;
+ printf("Generated compiler flags for %zu targets in %0.2Lfms\n", types.size(), diff);
+ }
+
+ if (cc1_flags.empty()) {
+ errx(1, "failed to initialize target CC1 flag cache");
+ }
+}
+
+void compileHeader(HeaderDatabase* header_database, CompilationType type,
+ const std::string& filename) {
+ auto diags = constructDiags();
+ std::vector<const char*> cc1_flags = getCC1Command(type, filename);
+ auto invocation = std::make_unique<CompilerInvocation>();
+ if (!CompilerInvocation::CreateFromArgs(*invocation.get(), &cc1_flags.front(),
+ &cc1_flags.front() + cc1_flags.size(), *diags)) {
+ errx(1, "failed to create CompilerInvocation");
+ }
+
+ clang::CompilerInstance Compiler;
+ Compiler.setInvocation(invocation.release());
+ Compiler.setDiagnostics(diags.get());
+
+ VersionerASTAction versioner_action(header_database, type);
+ if (!Compiler.ExecuteAction(versioner_action)) {
+ errx(1, "compilation generated warnings or errors");
+ }
+
+ if (diags->getNumWarnings() || diags->hasErrorOccurred()) {
+ errx(1, "compilation generated warnings or errors");
+ }
+}