[clang] 1c9a800 - Recommit [C++20] [Modules] Serialize the evaluated constant values for VarDecl
Chuanqi Xu via cfe-commits
cfe-commits at lists.llvm.org
Wed May 24 00:45:46 PDT 2023
Author: Chuanqi Xu
Date: 2023-05-24T15:45:16+08:00
New Revision: 1c9a8004ed88c9a5e42e5b247cb489456559b845
URL: https://github.com/llvm/llvm-project/commit/1c9a8004ed88c9a5e42e5b247cb489456559b845
DIFF: https://github.com/llvm/llvm-project/commit/1c9a8004ed88c9a5e42e5b247cb489456559b845.diff
LOG: Recommit [C++20] [Modules] Serialize the evaluated constant values for VarDecl
Close https://github.com/llvm/llvm-project/issues/62796.
Previously, we didn't serialize the evaluated result for VarDecl. This
caused the compilation of template metaprogramming become slower than
expect. This patch fixes the issue.
This is a recommit tested with asan built clang.
Added:
clang/test/Modules/pr62796.cppm
clang/unittests/Serialization/VarDeclConstantInitTest.cpp
Modified:
clang/lib/Serialization/ASTReaderDecl.cpp
clang/lib/Serialization/ASTWriter.cpp
clang/unittests/Serialization/CMakeLists.txt
Removed:
################################################################################
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 5ce7007d8acef..fb8677769d09b 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -1659,6 +1659,13 @@ void ASTDeclReader::ReadVarDeclInit(VarDecl *VD) {
EvaluatedStmt *Eval = VD->ensureEvaluatedStmt();
Eval->HasConstantInitialization = (Val & 2) != 0;
Eval->HasConstantDestruction = (Val & 4) != 0;
+ Eval->WasEvaluated = (Val & 8) != 0;
+ if (Eval->WasEvaluated) {
+ Eval->Evaluated = Record.readAPValue();
+ if (Eval->Evaluated.needsCleanup())
+ Reader.getContext().addDestruction(&Eval->Evaluated);
+ }
+
// Store the offset of the initializer. Don't deserialize it yet: it might
// not be needed, and might refer back to the variable, for example if it
// contains a lambda.
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 749aaa4cd6e19..4efc27b3d2434 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -5987,13 +5987,20 @@ void ASTRecordWriter::AddVarDeclInit(const VarDecl *VD) {
return;
}
- unsigned Val = 1;
+ uint64_t Val = 1;
if (EvaluatedStmt *ES = VD->getEvaluatedStmt()) {
Val |= (ES->HasConstantInitialization ? 2 : 0);
Val |= (ES->HasConstantDestruction ? 4 : 0);
- // FIXME: Also emit the constant initializer value.
+ APValue *Evaluated = VD->getEvaluatedValue();
+ // If the evaluted result is constant, emit it.
+ if (Evaluated && (Evaluated->isInt() || Evaluated->isFloat()))
+ Val |= 8;
}
push_back(Val);
+ if (Val & 8) {
+ AddAPValue(*VD->getEvaluatedValue());
+ }
+
writeStmtRef(Init);
}
diff --git a/clang/test/Modules/pr62796.cppm b/clang/test/Modules/pr62796.cppm
new file mode 100644
index 0000000000000..f96e54bc6aded
--- /dev/null
+++ b/clang/test/Modules/pr62796.cppm
@@ -0,0 +1,51 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+//
+// RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/Cache.cppm -o %t/Cache.pcm
+// RUN: %clang_cc1 -std=c++20 %t/Use.cpp -fmodule-file=Fibonacci.Cache=%t/Cache.pcm \
+// RUN: -fsyntax-only -verify
+
+//--- Cache.cppm
+export module Fibonacci.Cache;
+
+export namespace Fibonacci
+{
+ constexpr unsigned long Recursive(unsigned long n)
+ {
+ if (n == 0)
+ return 0;
+ if (n == 1)
+ return 1;
+ return Recursive(n - 2) + Recursive(n - 1);
+ }
+
+ template<unsigned long N>
+ struct Number{};
+
+ struct DefaultStrategy
+ {
+ constexpr unsigned long operator()(unsigned long n, auto... other) const
+ {
+ return (n + ... + other);
+ }
+ };
+
+ constexpr unsigned long Compute(Number<10ul>, auto strategy)
+ {
+ return strategy(Recursive(10ul));
+ }
+
+ template<unsigned long N, typename Strategy = DefaultStrategy>
+ constexpr unsigned long Cache = Compute(Number<N>{}, Strategy{});
+
+ template constexpr unsigned long Cache<10ul>;
+}
+
+//--- Use.cpp
+// expected-no-diagnostics
+import Fibonacci.Cache;
+
+constexpr bool value = Fibonacci::Cache<10ul> == 55;
+
+static_assert(value == true, "");
diff --git a/clang/unittests/Serialization/CMakeLists.txt b/clang/unittests/Serialization/CMakeLists.txt
index cfb4089167aad..88aca2e135200 100644
--- a/clang/unittests/Serialization/CMakeLists.txt
+++ b/clang/unittests/Serialization/CMakeLists.txt
@@ -8,6 +8,7 @@ add_clang_unittest(SerializationTests
InMemoryModuleCacheTest.cpp
ModuleCacheTest.cpp
SourceLocationEncodingTest.cpp
+ VarDeclConstantInitTest.cpp
)
clang_target_link_libraries(SerializationTests
@@ -18,4 +19,5 @@ clang_target_link_libraries(SerializationTests
clangLex
clangSema
clangSerialization
+ clangTooling
)
diff --git a/clang/unittests/Serialization/VarDeclConstantInitTest.cpp b/clang/unittests/Serialization/VarDeclConstantInitTest.cpp
new file mode 100644
index 0000000000000..33fc82b9adc75
--- /dev/null
+++ b/clang/unittests/Serialization/VarDeclConstantInitTest.cpp
@@ -0,0 +1,135 @@
+//===- unittests/Serialization/VarDeclConstantInitTest.cpp - CI tests -----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/Frontend/Utils.h"
+#include "clang/Lex/HeaderSearch.h"
+#include "clang/Tooling/Tooling.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+class VarDeclConstantInitTest : public ::testing::Test {
+ void SetUp() override {
+ ASSERT_FALSE(sys::fs::createUniqueDirectory("modules-test", TestDir));
+ }
+
+ void TearDown() override { sys::fs::remove_directories(TestDir); }
+
+public:
+ SmallString<256> TestDir;
+
+ void addFile(StringRef Path, StringRef Contents) {
+ ASSERT_FALSE(sys::path::is_absolute(Path));
+
+ SmallString<256> AbsPath(TestDir);
+ sys::path::append(AbsPath, Path);
+
+ ASSERT_FALSE(
+ sys::fs::create_directories(llvm::sys::path::parent_path(AbsPath)));
+
+ std::error_code EC;
+ llvm::raw_fd_ostream OS(AbsPath, EC);
+ ASSERT_FALSE(EC);
+ OS << Contents;
+ }
+};
+
+TEST_F(VarDeclConstantInitTest, CachedConstantInit) {
+ addFile("Cached.cppm", R"cpp(
+export module Fibonacci.Cache;
+
+export namespace Fibonacci
+{
+ constexpr unsigned long Recursive(unsigned long n)
+ {
+ if (n == 0)
+ return 0;
+ if (n == 1)
+ return 1;
+ return Recursive(n - 2) + Recursive(n - 1);
+ }
+
+ template<unsigned long N>
+ struct Number{};
+
+ struct DefaultStrategy
+ {
+ constexpr unsigned long operator()(unsigned long n, auto... other) const
+ {
+ return (n + ... + other);
+ }
+ };
+
+ constexpr unsigned long Compute(Number<10ul>, auto strategy)
+ {
+ return strategy(Recursive(10ul));
+ }
+
+ template<unsigned long N, typename Strategy = DefaultStrategy>
+ constexpr unsigned long Cache = Compute(Number<N>{}, Strategy{});
+
+ template constexpr unsigned long Cache<10ul>;
+}
+ )cpp");
+
+ IntrusiveRefCntPtr<DiagnosticsEngine> Diags =
+ CompilerInstance::createDiagnostics(new DiagnosticOptions());
+ CreateInvocationOptions CIOpts;
+ CIOpts.Diags = Diags;
+
+ std::string CacheBMIPath = llvm::Twine(TestDir + "/Cached.pcm").str();
+ const char *Args[] = {
+ "clang++", "-std=c++20", "--precompile", "-working-directory",
+ TestDir.c_str(), "Cached.cppm", "-o", CacheBMIPath.c_str()};
+ std::shared_ptr<CompilerInvocation> Invocation =
+ createInvocation(Args, CIOpts);
+ ASSERT_TRUE(Invocation);
+
+ CompilerInstance Instance;
+ Instance.setDiagnostics(Diags.get());
+ Instance.setInvocation(Invocation);
+ GenerateModuleInterfaceAction Action;
+ ASSERT_TRUE(Instance.ExecuteAction(Action));
+ ASSERT_FALSE(Diags->hasErrorOccurred());
+
+ std::string DepArg =
+ llvm::Twine("-fmodule-file=Fibonacci.Cache=" + CacheBMIPath).str();
+ std::unique_ptr<ASTUnit> AST = tooling::buildASTFromCodeWithArgs(
+ R"cpp(
+import Fibonacci.Cache;
+ )cpp",
+ /*Args=*/{"-std=c++20", DepArg.c_str()});
+
+ using namespace clang::ast_matchers;
+ ASTContext &Ctx = AST->getASTContext();
+ const auto *cached = selectFirst<VarDecl>(
+ "Cache",
+ match(varDecl(isTemplateInstantiation(), hasName("Cache")).bind("Cache"),
+ Ctx));
+ EXPECT_TRUE(cached);
+ EXPECT_TRUE(cached->getEvaluatedStmt());
+ EXPECT_TRUE(cached->getEvaluatedStmt()->WasEvaluated);
+ EXPECT_TRUE(cached->getEvaluatedValue());
+ EXPECT_TRUE(cached->getEvaluatedValue()->isInt());
+ EXPECT_EQ(cached->getEvaluatedValue()->getInt(), 55);
+}
+
+} // anonymous namespace
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