[clang] [C++20] [Modules] Introduce -fexperimental-modules-reduced-bmi (PR #85050)
Chuanqi Xu via cfe-commits
cfe-commits at lists.llvm.org
Sat Apr 6 19:19:17 PDT 2024
https://github.com/ChuanqiXu9 updated https://github.com/llvm/llvm-project/pull/85050
>From 7b0b9b52ac06a78a172e3628ab7fb3cdb3749d13 Mon Sep 17 00:00:00 2001
From: Chuanqi Xu <yedeng.yd at linux.alibaba.com>
Date: Tue, 12 Mar 2024 17:26:49 +0800
Subject: [PATCH] [C++20] [Modules] Introduce -fgen-reduced-bmi
---
clang/include/clang/CodeGen/CodeGenAction.h | 2 +
clang/include/clang/Driver/Options.td | 6 +++
.../include/clang/Frontend/FrontendOptions.h | 10 +++-
clang/lib/CodeGen/CodeGenAction.cpp | 19 +++++++
clang/lib/Driver/Driver.cpp | 12 ++++-
clang/lib/Driver/ToolChains/Clang.cpp | 18 +++++++
clang/lib/Frontend/FrontendActions.cpp | 7 +++
.../test/Driver/module-fgen-reduced-bmi.cppm | 51 +++++++++++++++++++
clang/test/Modules/modules-reduced-bmi.cppm | 36 +++++++++++++
9 files changed, 159 insertions(+), 2 deletions(-)
create mode 100644 clang/test/Driver/module-fgen-reduced-bmi.cppm
create mode 100644 clang/test/Modules/modules-reduced-bmi.cppm
diff --git a/clang/include/clang/CodeGen/CodeGenAction.h b/clang/include/clang/CodeGen/CodeGenAction.h
index 7ad2988e589eb2..186dbb43f01ef7 100644
--- a/clang/include/clang/CodeGen/CodeGenAction.h
+++ b/clang/include/clang/CodeGen/CodeGenAction.h
@@ -57,6 +57,8 @@ class CodeGenAction : public ASTFrontendAction {
bool loadLinkModules(CompilerInstance &CI);
protected:
+ bool BeginSourceFileAction(CompilerInstance &CI) override;
+
/// Create a new code generation action. If the optional \p _VMContext
/// parameter is supplied, the action uses it without taking ownership,
/// otherwise it creates a fresh LLVM context and takes ownership.
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 827d9d7c0c18e4..09feb1c775e2e8 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -3034,6 +3034,7 @@ defm prebuilt_implicit_modules : BoolFOption<"prebuilt-implicit-modules",
def fmodule_output_EQ : Joined<["-"], "fmodule-output=">,
Flags<[NoXarchOption]>, Visibility<[ClangOption, CC1Option]>,
+ MarshallingInfoString<FrontendOpts<"ModuleOutputPath">>,
HelpText<"Save intermediate module file results when compiling a standard C++ module unit.">;
def fmodule_output : Flag<["-"], "fmodule-output">, Flags<[NoXarchOption]>,
Visibility<[ClangOption, CC1Option]>,
@@ -3047,6 +3048,11 @@ defm skip_odr_check_in_gmf : BoolOption<"f", "skip-odr-check-in-gmf",
"Perform ODR checks for decls in the global module fragment.">>,
Group<f_Group>;
+def modules_reduced_bmi : Flag<["-"], "fexperimental-modules-reduced-bmi">,
+ Group<f_Group>, Visibility<[ClangOption, CC1Option]>,
+ HelpText<"Generate the reduced BMI">,
+ MarshallingInfoFlag<FrontendOpts<"GenReducedBMI">>;
+
def fmodules_prune_interval : Joined<["-"], "fmodules-prune-interval=">, Group<i_Group>,
Visibility<[ClangOption, CC1Option]>, MetaVarName<"<seconds>">,
HelpText<"Specify the interval (in seconds) between attempts to prune the module cache">,
diff --git a/clang/include/clang/Frontend/FrontendOptions.h b/clang/include/clang/Frontend/FrontendOptions.h
index 5ee4d471670f48..a738c1f3757682 100644
--- a/clang/include/clang/Frontend/FrontendOptions.h
+++ b/clang/include/clang/Frontend/FrontendOptions.h
@@ -404,6 +404,10 @@ class FrontendOptions {
LLVM_PREFERRED_TYPE(bool)
unsigned EmitPrettySymbolGraphs : 1;
+ /// Whether to generate reduced BMI for C++20 named modules.
+ LLVM_PREFERRED_TYPE(bool)
+ unsigned GenReducedBMI : 1;
+
CodeCompleteOptions CodeCompleteOpts;
/// Specifies the output format of the AST.
@@ -568,6 +572,9 @@ class FrontendOptions {
/// Path which stores the output files for -ftime-trace
std::string TimeTracePath;
+ /// Output Path for module output file.
+ std::string ModuleOutputPath;
+
public:
FrontendOptions()
: DisableFree(false), RelocatablePCH(false), ShowHelp(false),
@@ -582,7 +589,8 @@ class FrontendOptions {
AllowPCMWithCompilerErrors(false), ModulesShareFileManager(true),
EmitSymbolGraph(false), EmitExtensionSymbolGraphs(false),
EmitSymbolGraphSymbolLabelsForTesting(false),
- EmitPrettySymbolGraphs(false), TimeTraceGranularity(500) {}
+ EmitPrettySymbolGraphs(false), GenReducedBMI(false),
+ TimeTraceGranularity(500) {}
/// getInputKindForExtension - Return the appropriate input kind for a file
/// extension. For example, "c" would return Language::C.
diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
index bb9aaba025fa59..cd0d011e8c72b0 100644
--- a/clang/lib/CodeGen/CodeGenAction.cpp
+++ b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -25,8 +25,11 @@
#include "clang/CodeGen/ModuleBuilder.h"
#include "clang/Driver/DriverDiagnostic.h"
#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendActions.h"
#include "clang/Frontend/FrontendDiagnostic.h"
+#include "clang/Frontend/MultiplexConsumer.h"
#include "clang/Lex/Preprocessor.h"
+#include "clang/Serialization/ASTWriter.h"
#include "llvm/ADT/Hashing.h"
#include "llvm/Bitcode/BitcodeReader.h"
#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
@@ -1003,6 +1006,12 @@ CodeGenerator *CodeGenAction::getCodeGenerator() const {
return BEConsumer->getCodeGenerator();
}
+bool CodeGenAction::BeginSourceFileAction(CompilerInstance &CI) {
+ if (CI.getFrontendOpts().GenReducedBMI)
+ CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleInterface);
+ return true;
+}
+
static std::unique_ptr<raw_pwrite_stream>
GetOutputStream(CompilerInstance &CI, StringRef InFile, BackendAction Action) {
switch (Action) {
@@ -1061,6 +1070,16 @@ CodeGenAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
CI.getPreprocessor().addPPCallbacks(std::move(Callbacks));
}
+ if (CI.getFrontendOpts().GenReducedBMI &&
+ !CI.getFrontendOpts().ModuleOutputPath.empty()) {
+ std::vector<std::unique_ptr<ASTConsumer>> Consumers{2};
+ Consumers[0] = std::make_unique<ReducedBMIGenerator>(
+ CI.getPreprocessor(), CI.getModuleCache(),
+ CI.getFrontendOpts().ModuleOutputPath);
+ Consumers[1] = std::move(Result);
+ return std::make_unique<MultiplexConsumer>(std::move(Consumers));
+ }
+
return std::move(Result);
}
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index e7335a61b10c53..0da92001e08c27 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -4756,6 +4756,14 @@ Action *Driver::ConstructPhaseAction(
if (Args.hasArg(options::OPT_extract_api))
return C.MakeAction<ExtractAPIJobAction>(Input, types::TY_API_INFO);
+ // With 'fexperimental-modules-reduced-bmi', we don't want to run the
+ // precompile phase unless the user specified '--precompile'. In the case
+ // the '--precompile' flag is enabled, we will try to emit the reduced BMI
+ // as a by product in GenerateModuleInterfaceAction.
+ if (Args.hasArg(options::OPT_modules_reduced_bmi) &&
+ !Args.getLastArg(options::OPT__precompile))
+ return Input;
+
types::ID OutputTy = getPrecompiledType(Input->getType());
assert(OutputTy != types::TY_INVALID &&
"Cannot precompile this input type!");
@@ -5916,8 +5924,10 @@ const char *Driver::GetNamedOutputPath(Compilation &C, const JobAction &JA,
// If we're emitting a module output with the specified option
// `-fmodule-output`.
if (!AtTopLevel && isa<PrecompileJobAction>(JA) &&
- JA.getType() == types::TY_ModuleFile && SpecifiedModuleOutput)
+ JA.getType() == types::TY_ModuleFile && SpecifiedModuleOutput) {
+ assert(!C.getArgs().hasArg(options::OPT_modules_reduced_bmi));
return GetModuleOutputPath(C, JA, BaseInput);
+ }
// Output to a temporary file?
if ((!AtTopLevel && !isSaveTempsEnabled() &&
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 766a9b91e3c0ad..6d52eced104296 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4045,6 +4045,24 @@ static bool RenderModulesOptions(Compilation &C, const Driver &D,
// module fragment.
CmdArgs.push_back("-fskip-odr-check-in-gmf");
+ if (Args.hasArg(options::OPT_modules_reduced_bmi) &&
+ (Input.getType() == driver::types::TY_CXXModule ||
+ Input.getType() == driver::types::TY_PP_CXXModule)) {
+ CmdArgs.push_back("-fexperimental-modules-reduced-bmi");
+
+ if (Args.hasArg(options::OPT_fmodule_output_EQ))
+ Args.AddLastArg(CmdArgs, options::OPT_fmodule_output_EQ);
+ else
+ CmdArgs.push_back(Args.MakeArgString(
+ "-fmodule-output=" +
+ getCXX20NamedModuleOutputPath(Args, Input.getBaseInput())));
+ }
+
+ // Noop if we see '-fexperimental-modules-reduced-bmi' with other translation
+ // units than module units. This is more user friendly to allow end uers to
+ // enable this feature without asking for help from build systems.
+ Args.ClaimAllArgs(options::OPT_modules_reduced_bmi);
+
// We need to include the case the input file is a module file here.
// Since the default compilation model for C++ module interface unit will
// create temporary module file and compile the temporary module file
diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 7ee6ccf396a891..7f991a781409d7 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -284,6 +284,13 @@ GenerateModuleInterfaceAction::CreateASTConsumer(CompilerInstance &CI,
if (Consumers.empty())
return nullptr;
+ if (CI.getFrontendOpts().GenReducedBMI &&
+ !CI.getFrontendOpts().ModuleOutputPath.empty()) {
+ Consumers.push_back(std::make_unique<ReducedBMIGenerator>(
+ CI.getPreprocessor(), CI.getModuleCache(),
+ CI.getFrontendOpts().ModuleOutputPath));
+ }
+
return std::make_unique<MultiplexConsumer>(std::move(Consumers));
}
diff --git a/clang/test/Driver/module-fgen-reduced-bmi.cppm b/clang/test/Driver/module-fgen-reduced-bmi.cppm
new file mode 100644
index 00000000000000..1223189fb49b72
--- /dev/null
+++ b/clang/test/Driver/module-fgen-reduced-bmi.cppm
@@ -0,0 +1,51 @@
+// It is annoying to handle different slash direction
+// in Windows and Linux. So we disable the test on Windows
+// here.
+// REQUIRES: !system-windows
+// On AIX, the default output for `-c` may be `.s` instead of `.o`,
+// which makes the test fail. So disable the test on AIX.
+// UNSUPPORTED: system-aix
+//
+// RUN: rm -rf %t && split-file %s %t && cd %t
+//
+// RUN: %clang -std=c++20 Hello.cppm -fmodule-output=Hello.pcm \
+// RUN: -fexperimental-modules-reduced-bmi -c -o Hello.o -### 2>&1 | FileCheck Hello.cppm
+//
+// RUN: %clang -std=c++20 Hello.cppm \
+// RUN: -fexperimental-modules-reduced-bmi -c -o Hello.o -### 2>&1 | \
+// RUN: FileCheck Hello.cppm --check-prefix=CHECK-UNSPECIFIED
+//
+// RUN: %clang -std=c++20 Hello.cppm \
+// RUN: -fexperimental-modules-reduced-bmi -c -### 2>&1 | \
+// RUN: FileCheck Hello.cppm --check-prefix=CHECK-NO-O
+//
+// RUN: %clang -std=c++20 Hello.cppm \
+// RUN: -fexperimental-modules-reduced-bmi -c -o AnotherName.o -### 2>&1 | \
+// RUN: FileCheck Hello.cppm --check-prefix=CHECK-ANOTHER-NAME
+//
+// RUN: %clang -std=c++20 Hello.cppm --precompile -fexperimental-modules-reduced-bmi \
+// RUN: -o Hello.full.pcm -### 2>&1 | FileCheck Hello.cppm \
+// RUN: --check-prefix=CHECK-EMIT-MODULE-INTERFACE
+//
+// RUN: %clang -std=c++20 Hello.cc -fexperimental-modules-reduced-bmi -Wall -Werror \
+// RUN: -c -o Hello.o -### 2>&1 | FileCheck Hello.cc
+
+//--- Hello.cppm
+export module Hello;
+
+// Test that we won't generate the emit-module-interface as 2 phase compilation model.
+// CHECK-NOT: -emit-module-interface
+// CHECK: "-fexperimental-modules-reduced-bmi"
+
+// CHECK-UNSPECIFIED: -fmodule-output=Hello.pcm
+
+// CHECK-NO-O: -fmodule-output=Hello.pcm
+// CHECK-ANOTHER-NAME: -fmodule-output=AnotherName.pcm
+
+// With `-emit-module-interface` specified, we should still see the `-emit-module-interface`
+// flag.
+// CHECK-EMIT-MODULE-INTERFACE: -emit-module-interface
+
+//--- Hello.cc
+
+// CHECK-NOT: "-fexperimental-modules-reduced-bmi"
diff --git a/clang/test/Modules/modules-reduced-bmi.cppm b/clang/test/Modules/modules-reduced-bmi.cppm
new file mode 100644
index 00000000000000..9b84220ae03032
--- /dev/null
+++ b/clang/test/Modules/modules-reduced-bmi.cppm
@@ -0,0 +1,36 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+//
+// RUN: %clang_cc1 -std=c++20 %t/a.cppm -emit-reduced-module-interface -o %t/a.reduced.pcm
+// RUN: %clang_cc1 -std=c++20 %t/a.cppm -fexperimental-modules-reduced-bmi -fmodule-output=%t/a.pcm \
+// RUN: -S -emit-llvm -o %t/a.ll
+//
+// Test that the generated BMI from `-fexperimental-modules-reduced-bmi -fmodule-output=` is same with
+// `-emit-reduced-module-interface`.
+// RUN: diff %t/a.reduced.pcm %t/a.pcm
+//
+// Test that we can consume the produced BMI correctly.
+// RUN: %clang_cc1 -std=c++20 %t/b.cppm -fmodule-file=a=%t/a.pcm -fsyntax-only -verify
+//
+// RUN: rm -f %t/a.pcm
+// RUN: %clang_cc1 -std=c++20 %t/a.cppm -fexperimental-modules-reduced-bmi -fmodule-output=%t/a.pcm \
+// RUN: -emit-module-interface -o %t/a.full.pcm
+// RUN: diff %t/a.reduced.pcm %t/a.pcm
+// RUN: not diff %t/a.pcm %t/a.full.pcm
+//
+// RUN: %clang_cc1 -std=c++20 %t/b.cppm -fmodule-file=a=%t/a.pcm -fsyntax-only -verify
+// RUN: %clang_cc1 -std=c++20 %t/b.cppm -fmodule-file=a=%t/a.full.pcm -fsyntax-only -verify
+
+//--- a.cppm
+export module a;
+export int a() {
+ return 43;
+}
+
+//--- b.cppm
+// Test that we can consume the produced BMI correctly as a smocking test.
+// expected-no-diagnostics
+export module b;
+import a;
+export int b() { return a(); }
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