[clang] [clang] Change representation of CurLexerKind (PR #70381)
via cfe-commits
cfe-commits at lists.llvm.org
Sun Oct 29 11:21:57 PDT 2023
https://github.com/serge-sans-paille updated https://github.com/llvm/llvm-project/pull/70381
>From 3fe63f81fcb999681daa11b2890c82fda3aaeef5 Mon Sep 17 00:00:00 2001
From: serge-sans-paille <sguelton at mozilla.com>
Date: Thu, 26 Oct 2023 22:31:43 +0200
Subject: [PATCH 1/2] [clang] Change representation of CurLexerKind
Previous representation used an enumeration combined to a switch to
dispatch to the appropriate lexer.
Use function pointer so that the dispatching is just an indirect call,
which is actually better because lexing is a costly task compared to a
function call.
This also makes the code slightly cleaner, speedup on
compile time tracker are consistent and range form -0.05% to -0.20%
for NewPM-O0-g, see
https://llvm-compile-time-tracker.com/compare.php?from=f9906508bc4f05d3950e2219b4c56f6c078a61ef&to=608c85ec1283638db949d73e062bcc3355001ce4&stat=instructions:u
Considering just the preprocessing task, preprocessing the sqlite
amalgametion takes -0.6% instructions (according to valgrind
--tool=callgrind)
---
clang/include/clang/Lex/Preprocessor.h | 46 +++++++++++-----
clang/lib/Lex/PPCaching.cpp | 8 +--
clang/lib/Lex/PPLexerChange.cpp | 20 +++----
clang/lib/Lex/Preprocessor.cpp | 67 ++++++-----------------
clang/utils/ClangVisualizers/clang.natvis | 2 +-
5 files changed, 62 insertions(+), 81 deletions(-)
diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
index 18d88407ae12c90..634d3924aa2248b 100644
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -751,13 +751,8 @@ class Preprocessor {
std::unique_ptr<TokenLexer> CurTokenLexer;
/// The kind of lexer we're currently working with.
- enum CurLexerKind {
- CLK_Lexer,
- CLK_TokenLexer,
- CLK_CachingLexer,
- CLK_DependencyDirectivesLexer,
- CLK_LexAfterModuleImport
- } CurLexerKind = CLK_Lexer;
+ typedef bool (*LexerCallback)(Preprocessor &, Token &);
+ LexerCallback CurLexerCallback = &CLK_Lexer;
/// If the current lexer is for a submodule that is being built, this
/// is that submodule.
@@ -767,7 +762,7 @@ class Preprocessor {
/// \#included, and macros currently being expanded from, not counting
/// CurLexer/CurTokenLexer.
struct IncludeStackInfo {
- enum CurLexerKind CurLexerKind;
+ LexerCallback CurLexerCallback;
Module *TheSubmodule;
std::unique_ptr<Lexer> TheLexer;
PreprocessorLexer *ThePPLexer;
@@ -776,12 +771,12 @@ class Preprocessor {
// The following constructors are completely useless copies of the default
// versions, only needed to pacify MSVC.
- IncludeStackInfo(enum CurLexerKind CurLexerKind, Module *TheSubmodule,
+ IncludeStackInfo(LexerCallback CurLexerCallback, Module *TheSubmodule,
std::unique_ptr<Lexer> &&TheLexer,
PreprocessorLexer *ThePPLexer,
std::unique_ptr<TokenLexer> &&TheTokenLexer,
ConstSearchDirIterator TheDirLookup)
- : CurLexerKind(std::move(CurLexerKind)),
+ : CurLexerCallback(std::move(CurLexerCallback)),
TheSubmodule(std::move(TheSubmodule)), TheLexer(std::move(TheLexer)),
ThePPLexer(std::move(ThePPLexer)),
TheTokenLexer(std::move(TheTokenLexer)),
@@ -1901,7 +1896,7 @@ class Preprocessor {
/// Determine whether it's possible for a future call to Lex to produce an
/// annotation token created by a previous call to EnterAnnotationToken.
bool mightHavePendingAnnotationTokens() {
- return CurLexerKind != CLK_Lexer;
+ return CurLexerCallback != CLK_Lexer;
}
/// Update the current token to represent the provided
@@ -1914,7 +1909,7 @@ class Preprocessor {
/// Recompute the current lexer kind based on the CurLexer/
/// CurTokenLexer pointers.
- void recomputeCurLexerKind();
+ void recomputeCurLexerCallback();
/// Returns true if incremental processing is enabled
bool isIncrementalProcessingEnabled() const { return IncrementalProcessing; }
@@ -2430,8 +2425,9 @@ class Preprocessor {
friend void TokenLexer::ExpandFunctionArguments();
void PushIncludeMacroStack() {
- assert(CurLexerKind != CLK_CachingLexer && "cannot push a caching lexer");
- IncludeMacroStack.emplace_back(CurLexerKind, CurLexerSubmodule,
+ assert(CurLexerCallback != CLK_CachingLexer &&
+ "cannot push a caching lexer");
+ IncludeMacroStack.emplace_back(CurLexerCallback, CurLexerSubmodule,
std::move(CurLexer), CurPPLexer,
std::move(CurTokenLexer), CurDirLookup);
CurPPLexer = nullptr;
@@ -2443,7 +2439,7 @@ class Preprocessor {
CurTokenLexer = std::move(IncludeMacroStack.back().TheTokenLexer);
CurDirLookup = IncludeMacroStack.back().TheDirLookup;
CurLexerSubmodule = IncludeMacroStack.back().TheSubmodule;
- CurLexerKind = IncludeMacroStack.back().CurLexerKind;
+ CurLexerCallback = IncludeMacroStack.back().CurLexerCallback;
IncludeMacroStack.pop_back();
}
@@ -2899,6 +2895,26 @@ class Preprocessor {
/// \return true iff this PP is currently in a "-Wunsafe-buffer-usage"
/// opt-out region
bool isPPInSafeBufferOptOutRegion(SourceLocation &StartLoc);
+
+private:
+ /// Helper functions to forward lexing to the actual lexer. They all share the
+ /// same signature.
+ static bool CLK_Lexer(Preprocessor &P, Token &Result) {
+ return P.CurLexer->Lex(Result);
+ }
+ static bool CLK_TokenLexer(Preprocessor &P, Token &Result) {
+ return P.CurTokenLexer->Lex(Result);
+ }
+ static bool CLK_CachingLexer(Preprocessor &P, Token &Result) {
+ P.CachingLex(Result);
+ return true;
+ }
+ static bool CLK_DependencyDirectivesLexer(Preprocessor &P, Token &Result) {
+ return P.CurLexer->LexDependencyDirectiveToken(Result);
+ }
+ static bool CLK_LexAfterModuleImport(Preprocessor &P, Token &Result) {
+ return P.LexAfterModuleImport(Result);
+ }
};
/// Abstract base class that describes a handler that will receive
diff --git a/clang/lib/Lex/PPCaching.cpp b/clang/lib/Lex/PPCaching.cpp
index e05e52ba9bb5362..b8219835a588bea 100644
--- a/clang/lib/Lex/PPCaching.cpp
+++ b/clang/lib/Lex/PPCaching.cpp
@@ -42,7 +42,7 @@ void Preprocessor::Backtrack() {
&& "EnableBacktrackAtThisPos was not called!");
CachedLexPos = BacktrackPositions.back();
BacktrackPositions.pop_back();
- recomputeCurLexerKind();
+ recomputeCurLexerCallback();
}
void Preprocessor::CachingLex(Token &Result) {
@@ -88,7 +88,7 @@ void Preprocessor::EnterCachingLexMode() {
"entered caching lex mode while lexing something else");
if (InCachingLexMode()) {
- assert(CurLexerKind == CLK_CachingLexer && "Unexpected lexer kind");
+ assert(CurLexerCallback == CLK_CachingLexer && "Unexpected lexer kind");
return;
}
@@ -96,9 +96,9 @@ void Preprocessor::EnterCachingLexMode() {
}
void Preprocessor::EnterCachingLexModeUnchecked() {
- assert(CurLexerKind != CLK_CachingLexer && "already in caching lex mode");
+ assert(CurLexerCallback != CLK_CachingLexer && "already in caching lex mode");
PushIncludeMacroStack();
- CurLexerKind = CLK_CachingLexer;
+ CurLexerCallback = CLK_CachingLexer;
}
diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index b8575e1adfc5b3f..1378880f8b0e5e0 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -122,10 +122,10 @@ void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer,
CurPPLexer = TheLexer;
CurDirLookup = CurDir;
CurLexerSubmodule = nullptr;
- if (CurLexerKind != CLK_LexAfterModuleImport)
- CurLexerKind = TheLexer->isDependencyDirectivesLexer()
- ? CLK_DependencyDirectivesLexer
- : CLK_Lexer;
+ if (CurLexerCallback != CLK_LexAfterModuleImport)
+ CurLexerCallback = TheLexer->isDependencyDirectivesLexer()
+ ? CLK_DependencyDirectivesLexer
+ : CLK_Lexer;
// Notify the client, if desired, that we are in a new source file.
if (Callbacks && !CurLexer->Is_PragmaLexer) {
@@ -161,8 +161,8 @@ void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd,
PushIncludeMacroStack();
CurDirLookup = nullptr;
CurTokenLexer = std::move(TokLexer);
- if (CurLexerKind != CLK_LexAfterModuleImport)
- CurLexerKind = CLK_TokenLexer;
+ if (CurLexerCallback != CLK_LexAfterModuleImport)
+ CurLexerCallback = CLK_TokenLexer;
}
/// EnterTokenStream - Add a "macro" context to the top of the include stack,
@@ -180,7 +180,7 @@ void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd,
void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
bool DisableMacroExpansion, bool OwnsTokens,
bool IsReinject) {
- if (CurLexerKind == CLK_CachingLexer) {
+ if (CurLexerCallback == CLK_CachingLexer) {
if (CachedLexPos < CachedTokens.size()) {
assert(IsReinject && "new tokens in the middle of cached stream");
// We're entering tokens into the middle of our cached token stream. We
@@ -216,8 +216,8 @@ void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
PushIncludeMacroStack();
CurDirLookup = nullptr;
CurTokenLexer = std::move(TokLexer);
- if (CurLexerKind != CLK_LexAfterModuleImport)
- CurLexerKind = CLK_TokenLexer;
+ if (CurLexerCallback != CLK_LexAfterModuleImport)
+ CurLexerCallback = CLK_TokenLexer;
}
/// Compute the relative path that names the given file relative to
@@ -452,7 +452,7 @@ bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
CurLexer.reset();
CurPPLexer = nullptr;
- recomputeCurLexerKind();
+ recomputeCurLexerCallback();
return true;
}
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index ede4c51487ffbe7..f791b4d2363c9fe 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -380,15 +380,15 @@ StringRef Preprocessor::getLastMacroWithSpelling(
return BestSpelling;
}
-void Preprocessor::recomputeCurLexerKind() {
+void Preprocessor::recomputeCurLexerCallback() {
if (CurLexer)
- CurLexerKind = CurLexer->isDependencyDirectivesLexer()
- ? CLK_DependencyDirectivesLexer
- : CLK_Lexer;
+ CurLexerCallback = CurLexer->isDependencyDirectivesLexer()
+ ? CLK_DependencyDirectivesLexer
+ : CLK_Lexer;
else if (CurTokenLexer)
- CurLexerKind = CLK_TokenLexer;
+ CurLexerCallback = CLK_TokenLexer;
else
- CurLexerKind = CLK_CachingLexer;
+ CurLexerCallback = CLK_CachingLexer;
}
bool Preprocessor::SetCodeCompletionPoint(FileEntryRef File,
@@ -643,23 +643,7 @@ void Preprocessor::SkipTokensWhileUsingPCH() {
while (true) {
bool InPredefines =
(CurLexer && CurLexer->getFileID() == getPredefinesFileID());
- switch (CurLexerKind) {
- case CLK_Lexer:
- CurLexer->Lex(Tok);
- break;
- case CLK_TokenLexer:
- CurTokenLexer->Lex(Tok);
- break;
- case CLK_CachingLexer:
- CachingLex(Tok);
- break;
- case CLK_DependencyDirectivesLexer:
- CurLexer->LexDependencyDirectiveToken(Tok);
- break;
- case CLK_LexAfterModuleImport:
- LexAfterModuleImport(Tok);
- break;
- }
+ CurLexerCallback(*this, Tok);
if (Tok.is(tok::eof) && !InPredefines) {
ReachedMainFileEOF = true;
break;
@@ -868,12 +852,12 @@ bool Preprocessor::HandleIdentifier(Token &Identifier) {
Identifier.is(tok::kw_import)) &&
!InMacroArgs && !DisableMacroExpansion &&
(getLangOpts().Modules || getLangOpts().DebuggerSupport) &&
- CurLexerKind != CLK_CachingLexer) {
+ CurLexerCallback != CLK_CachingLexer) {
ModuleImportLoc = Identifier.getLocation();
NamedModuleImportPath.clear();
IsAtImport = true;
ModuleImportExpectsIdentifier = true;
- CurLexerKind = CLK_LexAfterModuleImport;
+ CurLexerCallback = CLK_LexAfterModuleImport;
}
return true;
}
@@ -882,27 +866,8 @@ void Preprocessor::Lex(Token &Result) {
++LexLevel;
// We loop here until a lex function returns a token; this avoids recursion.
- bool ReturnedToken;
- do {
- switch (CurLexerKind) {
- case CLK_Lexer:
- ReturnedToken = CurLexer->Lex(Result);
- break;
- case CLK_TokenLexer:
- ReturnedToken = CurTokenLexer->Lex(Result);
- break;
- case CLK_CachingLexer:
- CachingLex(Result);
- ReturnedToken = true;
- break;
- case CLK_DependencyDirectivesLexer:
- ReturnedToken = CurLexer->LexDependencyDirectiveToken(Result);
- break;
- case CLK_LexAfterModuleImport:
- ReturnedToken = LexAfterModuleImport(Result);
- break;
- }
- } while (!ReturnedToken);
+ while (!CurLexerCallback(*this, Result))
+ ;
if (Result.is(tok::unknown) && TheModuleLoader.HadFatalFailure)
return;
@@ -965,7 +930,7 @@ void Preprocessor::Lex(Token &Result) {
NamedModuleImportPath.clear();
IsAtImport = false;
ModuleImportExpectsIdentifier = true;
- CurLexerKind = CLK_LexAfterModuleImport;
+ CurLexerCallback = CLK_LexAfterModuleImport;
}
break;
} else if (Result.getIdentifierInfo() == getIdentifierInfo("module")) {
@@ -1166,7 +1131,7 @@ void Preprocessor::CollectPpImportSuffix(SmallVectorImpl<Token> &Toks) {
/// We respond to a pp-import by importing macros from the named module.
bool Preprocessor::LexAfterModuleImport(Token &Result) {
// Figure out what kind of lexer we actually have.
- recomputeCurLexerKind();
+ recomputeCurLexerCallback();
// Lex the next token. The header-name lexing rules are used at the start of
// a pp-import.
@@ -1183,7 +1148,7 @@ bool Preprocessor::LexAfterModuleImport(Token &Result) {
Name += ":";
NamedModuleImportPath.push_back(
{getIdentifierInfo(Name), Result.getLocation()});
- CurLexerKind = CLK_LexAfterModuleImport;
+ CurLexerCallback = CLK_LexAfterModuleImport;
return true;
}
} else {
@@ -1283,7 +1248,7 @@ bool Preprocessor::LexAfterModuleImport(Token &Result) {
NamedModuleImportPath.push_back(
std::make_pair(Result.getIdentifierInfo(), Result.getLocation()));
ModuleImportExpectsIdentifier = false;
- CurLexerKind = CLK_LexAfterModuleImport;
+ CurLexerCallback = CLK_LexAfterModuleImport;
return true;
}
@@ -1292,7 +1257,7 @@ bool Preprocessor::LexAfterModuleImport(Token &Result) {
// attribute-specifier-seq here under the Standard C++ Modules.)
if (!ModuleImportExpectsIdentifier && Result.getKind() == tok::period) {
ModuleImportExpectsIdentifier = true;
- CurLexerKind = CLK_LexAfterModuleImport;
+ CurLexerCallback = CLK_LexAfterModuleImport;
return true;
}
diff --git a/clang/utils/ClangVisualizers/clang.natvis b/clang/utils/ClangVisualizers/clang.natvis
index cbb63dc08de2338..44b43ec05d8af59 100644
--- a/clang/utils/ClangVisualizers/clang.natvis
+++ b/clang/utils/ClangVisualizers/clang.natvis
@@ -817,7 +817,7 @@ For later versions of Visual Studio, no setup is required-->
<DisplayString IncludeView="cached"> {IncludeMacroStack._Mypair._Myval2._Mylast - 1,na}</DisplayString>
<DisplayString Condition="CurLexer._Mypair._Myval2 != 0">{CurLexer._Mypair._Myval2,na}</DisplayString>
<DisplayString Condition="CurTokenLexer._Mypair._Myval2 != 0">Expanding Macro: {CurTokenLexer._Mypair._Myval2,na}</DisplayString>
- <!-- Can't use CurLexerKind because natvis sees the type rather than the variable -->
+ <!-- Can't use CurLexerCallback because natvis sees the type rather than the variable -->
<DisplayString Condition="IncludeMacroStack._Mypair._Myval2._Mylast - IncludeMacroStack._Mypair._Myval2._Myfirst">
{this,view(cached)}
</DisplayString>
>From 7ad697255b075ecb18d09bdb6b465f4e1956909b Mon Sep 17 00:00:00 2001
From: serge-sans-paille <serge.guelton at telecom-bretagne.eu>
Date: Sun, 29 Oct 2023 18:17:55 +0000
Subject: [PATCH 2/2] fixup! [clang] Change representation of CurLexerKind
Co-authored-by: cor3ntin <corentinjabot at gmail.com>
---
clang/include/clang/Lex/Preprocessor.h | 2 +-
clang/lib/Lex/PPCaching.cpp | 2 +-
clang/lib/Lex/PPLexerChange.cpp | 2 +-
clang/lib/Lex/Preprocessor.cpp | 4 ++--
4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
index 634d3924aa2248b..3019143731db3ba 100644
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -1909,7 +1909,7 @@ class Preprocessor {
/// Recompute the current lexer kind based on the CurLexer/
/// CurTokenLexer pointers.
- void recomputeCurLexerCallback();
+ void recomputeCurLexerKind();
/// Returns true if incremental processing is enabled
bool isIncrementalProcessingEnabled() const { return IncrementalProcessing; }
diff --git a/clang/lib/Lex/PPCaching.cpp b/clang/lib/Lex/PPCaching.cpp
index b8219835a588bea..f38ff62ebf437ce 100644
--- a/clang/lib/Lex/PPCaching.cpp
+++ b/clang/lib/Lex/PPCaching.cpp
@@ -42,7 +42,7 @@ void Preprocessor::Backtrack() {
&& "EnableBacktrackAtThisPos was not called!");
CachedLexPos = BacktrackPositions.back();
BacktrackPositions.pop_back();
- recomputeCurLexerCallback();
+ recomputeCurLexerKind();
}
void Preprocessor::CachingLex(Token &Result) {
diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index 1378880f8b0e5e0..3b1b6df1dbae4e6 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -452,7 +452,7 @@ bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
CurLexer.reset();
CurPPLexer = nullptr;
- recomputeCurLexerCallback();
+ recomputeCurLexerKind();
return true;
}
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index f791b4d2363c9fe..e37e370f5526b38 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -380,7 +380,7 @@ StringRef Preprocessor::getLastMacroWithSpelling(
return BestSpelling;
}
-void Preprocessor::recomputeCurLexerCallback() {
+void Preprocessor::recomputeCurLexerKind() {
if (CurLexer)
CurLexerCallback = CurLexer->isDependencyDirectivesLexer()
? CLK_DependencyDirectivesLexer
@@ -1131,7 +1131,7 @@ void Preprocessor::CollectPpImportSuffix(SmallVectorImpl<Token> &Toks) {
/// We respond to a pp-import by importing macros from the named module.
bool Preprocessor::LexAfterModuleImport(Token &Result) {
// Figure out what kind of lexer we actually have.
- recomputeCurLexerCallback();
+ recomputeCurLexerKind();
// Lex the next token. The header-name lexing rules are used at the start of
// a pp-import.
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