clang 22.0.0git
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clang::MacroExpansionContext Class Reference

MacroExpansionContext tracks the macro expansions processed by the Preprocessor. More...

#include "clang/Analysis/MacroExpansionContext.h"

Public Member Functions

 MacroExpansionContext (const LangOptions &LangOpts)
 Creates a MacroExpansionContext.
void registerForPreprocessor (Preprocessor &PP)
 Register the necessary callbacks to the Preprocessor to record the expansion events and the generated tokens.
std::optional< StringRef > getExpandedText (SourceLocation MacroExpansionLoc) const
std::optional< StringRef > getOriginalText (SourceLocation MacroExpansionLoc) const
std::optional< StringRef > getFormattedExpandedText (SourceLocation MacroExpansionLoc) const
LLVM_DUMP_METHOD void dumpExpansionRangesToStream (raw_ostream &OS) const
LLVM_DUMP_METHOD void dumpExpandedTextsToStream (raw_ostream &OS) const
LLVM_DUMP_METHOD void dumpExpansionRanges () const
LLVM_DUMP_METHOD void dumpExpandedTexts () const

Friends

class detail::MacroExpansionRangeRecorder

Detailed Description

MacroExpansionContext tracks the macro expansions processed by the Preprocessor.

It means that it can track source locations from a single translation unit. For every macro expansion it can tell you what text will be substituted.

It was designed to deal with:

  • regular macros
  • macro functions
  • variadic macros
  • transitive macro expansions
  • macro redefinition
  • unbalanced parenthesis
void bar();
#define retArg(x) x
#define retArgUnclosed retArg(bar()
#define BB CC
#define applyInt BB(int)
#define CC(x) retArgUnclosed
void unbalancedMacros() {
applyInt );
//^~~~~~~~~~^ is the substituted range
// Substituted text is "applyInt )"
// Expanded text is "bar()"
}
#define expandArgUnclosedCommaExpr(x) (x, bar(), 1
#define f expandArgUnclosedCommaExpr
void unbalancedMacros2() {
int x = f(f(1)) )); // Look at the parenthesis!
// ^~~~~~^ is the substituted range
// Substituted text is "f(f(1))"
// Expanded text is "((1,bar(),1,bar(),1"
}
Remarks
Currently we don't respect the whitespaces between expanded tokens, so the output for this example might differ from the -E compiler invocation.
All whitespaces are consumed while constructing the expansion. After all identifier a single space inserted to produce a valid C code even if identifier follows an other identifiers such as variable declarations.
MacroExpansionContext object must outlive the Preprocessor parameter.

Definition at line 73 of file MacroExpansionContext.h.

Constructor & Destructor Documentation

◆ MacroExpansionContext()

MacroExpansionContext::MacroExpansionContext ( const LangOptions & LangOpts)
explicit

Creates a MacroExpansionContext.

Remarks
You must call registerForPreprocessor to set the required onTokenLexed callback and the PPCallbacks.

Definition at line 87 of file MacroExpansionContext.cpp.

Member Function Documentation

◆ dumpExpandedTexts()

void MacroExpansionContext::dumpExpandedTexts ( ) const

Definition at line 168 of file MacroExpansionContext.cpp.

References dumpExpandedTextsToStream().

◆ dumpExpandedTextsToStream()

void MacroExpansionContext::dumpExpandedTextsToStream ( raw_ostream & OS) const

Definition at line 190 of file MacroExpansionContext.cpp.

Referenced by dumpExpandedTexts().

◆ dumpExpansionRanges()

void MacroExpansionContext::dumpExpansionRanges ( ) const

Definition at line 165 of file MacroExpansionContext.cpp.

References dumpExpansionRangesToStream().

◆ dumpExpansionRangesToStream()

void MacroExpansionContext::dumpExpansionRangesToStream ( raw_ostream & OS) const

Definition at line 172 of file MacroExpansionContext.cpp.

Referenced by dumpExpansionRanges().

◆ getExpandedText()

std::optional< StringRef > MacroExpansionContext::getExpandedText ( SourceLocation MacroExpansionLoc) const
Parameters
MacroExpansionLocMust be the expansion location of a macro.
Returns
The textual representation of the token sequence which was substituted in place of the macro after the preprocessing. If no macro was expanded at that location, returns std::nullopt.

Definition at line 102 of file MacroExpansionContext.cpp.

References clang::SourceLocation::isMacroID().

Referenced by getFormattedExpandedText().

◆ getFormattedExpandedText()

std::optional< StringRef > MacroExpansionContext::getFormattedExpandedText ( SourceLocation MacroExpansionLoc) const
Parameters
MacroExpansionLocMust be the expansion location of a macro.
Returns
A formatted representation of the textual representation of the token sequence which was substituted in place of the macro. If no macro was expanded at that location, returns std::nullopt.

Definition at line 136 of file MacroExpansionContext.cpp.

References clang::tooling::applyAllReplacements(), getExpandedText(), clang::format::getLLVMStyle(), clang::format::reformat(), and clang::Result.

Referenced by getExpandedMacro().

◆ getOriginalText()

std::optional< StringRef > MacroExpansionContext::getOriginalText ( SourceLocation MacroExpansionLoc) const
Parameters
MacroExpansionLocMust be the expansion location of a macro.
Returns
The text from the original source code which were substituted by the macro expansion chain from the given location. If no macro was expanded at that location, returns std::nullopt.

Definition at line 120 of file MacroExpansionContext.cpp.

References clang::CharSourceRange::getCharRange(), clang::Lexer::getSourceText(), and clang::SourceLocation::isMacroID().

◆ registerForPreprocessor()

void MacroExpansionContext::registerForPreprocessor ( Preprocessor & PP)

Register the necessary callbacks to the Preprocessor to record the expansion events and the generated tokens.

Must ensure that this object outlives the given Preprocessor.

Definition at line 90 of file MacroExpansionContext.cpp.

References clang::Preprocessor::getSourceManager(), and Tok.

◆ detail::MacroExpansionRangeRecorder

friend class detail::MacroExpansionRangeRecorder
friend

Definition at line 112 of file MacroExpansionContext.h.

References Tok.

The documentation for this class was generated from the following files:
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