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. More...

void	registerForPreprocessor (Preprocessor &PP)
	Register the necessary callbacks to the Preprocessor to record the expansion events and the generated tokens. More...

Optional< StringRef >	getExpandedText (SourceLocation MacroExpansionLoc) const

Optional< StringRef >	getOriginalText (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 85 of file MacroExpansionContext.cpp.

Member Function Documentation

◆ dumpExpandedTexts()

void MacroExpansionContext::dumpExpandedTexts ( ) const

Definition at line 137 of file MacroExpansionContext.cpp.

References dumpExpandedTextsToStream().

◆ dumpExpandedTextsToStream()

void MacroExpansionContext::dumpExpandedTextsToStream ( raw_ostream & OS ) const

Definition at line 159 of file MacroExpansionContext.cpp.

Referenced by dumpExpandedTexts().

◆ dumpExpansionRanges()

void MacroExpansionContext::dumpExpansionRanges ( ) const

Definition at line 134 of file MacroExpansionContext.cpp.

References dumpExpansionRangesToStream().

◆ dumpExpansionRangesToStream()

void MacroExpansionContext::dumpExpansionRangesToStream ( raw_ostream & OS ) const

Definition at line 141 of file MacroExpansionContext.cpp.

Referenced by dumpExpansionRanges().

◆ getExpandedText()

Optional< StringRef > MacroExpansionContext::getExpandedText ( SourceLocation MacroExpansionLoc ) const

Parameters

MacroExpansionLoc Must 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 llvm::None.

Definition at line 100 of file MacroExpansionContext.cpp.

References clang::SourceLocation::isMacroID().

Referenced by getExpandedMacro().

◆ getOriginalText()

Optional< StringRef > MacroExpansionContext::getOriginalText ( SourceLocation MacroExpansionLoc ) const

Parameters

MacroExpansionLoc Must 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 llvm::None.

Definition at line 118 of file MacroExpansionContext.cpp.

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