PreprocessorTracker.h

//===- PreprocessorTracker.h - Tracks preprocessor activities -*- C++ -*-===//
//
// 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
//
//===--------------------------------------------------------------------===//
///
/// \file
/// \brief Macro expansions and preprocessor conditional consistency checker.
///
//===--------------------------------------------------------------------===//

#ifndef MODULARIZE_PREPROCESSOR_TRACKER_H
#defineMODULARIZE_PREPROCESSOR_TRACKER_H

#include"clang/Lex/Preprocessor.h"

namespaceModularize {

/// \brief Preprocessor tracker for modularize.
///
/// The PreprocessorTracker class defines an API for
/// checking macro expansions and preprocessor conditional expressions
/// in a header file for consistency among one or more compilations of
/// the header in a #include scenario. This is for helping a user
/// find which macro expansions or conditionals might be problematic with
/// respect to using the headers in the modules scenario, because they
/// evaluate to different values depending on how or where a header
/// is included.
///
/// The handlePreprocessorEntry function implementation will register
/// a PPCallbacks object in the given Preprocessor object. The calls to
/// the callbacks will collect information about the macro expansions
/// and preprocessor conditionals encountered, for later analysis and
/// reporting of inconsistencies between runs performed by calls to
/// the reportInconsistentMacros and reportInconsistentConditionals
/// functions respectively. The handlePreprocessorExit informs the
/// implementation that a preprocessing session is complete, allowing
/// it to do any needed compilation completion activities in the checker.
classPreprocessorTracker {
public:
virtual~PreprocessorTracker();

// Handle entering a preprocessing session.
// (Called after a Preprocessor object is created, but before preprocessing.)
virtualvoidhandlePreprocessorEntry(clang::Preprocessor &PP,
 llvm::StringRef RootHeaderFile) = 0;
// Handle exiting a preprocessing session.
// (Called after preprocessing is complete, but before the Preprocessor
// object is destroyed.)
virtualvoidhandlePreprocessorExit() = 0;

// Handle include directive.
// This function is called every time an include directive is seen by the
// preprocessor, for the purpose of later checking for 'extern "" {}' or
// "namespace {}" blocks containing #include directives.
virtualvoidhandleIncludeDirective(llvm::StringRef DirectivePath,
int DirectiveLine, int DirectiveColumn,
 llvm::StringRef TargetPath) = 0;

// Check for include directives within the given source line range.
// Report errors if any found. Returns true if no include directives
// found in block.
virtualboolcheckForIncludesInBlock(clang::Preprocessor &PP,
 clang::SourceRange BlockSourceRange,
constchar *BlockIdentifierMessage,
 llvm::raw_ostream &OS) = 0;

// Report on inconsistent macro instances.
// Returns true if any mismatches.
virtualboolreportInconsistentMacros(llvm::raw_ostream &OS) = 0;

// Report on inconsistent conditional directive instances.
// Returns true if any mismatches.
virtualboolreportInconsistentConditionals(llvm::raw_ostream &OS) = 0;

// Create instance of PreprocessorTracker.
static PreprocessorTracker *create(
 llvm::SmallVector<std::string, 32> &Headers,
bool DoBlockCheckHeaderListOnly);
};

} // end namespace Modularize

#endif