Modularize.cpp

//===- extra/modularize/Modularize.cpp - Check modularized headers --------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Introduction
//
// This file implements a tool that checks whether a set of headers provides
// the consistent definitions required to use modules. It can also check an
// existing module map for full coverage of the headers in a directory tree.
//
// For example, in examining headers, it detects whether the same entity
// (say, a NULL macro or size_t typedef) is defined in multiple headers
// or whether a header produces different definitions under
// different circumstances. These conditions cause modules built from the
// headers to behave poorly, and should be fixed before introducing a module
// map.
//
// Modularize takes as input either one or more module maps (by default,
// "module.modulemap") or one or more text files contatining lists of headers
// to check.
//
// In the case of a module map, the module map must be well-formed in
// terms of syntax. Modularize will extract the header file names
// from the map. Only normal headers are checked, assuming headers
// marked "private", "textual", or "exclude" are not to be checked
// as a top-level include, assuming they either are included by
// other headers which are checked, or they are not suitable for
// modules.
//
// In the case of a file list, the list is a newline-separated list of headers
// to check with respect to each other.
// Lines beginning with '#' and empty lines are ignored.
// Header file names followed by a colon and other space-separated
// file names will include those extra files as dependencies.
// The file names can be relative or full paths, but must be on the
// same line.
//
// Modularize also accepts regular clang front-end arguments.
//
// Usage: modularize [(modularize options)]
// [(include-files_list)|(module map)]+ [(front-end-options) ...]
//
// Options:
// -prefix=(optional header path prefix)
// Note that unless a "-prefix (header path)" option is specified,
// non-absolute file paths in the header list file will be relative
// to the header list file directory. Use -prefix to specify a
// different directory.
// -module-map-path=(module map)
// Skip the checks, and instead act as a module.map generation
// assistant, generating a module map file based on the header list.
// An optional "-root-module=(rootName)" argument can specify a root
// module to be created in the generated module.map file. Note that
// you will likely need to edit this file to suit the needs of your
// headers.
// -problem-files-list=(problem files list file name)
// For use only with module map assistant. Input list of files that
// have problems with respect to modules. These will still be
// included in the generated module map, but will be marked as
// "excluded" headers.
// -root-module=(root module name)
// Specifies a root module to be created in the generated module.map
// file.
// -block-check-header-list-only
// Only warn if #include directives are inside extern or namespace
// blocks if the included header is in the header list.
// -no-coverage-check
// Don't do the coverage check.
// -coverage-check-only
// Only do the coverage check.
// -display-file-lists
// Display lists of good files (no compile errors), problem files,
// and a combined list with problem files preceded by a '#'.
// This can be used to quickly determine which files have problems.
// The latter combined list might be useful in starting to modularize
// a set of headers. You can start with a full list of headers,
// use -display-file-lists option, and then use the combined list as
// your intermediate list, uncommenting-out headers as you fix them.
//
// Note that by default, the modularize assumes .h files contain C++ source.
// If your .h files in the file list contain another language, you should
// append an appropriate -x option to your command line, i.e.: -x c
//
// Modularization Issue Checks
//
// In the process of checking headers for modularization issues, modularize
// will do normal parsing, reporting normal errors and warnings,
// but will also report special error messages like the following:
//
// error: '(symbol)' defined at multiple locations:
// (file):(row):(column)
// (file):(row):(column)
//
// error: header '(file)' has different contents depending on how it was
// included
//
// The latter might be followed by messages like the following:
//
// note: '(symbol)' in (file) at (row):(column) not always provided
//
// Checks will also be performed for macro expansions, defined(macro)
// expressions, and preprocessor conditional directives that evaluate
// inconsistently, and can produce error messages like the following:
//
// (...)/SubHeader.h:11:5:
// #if SYMBOL == 1
// ^
// error: Macro instance 'SYMBOL' has different values in this header,
// depending on how it was included.
// 'SYMBOL' expanded to: '1' with respect to these inclusion paths:
// (...)/Header1.h
// (...)/SubHeader.h
// (...)/SubHeader.h:3:9:
// #define SYMBOL 1
// ^
// Macro defined here.
// 'SYMBOL' expanded to: '2' with respect to these inclusion paths:
// (...)/Header2.h
// (...)/SubHeader.h
// (...)/SubHeader.h:7:9:
// #define SYMBOL 2
// ^
// Macro defined here.
//
// Checks will also be performed for '#include' directives that are
// nested inside 'extern "C/C++" {}' or 'namespace (name) {}' blocks,
// and can produce error message like the following:
//
// IncludeInExtern.h:2:3
// #include "Empty.h"
// ^
// error: Include directive within extern "C" {}.
// IncludeInExtern.h:1:1
// extern "C" {
// ^
// The "extern "C" {}" block is here.
//
// See PreprocessorTracker.cpp for additional details.
//
// Module Map Coverage Check
//
// The coverage check uses the Clang ModuleMap class to read and parse the
// module map file. Starting at the module map file directory, or just the
// include paths, if specified, it will collect the names of all the files it
// considers headers (no extension, .h, or .inc--if you need more, modify the
// isHeader function). It then compares the headers against those referenced
// in the module map, either explicitly named, or implicitly named via an
// umbrella directory or umbrella file, as parsed by the ModuleMap object.
// If headers are found which are not referenced or covered by an umbrella
// directory or file, warning messages will be produced, and this program
// will return an error code of 1. Other errors result in an error code of 2.
// If no problems are found, an error code of 0 is returned.
//
// Note that in the case of umbrella headers, this tool invokes the compiler
// to preprocess the file, and uses a callback to collect the header files
// included by the umbrella header or any of its nested includes. If any
// front end options are needed for these compiler invocations, these
// can be included on the command line after the module map file argument.
//
// Warning message have the form:
//
// warning: module.modulemap does not account for file: Level3A.h
//
// Note that for the case of the module map referencing a file that does
// not exist, the module map parser in Clang will (at the time of this
// writing) display an error message.
//
// Module Map Assistant - Module Map Generation
//
// Modularize also has an option ("-module-map-path=module.modulemap") that will
// skip the checks, and instead act as a module.modulemap generation assistant,
// generating a module map file based on the header list. An optional
// "-root-module=(rootName)" argument can specify a root module to be
// created in the generated module.modulemap file. Note that you will likely
// need to edit this file to suit the needs of your headers.
//
// An example command line for generating a module.modulemap file:
//
// modularize -module-map-path=module.modulemap -root-module=myroot \
// headerlist.txt
//
// Note that if the headers in the header list have partial paths, sub-modules
// will be created for the subdirectires involved, assuming that the
// subdirectories contain headers to be grouped into a module, but still with
// individual modules for the headers in the subdirectory.
//
// See the ModuleAssistant.cpp file comments for additional details about the
// implementation of the assistant mode.
//
// Future directions:
//
// Basically, we want to add new checks for whatever we can check with respect
// to checking headers for module'ability.
//
// Some ideas:
//
// 1. Omit duplicate "not always provided" messages
//
// 2. Add options to disable any of the checks, in case
// there is some problem with them, or the messages get too verbose.
//
// 3. Try to figure out the preprocessor conditional directives that
// contribute to problems and tie them to the inconsistent definitions.
//
// 4. There are some legitimate uses of preprocessor macros that
// modularize will flag as errors, such as repeatedly #include'ing
// a file and using interleaving defined/undefined macros
// to change declarations in the included file. Is there a way
// to address this? Maybe have modularize accept a list of macros
// to ignore. Otherwise you can just exclude the file, after checking
// for legitimate errors.
//
// 5. What else?
//
// General clean-up and refactoring:
//
// 1. The Location class seems to be something that we might
// want to design to be applicable to a wider range of tools, and stick it
// somewhere into Tooling/ in mainline
//
//===----------------------------------------------------------------------===//

#include"Modularize.h"
#include"ModularizeUtilities.h"
#include"PreprocessorTracker.h"
#include"clang/AST/ASTConsumer.h"
#include"clang/AST/ASTContext.h"
#include"clang/AST/RecursiveASTVisitor.h"
#include"clang/Basic/SourceManager.h"
#include"clang/Driver/Options.h"
#include"clang/Frontend/CompilerInstance.h"
#include"clang/Frontend/FrontendActions.h"
#include"clang/Lex/Preprocessor.h"
#include"clang/Tooling/CompilationDatabase.h"
#include"clang/Tooling/Tooling.h"
#include"llvm/Option/Arg.h"
#include"llvm/Option/ArgList.h"
#include"llvm/Option/OptTable.h"
#include"llvm/Option/Option.h"
#include"llvm/Support/CommandLine.h"
#include"llvm/Support/FileSystem.h"
#include"llvm/Support/MemoryBuffer.h"
#include"llvm/Support/Path.h"
#include<algorithm>
#include<fstream>
#include<iterator>
#include<string>
#include<vector>

usingnamespaceclang;
usingnamespaceclang::driver;
usingnamespaceclang::driver::options;
usingnamespaceclang::tooling;
usingnamespacellvm;
usingnamespacellvm::opt;
usingnamespaceModularize;

// Option to specify a file name for a list of header files to check.
static cl::list<std::string>
ListFileNames(cl::Positional, cl::value_desc("list"),
 cl::desc("<list of one or more header list files>"),
 cl::CommaSeparated);

// Collect all other arguments, which will be passed to the front end.
static cl::list<std::string>
CC1Arguments(cl::ConsumeAfter,
cl::desc("<arguments to be passed to front end>..."));

// Option to specify a prefix to be prepended to the header names.
static cl::opt<std::string> HeaderPrefix(
"prefix", cl::init(""),
 cl::desc(
"Prepend header file paths with this prefix."
" If not specified,"
" the files are considered to be relative to the header list file."));

// Option for assistant mode, telling modularize to output a module map
// based on the headers list, and where to put it.
static cl::opt<std::string> ModuleMapPath(
"module-map-path", cl::init(""),
 cl::desc("Turn on module map output and specify output path or file name."
" If no path is specified and if prefix option is specified,"
" use prefix for file path."));

// Option to specify list of problem files for assistant.
// This will cause assistant to exclude these files.
static cl::opt<std::string> ProblemFilesList(
"problem-files-list", cl::init(""),
 cl::desc(
"List of files with compilation or modularization problems for"
" assistant mode. This will be excluded."));

// Option for assistant mode, telling modularize the name of the root module.
static cl::opt<std::string>
RootModule("root-module", cl::init(""),
 cl::desc("Specify the name of the root module."));

// Option for limiting the #include-inside-extern-or-namespace-block
// check to only those headers explicitly listed in the header list.
// This is a work-around for private includes that purposefully get
// included inside blocks.
static cl::opt<bool>
BlockCheckHeaderListOnly("block-check-header-list-only", cl::init(false),
cl::desc("Only warn if #include directives are inside extern or namespace"
" blocks if the included header is in the header list."));

// Option for include paths for coverage check.
static cl::list<std::string>
IncludePaths("I", cl::desc("Include path for coverage check."),
cl::ZeroOrMore, cl::value_desc("path"));

// Option for disabling the coverage check.
static cl::opt<bool>
NoCoverageCheck("no-coverage-check", cl::init(false),
cl::desc("Don't do the coverage check."));

// Option for just doing the coverage check.
static cl::opt<bool>
CoverageCheckOnly("coverage-check-only", cl::init(false),
cl::desc("Only do the coverage check."));

// Option for displaying lists of good, bad, and mixed files.
static cl::opt<bool>
DisplayFileLists("display-file-lists", cl::init(false),
cl::desc("Display lists of good files (no compile errors), problem files,"
" and a combined list with problem files preceded by a '#'."));

// Save the program name for error messages.
constchar *Argv0;
// Save the command line for comments.
std::string CommandLine;

// Helper function for finding the input file in an arguments list.
static std::string findInputFile(const CommandLineArguments &CLArgs) {
 std::unique_ptr<OptTable> Opts(createDriverOptTable());
constunsigned IncludedFlagsBitmask = options::CC1Option;
unsigned MissingArgIndex, MissingArgCount;
 SmallVector<constchar *, 256> Argv;
for (auto I = CLArgs.begin(), E = CLArgs.end(); I != E; ++I)
 Argv.push_back(I->c_str());
 InputArgList Args = Opts->ParseArgs(Argv, MissingArgIndex, MissingArgCount,
 IncludedFlagsBitmask);
 std::vector<std::string> Inputs = Args.getAllArgValues(OPT_INPUT);
returnModularizeUtilities::getCanonicalPath(Inputs.back());
}

// This arguments adjuster inserts "-include (file)" arguments for header
// dependencies. It also inserts a "-w" option and a "-x c++",
// if no other "-x" option is present.
static ArgumentsAdjuster
getModularizeArgumentsAdjuster(DependencyMap &Dependencies) {
return [&Dependencies](const CommandLineArguments &Args,
 StringRef /*unused*/) {
 std::string InputFile = findInputFile(Args);
 DependentsVector &FileDependents = Dependencies[InputFile];
 CommandLineArguments NewArgs(Args);
if (int Count = FileDependents.size()) {
for (int Index = 0; Index < Count; ++Index) {
 NewArgs.push_back("-include");
 std::string File(std::string("\"") + FileDependents[Index] +
std::string("\""));
 NewArgs.push_back(FileDependents[Index]);
 }
 }
// Ignore warnings. (Insert after "clang_tool" at beginning.)
 NewArgs.insert(NewArgs.begin() + 1, "-w");
// Since we are compiling .h files, assume C++ unless given a -x option.
if (std::find(NewArgs.begin(), NewArgs.end(), "-x") == NewArgs.end()) {
 NewArgs.insert(NewArgs.begin() + 2, "-x");
 NewArgs.insert(NewArgs.begin() + 3, "c++");
 }
return NewArgs;
 };
}

// FIXME: The Location class seems to be something that we might
// want to design to be applicable to a wider range of tools, and stick it
// somewhere into Tooling/ in mainline
structLocation {
const FileEntry *File;
unsigned Line, Column;

Location() : File(), Line(), Column() {}

Location(SourceManager &SM, SourceLocation Loc) : File(), Line(), Column() {
 Loc = SM.getExpansionLoc(Loc);
if (Loc.isInvalid())
return;

 std::pair<FileID, unsigned> Decomposed = SM.getDecomposedLoc(Loc);
 File = SM.getFileEntryForID(Decomposed.first);
if (!File)
return;

 Line = SM.getLineNumber(Decomposed.first, Decomposed.second);
 Column = SM.getColumnNumber(Decomposed.first, Decomposed.second);
 }

operatorbool() const { return File != nullptr; }

friendbooloperator==(const Location &X, const Location &Y) {
return X.File == Y.File && X.Line == Y.Line && X.Column == Y.Column;
 }

friendbooloperator!=(const Location &X, const Location &Y) {
return !(X == Y);
 }

friendbooloperator<(const Location &X, const Location &Y) {
if (X.File != Y.File)
return X.File < Y.File;
if (X.Line != Y.Line)
return X.Line < Y.Line;
return X.Column < Y.Column;
 }
friendbooloperator>(const Location &X, const Location &Y) { return Y < X; }
friendbooloperator<=(const Location &X, const Location &Y) {
return !(Y < X);
 }
friendbooloperator>=(const Location &X, const Location &Y) {
return !(X < Y);
 }
};

structEntry {
enum EntryKind {
 EK_Tag,
 EK_Value,
 EK_Macro,

 EK_NumberOfKinds
 } Kind;

 Location Loc;

 StringRef getKindName() { returngetKindName(Kind); }
static StringRef getKindName(EntryKind kind);
};

// Return a string representing the given kind.
StringRef Entry::getKindName(Entry::EntryKind kind) {
switch (kind) {
case EK_Tag:
return"tag";
case EK_Value:
return"value";
case EK_Macro:
return"macro";
case EK_NumberOfKinds:
break;
 }
llvm_unreachable("invalid Entry kind");
}

structHeaderEntry {
 std::string Name;
 Location Loc;

friendbooloperator==(const HeaderEntry &X, const HeaderEntry &Y) {
return X.Loc == Y.Loc && X.Name == Y.Name;
 }
friendbooloperator!=(const HeaderEntry &X, const HeaderEntry &Y) {
return !(X == Y);
 }
friendbooloperator<(const HeaderEntry &X, const HeaderEntry &Y) {
return X.Loc < Y.Loc || (X.Loc == Y.Loc && X.Name < Y.Name);
 }
friendbooloperator>(const HeaderEntry &X, const HeaderEntry &Y) {
return Y < X;
 }
friendbooloperator<=(const HeaderEntry &X, const HeaderEntry &Y) {
return !(Y < X);
 }
friendbooloperator>=(const HeaderEntry &X, const HeaderEntry &Y) {
return !(X < Y);
 }
};

typedef std::vector<HeaderEntry> HeaderContents;

classEntityMap : publicStringMap<SmallVector<Entry, 2> > {
public:
 DenseMap<const FileEntry *, HeaderContents> HeaderContentMismatches;

voidadd(const std::string &Name, enum Entry::EntryKind Kind, Location Loc) {
// Record this entity in its header.
 HeaderEntry HE = { Name, Loc };
 CurHeaderContents[Loc.File].push_back(HE);

// Check whether we've seen this entry before.
 SmallVector<Entry, 2> &Entries = (*this)[Name];
for (unsigned I = 0, N = Entries.size(); I != N; ++I) {
if (Entries[I].Kind == Kind && Entries[I].Loc == Loc)
return;
 }

// We have not seen this entry before; record it.
 Entry E = { Kind, Loc };
 Entries.push_back(E);
 }

voidmergeCurHeaderContents() {
for (DenseMap<const FileEntry *, HeaderContents>::iterator
 H = CurHeaderContents.begin(),
 HEnd = CurHeaderContents.end();
 H != HEnd; ++H) {
// Sort contents.
std::sort(H->second.begin(), H->second.end());

// Check whether we've seen this header before.
 DenseMap<const FileEntry *, HeaderContents>::iterator KnownH =
 AllHeaderContents.find(H->first);
if (KnownH == AllHeaderContents.end()) {
// We haven't seen this header before; record its contents.
 AllHeaderContents.insert(*H);
continue;
 }

// If the header contents are the same, we're done.
if (H->second == KnownH->second)
continue;

// Determine what changed.
std::set_symmetric_difference(
 H->second.begin(), H->second.end(), KnownH->second.begin(),
 KnownH->second.end(),
std::back_inserter(HeaderContentMismatches[H->first]));
 }

 CurHeaderContents.clear();
 }

private:
 DenseMap<const FileEntry *, HeaderContents> CurHeaderContents;
 DenseMap<const FileEntry *, HeaderContents> AllHeaderContents;
};

classCollectEntitiesVisitor
 : public RecursiveASTVisitor<CollectEntitiesVisitor> {
public:
CollectEntitiesVisitor(SourceManager &SM, EntityMap &Entities,
 Preprocessor &PP, PreprocessorTracker &PPTracker,
int &HadErrors)
 : SM(SM), Entities(Entities), PP(PP), PPTracker(PPTracker),
HadErrors(HadErrors) {}

boolTraverseStmt(Stmt *S) { returntrue; }
boolTraverseType(QualType T) { returntrue; }
boolTraverseTypeLoc(TypeLoc TL) { returntrue; }
boolTraverseNestedNameSpecifier(NestedNameSpecifier *NNS) { returntrue; }
boolTraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
returntrue;
 }
boolTraverseDeclarationNameInfo(DeclarationNameInfo NameInfo) {
returntrue;
 }
boolTraverseTemplateName(TemplateName Template) { returntrue; }
boolTraverseTemplateArgument(const TemplateArgument &Arg) { returntrue; }
boolTraverseTemplateArgumentLoc(const TemplateArgumentLoc &ArgLoc) {
returntrue;
 }
boolTraverseTemplateArguments(const TemplateArgument *Args,
unsigned NumArgs) {
returntrue;
 }
boolTraverseConstructorInitializer(CXXCtorInitializer *Init) { returntrue; }
boolTraverseLambdaCapture(LambdaExpr *LE, const LambdaCapture *C,
 Expr *Init) {
returntrue;
 }

// Check 'extern "*" {}' block for #include directives.
boolVisitLinkageSpecDecl(LinkageSpecDecl *D) {
// Bail if not a block.
if (!D->hasBraces())
returntrue;
 SourceRange BlockRange = D->getSourceRange();
constchar *LinkageLabel;
switch (D->getLanguage()) {
case LinkageSpecDecl::lang_c:
 LinkageLabel = "extern \"C\" {}";
break;
case LinkageSpecDecl::lang_cxx:
 LinkageLabel = "extern \"C++\" {}";
break;
 }
if (!PPTracker.checkForIncludesInBlock(PP, BlockRange, LinkageLabel,
errs()))
 HadErrors = 1;
returntrue;
 }

// Check 'namespace (name) {}' block for #include directives.
boolVisitNamespaceDecl(const NamespaceDecl *D) {
 SourceRange BlockRange = D->getSourceRange();
 std::string Label("namespace ");
 Label += D->getName();
 Label += " {}";
if (!PPTracker.checkForIncludesInBlock(PP, BlockRange, Label.c_str(),
errs()))
 HadErrors = 1;
returntrue;
 }

// Collect definition entities.
boolVisitNamedDecl(NamedDecl *ND) {
// We only care about file-context variables.
if (!ND->getDeclContext()->isFileContext())
returntrue;

// Skip declarations that tend to be properly multiply-declared.
if (isa<NamespaceDecl>(ND) || isa<UsingDirectiveDecl>(ND) ||
 isa<NamespaceAliasDecl>(ND) ||
 isa<ClassTemplateSpecializationDecl>(ND) || isa<UsingDecl>(ND) ||
 isa<ClassTemplateDecl>(ND) || isa<TemplateTypeParmDecl>(ND) ||
 isa<TypeAliasTemplateDecl>(ND) || isa<UsingShadowDecl>(ND) ||
 isa<FunctionDecl>(ND) || isa<FunctionTemplateDecl>(ND) ||
 (isa<TagDecl>(ND) &&
 !cast<TagDecl>(ND)->isThisDeclarationADefinition()))
returntrue;

// Skip anonymous declarations.
if (!ND->getDeclName())
returntrue;

// Get the qualified name.
 std::string Name;
 llvm::raw_string_ostream OS(Name);
 ND->printQualifiedName(OS);
 OS.flush();
if (Name.empty())
returntrue;

 Location Loc(SM, ND->getLocation());
if (!Loc)
returntrue;

 Entities.add(Name, isa<TagDecl>(ND) ? Entry::EK_Tag : Entry::EK_Value, Loc);
returntrue;
 }

private:
 SourceManager &SM;
 EntityMap &Entities;
 Preprocessor &PP;
 PreprocessorTracker &PPTracker;
int &HadErrors;
};

classCollectEntitiesConsumer : publicASTConsumer {
public:
CollectEntitiesConsumer(EntityMap &Entities,
 PreprocessorTracker &preprocessorTracker,
 Preprocessor &PP, StringRef InFile, int &HadErrors)
 : Entities(Entities), PPTracker(preprocessorTracker), PP(PP),
HadErrors(HadErrors) {
 PPTracker.handlePreprocessorEntry(PP, InFile);
 }

~CollectEntitiesConsumer() override { PPTracker.handlePreprocessorExit(); }

voidHandleTranslationUnit(ASTContext &Ctx) override {
 SourceManager &SM = Ctx.getSourceManager();

// Collect declared entities.
CollectEntitiesVisitor(SM, Entities, PP, PPTracker, HadErrors)
 .TraverseDecl(Ctx.getTranslationUnitDecl());

// Collect macro definitions.
for (Preprocessor::macro_iterator M = PP.macro_begin(),
 MEnd = PP.macro_end();
 M != MEnd; ++M) {
 Location Loc(SM, M->second.getLatest()->getLocation());
if (!Loc)
continue;

 Entities.add(M->first->getName().str(), Entry::EK_Macro, Loc);
 }

// Merge header contents.
 Entities.mergeCurHeaderContents();
 }

private:
 EntityMap &Entities;
 PreprocessorTracker &PPTracker;
 Preprocessor &PP;
int &HadErrors;
};

classCollectEntitiesAction : publicSyntaxOnlyAction {
public:
CollectEntitiesAction(EntityMap &Entities,
 PreprocessorTracker &preprocessorTracker,
int &HadErrors)
 : Entities(Entities), PPTracker(preprocessorTracker),
HadErrors(HadErrors) {}

protected:
 std::unique_ptr<clang::ASTConsumer>
CreateASTConsumer(CompilerInstance &CI, StringRef InFile) override {
return llvm::make_unique<CollectEntitiesConsumer>(
 Entities, PPTracker, CI.getPreprocessor(), InFile, HadErrors);
 }

private:
 EntityMap &Entities;
 PreprocessorTracker &PPTracker;
int &HadErrors;
};

classModularizeFrontendActionFactory : publicFrontendActionFactory {
public:
ModularizeFrontendActionFactory(EntityMap &Entities,
 PreprocessorTracker &preprocessorTracker,
int &HadErrors)
 : Entities(Entities), PPTracker(preprocessorTracker),
HadErrors(HadErrors) {}

 CollectEntitiesAction *create() override {
returnnewCollectEntitiesAction(Entities, PPTracker, HadErrors);
 }

private:
 EntityMap &Entities;
 PreprocessorTracker &PPTracker;
int &HadErrors;
};

classCompileCheckVisitor
 : public RecursiveASTVisitor<CompileCheckVisitor> {
public:
CompileCheckVisitor() {}

boolTraverseStmt(Stmt *S) { returntrue; }
boolTraverseType(QualType T) { returntrue; }
boolTraverseTypeLoc(TypeLoc TL) { returntrue; }
boolTraverseNestedNameSpecifier(NestedNameSpecifier *NNS) { returntrue; }
boolTraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
returntrue;
 }
boolTraverseDeclarationNameInfo(DeclarationNameInfo NameInfo) {
returntrue;
 }
boolTraverseTemplateName(TemplateName Template) { returntrue; }
boolTraverseTemplateArgument(const TemplateArgument &Arg) { returntrue; }
boolTraverseTemplateArgumentLoc(const TemplateArgumentLoc &ArgLoc) {
returntrue;
 }
boolTraverseTemplateArguments(const TemplateArgument *Args,
unsigned NumArgs) {
returntrue;
 }
boolTraverseConstructorInitializer(CXXCtorInitializer *Init) { returntrue; }
boolTraverseLambdaCapture(LambdaExpr *LE, const LambdaCapture *C,
 Expr *Init) {
returntrue;
 }

// Check 'extern "*" {}' block for #include directives.
boolVisitLinkageSpecDecl(LinkageSpecDecl *D) {
returntrue;
 }

// Check 'namespace (name) {}' block for #include directives.
boolVisitNamespaceDecl(const NamespaceDecl *D) {
returntrue;
 }

// Collect definition entities.
boolVisitNamedDecl(NamedDecl *ND) {
returntrue;
 }
};

classCompileCheckConsumer : publicASTConsumer {
public:
CompileCheckConsumer() {}

voidHandleTranslationUnit(ASTContext &Ctx) override {
CompileCheckVisitor().TraverseDecl(Ctx.getTranslationUnitDecl());
 }
};

classCompileCheckAction : publicSyntaxOnlyAction {
public:
CompileCheckAction() {}

protected:
 std::unique_ptr<clang::ASTConsumer>
CreateASTConsumer(CompilerInstance &CI, StringRef InFile) override {
return llvm::make_unique<CompileCheckConsumer>();
 }
};

classCompileCheckFrontendActionFactory : publicFrontendActionFactory {
public:
CompileCheckFrontendActionFactory() {}

 CompileCheckAction *create() override {
returnnewCompileCheckAction();
 }
};

intmain(int Argc, constchar **Argv) {

// Save program name for error messages.
 Argv0 = Argv[0];

// Save program arguments for use in module.modulemap comment.
 CommandLine = sys::path::stem(sys::path::filename(Argv0));
for (int ArgIndex = 1; ArgIndex < Argc; ArgIndex++) {
 CommandLine.append("");
 CommandLine.append(Argv[ArgIndex]);
 }

// This causes options to be parsed.
cl::ParseCommandLineOptions(Argc, Argv, "modularize.\n");

// No go if we have no header list file.
if (ListFileNames.size() == 0) {
cl::PrintHelpMessage();
return1;
 }

 std::unique_ptr<ModularizeUtilities> ModUtil;
int HadErrors = 0;

 ModUtil.reset(
ModularizeUtilities::createModularizeUtilities(
 ListFileNames, HeaderPrefix, ProblemFilesList));

// Get header file names and dependencies.
if (ModUtil->loadAllHeaderListsAndDependencies())
 HadErrors = 1;

// If we are in assistant mode, output the module map and quit.
if (ModuleMapPath.length() != 0) {
if (!createModuleMap(ModuleMapPath, ModUtil->HeaderFileNames,
 ModUtil->ProblemFileNames,
 ModUtil->Dependencies, HeaderPrefix, RootModule))
return1; // Failed.
return0; // Success - Skip checks in assistant mode.
 }

// If we're doing module maps.
if (!NoCoverageCheck && ModUtil->HasModuleMap) {
// Do coverage check.
if (ModUtil->doCoverageCheck(IncludePaths, CommandLine))
 HadErrors = 1;
 }

// Bail early if only doing the coverage check.
if (CoverageCheckOnly)
return HadErrors;

// Create the compilation database.
 SmallString<256> PathBuf;
sys::fs::current_path(PathBuf);
 std::unique_ptr<CompilationDatabase> Compilations;
 Compilations.reset(
newFixedCompilationDatabase(Twine(PathBuf), CC1Arguments));

// Create preprocessor tracker, to watch for macro and conditional problems.
 std::unique_ptr<PreprocessorTracker> PPTracker(
PreprocessorTracker::create(ModUtil->HeaderFileNames,
 BlockCheckHeaderListOnly));

// Coolect entities here.
 EntityMap Entities;

// Because we can't easily determine which files failed
// during the tool run, if we're collecting the file lists
// for display, we do a first compile pass on individual
// files to find which ones don't compile stand-alone.
if (DisplayFileLists) {
// First, make a pass to just get compile errors.
for (auto &CompileCheckFile : ModUtil->HeaderFileNames) {
 llvm::SmallVector<std::string, 32> CompileCheckFileArray;
 CompileCheckFileArray.push_back(CompileCheckFile);
 ClangTool CompileCheckTool(*Compilations, CompileCheckFileArray);
 CompileCheckTool.appendArgumentsAdjuster(
getModularizeArgumentsAdjuster(ModUtil->Dependencies));
int CompileCheckFileErrors = 0;
 CompileCheckFrontendActionFactory CompileCheckFactory;
 CompileCheckFileErrors |= CompileCheckTool.run(&CompileCheckFactory);
if (CompileCheckFileErrors != 0) {
 ModUtil->addUniqueProblemFile(CompileCheckFile); // Save problem file.
 HadErrors |= 1;
 }
else
 ModUtil->addNoCompileErrorsFile(CompileCheckFile); // Save good file.
 }
 }

// Then we make another pass on the good files to do the rest of the work.
 ClangTool Tool(*Compilations,
 (DisplayFileLists ? ModUtil->GoodFileNames : ModUtil->HeaderFileNames));
 Tool.appendArgumentsAdjuster(
getModularizeArgumentsAdjuster(ModUtil->Dependencies));
 ModularizeFrontendActionFactory Factory(Entities, *PPTracker, HadErrors);
 HadErrors |= Tool.run(&Factory);

// Create a place to save duplicate entity locations, separate bins per kind.
typedef SmallVector<Location, 8> LocationArray;
typedef SmallVector<LocationArray, Entry::EK_NumberOfKinds> EntryBinArray;
 EntryBinArray EntryBins;
int KindIndex;
for (KindIndex = 0; KindIndex < Entry::EK_NumberOfKinds; ++KindIndex) {
 LocationArray Array;
 EntryBins.push_back(Array);
 }

// Check for the same entity being defined in multiple places.
for (EntityMap::iterator E = Entities.begin(), EEnd = Entities.end();
 E != EEnd; ++E) {
// If only one occurrence, exit early.
if (E->second.size() == 1)
continue;
// Clear entity locations.
for (EntryBinArray::iterator CI = EntryBins.begin(), CE = EntryBins.end();
 CI != CE; ++CI) {
 CI->clear();
 }
// Walk the entities of a single name, collecting the locations,
// separated into separate bins.
for (unsigned I = 0, N = E->second.size(); I != N; ++I) {
 EntryBins[E->second[I].Kind].push_back(E->second[I].Loc);
 }
// Report any duplicate entity definition errors.
int KindIndex = 0;
for (EntryBinArray::iterator DI = EntryBins.begin(), DE = EntryBins.end();
 DI != DE; ++DI, ++KindIndex) {
int ECount = DI->size();
// If only 1 occurrence of this entity, skip it, we only report duplicates.
if (ECount <= 1)
continue;
 LocationArray::iterator FI = DI->begin();
 StringRef kindName = Entry::getKindName((Entry::EntryKind)KindIndex);
errs() << "error: " << kindName << " '" << E->first()
 << "' defined at multiple locations:\n";
for (LocationArray::iterator FE = DI->end(); FI != FE; ++FI) {
errs() << "" << FI->File->getName() << ":" << FI->Line << ":"
 << FI->Column << "\n";
 ModUtil->addUniqueProblemFile(FI->File->getName());
 }
 HadErrors = 1;
 }
 }

// Complain about macro instance in header files that differ based on how
// they are included.
if (PPTracker->reportInconsistentMacros(errs()))
 HadErrors = 1;

// Complain about preprocessor conditional directives in header files that
// differ based on how they are included.
if (PPTracker->reportInconsistentConditionals(errs()))
 HadErrors = 1;

// Complain about any headers that have contents that differ based on how
// they are included.
// FIXME: Could we provide information about which preprocessor conditionals
// are involved?
for (DenseMap<const FileEntry *, HeaderContents>::iterator
 H = Entities.HeaderContentMismatches.begin(),
 HEnd = Entities.HeaderContentMismatches.end();
 H != HEnd; ++H) {
if (H->second.empty()) {
errs() << "internal error: phantom header content mismatch\n";
continue;
 }

 HadErrors = 1;
 ModUtil->addUniqueProblemFile(H->first->getName());
errs() << "error: header '" << H->first->getName()
 << "' has different contents depending on how it was included.\n";
for (unsigned I = 0, N = H->second.size(); I != N; ++I) {
errs() << "note: '" << H->second[I].Name << "' in "
 << H->second[I].Loc.File->getName() << " at "
 << H->second[I].Loc.Line << ":" << H->second[I].Loc.Column
 << " not always provided\n";
 }
 }

if (DisplayFileLists) {
 ModUtil->displayProblemFiles();
 ModUtil->displayGoodFiles();
 ModUtil->displayCombinedFiles();
 }

return HadErrors;
}