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[clang][lex] Use SearchDirIterator types in for loops
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This patch replaces a lot of index-based loops with iterators and ranges.

Depends on D117566.

Reviewed By: ahoppen

Differential Revision: https://reviews.llvm.org/D119722
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@jansvoboda11
jansvoboda11 committed Feb 15, 2022
1 parent 17c9fcd commit e7dcf09
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Showing 2 changed files with 83 additions and 62 deletions.
60 changes: 47 additions & 13 deletions clang/include/clang/Lex/HeaderSearch.h
View file
Expand Up @@ -163,54 +163,79 @@ struct FrameworkCacheEntry {
bool IsUserSpecifiedSystemFramework;
};

/// Forward iterator over the search directories of \c HeaderSearch.
struct ConstSearchDirIterator
: llvm::iterator_facade_base<ConstSearchDirIterator,
namespace detail {
template <bool Const, typename T>
using Qualified = std::conditional_t<Const, const T, T>;

/// Forward iterator over the search directories of HeaderSearch.
/// Does not get invalidated by \c HeaderSearch::Add{,System}SearchPath.
template <bool IsConst>
struct SearchDirIteratorImpl
: llvm::iterator_facade_base<SearchDirIteratorImpl<IsConst>,
std::forward_iterator_tag,
const DirectoryLookup> {
ConstSearchDirIterator(const ConstSearchDirIterator &) = default;
Qualified<IsConst, DirectoryLookup>> {
/// Const -> non-const iterator conversion.
template <typename Enable = std::enable_if<IsConst, bool>>
SearchDirIteratorImpl(const SearchDirIteratorImpl<false> &Other)
: HS(Other.HS), Idx(Other.Idx) {}

ConstSearchDirIterator &operator=(const ConstSearchDirIterator &) = default;
SearchDirIteratorImpl(const SearchDirIteratorImpl &) = default;

bool operator==(const ConstSearchDirIterator &RHS) const {
SearchDirIteratorImpl &operator=(const SearchDirIteratorImpl &) = default;

bool operator==(const SearchDirIteratorImpl &RHS) const {
return HS == RHS.HS && Idx == RHS.Idx;
}

ConstSearchDirIterator &operator++() {
SearchDirIteratorImpl &operator++() {
assert(*this && "Invalid iterator.");
++Idx;
return *this;
}

const DirectoryLookup &operator*() const;
Qualified<IsConst, DirectoryLookup> &operator*() const {
assert(*this && "Invalid iterator.");
return HS->SearchDirs[Idx];
}

/// Creates an invalid iterator.
ConstSearchDirIterator(std::nullptr_t) : HS(nullptr), Idx(0) {}
SearchDirIteratorImpl(std::nullptr_t) : HS(nullptr), Idx(0) {}

/// Checks whether the iterator is valid.
explicit operator bool() const { return HS != nullptr; }

private:
/// The parent \c HeaderSearch. This is \c nullptr for invalid iterator.
const HeaderSearch *HS;
Qualified<IsConst, HeaderSearch> *HS;

/// The index of the current element.
size_t Idx;

/// The constructor that creates a valid iterator.
ConstSearchDirIterator(const HeaderSearch &HS, size_t Idx)
SearchDirIteratorImpl(Qualified<IsConst, HeaderSearch> &HS, size_t Idx)
: HS(&HS), Idx(Idx) {}

/// Only HeaderSearch is allowed to instantiate valid iterators.
friend HeaderSearch;

/// Enables const -> non-const conversion.
friend SearchDirIteratorImpl<!IsConst>;
};
} // namespace detail

using ConstSearchDirIterator = detail::SearchDirIteratorImpl<true>;
using SearchDirIterator = detail::SearchDirIteratorImpl<false>;

using ConstSearchDirRange = llvm::iterator_range<ConstSearchDirIterator>;
using SearchDirRange = llvm::iterator_range<SearchDirIterator>;

/// Encapsulates the information needed to find the file referenced
/// by a \#include or \#include_next, (sub-)framework lookup, etc.
class HeaderSearch {
friend class DirectoryLookup;

friend ConstSearchDirIterator;
friend SearchDirIterator;

/// Header-search options used to initialize this header search.
std::shared_ptr<HeaderSearchOptions> HSOpts;
Expand Down Expand Up @@ -778,8 +803,17 @@ class HeaderSearch {
const HeaderFileInfo *getExistingFileInfo(const FileEntry *FE,
bool WantExternal = true) const;

SearchDirIterator search_dir_begin() { return {*this, 0}; }
SearchDirIterator search_dir_end() { return {*this, SearchDirs.size()}; }
SearchDirRange search_dir_range() {
return {search_dir_begin(), search_dir_end()};
}

ConstSearchDirIterator search_dir_begin() const { return quoted_dir_begin(); }
ConstSearchDirIterator search_dir_end() const { return system_dir_end(); }
ConstSearchDirRange search_dir_range() const {
return {search_dir_begin(), search_dir_end()};
}

unsigned search_dir_size() const { return SearchDirs.size(); }

Expand All @@ -799,7 +833,7 @@ class HeaderSearch {
}

/// Get the index of the given search directory.
Optional<unsigned> searchDirIdx(const DirectoryLookup &DL) const;
unsigned searchDirIdx(const DirectoryLookup &DL) const;

/// Retrieve a uniqued framework name.
StringRef getUniqueFrameworkName(StringRef Framework);
Expand Down
85 changes: 36 additions & 49 deletions clang/lib/Lex/HeaderSearch.cpp
View file
Expand Up @@ -79,11 +79,6 @@ HeaderFileInfo::getControllingMacro(ExternalPreprocessorSource *External) {

ExternalHeaderFileInfoSource::~ExternalHeaderFileInfoSource() = default;

const DirectoryLookup &ConstSearchDirIterator::operator*() const {
assert(*this && "Invalid iterator.");
return HS->SearchDirs[Idx];
}

HeaderSearch::HeaderSearch(std::shared_ptr<HeaderSearchOptions> HSOpts,
SourceManager &SourceMgr, DiagnosticsEngine &Diags,
const LangOptions &LangOpts,
Expand Down Expand Up @@ -304,21 +299,20 @@ Module *HeaderSearch::lookupModule(StringRef ModuleName, StringRef SearchName,
SourceLocation ImportLoc,
bool AllowExtraModuleMapSearch) {
Module *Module = nullptr;
unsigned Idx;
SearchDirIterator It = nullptr;

// Look through the various header search paths to load any available module
// maps, searching for a module map that describes this module.
for (Idx = 0; Idx != SearchDirs.size(); ++Idx) {
if (SearchDirs[Idx].isFramework()) {
for (It = search_dir_begin(); It != search_dir_end(); ++It) {
if (It->isFramework()) {
// Search for or infer a module map for a framework. Here we use
// SearchName rather than ModuleName, to permit finding private modules
// named FooPrivate in buggy frameworks named Foo.
SmallString<128> FrameworkDirName;
FrameworkDirName += SearchDirs[Idx].getFrameworkDir()->getName();
FrameworkDirName += It->getFrameworkDir()->getName();
llvm::sys::path::append(FrameworkDirName, SearchName + ".framework");
if (auto FrameworkDir = FileMgr.getDirectory(FrameworkDirName)) {
bool IsSystem
= SearchDirs[Idx].getDirCharacteristic() != SrcMgr::C_User;
bool IsSystem = It->getDirCharacteristic() != SrcMgr::C_User;
Module = loadFrameworkModule(ModuleName, *FrameworkDir, IsSystem);
if (Module)
break;
Expand All @@ -328,12 +322,12 @@ Module *HeaderSearch::lookupModule(StringRef ModuleName, StringRef SearchName,
// FIXME: Figure out how header maps and module maps will work together.

// Only deal with normal search directories.
if (!SearchDirs[Idx].isNormalDir())
if (!It->isNormalDir())
continue;

bool IsSystem = SearchDirs[Idx].isSystemHeaderDirectory();
bool IsSystem = It->isSystemHeaderDirectory();
// Search for a module map file in this directory.
if (loadModuleMapFile(SearchDirs[Idx].getDir(), IsSystem,
if (loadModuleMapFile(It->getDir(), IsSystem,
/*IsFramework*/false) == LMM_NewlyLoaded) {
// We just loaded a module map file; check whether the module is
// available now.
Expand All @@ -345,7 +339,7 @@ Module *HeaderSearch::lookupModule(StringRef ModuleName, StringRef SearchName,
// Search for a module map in a subdirectory with the same name as the
// module.
SmallString<128> NestedModuleMapDirName;
NestedModuleMapDirName = SearchDirs[Idx].getDir()->getName();
NestedModuleMapDirName = It->getDir()->getName();
llvm::sys::path::append(NestedModuleMapDirName, ModuleName);
if (loadModuleMapFile(NestedModuleMapDirName, IsSystem,
/*IsFramework*/false) == LMM_NewlyLoaded){
Expand All @@ -357,13 +351,13 @@ Module *HeaderSearch::lookupModule(StringRef ModuleName, StringRef SearchName,

// If we've already performed the exhaustive search for module maps in this
// search directory, don't do it again.
if (SearchDirs[Idx].haveSearchedAllModuleMaps())
if (It->haveSearchedAllModuleMaps())
continue;

// Load all module maps in the immediate subdirectories of this search
// directory if ModuleName was from @import.
if (AllowExtraModuleMapSearch)
loadSubdirectoryModuleMaps(SearchDirs[Idx]);
loadSubdirectoryModuleMaps(*It);

// Look again for the module.
Module = ModMap.findModule(ModuleName);
Expand All @@ -372,7 +366,7 @@ Module *HeaderSearch::lookupModule(StringRef ModuleName, StringRef SearchName,
}

if (Module)
noteLookupUsage(Idx, ImportLoc);
noteLookupUsage(It.Idx, ImportLoc);

return Module;
}
Expand Down Expand Up @@ -498,7 +492,7 @@ Optional<FileEntryRef> DirectoryLookup::LookupFile(
// The case where the target file **exists** is handled by callee of this
// function as part of the regular logic that applies to include search paths.
// The case where the target file **does not exist** is handled here:
HS.noteLookupUsage(*HS.searchDirIdx(*this), IncludeLoc);
HS.noteLookupUsage(HS.searchDirIdx(*this), IncludeLoc);
return None;
}

Expand Down Expand Up @@ -1452,11 +1446,8 @@ size_t HeaderSearch::getTotalMemory() const {
+ FrameworkMap.getAllocator().getTotalMemory();
}

Optional<unsigned> HeaderSearch::searchDirIdx(const DirectoryLookup &DL) const {
for (unsigned I = 0; I < SearchDirs.size(); ++I)
if (&SearchDirs[I] == &DL)
return I;
return None;
unsigned HeaderSearch::searchDirIdx(const DirectoryLookup &DL) const {
return &DL - &*SearchDirs.begin();
}

StringRef HeaderSearch::getUniqueFrameworkName(StringRef Framework) {
Expand Down Expand Up @@ -1785,13 +1776,12 @@ void HeaderSearch::collectAllModules(SmallVectorImpl<Module *> &Modules) {

if (HSOpts->ImplicitModuleMaps) {
// Load module maps for each of the header search directories.
for (unsigned Idx = 0, N = SearchDirs.size(); Idx != N; ++Idx) {
bool IsSystem = SearchDirs[Idx].isSystemHeaderDirectory();
if (SearchDirs[Idx].isFramework()) {
for (DirectoryLookup &DL : search_dir_range()) {
bool IsSystem = DL.isSystemHeaderDirectory();
if (DL.isFramework()) {
std::error_code EC;
SmallString<128> DirNative;
llvm::sys::path::native(SearchDirs[Idx].getFrameworkDir()->getName(),
DirNative);
llvm::sys::path::native(DL.getFrameworkDir()->getName(), DirNative);

// Search each of the ".framework" directories to load them as modules.
llvm::vfs::FileSystem &FS = FileMgr.getVirtualFileSystem();
Expand All @@ -1814,16 +1804,15 @@ void HeaderSearch::collectAllModules(SmallVectorImpl<Module *> &Modules) {
}

// FIXME: Deal with header maps.
if (SearchDirs[Idx].isHeaderMap())
if (DL.isHeaderMap())
continue;

// Try to load a module map file for the search directory.
loadModuleMapFile(SearchDirs[Idx].getDir(), IsSystem,
/*IsFramework*/ false);
loadModuleMapFile(DL.getDir(), IsSystem, /*IsFramework*/ false);

// Try to load module map files for immediate subdirectories of this
// search directory.
loadSubdirectoryModuleMaps(SearchDirs[Idx]);
loadSubdirectoryModuleMaps(DL);
}
}

Expand All @@ -1837,16 +1826,14 @@ void HeaderSearch::loadTopLevelSystemModules() {
return;

// Load module maps for each of the header search directories.
for (unsigned Idx = 0, N = SearchDirs.size(); Idx != N; ++Idx) {
for (const DirectoryLookup &DL : search_dir_range()) {
// We only care about normal header directories.
if (!SearchDirs[Idx].isNormalDir()) {
if (!DL.isNormalDir())
continue;
}

// Try to load a module map file for the search directory.
loadModuleMapFile(SearchDirs[Idx].getDir(),
SearchDirs[Idx].isSystemHeaderDirectory(),
SearchDirs[Idx].isFramework());
loadModuleMapFile(DL.getDir(), DL.isSystemHeaderDirectory(),
DL.isFramework());
}
}

Expand Down Expand Up @@ -1943,19 +1930,19 @@ std::string HeaderSearch::suggestPathToFileForDiagnostics(
};

bool BestPrefixIsFramework = false;
for (unsigned I = 0; I != SearchDirs.size(); ++I) {
if (SearchDirs[I].isNormalDir()) {
StringRef Dir = SearchDirs[I].getDir()->getName();
for (const DirectoryLookup &DL : search_dir_range()) {
if (DL.isNormalDir()) {
StringRef Dir = DL.getDir()->getName();
if (CheckDir(Dir)) {
if (IsSystem)
*IsSystem = BestPrefixLength ? I >= SystemDirIdx : false;
*IsSystem = BestPrefixLength && isSystem(DL.getDirCharacteristic());
BestPrefixIsFramework = false;
}
} else if (SearchDirs[I].isFramework()) {
StringRef Dir = SearchDirs[I].getFrameworkDir()->getName();
} else if (DL.isFramework()) {
StringRef Dir = DL.getFrameworkDir()->getName();
if (CheckDir(Dir)) {
if (IsSystem)
*IsSystem = BestPrefixLength ? I >= SystemDirIdx : false;
*IsSystem = BestPrefixLength && isSystem(DL.getDirCharacteristic());
BestPrefixIsFramework = true;
}
}
Expand All @@ -1972,12 +1959,12 @@ std::string HeaderSearch::suggestPathToFileForDiagnostics(
// Try resolving resulting filename via reverse search in header maps,
// key from header name is user prefered name for the include file.
StringRef Filename = File.drop_front(BestPrefixLength);
for (unsigned I = 0; I != SearchDirs.size(); ++I) {
if (!SearchDirs[I].isHeaderMap())
for (const DirectoryLookup &DL : search_dir_range()) {
if (!DL.isHeaderMap())
continue;

StringRef SpelledFilename =
SearchDirs[I].getHeaderMap()->reverseLookupFilename(Filename);
DL.getHeaderMap()->reverseLookupFilename(Filename);
if (!SpelledFilename.empty()) {
Filename = SpelledFilename;
BestPrefixIsFramework = false;
Expand Down

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