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teak-llvm/clang/lib/Lex/PPLexerChange.cpp
Erich Keane 0a6b5b653e PTH-- Remove feature entirely- 
When debugging a boost build with a modified
version of Clang, I discovered that the PTH implementation
stores TokenKind in 8 bits. However, we currently have 368
TokenKinds.

The result is that the value gets truncated and the wrong token
gets picked up when including PTH files. It seems that this will
go wrong every time someone uses a token that uses the 9th bit.

Upon asking on IRC, it was brought up that this was a highly
experimental features that was considered a failure. I discovered
via googling that BoostBuild (mostly Boost.Math) is the only user of
this
feature, using the CC1 flag directly. I believe that this can be
transferred over to normal PCH with minimal effort:
https://github.com/boostorg/build/issues/367

Based on advice on IRC and research showing that this is a nearly
completely unused feature, this patch removes it entirely.

Note: I considered leaving the build-flags in place and making them
emit an error/warning, however since I've basically identified and
warned the only user, it seemed better to just remove them.

Differential Revision: https://reviews.llvm.org/D54547

Change-Id: If32744275ef1f585357bd6c1c813d96973c4d8d9
llvm-svn: 348266
2018-12-04 14:34:09 +00:00

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//===--- PPLexerChange.cpp - Handle changing lexers in the preprocessor ---===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements pieces of the Preprocessor interface that manage the
// current lexer stack.
//
//===----------------------------------------------------------------------===//
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/PreprocessorOptions.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Lex/MacroInfo.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
using namespace clang;
PPCallbacks::~PPCallbacks() {}
//===----------------------------------------------------------------------===//
// Miscellaneous Methods.
//===----------------------------------------------------------------------===//
/// isInPrimaryFile - Return true if we're in the top-level file, not in a
/// \#include. This looks through macro expansions and active _Pragma lexers.
bool Preprocessor::isInPrimaryFile() const {
if (IsFileLexer())
return IncludeMacroStack.empty();
// If there are any stacked lexers, we're in a #include.
assert(IsFileLexer(IncludeMacroStack[0]) &&
"Top level include stack isn't our primary lexer?");
return std::none_of(
IncludeMacroStack.begin() + 1, IncludeMacroStack.end(),
[&](const IncludeStackInfo &ISI) -> bool { return IsFileLexer(ISI); });
}
/// getCurrentLexer - Return the current file lexer being lexed from. Note
/// that this ignores any potentially active macro expansions and _Pragma
/// expansions going on at the time.
PreprocessorLexer *Preprocessor::getCurrentFileLexer() const {
if (IsFileLexer())
return CurPPLexer;
// Look for a stacked lexer.
for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
if (IsFileLexer(ISI))
return ISI.ThePPLexer;
}
return nullptr;
}
//===----------------------------------------------------------------------===//
// Methods for Entering and Callbacks for leaving various contexts
//===----------------------------------------------------------------------===//
/// EnterSourceFile - Add a source file to the top of the include stack and
/// start lexing tokens from it instead of the current buffer.
bool Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir,
SourceLocation Loc) {
assert(!CurTokenLexer && "Cannot #include a file inside a macro!");
++NumEnteredSourceFiles;
if (MaxIncludeStackDepth < IncludeMacroStack.size())
MaxIncludeStackDepth = IncludeMacroStack.size();
// Get the MemoryBuffer for this FID, if it fails, we fail.
bool Invalid = false;
const llvm::MemoryBuffer *InputFile =
getSourceManager().getBuffer(FID, Loc, &Invalid);
if (Invalid) {
SourceLocation FileStart = SourceMgr.getLocForStartOfFile(FID);
Diag(Loc, diag::err_pp_error_opening_file)
<< std::string(SourceMgr.getBufferName(FileStart)) << "";
return true;
}
if (isCodeCompletionEnabled() &&
SourceMgr.getFileEntryForID(FID) == CodeCompletionFile) {
CodeCompletionFileLoc = SourceMgr.getLocForStartOfFile(FID);
CodeCompletionLoc =
CodeCompletionFileLoc.getLocWithOffset(CodeCompletionOffset);
}
EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir);
return false;
}
/// EnterSourceFileWithLexer - Add a source file to the top of the include stack
/// and start lexing tokens from it instead of the current buffer.
void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer,
const DirectoryLookup *CurDir) {
// Add the current lexer to the include stack.
if (CurPPLexer || CurTokenLexer)
PushIncludeMacroStack();
CurLexer.reset(TheLexer);
CurPPLexer = TheLexer;
CurDirLookup = CurDir;
CurLexerSubmodule = nullptr;
if (CurLexerKind != CLK_LexAfterModuleImport)
CurLexerKind = CLK_Lexer;
// Notify the client, if desired, that we are in a new source file.
if (Callbacks && !CurLexer->Is_PragmaLexer) {
SrcMgr::CharacteristicKind FileType =
SourceMgr.getFileCharacteristic(CurLexer->getFileLoc());
Callbacks->FileChanged(CurLexer->getFileLoc(),
PPCallbacks::EnterFile, FileType);
}
}
/// EnterMacro - Add a Macro to the top of the include stack and start lexing
/// tokens from it instead of the current buffer.
void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd,
MacroInfo *Macro, MacroArgs *Args) {
std::unique_ptr<TokenLexer> TokLexer;
if (NumCachedTokenLexers == 0) {
TokLexer = llvm::make_unique<TokenLexer>(Tok, ILEnd, Macro, Args, *this);
} else {
TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
TokLexer->Init(Tok, ILEnd, Macro, Args);
}
PushIncludeMacroStack();
CurDirLookup = nullptr;
CurTokenLexer = std::move(TokLexer);
if (CurLexerKind != CLK_LexAfterModuleImport)
CurLexerKind = CLK_TokenLexer;
}
/// EnterTokenStream - Add a "macro" context to the top of the include stack,
/// which will cause the lexer to start returning the specified tokens.
///
/// If DisableMacroExpansion is true, tokens lexed from the token stream will
/// not be subject to further macro expansion. Otherwise, these tokens will
/// be re-macro-expanded when/if expansion is enabled.
///
/// If OwnsTokens is false, this method assumes that the specified stream of
/// tokens has a permanent owner somewhere, so they do not need to be copied.
/// If it is true, it assumes the array of tokens is allocated with new[] and
/// must be freed.
///
void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
bool DisableMacroExpansion,
bool OwnsTokens) {
if (CurLexerKind == CLK_CachingLexer) {
if (CachedLexPos < CachedTokens.size()) {
// We're entering tokens into the middle of our cached token stream. We
// can't represent that, so just insert the tokens into the buffer.
CachedTokens.insert(CachedTokens.begin() + CachedLexPos,
Toks, Toks + NumToks);
if (OwnsTokens)
delete [] Toks;
return;
}
// New tokens are at the end of the cached token sequnece; insert the
// token stream underneath the caching lexer.
ExitCachingLexMode();
EnterTokenStream(Toks, NumToks, DisableMacroExpansion, OwnsTokens);
EnterCachingLexMode();
return;
}
// Create a macro expander to expand from the specified token stream.
std::unique_ptr<TokenLexer> TokLexer;
if (NumCachedTokenLexers == 0) {
TokLexer = llvm::make_unique<TokenLexer>(
Toks, NumToks, DisableMacroExpansion, OwnsTokens, *this);
} else {
TokLexer = std::move(TokenLexerCache[--NumCachedTokenLexers]);
TokLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens);
}
// Save our current state.
PushIncludeMacroStack();
CurDirLookup = nullptr;
CurTokenLexer = std::move(TokLexer);
if (CurLexerKind != CLK_LexAfterModuleImport)
CurLexerKind = CLK_TokenLexer;
}
/// Compute the relative path that names the given file relative to
/// the given directory.
static void computeRelativePath(FileManager &FM, const DirectoryEntry *Dir,
const FileEntry *File,
SmallString<128> &Result) {
Result.clear();
StringRef FilePath = File->getDir()->getName();
StringRef Path = FilePath;
while (!Path.empty()) {
if (const DirectoryEntry *CurDir = FM.getDirectory(Path)) {
if (CurDir == Dir) {
Result = FilePath.substr(Path.size());
llvm::sys::path::append(Result,
llvm::sys::path::filename(File->getName()));
return;
}
}
Path = llvm::sys::path::parent_path(Path);
}
Result = File->getName();
}
void Preprocessor::PropagateLineStartLeadingSpaceInfo(Token &Result) {
if (CurTokenLexer) {
CurTokenLexer->PropagateLineStartLeadingSpaceInfo(Result);
return;
}
if (CurLexer) {
CurLexer->PropagateLineStartLeadingSpaceInfo(Result);
return;
}
// FIXME: Handle other kinds of lexers? It generally shouldn't matter,
// but it might if they're empty?
}
/// Determine the location to use as the end of the buffer for a lexer.
///
/// If the file ends with a newline, form the EOF token on the newline itself,
/// rather than "on the line following it", which doesn't exist. This makes
/// diagnostics relating to the end of file include the last file that the user
/// actually typed, which is goodness.
const char *Preprocessor::getCurLexerEndPos() {
const char *EndPos = CurLexer->BufferEnd;
if (EndPos != CurLexer->BufferStart &&
(EndPos[-1] == '\n' || EndPos[-1] == '\r')) {
--EndPos;
// Handle \n\r and \r\n:
if (EndPos != CurLexer->BufferStart &&
(EndPos[-1] == '\n' || EndPos[-1] == '\r') &&
EndPos[-1] != EndPos[0])
--EndPos;
}
return EndPos;
}
static void collectAllSubModulesWithUmbrellaHeader(
const Module &Mod, SmallVectorImpl<const Module *> &SubMods) {
if (Mod.getUmbrellaHeader())
SubMods.push_back(&Mod);
for (auto *M : Mod.submodules())
collectAllSubModulesWithUmbrellaHeader(*M, SubMods);
}
void Preprocessor::diagnoseMissingHeaderInUmbrellaDir(const Module &Mod) {
assert(Mod.getUmbrellaHeader() && "Module must use umbrella header");
SourceLocation StartLoc =
SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID());
if (getDiagnostics().isIgnored(diag::warn_uncovered_module_header, StartLoc))
return;
ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
const DirectoryEntry *Dir = Mod.getUmbrellaDir().Entry;
llvm::vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
std::error_code EC;
for (llvm::vfs::recursive_directory_iterator Entry(FS, Dir->getName(), EC),
End;
Entry != End && !EC; Entry.increment(EC)) {
using llvm::StringSwitch;
// Check whether this entry has an extension typically associated with
// headers.
if (!StringSwitch<bool>(llvm::sys::path::extension(Entry->path()))
.Cases(".h", ".H", ".hh", ".hpp", true)
.Default(false))
continue;
if (const FileEntry *Header = getFileManager().getFile(Entry->path()))
if (!getSourceManager().hasFileInfo(Header)) {
if (!ModMap.isHeaderInUnavailableModule(Header)) {
// Find the relative path that would access this header.
SmallString<128> RelativePath;
computeRelativePath(FileMgr, Dir, Header, RelativePath);
Diag(StartLoc, diag::warn_uncovered_module_header)
<< Mod.getFullModuleName() << RelativePath;
}
}
}
}
/// HandleEndOfFile - This callback is invoked when the lexer hits the end of
/// the current file. This either returns the EOF token or pops a level off
/// the include stack and keeps going.
bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
assert(!CurTokenLexer &&
"Ending a file when currently in a macro!");
// If we have an unclosed module region from a pragma at the end of a
// module, complain and close it now.
const bool LeavingSubmodule = CurLexer && CurLexerSubmodule;
if ((LeavingSubmodule || IncludeMacroStack.empty()) &&
!BuildingSubmoduleStack.empty() &&
BuildingSubmoduleStack.back().IsPragma) {
Diag(BuildingSubmoduleStack.back().ImportLoc,
diag::err_pp_module_begin_without_module_end);
Module *M = LeaveSubmodule(/*ForPragma*/true);
Result.startToken();
const char *EndPos = getCurLexerEndPos();
CurLexer->BufferPtr = EndPos;
CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
Result.setAnnotationEndLoc(Result.getLocation());
Result.setAnnotationValue(M);
return true;
}
// See if this file had a controlling macro.
if (CurPPLexer) { // Not ending a macro, ignore it.
if (const IdentifierInfo *ControllingMacro =
CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) {
// Okay, this has a controlling macro, remember in HeaderFileInfo.
if (const FileEntry *FE = CurPPLexer->getFileEntry()) {
HeaderInfo.SetFileControllingMacro(FE, ControllingMacro);
if (MacroInfo *MI =
getMacroInfo(const_cast<IdentifierInfo*>(ControllingMacro)))
MI->setUsedForHeaderGuard(true);
if (const IdentifierInfo *DefinedMacro =
CurPPLexer->MIOpt.GetDefinedMacro()) {
if (!isMacroDefined(ControllingMacro) &&
DefinedMacro != ControllingMacro &&
HeaderInfo.FirstTimeLexingFile(FE)) {
// If the edit distance between the two macros is more than 50%,
// DefinedMacro may not be header guard, or can be header guard of
// another header file. Therefore, it maybe defining something
// completely different. This can be observed in the wild when
// handling feature macros or header guards in different files.
const StringRef ControllingMacroName = ControllingMacro->getName();
const StringRef DefinedMacroName = DefinedMacro->getName();
const size_t MaxHalfLength = std::max(ControllingMacroName.size(),
DefinedMacroName.size()) / 2;
const unsigned ED = ControllingMacroName.edit_distance(
DefinedMacroName, true, MaxHalfLength);
if (ED <= MaxHalfLength) {
// Emit a warning for a bad header guard.
Diag(CurPPLexer->MIOpt.GetMacroLocation(),
diag::warn_header_guard)
<< CurPPLexer->MIOpt.GetMacroLocation() << ControllingMacro;
Diag(CurPPLexer->MIOpt.GetDefinedLocation(),
diag::note_header_guard)
<< CurPPLexer->MIOpt.GetDefinedLocation() << DefinedMacro
<< ControllingMacro
<< FixItHint::CreateReplacement(
CurPPLexer->MIOpt.GetDefinedLocation(),
ControllingMacro->getName());
}
}
}
}
}
}
// Complain about reaching a true EOF within arc_cf_code_audited.
// We don't want to complain about reaching the end of a macro
// instantiation or a _Pragma.
if (PragmaARCCFCodeAuditedLoc.isValid() &&
!isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
Diag(PragmaARCCFCodeAuditedLoc, diag::err_pp_eof_in_arc_cf_code_audited);
// Recover by leaving immediately.
PragmaARCCFCodeAuditedLoc = SourceLocation();
}
// Complain about reaching a true EOF within assume_nonnull.
// We don't want to complain about reaching the end of a macro
// instantiation or a _Pragma.
if (PragmaAssumeNonNullLoc.isValid() &&
!isEndOfMacro && !(CurLexer && CurLexer->Is_PragmaLexer)) {
Diag(PragmaAssumeNonNullLoc, diag::err_pp_eof_in_assume_nonnull);
// Recover by leaving immediately.
PragmaAssumeNonNullLoc = SourceLocation();
}
bool LeavingPCHThroughHeader = false;
// If this is a #include'd file, pop it off the include stack and continue
// lexing the #includer file.
if (!IncludeMacroStack.empty()) {
// If we lexed the code-completion file, act as if we reached EOF.
if (isCodeCompletionEnabled() && CurPPLexer &&
SourceMgr.getLocForStartOfFile(CurPPLexer->getFileID()) ==
CodeCompletionFileLoc) {
assert(CurLexer && "Got EOF but no current lexer set!");
Result.startToken();
CurLexer->FormTokenWithChars(Result, CurLexer->BufferEnd, tok::eof);
CurLexer.reset();
CurPPLexer = nullptr;
recomputeCurLexerKind();
return true;
}
if (!isEndOfMacro && CurPPLexer &&
SourceMgr.getIncludeLoc(CurPPLexer->getFileID()).isValid()) {
// Notify SourceManager to record the number of FileIDs that were created
// during lexing of the #include'd file.
unsigned NumFIDs =
SourceMgr.local_sloc_entry_size() -
CurPPLexer->getInitialNumSLocEntries() + 1/*#include'd file*/;
SourceMgr.setNumCreatedFIDsForFileID(CurPPLexer->getFileID(), NumFIDs);
}
bool ExitedFromPredefinesFile = false;
FileID ExitedFID;
if (!isEndOfMacro && CurPPLexer) {
ExitedFID = CurPPLexer->getFileID();
assert(PredefinesFileID.isValid() &&
"HandleEndOfFile is called before PredefinesFileId is set");
ExitedFromPredefinesFile = (PredefinesFileID == ExitedFID);
}
if (LeavingSubmodule) {
// We're done with this submodule.
Module *M = LeaveSubmodule(/*ForPragma*/false);
// Notify the parser that we've left the module.
const char *EndPos = getCurLexerEndPos();
Result.startToken();
CurLexer->BufferPtr = EndPos;
CurLexer->FormTokenWithChars(Result, EndPos, tok::annot_module_end);
Result.setAnnotationEndLoc(Result.getLocation());
Result.setAnnotationValue(M);
}
bool FoundPCHThroughHeader = false;
if (CurPPLexer && creatingPCHWithThroughHeader() &&
isPCHThroughHeader(
SourceMgr.getFileEntryForID(CurPPLexer->getFileID())))
FoundPCHThroughHeader = true;
// We're done with the #included file.
RemoveTopOfLexerStack();
// Propagate info about start-of-line/leading white-space/etc.
PropagateLineStartLeadingSpaceInfo(Result);
// Notify the client, if desired, that we are in a new source file.
if (Callbacks && !isEndOfMacro && CurPPLexer) {
SrcMgr::CharacteristicKind FileType =
SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation());
Callbacks->FileChanged(CurPPLexer->getSourceLocation(),
PPCallbacks::ExitFile, FileType, ExitedFID);
}
// Restore conditional stack from the preamble right after exiting from the
// predefines file.
if (ExitedFromPredefinesFile)
replayPreambleConditionalStack();
if (!isEndOfMacro && CurPPLexer && FoundPCHThroughHeader &&
(isInPrimaryFile() ||
CurPPLexer->getFileID() == getPredefinesFileID())) {
// Leaving the through header. Continue directly to end of main file
// processing.
LeavingPCHThroughHeader = true;
} else {
// Client should lex another token unless we generated an EOM.
return LeavingSubmodule;
}
}
// If this is the end of the main file, form an EOF token.
assert(CurLexer && "Got EOF but no current lexer set!");
const char *EndPos = getCurLexerEndPos();
Result.startToken();
CurLexer->BufferPtr = EndPos;
CurLexer->FormTokenWithChars(Result, EndPos, tok::eof);
if (isCodeCompletionEnabled()) {
// Inserting the code-completion point increases the source buffer by 1,
// but the main FileID was created before inserting the point.
// Compensate by reducing the EOF location by 1, otherwise the location
// will point to the next FileID.
// FIXME: This is hacky, the code-completion point should probably be
// inserted before the main FileID is created.
if (CurLexer->getFileLoc() == CodeCompletionFileLoc)
Result.setLocation(Result.getLocation().getLocWithOffset(-1));
}
if (creatingPCHWithThroughHeader() && !LeavingPCHThroughHeader) {
// Reached the end of the compilation without finding the through header.
Diag(CurLexer->getFileLoc(), diag::err_pp_through_header_not_seen)
<< PPOpts->PCHThroughHeader << 0;
}
if (!isIncrementalProcessingEnabled())
// We're done with lexing.
CurLexer.reset();
if (!isIncrementalProcessingEnabled())
CurPPLexer = nullptr;
if (TUKind == TU_Complete) {
// This is the end of the top-level file. 'WarnUnusedMacroLocs' has
// collected all macro locations that we need to warn because they are not
// used.
for (WarnUnusedMacroLocsTy::iterator
I=WarnUnusedMacroLocs.begin(), E=WarnUnusedMacroLocs.end();
I!=E; ++I)
Diag(*I, diag::pp_macro_not_used);
}
// If we are building a module that has an umbrella header, make sure that
// each of the headers within the directory, including all submodules, is
// covered by the umbrella header was actually included by the umbrella
// header.
if (Module *Mod = getCurrentModule()) {
llvm::SmallVector<const Module *, 4> AllMods;
collectAllSubModulesWithUmbrellaHeader(*Mod, AllMods);
for (auto *M : AllMods)
diagnoseMissingHeaderInUmbrellaDir(*M);
}
return true;
}
/// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer
/// hits the end of its token stream.
bool Preprocessor::HandleEndOfTokenLexer(Token &Result) {
assert(CurTokenLexer && !CurPPLexer &&
"Ending a macro when currently in a #include file!");
if (!MacroExpandingLexersStack.empty() &&
MacroExpandingLexersStack.back().first == CurTokenLexer.get())
removeCachedMacroExpandedTokensOfLastLexer();
// Delete or cache the now-dead macro expander.
if (NumCachedTokenLexers == TokenLexerCacheSize)
CurTokenLexer.reset();
else
TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
// Handle this like a #include file being popped off the stack.
return HandleEndOfFile(Result, true);
}
/// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the
/// lexer stack. This should only be used in situations where the current
/// state of the top-of-stack lexer is unknown.
void Preprocessor::RemoveTopOfLexerStack() {
assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load");
if (CurTokenLexer) {
// Delete or cache the now-dead macro expander.
if (NumCachedTokenLexers == TokenLexerCacheSize)
CurTokenLexer.reset();
else
TokenLexerCache[NumCachedTokenLexers++] = std::move(CurTokenLexer);
}
PopIncludeMacroStack();
}
/// HandleMicrosoftCommentPaste - When the macro expander pastes together a
/// comment (/##/) in microsoft mode, this method handles updating the current
/// state, returning the token on the next source line.
void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) {
assert(CurTokenLexer && !CurPPLexer &&
"Pasted comment can only be formed from macro");
// We handle this by scanning for the closest real lexer, switching it to
// raw mode and preprocessor mode. This will cause it to return \n as an
// explicit EOD token.
PreprocessorLexer *FoundLexer = nullptr;
bool LexerWasInPPMode = false;
for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
if (ISI.ThePPLexer == nullptr) continue; // Scan for a real lexer.
// Once we find a real lexer, mark it as raw mode (disabling macro
// expansions) and preprocessor mode (return EOD). We know that the lexer
// was *not* in raw mode before, because the macro that the comment came
// from was expanded. However, it could have already been in preprocessor
// mode (#if COMMENT) in which case we have to return it to that mode and
// return EOD.
FoundLexer = ISI.ThePPLexer;
FoundLexer->LexingRawMode = true;
LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective;
FoundLexer->ParsingPreprocessorDirective = true;
break;
}
// Okay, we either found and switched over the lexer, or we didn't find a
// lexer. In either case, finish off the macro the comment came from, getting
// the next token.
if (!HandleEndOfTokenLexer(Tok)) Lex(Tok);
// Discarding comments as long as we don't have EOF or EOD. This 'comments
// out' the rest of the line, including any tokens that came from other macros
// that were active, as in:
// #define submacro a COMMENT b
// submacro c
// which should lex to 'a' only: 'b' and 'c' should be removed.
while (Tok.isNot(tok::eod) && Tok.isNot(tok::eof))
Lex(Tok);
// If we got an eod token, then we successfully found the end of the line.
if (Tok.is(tok::eod)) {
assert(FoundLexer && "Can't get end of line without an active lexer");
// Restore the lexer back to normal mode instead of raw mode.
FoundLexer->LexingRawMode = false;
// If the lexer was already in preprocessor mode, just return the EOD token
// to finish the preprocessor line.
if (LexerWasInPPMode) return;
// Otherwise, switch out of PP mode and return the next lexed token.
FoundLexer->ParsingPreprocessorDirective = false;
return Lex(Tok);
}
// If we got an EOF token, then we reached the end of the token stream but
// didn't find an explicit \n. This can only happen if there was no lexer
// active (an active lexer would return EOD at EOF if there was no \n in
// preprocessor directive mode), so just return EOF as our token.
assert(!FoundLexer && "Lexer should return EOD before EOF in PP mode");
}
void Preprocessor::EnterSubmodule(Module *M, SourceLocation ImportLoc,
bool ForPragma) {
if (!getLangOpts().ModulesLocalVisibility) {
// Just track that we entered this submodule.
BuildingSubmoduleStack.push_back(
BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
PendingModuleMacroNames.size()));
return;
}
// Resolve as much of the module definition as we can now, before we enter
// one of its headers.
// FIXME: Can we enable Complain here?
// FIXME: Can we do this when local visibility is disabled?
ModuleMap &ModMap = getHeaderSearchInfo().getModuleMap();
ModMap.resolveExports(M, /*Complain=*/false);
ModMap.resolveUses(M, /*Complain=*/false);
ModMap.resolveConflicts(M, /*Complain=*/false);
// If this is the first time we've entered this module, set up its state.
auto R = Submodules.insert(std::make_pair(M, SubmoduleState()));
auto &State = R.first->second;
bool FirstTime = R.second;
if (FirstTime) {
// Determine the set of starting macros for this submodule; take these
// from the "null" module (the predefines buffer).
//
// FIXME: If we have local visibility but not modules enabled, the
// NullSubmoduleState is polluted by #defines in the top-level source
// file.
auto &StartingMacros = NullSubmoduleState.Macros;
// Restore to the starting state.
// FIXME: Do this lazily, when each macro name is first referenced.
for (auto &Macro : StartingMacros) {
// Skip uninteresting macros.
if (!Macro.second.getLatest() &&
Macro.second.getOverriddenMacros().empty())
continue;
MacroState MS(Macro.second.getLatest());
MS.setOverriddenMacros(*this, Macro.second.getOverriddenMacros());
State.Macros.insert(std::make_pair(Macro.first, std::move(MS)));
}
}
// Track that we entered this module.
BuildingSubmoduleStack.push_back(
BuildingSubmoduleInfo(M, ImportLoc, ForPragma, CurSubmoduleState,
PendingModuleMacroNames.size()));
// Switch to this submodule as the current submodule.
CurSubmoduleState = &State;
// This module is visible to itself.
if (FirstTime)
makeModuleVisible(M, ImportLoc);
}
bool Preprocessor::needModuleMacros() const {
// If we're not within a submodule, we never need to create ModuleMacros.
if (BuildingSubmoduleStack.empty())
return false;
// If we are tracking module macro visibility even for textually-included
// headers, we need ModuleMacros.
if (getLangOpts().ModulesLocalVisibility)
return true;
// Otherwise, we only need module macros if we're actually compiling a module
// interface.
return getLangOpts().isCompilingModule();
}
Module *Preprocessor::LeaveSubmodule(bool ForPragma) {
if (BuildingSubmoduleStack.empty() ||
BuildingSubmoduleStack.back().IsPragma != ForPragma) {
assert(ForPragma && "non-pragma module enter/leave mismatch");
return nullptr;
}
auto &Info = BuildingSubmoduleStack.back();
Module *LeavingMod = Info.M;
SourceLocation ImportLoc = Info.ImportLoc;
if (!needModuleMacros() ||
(!getLangOpts().ModulesLocalVisibility &&
LeavingMod->getTopLevelModuleName() != getLangOpts().CurrentModule)) {
// If we don't need module macros, or this is not a module for which we
// are tracking macro visibility, don't build any, and preserve the list
// of pending names for the surrounding submodule.
BuildingSubmoduleStack.pop_back();
makeModuleVisible(LeavingMod, ImportLoc);
return LeavingMod;
}
// Create ModuleMacros for any macros defined in this submodule.
llvm::SmallPtrSet<const IdentifierInfo*, 8> VisitedMacros;
for (unsigned I = Info.OuterPendingModuleMacroNames;
I != PendingModuleMacroNames.size(); ++I) {
auto *II = const_cast<IdentifierInfo*>(PendingModuleMacroNames[I]);
if (!VisitedMacros.insert(II).second)
continue;
auto MacroIt = CurSubmoduleState->Macros.find(II);
if (MacroIt == CurSubmoduleState->Macros.end())
continue;
auto &Macro = MacroIt->second;
// Find the starting point for the MacroDirective chain in this submodule.
MacroDirective *OldMD = nullptr;
auto *OldState = Info.OuterSubmoduleState;
if (getLangOpts().ModulesLocalVisibility)
OldState = &NullSubmoduleState;
if (OldState && OldState != CurSubmoduleState) {
// FIXME: It'd be better to start at the state from when we most recently
// entered this submodule, but it doesn't really matter.
auto &OldMacros = OldState->Macros;
auto OldMacroIt = OldMacros.find(II);
if (OldMacroIt == OldMacros.end())
OldMD = nullptr;
else
OldMD = OldMacroIt->second.getLatest();
}
// This module may have exported a new macro. If so, create a ModuleMacro
// representing that fact.
bool ExplicitlyPublic = false;
for (auto *MD = Macro.getLatest(); MD != OldMD; MD = MD->getPrevious()) {
assert(MD && "broken macro directive chain");
if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
// The latest visibility directive for a name in a submodule affects
// all the directives that come before it.
if (VisMD->isPublic())
ExplicitlyPublic = true;
else if (!ExplicitlyPublic)
// Private with no following public directive: not exported.
break;
} else {
MacroInfo *Def = nullptr;
if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD))
Def = DefMD->getInfo();
// FIXME: Issue a warning if multiple headers for the same submodule
// define a macro, rather than silently ignoring all but the first.
bool IsNew;
// Don't bother creating a module macro if it would represent a #undef
// that doesn't override anything.
if (Def || !Macro.getOverriddenMacros().empty())
addModuleMacro(LeavingMod, II, Def,
Macro.getOverriddenMacros(), IsNew);
if (!getLangOpts().ModulesLocalVisibility) {
// This macro is exposed to the rest of this compilation as a
// ModuleMacro; we don't need to track its MacroDirective any more.
Macro.setLatest(nullptr);
Macro.setOverriddenMacros(*this, {});
}
break;
}
}
}
PendingModuleMacroNames.resize(Info.OuterPendingModuleMacroNames);
// FIXME: Before we leave this submodule, we should parse all the other
// headers within it. Otherwise, we're left with an inconsistent state
// where we've made the module visible but don't yet have its complete
// contents.
// Put back the outer module's state, if we're tracking it.
if (getLangOpts().ModulesLocalVisibility)
CurSubmoduleState = Info.OuterSubmoduleState;
BuildingSubmoduleStack.pop_back();
// A nested #include makes the included submodule visible.
makeModuleVisible(LeavingMod, ImportLoc);
return LeavingMod;
}
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