| //===--- SourceCode.cpp - Source code manipulation routines -----*- 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file provides functions that simplify extraction of source code. |
| // |
| //===----------------------------------------------------------------------===// |
| #include "clang/Tooling/Transformer/SourceCode.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Attr.h" |
| #include "clang/AST/Comment.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/DeclTemplate.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Lex/Lexer.h" |
| #include "llvm/Support/Errc.h" |
| #include "llvm/Support/Error.h" |
| #include <set> |
| |
| using namespace clang; |
| |
| using llvm::errc; |
| using llvm::StringError; |
| |
| StringRef clang::tooling::getText(CharSourceRange Range, |
| const ASTContext &Context) { |
| return Lexer::getSourceText(Range, Context.getSourceManager(), |
| Context.getLangOpts()); |
| } |
| |
| CharSourceRange clang::tooling::maybeExtendRange(CharSourceRange Range, |
| tok::TokenKind Next, |
| ASTContext &Context) { |
| CharSourceRange R = Lexer::getAsCharRange(Range, Context.getSourceManager(), |
| Context.getLangOpts()); |
| if (R.isInvalid()) |
| return Range; |
| Token Tok; |
| bool Err = |
| Lexer::getRawToken(R.getEnd(), Tok, Context.getSourceManager(), |
| Context.getLangOpts(), /*IgnoreWhiteSpace=*/true); |
| if (Err || !Tok.is(Next)) |
| return Range; |
| return CharSourceRange::getTokenRange(Range.getBegin(), Tok.getLocation()); |
| } |
| |
| llvm::Error clang::tooling::validateEditRange(const CharSourceRange &Range, |
| const SourceManager &SM) { |
| if (Range.isInvalid()) |
| return llvm::make_error<StringError>(errc::invalid_argument, |
| "Invalid range"); |
| |
| if (Range.getBegin().isMacroID() || Range.getEnd().isMacroID()) |
| return llvm::make_error<StringError>( |
| errc::invalid_argument, "Range starts or ends in a macro expansion"); |
| |
| if (SM.isInSystemHeader(Range.getBegin()) || |
| SM.isInSystemHeader(Range.getEnd())) |
| return llvm::make_error<StringError>(errc::invalid_argument, |
| "Range is in system header"); |
| |
| std::pair<FileID, unsigned> BeginInfo = SM.getDecomposedLoc(Range.getBegin()); |
| std::pair<FileID, unsigned> EndInfo = SM.getDecomposedLoc(Range.getEnd()); |
| if (BeginInfo.first != EndInfo.first) |
| return llvm::make_error<StringError>( |
| errc::invalid_argument, "Range begins and ends in different files"); |
| |
| if (BeginInfo.second > EndInfo.second) |
| return llvm::make_error<StringError>( |
| errc::invalid_argument, "Range's begin is past its end"); |
| |
| return llvm::Error::success(); |
| } |
| |
| llvm::Optional<CharSourceRange> |
| clang::tooling::getRangeForEdit(const CharSourceRange &EditRange, |
| const SourceManager &SM, |
| const LangOptions &LangOpts) { |
| // FIXME: makeFileCharRange() has the disadvantage of stripping off "identity" |
| // macros. For example, if we're looking to rewrite the int literal 3 to 6, |
| // and we have the following definition: |
| // #define DO_NOTHING(x) x |
| // then |
| // foo(DO_NOTHING(3)) |
| // will be rewritten to |
| // foo(6) |
| // rather than the arguably better |
| // foo(DO_NOTHING(6)) |
| // Decide whether the current behavior is desirable and modify if not. |
| CharSourceRange Range = Lexer::makeFileCharRange(EditRange, SM, LangOpts); |
| bool IsInvalid = llvm::errorToBool(validateEditRange(Range, SM)); |
| if (IsInvalid) |
| return llvm::None; |
| return Range; |
| |
| } |
| |
| static bool startsWithNewline(const SourceManager &SM, const Token &Tok) { |
| return isVerticalWhitespace(SM.getCharacterData(Tok.getLocation())[0]); |
| } |
| |
| static bool contains(const std::set<tok::TokenKind> &Terminators, |
| const Token &Tok) { |
| return Terminators.count(Tok.getKind()) > 0; |
| } |
| |
| // Returns the exclusive, *file* end location of the entity whose last token is |
| // at location 'EntityLast'. That is, it returns the location one past the last |
| // relevant character. |
| // |
| // Associated tokens include comments, horizontal whitespace and 'Terminators' |
| // -- optional tokens, which, if any are found, will be included; if |
| // 'Terminators' is empty, we will not include any extra tokens beyond comments |
| // and horizontal whitespace. |
| static SourceLocation |
| getEntityEndLoc(const SourceManager &SM, SourceLocation EntityLast, |
| const std::set<tok::TokenKind> &Terminators, |
| const LangOptions &LangOpts) { |
| assert(EntityLast.isValid() && "Invalid end location found."); |
| |
| // We remember the last location of a non-horizontal-whitespace token we have |
| // lexed; this is the location up to which we will want to delete. |
| // FIXME: Support using the spelling loc here for cases where we want to |
| // analyze the macro text. |
| |
| CharSourceRange ExpansionRange = SM.getExpansionRange(EntityLast); |
| // FIXME: Should check isTokenRange(), for the (rare) case that |
| // `ExpansionRange` is a character range. |
| std::unique_ptr<Lexer> Lexer = [&]() { |
| bool Invalid = false; |
| auto FileOffset = SM.getDecomposedLoc(ExpansionRange.getEnd()); |
| llvm::StringRef File = SM.getBufferData(FileOffset.first, &Invalid); |
| assert(!Invalid && "Cannot get file/offset"); |
| return std::make_unique<clang::Lexer>( |
| SM.getLocForStartOfFile(FileOffset.first), LangOpts, File.begin(), |
| File.data() + FileOffset.second, File.end()); |
| }(); |
| |
| // Tell Lexer to return whitespace as pseudo-tokens (kind is tok::unknown). |
| Lexer->SetKeepWhitespaceMode(true); |
| |
| // Generally, the code we want to include looks like this ([] are optional), |
| // If Terminators is empty: |
| // [ <comment> ] [ <newline> ] |
| // Otherwise: |
| // ... <terminator> [ <comment> ] [ <newline> ] |
| |
| Token Tok; |
| bool Terminated = false; |
| |
| // First, lex to the current token (which is the last token of the range that |
| // is definitely associated with the decl). Then, we process the first token |
| // separately from the rest based on conditions that hold specifically for |
| // that first token. |
| // |
| // We do not search for a terminator if none is required or we've already |
| // encountered it. Otherwise, if the original `EntityLast` location was in a |
| // macro expansion, we don't have visibility into the text, so we assume we've |
| // already terminated. However, we note this assumption with |
| // `TerminatedByMacro`, because we'll want to handle it somewhat differently |
| // for the terminators semicolon and comma. These terminators can be safely |
| // associated with the entity when they appear after the macro -- extra |
| // semicolons have no effect on the program and a well-formed program won't |
| // have multiple commas in a row, so we're guaranteed that there is only one. |
| // |
| // FIXME: This handling of macros is more conservative than necessary. When |
| // the end of the expansion coincides with the end of the node, we can still |
| // safely analyze the code. But, it is more complicated, because we need to |
| // start by lexing the spelling loc for the first token and then switch to the |
| // expansion loc. |
| bool TerminatedByMacro = false; |
| Lexer->LexFromRawLexer(Tok); |
| if (Terminators.empty() || contains(Terminators, Tok)) |
| Terminated = true; |
| else if (EntityLast.isMacroID()) { |
| Terminated = true; |
| TerminatedByMacro = true; |
| } |
| |
| // We save the most recent candidate for the exclusive end location. |
| SourceLocation End = Tok.getEndLoc(); |
| |
| while (!Terminated) { |
| // Lex the next token we want to possibly expand the range with. |
| Lexer->LexFromRawLexer(Tok); |
| |
| switch (Tok.getKind()) { |
| case tok::eof: |
| // Unexpected separators. |
| case tok::l_brace: |
| case tok::r_brace: |
| case tok::comma: |
| return End; |
| // Whitespace pseudo-tokens. |
| case tok::unknown: |
| if (startsWithNewline(SM, Tok)) |
| // Include at least until the end of the line. |
| End = Tok.getEndLoc(); |
| break; |
| default: |
| if (contains(Terminators, Tok)) |
| Terminated = true; |
| End = Tok.getEndLoc(); |
| break; |
| } |
| } |
| |
| do { |
| // Lex the next token we want to possibly expand the range with. |
| Lexer->LexFromRawLexer(Tok); |
| |
| switch (Tok.getKind()) { |
| case tok::unknown: |
| if (startsWithNewline(SM, Tok)) |
| // We're done, but include this newline. |
| return Tok.getEndLoc(); |
| break; |
| case tok::comment: |
| // Include any comments we find on the way. |
| End = Tok.getEndLoc(); |
| break; |
| case tok::semi: |
| case tok::comma: |
| if (TerminatedByMacro && contains(Terminators, Tok)) { |
| End = Tok.getEndLoc(); |
| // We've found a real terminator. |
| TerminatedByMacro = false; |
| break; |
| } |
| // Found an unrelated token; stop and don't include it. |
| return End; |
| default: |
| // Found an unrelated token; stop and don't include it. |
| return End; |
| } |
| } while (true); |
| } |
| |
| // Returns the expected terminator tokens for the given declaration. |
| // |
| // If we do not know the correct terminator token, returns an empty set. |
| // |
| // There are cases where we have more than one possible terminator (for example, |
| // we find either a comma or a semicolon after a VarDecl). |
| static std::set<tok::TokenKind> getTerminators(const Decl &D) { |
| if (llvm::isa<RecordDecl>(D) || llvm::isa<UsingDecl>(D)) |
| return {tok::semi}; |
| |
| if (llvm::isa<FunctionDecl>(D) || llvm::isa<LinkageSpecDecl>(D)) |
| return {tok::r_brace, tok::semi}; |
| |
| if (llvm::isa<VarDecl>(D) || llvm::isa<FieldDecl>(D)) |
| return {tok::comma, tok::semi}; |
| |
| return {}; |
| } |
| |
| // Starting from `Loc`, skips whitespace up to, and including, a single |
| // newline. Returns the (exclusive) end of any skipped whitespace (that is, the |
| // location immediately after the whitespace). |
| static SourceLocation skipWhitespaceAndNewline(const SourceManager &SM, |
| SourceLocation Loc, |
| const LangOptions &LangOpts) { |
| const char *LocChars = SM.getCharacterData(Loc); |
| int i = 0; |
| while (isHorizontalWhitespace(LocChars[i])) |
| ++i; |
| if (isVerticalWhitespace(LocChars[i])) |
| ++i; |
| return Loc.getLocWithOffset(i); |
| } |
| |
| // Is `Loc` separated from any following decl by something meaningful (e.g. an |
| // empty line, a comment), ignoring horizontal whitespace? Since this is a |
| // heuristic, we return false when in doubt. `Loc` cannot be the first location |
| // in the file. |
| static bool atOrBeforeSeparation(const SourceManager &SM, SourceLocation Loc, |
| const LangOptions &LangOpts) { |
| // If the preceding character is a newline, we'll check for an empty line as a |
| // separator. However, we can't identify an empty line using tokens, so we |
| // analyse the characters. If we try to use tokens, we'll just end up with a |
| // whitespace token, whose characters we'd have to analyse anyhow. |
| bool Invalid = false; |
| const char *LocChars = |
| SM.getCharacterData(Loc.getLocWithOffset(-1), &Invalid); |
| assert(!Invalid && |
| "Loc must be a valid character and not the first of the source file."); |
| if (isVerticalWhitespace(LocChars[0])) { |
| for (int i = 1; isWhitespace(LocChars[i]); ++i) |
| if (isVerticalWhitespace(LocChars[i])) |
| return true; |
| } |
| // We didn't find an empty line, so lex the next token, skipping past any |
| // whitespace we just scanned. |
| Token Tok; |
| bool Failed = Lexer::getRawToken(Loc, Tok, SM, LangOpts, |
| /*IgnoreWhiteSpace=*/true); |
| if (Failed) |
| // Any text that confuses the lexer seems fair to consider a separation. |
| return true; |
| |
| switch (Tok.getKind()) { |
| case tok::comment: |
| case tok::l_brace: |
| case tok::r_brace: |
| case tok::eof: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| CharSourceRange tooling::getAssociatedRange(const Decl &Decl, |
| ASTContext &Context) { |
| const SourceManager &SM = Context.getSourceManager(); |
| const LangOptions &LangOpts = Context.getLangOpts(); |
| CharSourceRange Range = CharSourceRange::getTokenRange(Decl.getSourceRange()); |
| |
| // First, expand to the start of the template<> declaration if necessary. |
| if (const auto *Record = llvm::dyn_cast<CXXRecordDecl>(&Decl)) { |
| if (const auto *T = Record->getDescribedClassTemplate()) |
| if (SM.isBeforeInTranslationUnit(T->getBeginLoc(), Range.getBegin())) |
| Range.setBegin(T->getBeginLoc()); |
| } else if (const auto *F = llvm::dyn_cast<FunctionDecl>(&Decl)) { |
| if (const auto *T = F->getDescribedFunctionTemplate()) |
| if (SM.isBeforeInTranslationUnit(T->getBeginLoc(), Range.getBegin())) |
| Range.setBegin(T->getBeginLoc()); |
| } |
| |
| // Next, expand the end location past trailing comments to include a potential |
| // newline at the end of the decl's line. |
| Range.setEnd( |
| getEntityEndLoc(SM, Decl.getEndLoc(), getTerminators(Decl), LangOpts)); |
| Range.setTokenRange(false); |
| |
| // Expand to include preceeding associated comments. We ignore any comments |
| // that are not preceeding the decl, since we've already skipped trailing |
| // comments with getEntityEndLoc. |
| if (const RawComment *Comment = |
| Decl.getASTContext().getRawCommentForDeclNoCache(&Decl)) |
| // Only include a preceding comment if: |
| // * it is *not* separate from the declaration (not including any newline |
| // that immediately follows the comment), |
| // * the decl *is* separate from any following entity (so, there are no |
| // other entities the comment could refer to), and |
| // * it is not a IfThisThenThat lint check. |
| if (SM.isBeforeInTranslationUnit(Comment->getBeginLoc(), |
| Range.getBegin()) && |
| !atOrBeforeSeparation( |
| SM, skipWhitespaceAndNewline(SM, Comment->getEndLoc(), LangOpts), |
| LangOpts) && |
| atOrBeforeSeparation(SM, Range.getEnd(), LangOpts)) { |
| const StringRef CommentText = Comment->getRawText(SM); |
| if (!CommentText.contains("LINT.IfChange") && |
| !CommentText.contains("LINT.ThenChange")) |
| Range.setBegin(Comment->getBeginLoc()); |
| } |
| // Add leading attributes. |
| for (auto *Attr : Decl.attrs()) { |
| if (Attr->getLocation().isInvalid() || |
| !SM.isBeforeInTranslationUnit(Attr->getLocation(), Range.getBegin())) |
| continue; |
| Range.setBegin(Attr->getLocation()); |
| |
| // Extend to the left '[[' or '__attribute((' if we saw the attribute, |
| // unless it is not a valid location. |
| bool Invalid; |
| StringRef Source = |
| SM.getBufferData(SM.getFileID(Range.getBegin()), &Invalid); |
| if (Invalid) |
| continue; |
| llvm::StringRef BeforeAttr = |
| Source.substr(0, SM.getFileOffset(Range.getBegin())); |
| llvm::StringRef BeforeAttrStripped = BeforeAttr.rtrim(); |
| |
| for (llvm::StringRef Prefix : {"[[", "__attribute__(("}) { |
| // Handle whitespace between attribute prefix and attribute value. |
| if (BeforeAttrStripped.endswith(Prefix)) { |
| // Move start to start position of prefix, which is |
| // length(BeforeAttr) - length(BeforeAttrStripped) + length(Prefix) |
| // positions to the left. |
| Range.setBegin(Range.getBegin().getLocWithOffset(static_cast<int>( |
| -BeforeAttr.size() + BeforeAttrStripped.size() - Prefix.size()))); |
| break; |
| // If we didn't see '[[' or '__attribute' it's probably coming from a |
| // macro expansion which is already handled by makeFileCharRange(), |
| // below. |
| } |
| } |
| } |
| |
| // Range.getEnd() is already fully un-expanded by getEntityEndLoc. But, |
| // Range.getBegin() may be inside an expansion. |
| return Lexer::makeFileCharRange(Range, SM, LangOpts); |
| } |
