402 lines
16 KiB
C++
402 lines
16 KiB
C++
//===--- 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);
|
|
}
|