clang  14.0.0git
SourceExtraction.cpp
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1 //===--- SourceExtraction.cpp - Clang refactoring library -----------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
10 #include "clang/AST/Stmt.h"
11 #include "clang/AST/StmtCXX.h"
12 #include "clang/AST/StmtObjC.h"
14 #include "clang/Lex/Lexer.h"
15 
16 using namespace clang;
17 
18 namespace {
19 
20 /// Returns true if the token at the given location is a semicolon.
21 bool isSemicolonAtLocation(SourceLocation TokenLoc, const SourceManager &SM,
22  const LangOptions &LangOpts) {
23  return Lexer::getSourceText(
24  CharSourceRange::getTokenRange(TokenLoc, TokenLoc), SM,
25  LangOpts) == ";";
26 }
27 
28 /// Returns true if there should be a semicolon after the given statement.
29 bool isSemicolonRequiredAfter(const Stmt *S) {
30  if (isa<CompoundStmt>(S))
31  return false;
32  if (const auto *If = dyn_cast<IfStmt>(S))
33  return isSemicolonRequiredAfter(If->getElse() ? If->getElse()
34  : If->getThen());
35  if (const auto *While = dyn_cast<WhileStmt>(S))
36  return isSemicolonRequiredAfter(While->getBody());
37  if (const auto *For = dyn_cast<ForStmt>(S))
38  return isSemicolonRequiredAfter(For->getBody());
39  if (const auto *CXXFor = dyn_cast<CXXForRangeStmt>(S))
40  return isSemicolonRequiredAfter(CXXFor->getBody());
41  if (const auto *ObjCFor = dyn_cast<ObjCForCollectionStmt>(S))
42  return isSemicolonRequiredAfter(ObjCFor->getBody());
43  if(const auto *Switch = dyn_cast<SwitchStmt>(S))
44  return isSemicolonRequiredAfter(Switch->getBody());
45  if(const auto *Case = dyn_cast<SwitchCase>(S))
46  return isSemicolonRequiredAfter(Case->getSubStmt());
47  switch (S->getStmtClass()) {
48  case Stmt::DeclStmtClass:
49  case Stmt::CXXTryStmtClass:
50  case Stmt::ObjCAtSynchronizedStmtClass:
51  case Stmt::ObjCAutoreleasePoolStmtClass:
52  case Stmt::ObjCAtTryStmtClass:
53  return false;
54  default:
55  return true;
56  }
57 }
58 
59 /// Returns true if the two source locations are on the same line.
60 bool areOnSameLine(SourceLocation Loc1, SourceLocation Loc2,
61  const SourceManager &SM) {
62  return !Loc1.isMacroID() && !Loc2.isMacroID() &&
63  SM.getSpellingLineNumber(Loc1) == SM.getSpellingLineNumber(Loc2);
64 }
65 
66 } // end anonymous namespace
67 
68 namespace clang {
69 namespace tooling {
70 
71 ExtractionSemicolonPolicy
73  const SourceManager &SM,
74  const LangOptions &LangOpts) {
75  auto neededInExtractedFunction = []() {
76  return ExtractionSemicolonPolicy(true, false);
77  };
78  auto neededInOriginalFunction = []() {
79  return ExtractionSemicolonPolicy(false, true);
80  };
81 
82  /// The extracted expression should be terminated with a ';'. The call to
83  /// the extracted function will replace this expression, so it won't need
84  /// a terminating ';'.
85  if (isa<Expr>(S))
86  return neededInExtractedFunction();
87 
88  /// Some statements don't need to be terminated with ';'. The call to the
89  /// extracted function will be a standalone statement, so it should be
90  /// terminated with a ';'.
91  bool NeedsSemi = isSemicolonRequiredAfter(S);
92  if (!NeedsSemi)
93  return neededInOriginalFunction();
94 
95  /// Some statements might end at ';'. The extraction will move that ';', so
96  /// the call to the extracted function should be terminated with a ';'.
97  SourceLocation End = ExtractedRange.getEnd();
98  if (isSemicolonAtLocation(End, SM, LangOpts))
99  return neededInOriginalFunction();
100 
101  /// Other statements should generally have a trailing ';'. We can try to find
102  /// it and move it together it with the extracted code.
103  Optional<Token> NextToken = Lexer::findNextToken(End, SM, LangOpts);
104  if (NextToken && NextToken->is(tok::semi) &&
105  areOnSameLine(NextToken->getLocation(), End, SM)) {
106  ExtractedRange.setEnd(NextToken->getLocation());
107  return neededInOriginalFunction();
108  }
109 
110  /// Otherwise insert semicolons in both places.
111  return ExtractionSemicolonPolicy(true, true);
112 }
113 
114 } // end namespace tooling
115 } // end namespace clang
SourceExtraction.h
clang::SourceRange
A trivial tuple used to represent a source range.
Definition: SourceLocation.h:212
clang::SourceLocation
Encodes a location in the source.
Definition: SourceLocation.h:88
llvm::Optional
Definition: LLVM.h:40
clang::Lexer::getSourceText
static StringRef getSourceText(CharSourceRange Range, const SourceManager &SM, const LangOptions &LangOpts, bool *Invalid=nullptr)
Returns a string for the source that the range encompasses.
Definition: Lexer.cpp:957
SourceManager.h
clang::tooling::ExtractionSemicolonPolicy::compute
static ExtractionSemicolonPolicy compute(const Stmt *S, SourceRange &ExtractedRange, const SourceManager &SM, const LangOptions &LangOpts)
Returns the semicolon insertion policy that is needed for extraction of the given statement from the ...
Definition: SourceExtraction.cpp:72
End
SourceLocation End
Definition: USRLocFinder.cpp:167
clang::SourceManager
This class handles loading and caching of source files into memory.
Definition: SourceManager.h:626
clang::SourceRange::getEnd
SourceLocation getEnd() const
Definition: SourceLocation.h:222
clang::tooling::ExtractionSemicolonPolicy
Determines which semicolons should be inserted during extraction.
Definition: SourceExtraction.h:24
clang::SourceRange::setEnd
void setEnd(SourceLocation e)
Definition: SourceLocation.h:225
clang::Lexer::findNextToken
static Optional< Token > findNextToken(SourceLocation Loc, const SourceManager &SM, const LangOptions &LangOpts)
Finds the token that comes right after the given location.
Definition: Lexer.cpp:1255
StmtObjC.h
clang::CharSourceRange::getTokenRange
static CharSourceRange getTokenRange(SourceRange R)
Definition: SourceLocation.h:263
Lexer.h
clang::SourceLocation::isMacroID
bool isMacroID() const
Definition: SourceLocation.h:105
clang::LangOptions
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:58
clang
Definition: CalledOnceCheck.h:17
clang::NeverCalledReason::Switch
@ Switch
clang::Stmt
Stmt - This represents one statement.
Definition: Stmt.h:69
Stmt.h
SM
#define SM(sm)
Definition: Cuda.cpp:78
StmtCXX.h