clang-tools 6.0.0

MisleadingIndentationCheck.cpp
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1 //===--- MisleadingIndentationCheck.cpp - clang-tidy-----------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "MisleadingIndentationCheck.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13
14 using namespace clang::ast_matchers;
15
16 namespace clang {
17 namespace tidy {
18 namespace readability {
19
20 static const IfStmt *getPrecedingIf(const SourceManager &SM,
21 ASTContext *Context, const IfStmt *If) {
22 auto parents = Context->getParents(*If);
23 if (parents.size() != 1)
24 return nullptr;
25 if (const auto *PrecedingIf = parents[0].get<IfStmt>()) {
26 SourceLocation PreviousElseLoc = PrecedingIf->getElseLoc();
27 if (SM.getExpansionLineNumber(PreviousElseLoc) ==
28 SM.getExpansionLineNumber(If->getIfLoc()))
29 return PrecedingIf;
30 }
31 return nullptr;
32 }
33
34 void MisleadingIndentationCheck::danglingElseCheck(const SourceManager &SM,
35 ASTContext *Context,
36 const IfStmt *If) {
37 SourceLocation IfLoc = If->getIfLoc();
38 SourceLocation ElseLoc = If->getElseLoc();
39
40 if (IfLoc.isMacroID() || ElseLoc.isMacroID())
41 return;
42
43 if (SM.getExpansionLineNumber(If->getThen()->getLocEnd()) ==
44 SM.getExpansionLineNumber(ElseLoc))
45 return;
46
47 // Find location of first 'if' in a 'if else if' chain.
48 for (auto PrecedingIf = getPrecedingIf(SM, Context, If); PrecedingIf;
49 PrecedingIf = getPrecedingIf(SM, Context, PrecedingIf))
50 IfLoc = PrecedingIf->getIfLoc();
51
52 if (SM.getExpansionColumnNumber(IfLoc) !=
53 SM.getExpansionColumnNumber(ElseLoc))
54 diag(ElseLoc, "different indentation for 'if' and corresponding 'else'");
55 }
56
57 void MisleadingIndentationCheck::missingBracesCheck(const SourceManager &SM,
58 const CompoundStmt *CStmt) {
59 const static StringRef StmtNames[] = {"if", "for", "while"};
60 for (unsigned int i = 0; i < CStmt->size() - 1; i++) {
61 const Stmt *CurrentStmt = CStmt->body_begin()[i];
62 const Stmt *Inner = nullptr;
63 int StmtKind = 0;
64
65 if (const auto *CurrentIf = dyn_cast<IfStmt>(CurrentStmt)) {
66 StmtKind = 0;
67 Inner =
68 CurrentIf->getElse() ? CurrentIf->getElse() : CurrentIf->getThen();
69 } else if (const auto *CurrentFor = dyn_cast<ForStmt>(CurrentStmt)) {
70 StmtKind = 1;
71 Inner = CurrentFor->getBody();
72 } else if (const auto *CurrentWhile = dyn_cast<WhileStmt>(CurrentStmt)) {
73 StmtKind = 2;
74 Inner = CurrentWhile->getBody();
75 } else {
76 continue;
77 }
78
79 if (isa<CompoundStmt>(Inner))
80 continue;
81
82 SourceLocation InnerLoc = Inner->getLocStart();
83 SourceLocation OuterLoc = CurrentStmt->getLocStart();
84
85 if (SM.getExpansionLineNumber(InnerLoc) ==
86 SM.getExpansionLineNumber(OuterLoc))
87 continue;
88
89 const Stmt *NextStmt = CStmt->body_begin()[i + 1];
90 SourceLocation NextLoc = NextStmt->getLocStart();
91
92 if (InnerLoc.isMacroID() || OuterLoc.isMacroID() || NextLoc.isMacroID())
93 continue;
94
95 if (SM.getExpansionColumnNumber(InnerLoc) ==
96 SM.getExpansionColumnNumber(NextLoc)) {
97 diag(NextLoc, "misleading indentation: statement is indented too deeply");
98 diag(OuterLoc, "did you mean this line to be inside this '%0'",
99 DiagnosticIDs::Note)
100 << StmtNames[StmtKind];
101 }
102 }
103 }
104
105 void MisleadingIndentationCheck::registerMatchers(MatchFinder *Finder) {
106 Finder->addMatcher(ifStmt(hasElse(stmt())).bind("if"), this);
107 Finder->addMatcher(
108 compoundStmt(has(stmt(anyOf(ifStmt(), forStmt(), whileStmt()))))
109 .bind("compound"),
110 this);
111 }
112
113 void MisleadingIndentationCheck::check(const MatchFinder::MatchResult &Result) {
114 if (const auto *If = Result.Nodes.getNodeAs<IfStmt>("if"))
115 danglingElseCheck(*Result.SourceManager, Result.Context, If);
116
117 if (const auto *CStmt = Result.Nodes.getNodeAs<CompoundStmt>("compound"))
118 missingBracesCheck(*Result.SourceManager, CStmt);
119 }
120
121 } // namespace readability
122 } // namespace tidy
123 } // namespace clang
clang::ast_matchers
Definition: ClangTidyDiagnosticConsumer.h:27
MisleadingIndentationCheck.h
clang::tidy::readability::getPrecedingIf
static const IfStmt * getPrecedingIf(const SourceManager &SM, ASTContext *Context, const IfStmt *If)
Definition: MisleadingIndentationCheck.cpp:20
clang
Definition: AndroidTidyModule.cpp:28