clang-tools 6.0.0

MultipleStatementMacroCheck.cpp
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1 //===--- MultipleStatementMacroCheck.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 "MultipleStatementMacroCheck.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 bugprone {
19
20 namespace {
21
22 AST_MATCHER(Expr, isInMacro) { return Node.getLocStart().isMacroID(); }
23
24 /// \brief Find the next statement after `S`.
25 const Stmt *nextStmt(const MatchFinder::MatchResult &Result, const Stmt *S) {
26 auto Parents = Result.Context->getParents(*S);
27 if (Parents.empty())
28 return nullptr;
29 const auto *Parent = Parents[0].get<Stmt>();
30 if (!Parent)
31 return nullptr;
32 const Stmt *Prev = nullptr;
33 for (const Stmt *Child : Parent->children()) {
34 if (Prev == S)
35 return Child;
36 Prev = Child;
37 }
38 return nextStmt(Result, Parent);
39 }
40
41 using ExpansionRanges = std::vector<std::pair<SourceLocation, SourceLocation>>;
42
43 /// \bried Get all the macro expansion ranges related to `Loc`.
44 ///
45 /// The result is ordered from most inner to most outer.
46 ExpansionRanges getExpansionRanges(SourceLocation Loc,
47 const MatchFinder::MatchResult &Result) {
48 ExpansionRanges Locs;
49 while (Loc.isMacroID()) {
50 Locs.push_back(Result.SourceManager->getImmediateExpansionRange(Loc));
51 Loc = Locs.back().first;
52 }
53 return Locs;
54 }
55
56 } // namespace
57
58 void MultipleStatementMacroCheck::registerMatchers(MatchFinder *Finder) {
59 const auto Inner = expr(isInMacro(), unless(compoundStmt())).bind("inner");
60 Finder->addMatcher(
61 stmt(anyOf(ifStmt(hasThen(Inner)), ifStmt(hasElse(Inner)).bind("else"),
62 whileStmt(hasBody(Inner)), forStmt(hasBody(Inner))))
63 .bind("outer"),
64 this);
65 }
66
67 void MultipleStatementMacroCheck::check(
68 const MatchFinder::MatchResult &Result) {
69 const auto *Inner = Result.Nodes.getNodeAs<Expr>("inner");
70 const auto *Outer = Result.Nodes.getNodeAs<Stmt>("outer");
71 const auto *Next = nextStmt(Result, Outer);
72 if (!Next)
73 return;
74
75 SourceLocation OuterLoc = Outer->getLocStart();
76 if (Result.Nodes.getNodeAs<Stmt>("else"))
77 OuterLoc = cast<IfStmt>(Outer)->getElseLoc();
78
79 auto InnerRanges = getExpansionRanges(Inner->getLocStart(), Result);
80 auto OuterRanges = getExpansionRanges(OuterLoc, Result);
81 auto NextRanges = getExpansionRanges(Next->getLocStart(), Result);
82
83 // Remove all the common ranges, starting from the top (the last ones in the
84 // list).
85 while (!InnerRanges.empty() && !OuterRanges.empty() && !NextRanges.empty() &&
86 InnerRanges.back() == OuterRanges.back() &&
87 InnerRanges.back() == NextRanges.back()) {
88 InnerRanges.pop_back();
89 OuterRanges.pop_back();
90 NextRanges.pop_back();
91 }
92
93 // Inner and Next must have at least one more macro that Outer doesn't have,
94 // and that range must be common to both.
95 if (InnerRanges.empty() || NextRanges.empty() ||
96 InnerRanges.back() != NextRanges.back())
97 return;
98
99 diag(InnerRanges.back().first, "multiple statement macro used without "
100 "braces; some statements will be "
101 "unconditionally executed");
102 }
103
104 } // namespace bugprone
105 } // namespace tidy
106 } // namespace clang
Loc
SourceLocation Loc
&#39;#&#39; location in the include directive
Definition: IncludeOrderCheck.cpp:36
clang::ast_matchers
Definition: ClangTidyDiagnosticConsumer.h:27
MultipleStatementMacroCheck.h
clang
Definition: AndroidTidyModule.cpp:28
clang::ast_matchers::AST_MATCHER
AST_MATCHER(VarDecl, isAsm)
Definition: NoAssemblerCheck.cpp:18