1 //== CheckerContext.cpp - Context info for path-sensitive checkers-----------=//
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 // This file defines CheckerContext that provides contextual info for
11 // path-sensitive checkers.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
16 #include "clang/Basic/Builtins.h"
17 #include "clang/Lex/Lexer.h"
18
19 using namespace clang;
20 using namespace ento;
21
getCalleeDecl(const CallExpr * CE) const22 const FunctionDecl *CheckerContext::getCalleeDecl(const CallExpr *CE) const {
23 ProgramStateRef State = getState();
24 const Expr *Callee = CE->getCallee();
25 SVal L = State->getSVal(Callee, Pred->getLocationContext());
26 return L.getAsFunctionDecl();
27 }
28
getCalleeName(const FunctionDecl * FunDecl) const29 StringRef CheckerContext::getCalleeName(const FunctionDecl *FunDecl) const {
30 if (!FunDecl)
31 return StringRef();
32 IdentifierInfo *funI = FunDecl->getIdentifier();
33 if (!funI)
34 return StringRef();
35 return funI->getName();
36 }
37
38
isCLibraryFunction(const FunctionDecl * FD,StringRef Name)39 bool CheckerContext::isCLibraryFunction(const FunctionDecl *FD,
40 StringRef Name) {
41 // To avoid false positives (Ex: finding user defined functions with
42 // similar names), only perform fuzzy name matching when it's a builtin.
43 // Using a string compare is slow, we might want to switch on BuiltinID here.
44 unsigned BId = FD->getBuiltinID();
45 if (BId != 0) {
46 if (Name.empty())
47 return true;
48 StringRef BName = FD->getASTContext().BuiltinInfo.getName(BId);
49 if (BName.find(Name) != StringRef::npos)
50 return true;
51 }
52
53 const IdentifierInfo *II = FD->getIdentifier();
54 // If this is a special C++ name without IdentifierInfo, it can't be a
55 // C library function.
56 if (!II)
57 return false;
58
59 // Look through 'extern "C"' and anything similar invented in the future.
60 const DeclContext *DC = FD->getDeclContext();
61 while (DC->isTransparentContext())
62 DC = DC->getParent();
63
64 // If this function is in a namespace, it is not a C library function.
65 if (!DC->isTranslationUnit())
66 return false;
67
68 // If this function is not externally visible, it is not a C library function.
69 // Note that we make an exception for inline functions, which may be
70 // declared in header files without external linkage.
71 if (!FD->isInlined() && !FD->isExternallyVisible())
72 return false;
73
74 if (Name.empty())
75 return true;
76
77 StringRef FName = II->getName();
78 if (FName.equals(Name))
79 return true;
80
81 if (FName.startswith("__inline") && (FName.find(Name) != StringRef::npos))
82 return true;
83
84 if (FName.startswith("__") && FName.endswith("_chk") &&
85 FName.find(Name) != StringRef::npos)
86 return true;
87
88 return false;
89 }
90
getMacroNameOrSpelling(SourceLocation & Loc)91 StringRef CheckerContext::getMacroNameOrSpelling(SourceLocation &Loc) {
92 if (Loc.isMacroID())
93 return Lexer::getImmediateMacroName(Loc, getSourceManager(),
94 getLangOpts());
95 SmallVector<char, 16> buf;
96 return Lexer::getSpelling(Loc, buf, getSourceManager(), getLangOpts());
97 }
98
99