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
19using namespace clang;
20using namespace ento;
21
22const 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
29StringRef 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
39bool 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
91StringRef 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