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
38StringRef CheckerContext::getDeclDescription(const Decl *D) {
39  if (isa<ObjCMethodDecl>(D) || isa<CXXMethodDecl>(D))
40    return "method";
41  if (isa<BlockDecl>(D))
42    return "anonymous block";
43  return "function";
44}
45
46bool CheckerContext::isCLibraryFunction(const FunctionDecl *FD,
47                                        StringRef Name) {
48  // To avoid false positives (Ex: finding user defined functions with
49  // similar names), only perform fuzzy name matching when it's a builtin.
50  // Using a string compare is slow, we might want to switch on BuiltinID here.
51  unsigned BId = FD->getBuiltinID();
52  if (BId != 0) {
53    if (Name.empty())
54      return true;
55    StringRef BName = FD->getASTContext().BuiltinInfo.getName(BId);
56    if (BName.find(Name) != StringRef::npos)
57      return true;
58  }
59
60  const IdentifierInfo *II = FD->getIdentifier();
61  // If this is a special C++ name without IdentifierInfo, it can't be a
62  // C library function.
63  if (!II)
64    return false;
65
66  // Look through 'extern "C"' and anything similar invented in the future.
67  // If this function is not in TU directly, it is not a C library function.
68  if (!FD->getDeclContext()->getRedeclContext()->isTranslationUnit())
69    return false;
70
71  // If this function is not externally visible, it is not a C library function.
72  // Note that we make an exception for inline functions, which may be
73  // declared in header files without external linkage.
74  if (!FD->isInlined() && !FD->isExternallyVisible())
75    return false;
76
77  if (Name.empty())
78    return true;
79
80  StringRef FName = II->getName();
81  if (FName.equals(Name))
82    return true;
83
84  if (FName.startswith("__inline") && (FName.find(Name) != StringRef::npos))
85    return true;
86
87  if (FName.startswith("__") && FName.endswith("_chk") &&
88      FName.find(Name) != StringRef::npos)
89    return true;
90
91  return false;
92}
93
94StringRef CheckerContext::getMacroNameOrSpelling(SourceLocation &Loc) {
95  if (Loc.isMacroID())
96    return Lexer::getImmediateMacroName(Loc, getSourceManager(),
97                                             getLangOpts());
98  SmallVector<char, 16> buf;
99  return Lexer::getSpelling(Loc, buf, getSourceManager(), getLangOpts());
100}
101
102