1 //==- CheckSecuritySyntaxOnly.cpp - Basic security checks --------*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a set of flow-insensitive security checks.
12 //===----------------------------------------------------------------------===//
14 #include "ClangSACheckers.h"
15 #include "clang/AST/StmtVisitor.h"
16 #include "clang/Analysis/AnalysisDeclContext.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
19 #include "clang/StaticAnalyzer/Core/Checker.h"
20 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
21 #include "llvm/ADT/SmallString.h"
22 #include "llvm/ADT/StringSwitch.h"
23 #include "llvm/Support/raw_ostream.h"
25 using namespace clang;
28 static bool isArc4RandomAvailable(const ASTContext &Ctx) {
29 const llvm::Triple &T = Ctx.getTargetInfo().getTriple();
30 return T.getVendor() == llvm::Triple::Apple ||
31 T.getOS() == llvm::Triple::CloudABI ||
32 T.getOS() == llvm::Triple::FreeBSD ||
33 T.getOS() == llvm::Triple::NetBSD ||
34 T.getOS() == llvm::Triple::OpenBSD ||
35 T.getOS() == llvm::Triple::DragonFly;
40 DefaultBool check_gets;
41 DefaultBool check_getpw;
42 DefaultBool check_mktemp;
43 DefaultBool check_mkstemp;
44 DefaultBool check_strcpy;
45 DefaultBool check_rand;
46 DefaultBool check_vfork;
47 DefaultBool check_FloatLoopCounter;
48 DefaultBool check_UncheckedReturn;
50 CheckName checkName_gets;
51 CheckName checkName_getpw;
52 CheckName checkName_mktemp;
53 CheckName checkName_mkstemp;
54 CheckName checkName_strcpy;
55 CheckName checkName_rand;
56 CheckName checkName_vfork;
57 CheckName checkName_FloatLoopCounter;
58 CheckName checkName_UncheckedReturn;
61 class WalkAST : public StmtVisitor<WalkAST> {
63 AnalysisDeclContext* AC;
64 enum { num_setids = 6 };
65 IdentifierInfo *II_setid[num_setids];
68 const ChecksFilter &filter;
71 WalkAST(BugReporter &br, AnalysisDeclContext* ac,
72 const ChecksFilter &f)
73 : BR(br), AC(ac), II_setid(),
74 CheckRand(isArc4RandomAvailable(BR.getContext())),
77 // Statement visitor methods.
78 void VisitCallExpr(CallExpr *CE);
79 void VisitForStmt(ForStmt *S);
80 void VisitCompoundStmt (CompoundStmt *S);
81 void VisitStmt(Stmt *S) { VisitChildren(S); }
83 void VisitChildren(Stmt *S);
86 bool checkCall_strCommon(const CallExpr *CE, const FunctionDecl *FD);
88 typedef void (WalkAST::*FnCheck)(const CallExpr *, const FunctionDecl *);
90 // Checker-specific methods.
91 void checkLoopConditionForFloat(const ForStmt *FS);
92 void checkCall_gets(const CallExpr *CE, const FunctionDecl *FD);
93 void checkCall_getpw(const CallExpr *CE, const FunctionDecl *FD);
94 void checkCall_mktemp(const CallExpr *CE, const FunctionDecl *FD);
95 void checkCall_mkstemp(const CallExpr *CE, const FunctionDecl *FD);
96 void checkCall_strcpy(const CallExpr *CE, const FunctionDecl *FD);
97 void checkCall_strcat(const CallExpr *CE, const FunctionDecl *FD);
98 void checkCall_rand(const CallExpr *CE, const FunctionDecl *FD);
99 void checkCall_random(const CallExpr *CE, const FunctionDecl *FD);
100 void checkCall_vfork(const CallExpr *CE, const FunctionDecl *FD);
101 void checkUncheckedReturnValue(CallExpr *CE);
103 } // end anonymous namespace
105 //===----------------------------------------------------------------------===//
107 //===----------------------------------------------------------------------===//
109 void WalkAST::VisitChildren(Stmt *S) {
110 for (Stmt *Child : S->children())
115 void WalkAST::VisitCallExpr(CallExpr *CE) {
117 const FunctionDecl *FD = CE->getDirectCallee();
122 // Get the name of the callee. If it's a builtin, strip off the prefix.
123 IdentifierInfo *II = FD->getIdentifier();
124 if (!II) // if no identifier, not a simple C function
126 StringRef Name = II->getName();
127 if (Name.startswith("__builtin_"))
128 Name = Name.substr(10);
130 // Set the evaluation function by switching on the callee name.
131 FnCheck evalFunction = llvm::StringSwitch<FnCheck>(Name)
132 .Case("gets", &WalkAST::checkCall_gets)
133 .Case("getpw", &WalkAST::checkCall_getpw)
134 .Case("mktemp", &WalkAST::checkCall_mktemp)
135 .Case("mkstemp", &WalkAST::checkCall_mkstemp)
136 .Case("mkdtemp", &WalkAST::checkCall_mkstemp)
137 .Case("mkstemps", &WalkAST::checkCall_mkstemp)
138 .Cases("strcpy", "__strcpy_chk", &WalkAST::checkCall_strcpy)
139 .Cases("strcat", "__strcat_chk", &WalkAST::checkCall_strcat)
140 .Case("drand48", &WalkAST::checkCall_rand)
141 .Case("erand48", &WalkAST::checkCall_rand)
142 .Case("jrand48", &WalkAST::checkCall_rand)
143 .Case("lrand48", &WalkAST::checkCall_rand)
144 .Case("mrand48", &WalkAST::checkCall_rand)
145 .Case("nrand48", &WalkAST::checkCall_rand)
146 .Case("lcong48", &WalkAST::checkCall_rand)
147 .Case("rand", &WalkAST::checkCall_rand)
148 .Case("rand_r", &WalkAST::checkCall_rand)
149 .Case("random", &WalkAST::checkCall_random)
150 .Case("vfork", &WalkAST::checkCall_vfork)
153 // If the callee isn't defined, it is not of security concern.
154 // Check and evaluate the call.
156 (this->*evalFunction)(CE, FD);
158 // Recurse and check children.
162 void WalkAST::VisitCompoundStmt(CompoundStmt *S) {
163 for (Stmt *Child : S->children())
165 if (CallExpr *CE = dyn_cast<CallExpr>(Child))
166 checkUncheckedReturnValue(CE);
171 void WalkAST::VisitForStmt(ForStmt *FS) {
172 checkLoopConditionForFloat(FS);
174 // Recurse and check children.
178 //===----------------------------------------------------------------------===//
179 // Check: floating poing variable used as loop counter.
180 // Originally: <rdar://problem/6336718>
181 // Implements: CERT security coding advisory FLP-30.
182 //===----------------------------------------------------------------------===//
184 static const DeclRefExpr*
185 getIncrementedVar(const Expr *expr, const VarDecl *x, const VarDecl *y) {
186 expr = expr->IgnoreParenCasts();
188 if (const BinaryOperator *B = dyn_cast<BinaryOperator>(expr)) {
189 if (!(B->isAssignmentOp() || B->isCompoundAssignmentOp() ||
190 B->getOpcode() == BO_Comma))
193 if (const DeclRefExpr *lhs = getIncrementedVar(B->getLHS(), x, y))
196 if (const DeclRefExpr *rhs = getIncrementedVar(B->getRHS(), x, y))
202 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(expr)) {
203 const NamedDecl *ND = DR->getDecl();
204 return ND == x || ND == y ? DR : nullptr;
207 if (const UnaryOperator *U = dyn_cast<UnaryOperator>(expr))
208 return U->isIncrementDecrementOp()
209 ? getIncrementedVar(U->getSubExpr(), x, y) : nullptr;
214 /// CheckLoopConditionForFloat - This check looks for 'for' statements that
215 /// use a floating point variable as a loop counter.
216 /// CERT: FLP30-C, FLP30-CPP.
218 void WalkAST::checkLoopConditionForFloat(const ForStmt *FS) {
219 if (!filter.check_FloatLoopCounter)
222 // Does the loop have a condition?
223 const Expr *condition = FS->getCond();
228 // Does the loop have an increment?
229 const Expr *increment = FS->getInc();
234 // Strip away '()' and casts.
235 condition = condition->IgnoreParenCasts();
236 increment = increment->IgnoreParenCasts();
238 // Is the loop condition a comparison?
239 const BinaryOperator *B = dyn_cast<BinaryOperator>(condition);
244 // Is this a comparison?
245 if (!(B->isRelationalOp() || B->isEqualityOp()))
248 // Are we comparing variables?
249 const DeclRefExpr *drLHS =
250 dyn_cast<DeclRefExpr>(B->getLHS()->IgnoreParenLValueCasts());
251 const DeclRefExpr *drRHS =
252 dyn_cast<DeclRefExpr>(B->getRHS()->IgnoreParenLValueCasts());
254 // Does at least one of the variables have a floating point type?
255 drLHS = drLHS && drLHS->getType()->isRealFloatingType() ? drLHS : nullptr;
256 drRHS = drRHS && drRHS->getType()->isRealFloatingType() ? drRHS : nullptr;
258 if (!drLHS && !drRHS)
261 const VarDecl *vdLHS = drLHS ? dyn_cast<VarDecl>(drLHS->getDecl()) : nullptr;
262 const VarDecl *vdRHS = drRHS ? dyn_cast<VarDecl>(drRHS->getDecl()) : nullptr;
264 if (!vdLHS && !vdRHS)
267 // Does either variable appear in increment?
268 const DeclRefExpr *drInc = getIncrementedVar(increment, vdLHS, vdRHS);
273 // Emit the error. First figure out which DeclRefExpr in the condition
274 // referenced the compared variable.
275 assert(drInc->getDecl());
276 const DeclRefExpr *drCond = vdLHS == drInc->getDecl() ? drLHS : drRHS;
278 SmallVector<SourceRange, 2> ranges;
279 SmallString<256> sbuf;
280 llvm::raw_svector_ostream os(sbuf);
282 os << "Variable '" << drCond->getDecl()->getName()
283 << "' with floating point type '" << drCond->getType().getAsString()
284 << "' should not be used as a loop counter";
286 ranges.push_back(drCond->getSourceRange());
287 ranges.push_back(drInc->getSourceRange());
289 const char *bugType = "Floating point variable used as loop counter";
291 PathDiagnosticLocation FSLoc =
292 PathDiagnosticLocation::createBegin(FS, BR.getSourceManager(), AC);
293 BR.EmitBasicReport(AC->getDecl(), filter.checkName_FloatLoopCounter,
294 bugType, "Security", os.str(),
298 //===----------------------------------------------------------------------===//
299 // Check: Any use of 'gets' is insecure.
300 // Originally: <rdar://problem/6335715>
301 // Implements (part of): 300-BSI (buildsecurityin.us-cert.gov)
302 // CWE-242: Use of Inherently Dangerous Function
303 //===----------------------------------------------------------------------===//
305 void WalkAST::checkCall_gets(const CallExpr *CE, const FunctionDecl *FD) {
306 if (!filter.check_gets)
309 const FunctionProtoType *FPT = FD->getType()->getAs<FunctionProtoType>();
313 // Verify that the function takes a single argument.
314 if (FPT->getNumParams() != 1)
317 // Is the argument a 'char*'?
318 const PointerType *PT = FPT->getParamType(0)->getAs<PointerType>();
322 if (PT->getPointeeType().getUnqualifiedType() != BR.getContext().CharTy)
326 PathDiagnosticLocation CELoc =
327 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
328 BR.EmitBasicReport(AC->getDecl(), filter.checkName_gets,
329 "Potential buffer overflow in call to 'gets'",
331 "Call to function 'gets' is extremely insecure as it can "
332 "always result in a buffer overflow",
333 CELoc, CE->getCallee()->getSourceRange());
336 //===----------------------------------------------------------------------===//
337 // Check: Any use of 'getpwd' is insecure.
338 // CWE-477: Use of Obsolete Functions
339 //===----------------------------------------------------------------------===//
341 void WalkAST::checkCall_getpw(const CallExpr *CE, const FunctionDecl *FD) {
342 if (!filter.check_getpw)
345 const FunctionProtoType *FPT = FD->getType()->getAs<FunctionProtoType>();
349 // Verify that the function takes two arguments.
350 if (FPT->getNumParams() != 2)
353 // Verify the first argument type is integer.
354 if (!FPT->getParamType(0)->isIntegralOrUnscopedEnumerationType())
357 // Verify the second argument type is char*.
358 const PointerType *PT = FPT->getParamType(1)->getAs<PointerType>();
362 if (PT->getPointeeType().getUnqualifiedType() != BR.getContext().CharTy)
366 PathDiagnosticLocation CELoc =
367 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
368 BR.EmitBasicReport(AC->getDecl(), filter.checkName_getpw,
369 "Potential buffer overflow in call to 'getpw'",
371 "The getpw() function is dangerous as it may overflow the "
372 "provided buffer. It is obsoleted by getpwuid().",
373 CELoc, CE->getCallee()->getSourceRange());
376 //===----------------------------------------------------------------------===//
377 // Check: Any use of 'mktemp' is insecure. It is obsoleted by mkstemp().
378 // CWE-377: Insecure Temporary File
379 //===----------------------------------------------------------------------===//
381 void WalkAST::checkCall_mktemp(const CallExpr *CE, const FunctionDecl *FD) {
382 if (!filter.check_mktemp) {
383 // Fall back to the security check of looking for enough 'X's in the
384 // format string, since that is a less severe warning.
385 checkCall_mkstemp(CE, FD);
389 const FunctionProtoType *FPT = FD->getType()->getAs<FunctionProtoType>();
393 // Verify that the function takes a single argument.
394 if (FPT->getNumParams() != 1)
397 // Verify that the argument is Pointer Type.
398 const PointerType *PT = FPT->getParamType(0)->getAs<PointerType>();
402 // Verify that the argument is a 'char*'.
403 if (PT->getPointeeType().getUnqualifiedType() != BR.getContext().CharTy)
407 PathDiagnosticLocation CELoc =
408 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
409 BR.EmitBasicReport(AC->getDecl(), filter.checkName_mktemp,
410 "Potential insecure temporary file in call 'mktemp'",
412 "Call to function 'mktemp' is insecure as it always "
413 "creates or uses insecure temporary file. Use 'mkstemp' "
415 CELoc, CE->getCallee()->getSourceRange());
419 //===----------------------------------------------------------------------===//
420 // Check: Use of 'mkstemp', 'mktemp', 'mkdtemp' should contain at least 6 X's.
421 //===----------------------------------------------------------------------===//
423 void WalkAST::checkCall_mkstemp(const CallExpr *CE, const FunctionDecl *FD) {
424 if (!filter.check_mkstemp)
427 StringRef Name = FD->getIdentifier()->getName();
428 std::pair<signed, signed> ArgSuffix =
429 llvm::StringSwitch<std::pair<signed, signed> >(Name)
430 .Case("mktemp", std::make_pair(0,-1))
431 .Case("mkstemp", std::make_pair(0,-1))
432 .Case("mkdtemp", std::make_pair(0,-1))
433 .Case("mkstemps", std::make_pair(0,1))
434 .Default(std::make_pair(-1, -1));
436 assert(ArgSuffix.first >= 0 && "Unsupported function");
438 // Check if the number of arguments is consistent with out expectations.
439 unsigned numArgs = CE->getNumArgs();
440 if ((signed) numArgs <= ArgSuffix.first)
443 const StringLiteral *strArg =
444 dyn_cast<StringLiteral>(CE->getArg((unsigned)ArgSuffix.first)
445 ->IgnoreParenImpCasts());
447 // Currently we only handle string literals. It is possible to do better,
448 // either by looking at references to const variables, or by doing real
450 if (!strArg || strArg->getCharByteWidth() != 1)
453 // Count the number of X's, taking into account a possible cutoff suffix.
454 StringRef str = strArg->getString();
456 unsigned n = str.size();
458 // Take into account the suffix.
460 if (ArgSuffix.second >= 0) {
461 const Expr *suffixEx = CE->getArg((unsigned)ArgSuffix.second);
463 if (!suffixEx->EvaluateAsInt(Result, BR.getContext()))
465 // FIXME: Issue a warning.
466 if (Result.isNegative())
468 suffix = (unsigned) Result.getZExtValue();
469 n = (n > suffix) ? n - suffix : 0;
472 for (unsigned i = 0; i < n; ++i)
473 if (str[i] == 'X') ++numX;
479 PathDiagnosticLocation CELoc =
480 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
481 SmallString<512> buf;
482 llvm::raw_svector_ostream out(buf);
483 out << "Call to '" << Name << "' should have at least 6 'X's in the"
484 " format string to be secure (" << numX << " 'X'";
489 out << ", " << suffix << " character";
492 out << " used as a suffix";
495 BR.EmitBasicReport(AC->getDecl(), filter.checkName_mkstemp,
496 "Insecure temporary file creation", "Security",
497 out.str(), CELoc, strArg->getSourceRange());
500 //===----------------------------------------------------------------------===//
501 // Check: Any use of 'strcpy' is insecure.
503 // CWE-119: Improper Restriction of Operations within
504 // the Bounds of a Memory Buffer
505 //===----------------------------------------------------------------------===//
506 void WalkAST::checkCall_strcpy(const CallExpr *CE, const FunctionDecl *FD) {
507 if (!filter.check_strcpy)
510 if (!checkCall_strCommon(CE, FD))
514 PathDiagnosticLocation CELoc =
515 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
516 BR.EmitBasicReport(AC->getDecl(), filter.checkName_strcpy,
517 "Potential insecure memory buffer bounds restriction in "
520 "Call to function 'strcpy' is insecure as it does not "
521 "provide bounding of the memory buffer. Replace "
522 "unbounded copy functions with analogous functions that "
523 "support length arguments such as 'strlcpy'. CWE-119.",
524 CELoc, CE->getCallee()->getSourceRange());
527 //===----------------------------------------------------------------------===//
528 // Check: Any use of 'strcat' is insecure.
530 // CWE-119: Improper Restriction of Operations within
531 // the Bounds of a Memory Buffer
532 //===----------------------------------------------------------------------===//
533 void WalkAST::checkCall_strcat(const CallExpr *CE, const FunctionDecl *FD) {
534 if (!filter.check_strcpy)
537 if (!checkCall_strCommon(CE, FD))
541 PathDiagnosticLocation CELoc =
542 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
543 BR.EmitBasicReport(AC->getDecl(), filter.checkName_strcpy,
544 "Potential insecure memory buffer bounds restriction in "
547 "Call to function 'strcat' is insecure as it does not "
548 "provide bounding of the memory buffer. Replace "
549 "unbounded copy functions with analogous functions that "
550 "support length arguments such as 'strlcat'. CWE-119.",
551 CELoc, CE->getCallee()->getSourceRange());
554 //===----------------------------------------------------------------------===//
555 // Common check for str* functions with no bounds parameters.
556 //===----------------------------------------------------------------------===//
557 bool WalkAST::checkCall_strCommon(const CallExpr *CE, const FunctionDecl *FD) {
558 const FunctionProtoType *FPT = FD->getType()->getAs<FunctionProtoType>();
562 // Verify the function takes two arguments, three in the _chk version.
563 int numArgs = FPT->getNumParams();
564 if (numArgs != 2 && numArgs != 3)
567 // Verify the type for both arguments.
568 for (int i = 0; i < 2; i++) {
569 // Verify that the arguments are pointers.
570 const PointerType *PT = FPT->getParamType(i)->getAs<PointerType>();
574 // Verify that the argument is a 'char*'.
575 if (PT->getPointeeType().getUnqualifiedType() != BR.getContext().CharTy)
582 //===----------------------------------------------------------------------===//
583 // Check: Linear congruent random number generators should not be used
584 // Originally: <rdar://problem/63371000>
585 // CWE-338: Use of cryptographically weak prng
586 //===----------------------------------------------------------------------===//
588 void WalkAST::checkCall_rand(const CallExpr *CE, const FunctionDecl *FD) {
589 if (!filter.check_rand || !CheckRand)
592 const FunctionProtoType *FTP = FD->getType()->getAs<FunctionProtoType>();
596 if (FTP->getNumParams() == 1) {
597 // Is the argument an 'unsigned short *'?
598 // (Actually any integer type is allowed.)
599 const PointerType *PT = FTP->getParamType(0)->getAs<PointerType>();
603 if (! PT->getPointeeType()->isIntegralOrUnscopedEnumerationType())
605 } else if (FTP->getNumParams() != 0)
609 SmallString<256> buf1;
610 llvm::raw_svector_ostream os1(buf1);
611 os1 << '\'' << *FD << "' is a poor random number generator";
613 SmallString<256> buf2;
614 llvm::raw_svector_ostream os2(buf2);
615 os2 << "Function '" << *FD
616 << "' is obsolete because it implements a poor random number generator."
617 << " Use 'arc4random' instead";
619 PathDiagnosticLocation CELoc =
620 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
621 BR.EmitBasicReport(AC->getDecl(), filter.checkName_rand, os1.str(),
622 "Security", os2.str(), CELoc,
623 CE->getCallee()->getSourceRange());
626 //===----------------------------------------------------------------------===//
627 // Check: 'random' should not be used
628 // Originally: <rdar://problem/63371000>
629 //===----------------------------------------------------------------------===//
631 void WalkAST::checkCall_random(const CallExpr *CE, const FunctionDecl *FD) {
632 if (!CheckRand || !filter.check_rand)
635 const FunctionProtoType *FTP = FD->getType()->getAs<FunctionProtoType>();
639 // Verify that the function takes no argument.
640 if (FTP->getNumParams() != 0)
644 PathDiagnosticLocation CELoc =
645 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
646 BR.EmitBasicReport(AC->getDecl(), filter.checkName_rand,
647 "'random' is not a secure random number generator",
649 "The 'random' function produces a sequence of values that "
650 "an adversary may be able to predict. Use 'arc4random' "
651 "instead", CELoc, CE->getCallee()->getSourceRange());
654 //===----------------------------------------------------------------------===//
655 // Check: 'vfork' should not be used.
656 // POS33-C: Do not use vfork().
657 //===----------------------------------------------------------------------===//
659 void WalkAST::checkCall_vfork(const CallExpr *CE, const FunctionDecl *FD) {
660 if (!filter.check_vfork)
663 // All calls to vfork() are insecure, issue a warning.
664 PathDiagnosticLocation CELoc =
665 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
666 BR.EmitBasicReport(AC->getDecl(), filter.checkName_vfork,
667 "Potential insecure implementation-specific behavior in "
670 "Call to function 'vfork' is insecure as it can lead to "
671 "denial of service situations in the parent process. "
672 "Replace calls to vfork with calls to the safer "
673 "'posix_spawn' function",
674 CELoc, CE->getCallee()->getSourceRange());
677 //===----------------------------------------------------------------------===//
678 // Check: Should check whether privileges are dropped successfully.
679 // Originally: <rdar://problem/6337132>
680 //===----------------------------------------------------------------------===//
682 void WalkAST::checkUncheckedReturnValue(CallExpr *CE) {
683 if (!filter.check_UncheckedReturn)
686 const FunctionDecl *FD = CE->getDirectCallee();
690 if (II_setid[0] == nullptr) {
691 static const char * const identifiers[num_setids] = {
692 "setuid", "setgid", "seteuid", "setegid",
693 "setreuid", "setregid"
696 for (size_t i = 0; i < num_setids; i++)
697 II_setid[i] = &BR.getContext().Idents.get(identifiers[i]);
700 const IdentifierInfo *id = FD->getIdentifier();
703 for (identifierid = 0; identifierid < num_setids; identifierid++)
704 if (id == II_setid[identifierid])
707 if (identifierid >= num_setids)
710 const FunctionProtoType *FTP = FD->getType()->getAs<FunctionProtoType>();
714 // Verify that the function takes one or two arguments (depending on
716 if (FTP->getNumParams() != (identifierid < 4 ? 1 : 2))
719 // The arguments must be integers.
720 for (unsigned i = 0; i < FTP->getNumParams(); i++)
721 if (!FTP->getParamType(i)->isIntegralOrUnscopedEnumerationType())
725 SmallString<256> buf1;
726 llvm::raw_svector_ostream os1(buf1);
727 os1 << "Return value is not checked in call to '" << *FD << '\'';
729 SmallString<256> buf2;
730 llvm::raw_svector_ostream os2(buf2);
731 os2 << "The return value from the call to '" << *FD
732 << "' is not checked. If an error occurs in '" << *FD
733 << "', the following code may execute with unexpected privileges";
735 PathDiagnosticLocation CELoc =
736 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
737 BR.EmitBasicReport(AC->getDecl(), filter.checkName_UncheckedReturn, os1.str(),
738 "Security", os2.str(), CELoc,
739 CE->getCallee()->getSourceRange());
742 //===----------------------------------------------------------------------===//
743 // SecuritySyntaxChecker
744 //===----------------------------------------------------------------------===//
747 class SecuritySyntaxChecker : public Checker<check::ASTCodeBody> {
751 void checkASTCodeBody(const Decl *D, AnalysisManager& mgr,
752 BugReporter &BR) const {
753 WalkAST walker(BR, mgr.getAnalysisDeclContext(D), filter);
754 walker.Visit(D->getBody());
759 #define REGISTER_CHECKER(name) \
760 void ento::register##name(CheckerManager &mgr) { \
761 SecuritySyntaxChecker *checker = \
762 mgr.registerChecker<SecuritySyntaxChecker>(); \
763 checker->filter.check_##name = true; \
764 checker->filter.checkName_##name = mgr.getCurrentCheckName(); \
767 REGISTER_CHECKER(gets)
768 REGISTER_CHECKER(getpw)
769 REGISTER_CHECKER(mkstemp)
770 REGISTER_CHECKER(mktemp)
771 REGISTER_CHECKER(strcpy)
772 REGISTER_CHECKER(rand)
773 REGISTER_CHECKER(vfork)
774 REGISTER_CHECKER(FloatLoopCounter)
775 REGISTER_CHECKER(UncheckedReturn)