//=== StdLibraryFunctionsChecker.cpp - Model standard functions -*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This checker improves modeling of a few simple library functions.
// It does not generate warnings.
//
// This checker provides a specification format - `FunctionSummaryTy' - and
// contains descriptions of some library functions in this format. Each
// specification contains a list of branches for splitting the program state
// upon call, and range constraints on argument and return-value symbols that
// are satisfied on each branch. This spec can be expanded to include more
// items, like external effects of the function.
//
// The main difference between this approach and the body farms technique is
// in more explicit control over how many branches are produced. For example,
// consider standard C function `ispunct(int x)', which returns a non-zero value
// iff `x' is a punctuation character, that is, when `x' is in range
// ['!', '/'] [':', '@'] U ['[', '\`'] U ['{', '~'].
// `FunctionSummaryTy' provides only two branches for this function. However,
// any attempt to describe this range with if-statements in the body farm
// would result in many more branches. Because each branch needs to be analyzed
// independently, this significantly reduces performance. Additionally,
// once we consider a branch on which `x' is in range, say, ['!', '/'],
// we assume that such branch is an important separate path through the program,
// which may lead to false positives because considering this particular path
// was not consciously intended, and therefore it might have been unreachable.
//
// This checker uses eval::Call for modeling "pure" functions, for which
// their `FunctionSummaryTy' is a precise model. This avoids unnecessary
// invalidation passes. Conflicts with other checkers are unlikely because
// if the function has no other effects, other checkers would probably never
// want to improve upon the modeling done by this checker.
//
// Non-"pure" functions, for which only partial improvement over the default
// behavior is expected, are modeled via check::PostCall, non-intrusively.
//
// The following standard C functions are currently supported:
//
// fgetc getline isdigit isupper
// fread isalnum isgraph isxdigit
// fwrite isalpha islower read
// getc isascii isprint write
// getchar isblank ispunct
// getdelim iscntrl isspace
//
//===----------------------------------------------------------------------===//
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
using namespace clang;
using namespace clang::ento;
namespace {
class StdLibraryFunctionsChecker : public Checker<check::PostCall, eval::Call> {
/// Below is a series of typedefs necessary to define function specs.
/// We avoid nesting types here because each additional qualifier
/// would need to be repeated in every function spec.
struct FunctionSummaryTy;
/// Specify how much the analyzer engine should entrust modeling this function
/// to us. If he doesn't, he performs additional invalidations.
enum InvalidationKindTy { NoEvalCall, EvalCallAsPure };
/// A pair of ValueRangeKindTy and IntRangeVectorTy would describe a range
/// imposed on a particular argument or return value symbol.
///
/// Given a range, should the argument stay inside or outside this range?
/// The special `ComparesToArgument' value indicates that we should
/// impose a constraint that involves other argument or return value symbols.
enum ValueRangeKindTy { OutOfRange, WithinRange, ComparesToArgument };
// The universal integral type to use in value range descriptions.
// Unsigned to make sure overflows are well-defined.
typedef uint64_t RangeIntTy;
/// Normally, describes a single range constraint, eg. {{0, 1}, {3, 4}} is
/// a non-negative integer, which less than 5 and not equal to 2. For
/// `ComparesToArgument', holds information about how exactly to compare to
/// the argument.
typedef std::vector<std::pair<RangeIntTy, RangeIntTy>> IntRangeVectorTy;
/// A reference to an argument or return value by its number.
/// ArgNo in CallExpr and CallEvent is defined as Unsigned, but
/// obviously uint32_t should be enough for all practical purposes.
typedef uint32_t ArgNoTy;
static const ArgNoTy Ret = std::numeric_limits<ArgNoTy>::max();
/// Incapsulates a single range on a single symbol within a branch.
class ValueRange {
ArgNoTy ArgNo; // Argument to which we apply the range.
ValueRangeKindTy Kind; // Kind of range definition.
IntRangeVectorTy Args; // Polymorphic arguments.
public:
ValueRange(ArgNoTy ArgNo, ValueRangeKindTy Kind,
const IntRangeVectorTy &Args)
: ArgNo(ArgNo), Kind(Kind), Args(Args) {}
ArgNoTy getArgNo() const { return ArgNo; }
ValueRangeKindTy getKind() const { return Kind; }
BinaryOperator::Opcode getOpcode() const {
assert(Kind == ComparesToArgument);
assert(Args.size() == 1);
BinaryOperator::Opcode Op =
static_cast<BinaryOperator::Opcode>(Args[0].first);
assert(BinaryOperator::isComparisonOp(Op) &&
"Only comparison ops are supported for ComparesToArgument");
return Op;
}
ArgNoTy getOtherArgNo() const {
assert(Kind == ComparesToArgument);
assert(Args.size() == 1);
return static_cast<ArgNoTy>(Args[0].second);
}
const IntRangeVectorTy &getRanges() const {
assert(Kind != ComparesToArgument);
return Args;
}
// We avoid creating a virtual apply() method because
// it makes initializer lists harder to write.
private:
ProgramStateRef
applyAsOutOfRange(ProgramStateRef State, const CallEvent &Call,
const FunctionSummaryTy &Summary) const;
ProgramStateRef
applyAsWithinRange(ProgramStateRef State, const CallEvent &Call,
const FunctionSummaryTy &Summary) const;
ProgramStateRef
applyAsComparesToArgument(ProgramStateRef State, const CallEvent &Call,
const FunctionSummaryTy &Summary) const;
public:
ProgramStateRef apply(ProgramStateRef State, const CallEvent &Call,
const FunctionSummaryTy &Summary) const {
switch (Kind) {
case OutOfRange:
return applyAsOutOfRange(State, Call, Summary);
case WithinRange:
return applyAsWithinRange(State, Call, Summary);
case ComparesToArgument:
return applyAsComparesToArgument(State, Call, Summary);
}
llvm_unreachable("Unknown ValueRange kind!");
}
};
/// The complete list of ranges that defines a single branch.
typedef std::vector<ValueRange> ValueRangeSet;
/// Includes information about function prototype (which is necessary to
/// ensure we're modeling the right function and casting values properly),
/// approach to invalidation, and a list of branches - essentially, a list
/// of list of ranges - essentially, a list of lists of lists of segments.
struct FunctionSummaryTy {
const std::vector<QualType> ArgTypes;
const QualType RetType;
const InvalidationKindTy InvalidationKind;
const std::vector<ValueRangeSet> Ranges;
private:
static void assertTypeSuitableForSummary(QualType T) {
assert(!T->isVoidType() &&
"We should have had no significant void types in the spec");
assert(T.isCanonical() &&
"We should only have canonical types in the spec");
// FIXME: lift this assert (but not the ones above!)
assert(T->isIntegralOrEnumerationType() &&
"We only support integral ranges in the spec");
}
public:
QualType getArgType(ArgNoTy ArgNo) const {
QualType T = (ArgNo == Ret) ? RetType : ArgTypes[ArgNo];
assertTypeSuitableForSummary(T);
return T;
}
/// Try our best to figure out if the call expression is the call of
/// *the* library function to which this specification applies.
bool matchesCall(const CallExpr *CE) const;
};
// The same function (as in, function identifier) may have different
// summaries assigned to it, with different argument and return value types.
// We call these "variants" of the function. This can be useful for handling
// C++ function overloads, and also it can be used when the same function
// may have different definitions on different platforms.
typedef std::vector<FunctionSummaryTy> FunctionVariantsTy;
// The map of all functions supported by the checker. It is initialized
// lazily, and it doesn't change after initialization.
typedef llvm::StringMap<FunctionVariantsTy> FunctionSummaryMapTy;
mutable FunctionSummaryMapTy FunctionSummaryMap;
// Auxiliary functions to support ArgNoTy within all structures
// in a unified manner.
static QualType getArgType(const FunctionSummaryTy &Summary, ArgNoTy ArgNo) {
return Summary.getArgType(ArgNo);
}
static QualType getArgType(const CallEvent &Call, ArgNoTy ArgNo) {
return ArgNo == Ret ? Call.getResultType().getCanonicalType()
: Call.getArgExpr(ArgNo)->getType().getCanonicalType();
}
static QualType getArgType(const CallExpr *CE, ArgNoTy ArgNo) {
return ArgNo == Ret ? CE->getType().getCanonicalType()
: CE->getArg(ArgNo)->getType().getCanonicalType();
}
static SVal getArgSVal(const CallEvent &Call, ArgNoTy ArgNo) {
return ArgNo == Ret ? Call.getReturnValue() : Call.getArgSVal(ArgNo);
}
public:
void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
bool evalCall(const CallEvent &Call, CheckerContext &C) const;
private:
Optional<FunctionSummaryTy> findFunctionSummary(const FunctionDecl *FD,
const CallExpr *CE,
CheckerContext &C) const;
void initFunctionSummaries(BasicValueFactory &BVF) const;
};
} // end of anonymous namespace
ProgramStateRef StdLibraryFunctionsChecker::ValueRange::applyAsOutOfRange(
ProgramStateRef State, const CallEvent &Call,
const FunctionSummaryTy &Summary) const {
ProgramStateManager &Mgr = State->getStateManager();
SValBuilder &SVB = Mgr.getSValBuilder();
BasicValueFactory &BVF = SVB.getBasicValueFactory();
ConstraintManager &CM = Mgr.getConstraintManager();
QualType T = getArgType(Summary, getArgNo());
SVal V = getArgSVal(Call, getArgNo());
if (auto N = V.getAs<NonLoc>()) {
const IntRangeVectorTy &R = getRanges();
size_t E = R.size();
for (size_t I = 0; I != E; ++I) {
const llvm::APSInt &Min = BVF.getValue(R[I].first, T);
const llvm::APSInt &Max = BVF.getValue(R[I].second, T);
assert(Min <= Max);
State = CM.assumeInclusiveRange(State, *N, Min, Max, false);
if (!State)
break;
}
}
return State;
}
ProgramStateRef
StdLibraryFunctionsChecker::ValueRange::applyAsWithinRange(
ProgramStateRef State, const CallEvent &Call,
const FunctionSummaryTy &Summary) const {
ProgramStateManager &Mgr = State->getStateManager();
SValBuilder &SVB = Mgr.getSValBuilder();
BasicValueFactory &BVF = SVB.getBasicValueFactory();
ConstraintManager &CM = Mgr.getConstraintManager();
QualType T = getArgType(Summary, getArgNo());
SVal V = getArgSVal(Call, getArgNo());
// "WithinRange R" is treated as "outside [T_MIN, T_MAX] \ R".
// We cut off [T_MIN, min(R) - 1] and [max(R) + 1, T_MAX] if necessary,
// and then cut away all holes in R one by one.
if (auto N = V.getAs<NonLoc>()) {
const IntRangeVectorTy &R = getRanges();
size_t E = R.size();
const llvm::APSInt &MinusInf = BVF.getMinValue(T);
const llvm::APSInt &PlusInf = BVF.getMaxValue(T);
const llvm::APSInt &Left = BVF.getValue(R[0].first - 1ULL, T);
if (Left != PlusInf) {
assert(MinusInf <= Left);
State = CM.assumeInclusiveRange(State, *N, MinusInf, Left, false);
if (!State)
return nullptr;
}
const llvm::APSInt &Right = BVF.getValue(R[E - 1].second + 1ULL, T);
if (Right != MinusInf) {
assert(Right <= PlusInf);
State = CM.assumeInclusiveRange(State, *N, Right, PlusInf, false);
if (!State)
return nullptr;
}
for (size_t I = 1; I != E; ++I) {
const llvm::APSInt &Min = BVF.getValue(R[I - 1].second + 1ULL, T);
const llvm::APSInt &Max = BVF.getValue(R[I].first - 1ULL, T);
assert(Min <= Max);
State = CM.assumeInclusiveRange(State, *N, Min, Max, false);
if (!State)
return nullptr;
}
}
return State;
}
ProgramStateRef
StdLibraryFunctionsChecker::ValueRange::applyAsComparesToArgument(
ProgramStateRef State, const CallEvent &Call,
const FunctionSummaryTy &Summary) const {
ProgramStateManager &Mgr = State->getStateManager();
SValBuilder &SVB = Mgr.getSValBuilder();
QualType CondT = SVB.getConditionType();
QualType T = getArgType(Summary, getArgNo());
SVal V = getArgSVal(Call, getArgNo());
BinaryOperator::Opcode Op = getOpcode();
ArgNoTy OtherArg = getOtherArgNo();
SVal OtherV = getArgSVal(Call, OtherArg);
QualType OtherT = getArgType(Call, OtherArg);
// Note: we avoid integral promotion for comparison.
OtherV = SVB.evalCast(OtherV, T, OtherT);
if (auto CompV = SVB.evalBinOp(State, Op, V, OtherV, CondT)
.getAs<DefinedOrUnknownSVal>())
State = State->assume(*CompV, true);
return State;
}
void StdLibraryFunctionsChecker::checkPostCall(const CallEvent &Call,
CheckerContext &C) const {
const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(Call.getDecl());
if (!FD)
return;
const CallExpr *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr());
if (!CE)
return;
Optional<FunctionSummaryTy> FoundSummary = findFunctionSummary(FD, CE, C);
if (!FoundSummary)
return;
// Now apply ranges.
const FunctionSummaryTy &Summary = *FoundSummary;
ProgramStateRef State = C.getState();
for (const auto &VRS: Summary.Ranges) {
ProgramStateRef NewState = State;
for (const auto &VR: VRS) {
NewState = VR.apply(NewState, Call, Summary);
if (!NewState)
break;
}
if (NewState && NewState != State)
C.addTransition(NewState);
}
}
bool StdLibraryFunctionsChecker::evalCall(const CallEvent &Call,
CheckerContext &C) const {
const auto *FD = dyn_cast_or_null<FunctionDecl>(Call.getDecl());
if (!FD)
return false;
const auto *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr());
if (!CE)
return false;
Optional<FunctionSummaryTy> FoundSummary = findFunctionSummary(FD, CE, C);
if (!FoundSummary)
return false;
const FunctionSummaryTy &Summary = *FoundSummary;
switch (Summary.InvalidationKind) {
case EvalCallAsPure: {
ProgramStateRef State = C.getState();
const LocationContext *LC = C.getLocationContext();
SVal V = C.getSValBuilder().conjureSymbolVal(
CE, LC, CE->getType().getCanonicalType(), C.blockCount());
State = State->BindExpr(CE, LC, V);
C.addTransition(State);
return true;
}
case NoEvalCall:
// Summary tells us to avoid performing eval::Call. The function is possibly
// evaluated by another checker, or evaluated conservatively.
return false;
}
llvm_unreachable("Unknown invalidation kind!");
}
bool StdLibraryFunctionsChecker::FunctionSummaryTy::matchesCall(
const CallExpr *CE) const {
// Check number of arguments:
if (CE->getNumArgs() != ArgTypes.size())
return false;
// Check return type if relevant:
if (!RetType.isNull() && RetType != CE->getType().getCanonicalType())
return false;
// Check argument types when relevant:
for (size_t I = 0, E = ArgTypes.size(); I != E; ++I) {
QualType FormalT = ArgTypes[I];
// Null type marks irrelevant arguments.
if (FormalT.isNull())
continue;
assertTypeSuitableForSummary(FormalT);
QualType ActualT = StdLibraryFunctionsChecker::getArgType(CE, I);
assert(ActualT.isCanonical());
if (ActualT != FormalT)
return false;
}
return true;
}
Optional<StdLibraryFunctionsChecker::FunctionSummaryTy>
StdLibraryFunctionsChecker::findFunctionSummary(const FunctionDecl *FD,
const CallExpr *CE,
CheckerContext &C) const {
// Note: we cannot always obtain FD from CE
// (eg. virtual call, or call by pointer).
assert(CE);
if (!FD)
return None;
SValBuilder &SVB = C.getSValBuilder();
BasicValueFactory &BVF = SVB.getBasicValueFactory();
initFunctionSummaries(BVF);
IdentifierInfo *II = FD->getIdentifier();
if (!II)
return None;
StringRef Name = II->getName();
if (Name.empty() || !C.isCLibraryFunction(FD, Name))
return None;
auto FSMI = FunctionSummaryMap.find(Name);
if (FSMI == FunctionSummaryMap.end())
return None;
// Verify that function signature matches the spec in advance.
// Otherwise we might be modeling the wrong function.
// Strict checking is important because we will be conducting
// very integral-type-sensitive operations on arguments and
// return values.
const FunctionVariantsTy &SpecVariants = FSMI->second;
for (const FunctionSummaryTy &Spec : SpecVariants)
if (Spec.matchesCall(CE))
return Spec;
return None;
}
void StdLibraryFunctionsChecker::initFunctionSummaries(
BasicValueFactory &BVF) const {
if (!FunctionSummaryMap.empty())
return;
ASTContext &ACtx = BVF.getContext();
// These types are useful for writing specifications quickly,
// New specifications should probably introduce more types.
// Some types are hard to obtain from the AST, eg. "ssize_t".
// In such cases it should be possible to provide multiple variants
// of function summary for common cases (eg. ssize_t could be int or long
// or long long, so three summary variants would be enough).
// Of course, function variants are also useful for C++ overloads.
QualType Irrelevant; // A placeholder, whenever we do not care about the type.
QualType IntTy = ACtx.IntTy;
QualType LongTy = ACtx.LongTy;
QualType LongLongTy = ACtx.LongLongTy;
QualType SizeTy = ACtx.getSizeType();
RangeIntTy IntMax = BVF.getMaxValue(IntTy).getLimitedValue();
RangeIntTy LongMax = BVF.getMaxValue(LongTy).getLimitedValue();
RangeIntTy LongLongMax = BVF.getMaxValue(LongLongTy).getLimitedValue();
// We are finally ready to define specifications for all supported functions.
//
// The signature needs to have the correct number of arguments.
// However, we insert `Irrelevant' when the type is insignificant.
//
// Argument ranges should always cover all variants. If return value
// is completely unknown, omit it from the respective range set.
//
// All types in the spec need to be canonical.
//
// Every item in the list of range sets represents a particular
// execution path the analyzer would need to explore once
// the call is modeled - a new program state is constructed
// for every range set, and each range line in the range set
// corresponds to a specific constraint within this state.
//
// Upon comparing to another argument, the other argument is casted
// to the current argument's type. This avoids proper promotion but
// seems useful. For example, read() receives size_t argument,
// and its return value, which is of type ssize_t, cannot be greater
// than this argument. If we made a promotion, and the size argument
// is equal to, say, 10, then we'd impose a range of [0, 10] on the
// return value, however the correct range is [-1, 10].
//
// Please update the list of functions in the header after editing!
//
// The format is as follows:
//
//{ "function name",
// { spec:
// { argument types list, ... },
// return type, purity, { range set list:
// { range list:
// { argument index, within or out of, {{from, to}, ...} },
// { argument index, compares to argument, {{how, which}} },
// ...
// }
// }
// }
//}
#define SUMMARY_WITH_VARIANTS(identifier) {#identifier, {
#define END_SUMMARY_WITH_VARIANTS }},
#define VARIANT(argument_types, return_type, invalidation_approach) \
{ argument_types, return_type, invalidation_approach, {
#define END_VARIANT } },
#define SUMMARY(identifier, argument_types, return_type, \
invalidation_approach) \
{ #identifier, { { argument_types, return_type, invalidation_approach, {
#define END_SUMMARY } } } },
#define ARGUMENT_TYPES(...) { __VA_ARGS__ }
#define RETURN_TYPE(x) x
#define INVALIDATION_APPROACH(x) x
#define CASE {
#define END_CASE },
#define ARGUMENT_CONDITION(argument_number, condition_kind) \
{ argument_number, condition_kind, {
#define END_ARGUMENT_CONDITION }},
#define RETURN_VALUE_CONDITION(condition_kind) \
{ Ret, condition_kind, {
#define END_RETURN_VALUE_CONDITION }},
#define ARG_NO(x) x##U
#define RANGE(x, y) { x, y },
#define SINGLE_VALUE(x) RANGE(x, x)
#define IS_LESS_THAN(arg) { BO_LE, arg }
FunctionSummaryMap = {
// The isascii() family of functions.
SUMMARY(isalnum, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE // Boils down to isupper() or islower() or isdigit()
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE('0', '9')
RANGE('A', 'Z')
RANGE('a', 'z')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE // The locale-specific range.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(128, 255)
END_ARGUMENT_CONDITION
// No post-condition. We are completely unaware of
// locale-specific return values.
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE('0', '9')
RANGE('A', 'Z')
RANGE('a', 'z')
RANGE(128, 255)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(isalpha, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE // isupper() or islower(). Note that 'Z' is less than 'a'.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE('A', 'Z')
RANGE('a', 'z')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE // The locale-specific range.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(128, 255)
END_ARGUMENT_CONDITION
END_CASE
CASE // Other.
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE('A', 'Z')
RANGE('a', 'z')
RANGE(128, 255)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(isascii, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE // Is ASCII.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(0, 127)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE(0, 127)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(isblank, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
SINGLE_VALUE('\t')
SINGLE_VALUE(' ')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
SINGLE_VALUE('\t')
SINGLE_VALUE(' ')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(iscntrl, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE // 0..31 or 127
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(0, 32)
SINGLE_VALUE(127)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE(0, 32)
SINGLE_VALUE(127)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(isdigit, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE // Is a digit.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE('0', '9')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE('0', '9')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(isgraph, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(33, 126)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE(33, 126)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(islower, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE // Is certainly lowercase.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE('a', 'z')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE // Is ascii but not lowercase.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(0, 127)
END_ARGUMENT_CONDITION
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE('a', 'z')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE // The locale-specific range.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(128, 255)
END_ARGUMENT_CONDITION
END_CASE
CASE // Is not an unsigned char.
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE(0, 255)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(isprint, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(32, 126)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE(32, 126)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(ispunct, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE('!', '/')
RANGE(':', '@')
RANGE('[', '`')
RANGE('{', '~')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE('!', '/')
RANGE(':', '@')
RANGE('[', '`')
RANGE('{', '~')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(isspace, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE // Space, '\f', '\n', '\r', '\t', '\v'.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(9, 13)
SINGLE_VALUE(' ')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE // The locale-specific range.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(128, 255)
END_ARGUMENT_CONDITION
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE(9, 13)
SINGLE_VALUE(' ')
RANGE(128, 255)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(isupper, ARGUMENT_TYPES(IntTy), RETURN_TYPE (IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE // Is certainly uppercase.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE('A', 'Z')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE // The locale-specific range.
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE(128, 255)
END_ARGUMENT_CONDITION
END_CASE
CASE // Other.
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE('A', 'Z') RANGE(128, 255)
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(isxdigit, ARGUMENT_TYPES(IntTy), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(EvalCallAsPure))
CASE
ARGUMENT_CONDITION(ARG_NO(0), WithinRange)
RANGE('0', '9')
RANGE('A', 'F')
RANGE('a', 'f')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(OutOfRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
CASE
ARGUMENT_CONDITION(ARG_NO(0), OutOfRange)
RANGE('0', '9')
RANGE('A', 'F')
RANGE('a', 'f')
END_ARGUMENT_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(0)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
// The getc() family of functions that returns either a char or an EOF.
SUMMARY(getc, ARGUMENT_TYPES(Irrelevant), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(NoEvalCall))
CASE // FIXME: EOF is assumed to be defined as -1.
RETURN_VALUE_CONDITION(WithinRange)
RANGE(-1, 255)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(fgetc, ARGUMENT_TYPES(Irrelevant), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(NoEvalCall))
CASE // FIXME: EOF is assumed to be defined as -1.
RETURN_VALUE_CONDITION(WithinRange)
RANGE(-1, 255)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(getchar, ARGUMENT_TYPES(), RETURN_TYPE(IntTy),
INVALIDATION_APPROACH(NoEvalCall))
CASE // FIXME: EOF is assumed to be defined as -1.
RETURN_VALUE_CONDITION(WithinRange)
RANGE(-1, 255)
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
// read()-like functions that never return more than buffer size.
// We are not sure how ssize_t is defined on every platform, so we provide
// three variants that should cover common cases.
SUMMARY_WITH_VARIANTS(read)
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, SizeTy),
RETURN_TYPE(IntTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(ComparesToArgument)
IS_LESS_THAN(ARG_NO(2))
END_RETURN_VALUE_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
RANGE(-1, IntMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, SizeTy),
RETURN_TYPE(LongTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(ComparesToArgument)
IS_LESS_THAN(ARG_NO(2))
END_RETURN_VALUE_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
RANGE(-1, LongMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, SizeTy),
RETURN_TYPE(LongLongTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(ComparesToArgument)
IS_LESS_THAN(ARG_NO(2))
END_RETURN_VALUE_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
RANGE(-1, LongLongMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
END_SUMMARY_WITH_VARIANTS
SUMMARY_WITH_VARIANTS(write)
// Again, due to elusive nature of ssize_t, we have duplicate
// our summaries to cover different variants.
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, SizeTy),
RETURN_TYPE(IntTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(ComparesToArgument)
IS_LESS_THAN(ARG_NO(2))
END_RETURN_VALUE_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
RANGE(-1, IntMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, SizeTy),
RETURN_TYPE(LongTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(ComparesToArgument)
IS_LESS_THAN(ARG_NO(2))
END_RETURN_VALUE_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
RANGE(-1, LongMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, SizeTy),
RETURN_TYPE(LongLongTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(ComparesToArgument)
IS_LESS_THAN(ARG_NO(2))
END_RETURN_VALUE_CONDITION
RETURN_VALUE_CONDITION(WithinRange)
RANGE(-1, LongLongMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
END_SUMMARY_WITH_VARIANTS
SUMMARY(fread,
ARGUMENT_TYPES(Irrelevant, Irrelevant, SizeTy, Irrelevant),
RETURN_TYPE(SizeTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(ComparesToArgument)
IS_LESS_THAN(ARG_NO(2))
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
SUMMARY(fwrite,
ARGUMENT_TYPES(Irrelevant, Irrelevant, SizeTy, Irrelevant),
RETURN_TYPE(SizeTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(ComparesToArgument)
IS_LESS_THAN(ARG_NO(2))
END_RETURN_VALUE_CONDITION
END_CASE
END_SUMMARY
// getline()-like functions either fail or read at least the delimiter.
SUMMARY_WITH_VARIANTS(getline)
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, Irrelevant),
RETURN_TYPE(IntTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(-1)
RANGE(1, IntMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, Irrelevant),
RETURN_TYPE(LongTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(-1)
RANGE(1, LongMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, Irrelevant),
RETURN_TYPE(LongLongTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(-1)
RANGE(1, LongLongMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
END_SUMMARY_WITH_VARIANTS
SUMMARY_WITH_VARIANTS(getdelim)
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, Irrelevant, Irrelevant),
RETURN_TYPE(IntTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(-1)
RANGE(1, IntMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, Irrelevant, Irrelevant),
RETURN_TYPE(LongTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(-1)
RANGE(1, LongMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
VARIANT(ARGUMENT_TYPES(Irrelevant, Irrelevant, Irrelevant, Irrelevant),
RETURN_TYPE(LongLongTy), INVALIDATION_APPROACH(NoEvalCall))
CASE
RETURN_VALUE_CONDITION(WithinRange)
SINGLE_VALUE(-1)
RANGE(1, LongLongMax)
END_RETURN_VALUE_CONDITION
END_CASE
END_VARIANT
END_SUMMARY_WITH_VARIANTS
};
}
void ento::registerStdCLibraryFunctionsChecker(CheckerManager &mgr) {
// If this checker grows large enough to support C++, Objective-C, or other
// standard libraries, we could use multiple register...Checker() functions,
// which would register various checkers with the help of the same Checker
// class, turning on different function summaries.
mgr.registerChecker<StdLibraryFunctionsChecker>();
}
bool ento::shouldRegisterStdCLibraryFunctionsChecker(const LangOptions &LO) {
return true;
}