335 lines
15 KiB
C++
335 lines
15 KiB
C++
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//===- CheckerDocumentation.cpp - Documentation checker ---------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This checker lists all the checker callbacks and provides documentation for
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// checker writers.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
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#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
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#include "clang/StaticAnalyzer/Core/Checker.h"
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#include "clang/StaticAnalyzer/Core/CheckerManager.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
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using namespace clang;
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using namespace ento;
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// All checkers should be placed into anonymous namespace.
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// We place the CheckerDocumentation inside ento namespace to make the
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// it visible in doxygen.
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namespace clang {
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namespace ento {
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/// This checker documents the callback functions checkers can use to implement
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/// the custom handling of the specific events during path exploration as well
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/// as reporting bugs. Most of the callbacks are targeted at path-sensitive
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/// checking.
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///
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/// \sa CheckerContext
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class CheckerDocumentation : public Checker< check::PreStmt<ReturnStmt>,
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check::PostStmt<DeclStmt>,
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check::PreObjCMessage,
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check::PostObjCMessage,
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check::ObjCMessageNil,
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check::PreCall,
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check::PostCall,
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check::BranchCondition,
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check::NewAllocator,
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check::Location,
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check::Bind,
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check::DeadSymbols,
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check::BeginFunction,
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check::EndFunction,
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check::EndAnalysis,
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check::EndOfTranslationUnit,
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eval::Call,
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eval::Assume,
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check::LiveSymbols,
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check::RegionChanges,
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check::PointerEscape,
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check::ConstPointerEscape,
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check::Event<ImplicitNullDerefEvent>,
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check::ASTDecl<FunctionDecl> > {
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public:
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/// Pre-visit the Statement.
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///
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/// The method will be called before the analyzer core processes the
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/// statement. The notification is performed for every explored CFGElement,
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/// which does not include the control flow statements such as IfStmt. The
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/// callback can be specialized to be called with any subclass of Stmt.
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///
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/// See checkBranchCondition() callback for performing custom processing of
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/// the branching statements.
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///
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/// check::PreStmt<ReturnStmt>
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void checkPreStmt(const ReturnStmt *DS, CheckerContext &C) const {}
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/// Post-visit the Statement.
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///
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/// The method will be called after the analyzer core processes the
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/// statement. The notification is performed for every explored CFGElement,
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/// which does not include the control flow statements such as IfStmt. The
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/// callback can be specialized to be called with any subclass of Stmt.
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///
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/// check::PostStmt<DeclStmt>
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void checkPostStmt(const DeclStmt *DS, CheckerContext &C) const;
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/// Pre-visit the Objective C message.
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///
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/// This will be called before the analyzer core processes the method call.
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/// This is called for any action which produces an Objective-C message send,
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/// including explicit message syntax and property access.
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///
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/// check::PreObjCMessage
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void checkPreObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const {}
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/// Post-visit the Objective C message.
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/// \sa checkPreObjCMessage()
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///
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/// check::PostObjCMessage
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void checkPostObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const {}
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/// Visit an Objective-C message whose receiver is nil.
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///
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/// This will be called when the analyzer core processes a method call whose
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/// receiver is definitely nil. In this case, check{Pre/Post}ObjCMessage and
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/// check{Pre/Post}Call will not be called.
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///
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/// check::ObjCMessageNil
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void checkObjCMessageNil(const ObjCMethodCall &M, CheckerContext &C) const {}
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/// Pre-visit an abstract "call" event.
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///
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/// This is used for checkers that want to check arguments or attributed
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/// behavior for functions and methods no matter how they are being invoked.
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///
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/// Note that this includes ALL cross-body invocations, so if you want to
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/// limit your checks to, say, function calls, you should test for that at the
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/// beginning of your callback function.
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///
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/// check::PreCall
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void checkPreCall(const CallEvent &Call, CheckerContext &C) const {}
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/// Post-visit an abstract "call" event.
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/// \sa checkPreObjCMessage()
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///
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/// check::PostCall
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void checkPostCall(const CallEvent &Call, CheckerContext &C) const {}
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/// Pre-visit of the condition statement of a branch (such as IfStmt).
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void checkBranchCondition(const Stmt *Condition, CheckerContext &Ctx) const {}
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/// Post-visit the C++ operator new's allocation call.
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///
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/// Execution of C++ operator new consists of the following phases: (1) call
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/// default or overridden operator new() to allocate memory (2) cast the
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/// return value of operator new() from void pointer type to class pointer
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/// type, (3) assuming that the value is non-null, call the object's
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/// constructor over this pointer, (4) declare that the value of the
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/// new-expression is this pointer. This callback is called between steps
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/// (2) and (3). Post-call for the allocator is called after step (1).
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/// Pre-statement for the new-expression is called on step (4) when the value
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/// of the expression is evaluated.
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/// \param NE The C++ new-expression that triggered the allocation.
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/// \param Target The allocated region, casted to the class type.
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void checkNewAllocator(const CXXNewExpr *NE, SVal Target,
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CheckerContext &) const {}
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/// Called on a load from and a store to a location.
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///
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/// The method will be called each time a location (pointer) value is
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/// accessed.
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/// \param Loc The value of the location (pointer).
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/// \param IsLoad The flag specifying if the location is a store or a load.
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/// \param S The load is performed while processing the statement.
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///
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/// check::Location
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void checkLocation(SVal Loc, bool IsLoad, const Stmt *S,
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CheckerContext &) const {}
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/// Called on binding of a value to a location.
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///
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/// \param Loc The value of the location (pointer).
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/// \param Val The value which will be stored at the location Loc.
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/// \param S The bind is performed while processing the statement S.
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///
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/// check::Bind
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void checkBind(SVal Loc, SVal Val, const Stmt *S, CheckerContext &) const {}
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/// Called whenever a symbol becomes dead.
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///
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/// This callback should be used by the checkers to aggressively clean
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/// up/reduce the checker state, which is important for reducing the overall
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/// memory usage. Specifically, if a checker keeps symbol specific information
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/// in the state, it can and should be dropped after the symbol becomes dead.
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/// In addition, reporting a bug as soon as the checker becomes dead leads to
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/// more precise diagnostics. (For example, one should report that a malloced
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/// variable is not freed right after it goes out of scope.)
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///
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/// \param SR The SymbolReaper object can be queried to determine which
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/// symbols are dead.
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///
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/// check::DeadSymbols
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void checkDeadSymbols(SymbolReaper &SR, CheckerContext &C) const {}
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/// Called when the analyzer core starts analyzing a function,
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/// regardless of whether it is analyzed at the top level or is inlined.
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///
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/// check::BeginFunction
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void checkBeginFunction(CheckerContext &Ctx) const {}
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/// Called when the analyzer core reaches the end of a
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/// function being analyzed regardless of whether it is analyzed at the top
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/// level or is inlined.
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///
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/// check::EndFunction
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void checkEndFunction(const ReturnStmt *RS, CheckerContext &Ctx) const {}
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/// Called after all the paths in the ExplodedGraph reach end of path
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/// - the symbolic execution graph is fully explored.
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///
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/// This callback should be used in cases when a checker needs to have a
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/// global view of the information generated on all paths. For example, to
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/// compare execution summary/result several paths.
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/// See IdempotentOperationChecker for a usage example.
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///
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/// check::EndAnalysis
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void checkEndAnalysis(ExplodedGraph &G,
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BugReporter &BR,
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ExprEngine &Eng) const {}
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/// Called after analysis of a TranslationUnit is complete.
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///
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/// check::EndOfTranslationUnit
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void checkEndOfTranslationUnit(const TranslationUnitDecl *TU,
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AnalysisManager &Mgr,
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BugReporter &BR) const {}
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/// Evaluates function call.
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///
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/// The analysis core treats all function calls in the same way. However, some
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/// functions have special meaning, which should be reflected in the program
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/// state. This callback allows a checker to provide domain specific knowledge
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/// about the particular functions it knows about.
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///
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/// \returns true if the call has been successfully evaluated
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/// and false otherwise. Note, that only one checker can evaluate a call. If
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/// more than one checker claims that they can evaluate the same call the
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/// first one wins.
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///
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/// eval::Call
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bool evalCall(const CallExpr *CE, CheckerContext &C) const { return true; }
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/// Handles assumptions on symbolic values.
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///
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/// This method is called when a symbolic expression is assumed to be true or
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/// false. For example, the assumptions are performed when evaluating a
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/// condition at a branch. The callback allows checkers track the assumptions
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/// performed on the symbols of interest and change the state accordingly.
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///
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/// eval::Assume
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ProgramStateRef evalAssume(ProgramStateRef State,
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SVal Cond,
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bool Assumption) const { return State; }
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/// Allows modifying SymbolReaper object. For example, checkers can explicitly
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/// register symbols of interest as live. These symbols will not be marked
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/// dead and removed.
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///
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/// check::LiveSymbols
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void checkLiveSymbols(ProgramStateRef State, SymbolReaper &SR) const {}
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/// Called when the contents of one or more regions change.
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///
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/// This can occur in many different ways: an explicit bind, a blanket
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/// invalidation of the region contents, or by passing a region to a function
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/// call whose behavior the analyzer cannot model perfectly.
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///
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/// \param State The current program state.
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/// \param Invalidated A set of all symbols potentially touched by the change.
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/// \param ExplicitRegions The regions explicitly requested for invalidation.
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/// For a function call, this would be the arguments. For a bind, this
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/// would be the region being bound to.
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/// \param Regions The transitive closure of regions accessible from,
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/// \p ExplicitRegions, i.e. all regions that may have been touched
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/// by this change. For a simple bind, this list will be the same as
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/// \p ExplicitRegions, since a bind does not affect the contents of
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/// anything accessible through the base region.
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/// \param LCtx LocationContext that is useful for getting various contextual
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/// info, like callstack, CFG etc.
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/// \param Call The opaque call triggering this invalidation. Will be 0 if the
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/// change was not triggered by a call.
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///
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/// check::RegionChanges
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ProgramStateRef
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checkRegionChanges(ProgramStateRef State,
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const InvalidatedSymbols *Invalidated,
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ArrayRef<const MemRegion *> ExplicitRegions,
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ArrayRef<const MemRegion *> Regions,
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const LocationContext *LCtx,
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const CallEvent *Call) const {
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return State;
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}
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/// Called when pointers escape.
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///
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/// This notifies the checkers about pointer escape, which occurs whenever
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/// the analyzer cannot track the symbol any more. For example, as a
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/// result of assigning a pointer into a global or when it's passed to a
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/// function call the analyzer cannot model.
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///
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/// \param State The state at the point of escape.
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/// \param Escaped The list of escaped symbols.
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/// \param Call The corresponding CallEvent, if the symbols escape as
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/// parameters to the given call.
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/// \param Kind How the symbols have escaped.
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/// \returns Checkers can modify the state by returning a new state.
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ProgramStateRef checkPointerEscape(ProgramStateRef State,
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const InvalidatedSymbols &Escaped,
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const CallEvent *Call,
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PointerEscapeKind Kind) const {
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return State;
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}
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/// Called when const pointers escape.
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///
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/// Note: in most cases checkPointerEscape callback is sufficient.
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/// \sa checkPointerEscape
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ProgramStateRef checkConstPointerEscape(ProgramStateRef State,
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const InvalidatedSymbols &Escaped,
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const CallEvent *Call,
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PointerEscapeKind Kind) const {
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return State;
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}
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/// check::Event<ImplicitNullDerefEvent>
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void checkEvent(ImplicitNullDerefEvent Event) const {}
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/// Check every declaration in the AST.
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///
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/// An AST traversal callback, which should only be used when the checker is
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/// not path sensitive. It will be called for every Declaration in the AST and
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/// can be specialized to only be called on subclasses of Decl, for example,
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/// FunctionDecl.
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///
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/// check::ASTDecl<FunctionDecl>
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void checkASTDecl(const FunctionDecl *D,
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AnalysisManager &Mgr,
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BugReporter &BR) const {}
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};
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void CheckerDocumentation::checkPostStmt(const DeclStmt *DS,
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CheckerContext &C) const {
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}
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} // end namespace ento
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} // end namespace clang
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