Diff 81188

clang-tidy/misc/UseAfterMoveCheck.cpp

//===--- UseAfterMoveCheck.cpp - clang-tidy -------------------------------===//		//===--- UseAfterMoveCheck.cpp - clang-tidy -------------------------------===//
//		//
// The LLVM Compiler Infrastructure		// The LLVM Compiler Infrastructure
//		//
// This file is distributed under the University of Illinois Open Source		// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.		// License. See LICENSE.TXT for details.
//		//
//===----------------------------------------------------------------------===//		//===----------------------------------------------------------------------===//

#include "UseAfterMoveCheck.h"		#include "UseAfterMoveCheck.h"

#include "clang/Analysis/CFG.h"		#include "clang/Analysis/CFG.h"
#include "clang/Lex/Lexer.h"		#include "clang/Lex/Lexer.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"

#include <algorithm>		#include "../utils/ExprSequence.h"

using namespace clang::ast_matchers;		using namespace clang::ast_matchers;
		using namespace clang::tidy::utils;
		PrazekUnsubmitted Done Reply Inline Actions I don't think it is required Prazek: I don't think it is required
		PrazekUnsubmitted Done Reply Inline Actions ok I guess I am wrong Prazek: ok I guess I am wrong
		mboehmeUnsubmitted Not Done Reply Inline Actions I would suggest instead adding an explicit "utils::" qualifier -- it's only needed in two places anyway. I don't feel strongly about this though. mboehme: I would suggest instead adding an explicit "utils::" qualifier -- it's only needed in two…
		mnbvmarAuthorUnsubmitted Not Done Reply Inline Actions It's actually needed in more places (I think at least four). I feel like leaving it here. mnbvmar: It's actually needed in more places (I think at least four). I feel like leaving it here.


namespace clang {		namespace clang {
namespace tidy {		namespace tidy {
namespace misc {		namespace misc {

namespace {		namespace {

/// Provides information about the evaluation order of (sub-)expressions within
/// a `CFGBlock`.
///
/// While a `CFGBlock` does contain individual `CFGElement`s for some
/// sub-expressions, the order in which those `CFGElement`s appear reflects
/// only one possible order in which the sub-expressions may be evaluated.
/// However, we want to warn if any of the potential evaluation orders can lead
/// to a use-after-move, not just the one contained in the `CFGBlock`.
///
/// This class implements only a simplified version of the C++ sequencing rules
/// that is, however, sufficient for the purposes of this check. The main
/// limitation is that we do not distinguish between value computation and side
/// effect -- see the "Implementation" section for more details.
///
/// Note: `SequenceChecker` from SemaChecking.cpp does a similar job (and much
/// more thoroughly), but using it would require
/// - Pulling `SequenceChecker` out into a header file (i.e. making it part of
/// the API),
/// - Removing the dependency of `SequenceChecker` on `Sema`, and
/// - (Probably) modifying `SequenceChecker` to make it suitable to be used in
/// this context.
/// For the moment, it seems preferable to re-implement our own version of
/// sequence checking that is special-cased to what we need here.
///
/// Implementation
/// --------------
///
/// `ExprSequence` uses two types of sequencing edges between nodes in the AST:
///
/// - Every `Stmt` is assumed to be sequenced after its children. This is
/// overly optimistic because the standard only states that value computations
/// of operands are sequenced before the value computation of the operator,
/// making no guarantees about side effects (in general).
///
/// For our purposes, this rule is sufficient, however, because this check is
/// interested in operations on objects, which are generally performed through
/// function calls (whether explicit and implicit). Function calls guarantee
/// that the value computations and side effects for all function arguments
/// are sequenced before the execution fo the function.
///
/// - In addition, some `Stmt`s are known to be sequenced before or after
/// their siblings. For example, the `Stmt`s that make up a `CompoundStmt`are
/// all sequenced relative to each other. The function
/// `getSequenceSuccessor()` implements these sequencing rules.
class ExprSequence {
public:
/// Initializes this `ExprSequence` with sequence information for the given
/// `CFG`.
ExprSequence(const CFG TheCFG, ASTContext TheContext);

/// Returns whether \p Before is sequenced before \p After.
bool inSequence(const Stmt Before, const Stmt After) const;

/// Returns whether \p After can potentially be evaluated after \p Before.
/// This is exactly equivalent to `!inSequence(After, Before)` but makes some
/// conditions read more naturally.
bool potentiallyAfter(const Stmt After, const Stmt Before) const;

private:
// Returns the sibling of \p S (if any) that is directly sequenced after \p S,
// or nullptr if no such sibling exists. For example, if \p S is the child of
// a `CompoundStmt`, this would return the Stmt that directly follows \p S in
// the `CompoundStmt`.
//
// As the sequencing of many constructs that change control flow is already
// encoded in the `CFG`, this function only implements the sequencing rules
// for those constructs where sequencing cannot be inferred from the `CFG`.
const Stmt getSequenceSuccessor(const Stmt S) const;

const Stmt resolveSyntheticStmt(const Stmt S) const;

ASTContext *Context;

llvm::DenseMap<const Stmt , const Stmt > SyntheticStmtSourceMap;
};

/// Maps `Stmt`s to the `CFGBlock` that contains them. Some `Stmt`s may be
/// contained in more than one `CFGBlock`; in this case, they are mapped to the
/// innermost block (i.e. the one that is furthest from the root of the tree).
class StmtToBlockMap {
public:
/// Initializes the map for the given `CFG`.
StmtToBlockMap(const CFG TheCFG, ASTContext TheContext);

/// Returns the block that \p S is contained in. Some `Stmt`s may be contained
/// in more than one `CFGBlock`; in this case, this function returns the
/// innermost block (i.e. the one that is furthest from the root of the tree).
const CFGBlock blockContainingStmt(const Stmt S) const;

private:
ASTContext *Context;

llvm::DenseMap<const Stmt , const CFGBlock > Map;
};

/// Contains information about a use-after-move.		/// Contains information about a use-after-move.
struct UseAfterMove {		struct UseAfterMove {
// The DeclRefExpr that constituted the use of the object.		// The DeclRefExpr that constituted the use of the object.
const DeclRefExpr *DeclRef;		const DeclRefExpr *DeclRef;

// Is the order in which the move and the use are evaluated undefined?		// Is the order in which the move and the use are evaluated undefined?
bool EvaluationOrderUndefined;		bool EvaluationOrderUndefined;
};		};
Show All 27 Lines	private:
ASTContext *Context;		ASTContext *Context;
std::unique_ptr<ExprSequence> Sequence;		std::unique_ptr<ExprSequence> Sequence;
std::unique_ptr<StmtToBlockMap> BlockMap;		std::unique_ptr<StmtToBlockMap> BlockMap;
llvm::SmallPtrSet<const CFGBlock *, 8> Visited;		llvm::SmallPtrSet<const CFGBlock *, 8> Visited;
};		};

} // namespace		} // namespace

// Returns the Stmt nodes that are parents of 'S', skipping any potential
// intermediate non-Stmt nodes.
//
// In almost all cases, this function returns a single parent or no parents at
// all.
//
// The case that a Stmt has multiple parents is rare but does actually occur in
// the parts of the AST that we're interested in. Specifically, InitListExpr
// nodes cause ASTContext::getParent() to return multiple parents for certain
// nodes in their subtree because RecursiveASTVisitor visits both the syntactic
// and semantic forms of InitListExpr, and the parent-child relationships are
// different between the two forms.
static SmallVector<const Stmt , 1> getParentStmts(const Stmt S,
ASTContext *Context) {
SmallVector<const Stmt *, 1> Result;

ASTContext::DynTypedNodeList Parents = Context->getParents(*S);

SmallVector<ast_type_traits::DynTypedNode, 1> NodesToProcess(Parents.begin(),
Parents.end());

while (!NodesToProcess.empty()) {
ast_type_traits::DynTypedNode Node = NodesToProcess.back();
NodesToProcess.pop_back();

if (const auto *S = Node.get<Stmt>()) {
Result.push_back(S);
} else {
Parents = Context->getParents(Node);
NodesToProcess.append(Parents.begin(), Parents.end());
}
}

return Result;
}

bool isDescendantOrEqual(const Stmt Descendant, const Stmt Ancestor,
ASTContext *Context) {
if (Descendant == Ancestor)
return true;
for (const Stmt *Parent : getParentStmts(Descendant, Context)) {
if (isDescendantOrEqual(Parent, Ancestor, Context))
return true;
}

return false;
}

ExprSequence::ExprSequence(const CFG TheCFG, ASTContext TheContext)
: Context(TheContext) {
for (const auto &SyntheticStmt : TheCFG->synthetic_stmts()) {
SyntheticStmtSourceMap[SyntheticStmt.first] = SyntheticStmt.second;
}
}

bool ExprSequence::inSequence(const Stmt Before, const Stmt After) const {
Before = resolveSyntheticStmt(Before);
After = resolveSyntheticStmt(After);

// If 'After' is in the subtree of the siblings that follow 'Before' in the
// chain of successors, we know that 'After' is sequenced after 'Before'.
for (const Stmt *Successor = getSequenceSuccessor(Before); Successor;
Successor = getSequenceSuccessor(Successor)) {
if (isDescendantOrEqual(After, Successor, Context))
return true;
}

// If 'After' is a parent of 'Before' or is sequenced after one of these
// parents, we know that it is sequenced after 'Before'.
for (const Stmt *Parent : getParentStmts(Before, Context)) {
if (Parent == After \|\| inSequence(Parent, After))
return true;
}

return false;
}

bool ExprSequence::potentiallyAfter(const Stmt *After,
const Stmt *Before) const {
return !inSequence(After, Before);
}

const Stmt ExprSequence::getSequenceSuccessor(const Stmt S) const {
for (const Stmt *Parent : getParentStmts(S, Context)) {
if (const auto *BO = dyn_cast<BinaryOperator>(Parent)) {
// Comma operator: Right-hand side is sequenced after the left-hand side.
if (BO->getLHS() == S && BO->getOpcode() == BO_Comma)
return BO->getRHS();
} else if (const auto *InitList = dyn_cast<InitListExpr>(Parent)) {
// Initializer list: Each initializer clause is sequenced after the
// clauses that precede it.
for (unsigned I = 1; I < InitList->getNumInits(); ++I) {
if (InitList->getInit(I - 1) == S)
return InitList->getInit(I);
}
} else if (const auto *Compound = dyn_cast<CompoundStmt>(Parent)) {
// Compound statement: Each sub-statement is sequenced after the
// statements that precede it.
const Stmt *Previous = nullptr;
for (const auto *Child : Compound->body()) {
if (Previous == S)
return Child;
Previous = Child;
}
} else if (const auto *TheDeclStmt = dyn_cast<DeclStmt>(Parent)) {
// Declaration: Every initializer expression is sequenced after the
// initializer expressions that precede it.
const Expr *PreviousInit = nullptr;
for (const Decl *TheDecl : TheDeclStmt->decls()) {
if (const auto *TheVarDecl = dyn_cast<VarDecl>(TheDecl)) {
if (const Expr *Init = TheVarDecl->getInit()) {
if (PreviousInit == S)
return Init;
PreviousInit = Init;
}
}
}
} else if (const auto *ForRange = dyn_cast<CXXForRangeStmt>(Parent)) {
// Range-based for: Loop variable declaration is sequenced before the
// body. (We need this rule because these get placed in the same
// CFGBlock.)
if (S == ForRange->getLoopVarStmt())
return ForRange->getBody();
} else if (const auto *TheIfStmt = dyn_cast<IfStmt>(Parent)) {
// If statement: If a variable is declared inside the condition, the
// expression used to initialize the variable is sequenced before the
// evaluation of the condition.
if (S == TheIfStmt->getConditionVariableDeclStmt())
return TheIfStmt->getCond();
}
}

return nullptr;
}

const Stmt ExprSequence::resolveSyntheticStmt(const Stmt S) const {
if (SyntheticStmtSourceMap.count(S))
return SyntheticStmtSourceMap.lookup(S);
else
return S;
}

StmtToBlockMap::StmtToBlockMap(const CFG TheCFG, ASTContext TheContext)
: Context(TheContext) {
for (const auto B : TheCFG) {
for (const auto &Elem : *B) {
if (Optional<CFGStmt> S = Elem.getAs<CFGStmt>())
Map[S->getStmt()] = B;
}
}
}

const CFGBlock StmtToBlockMap::blockContainingStmt(const Stmt S) const {
while (!Map.count(S)) {
SmallVector<const Stmt *, 1> Parents = getParentStmts(S, Context);
if (Parents.empty())
return nullptr;
S = Parents[0];
}

return Map.lookup(S);
}

// Matches nodes that are		// Matches nodes that are
// - Part of a decltype argument or class template argument (we check this by		// - Part of a decltype argument or class template argument (we check this by
// seeing if they are children of a TypeLoc), or		// seeing if they are children of a TypeLoc), or
// - Part of a function template argument (we check this by seeing if they are		// - Part of a function template argument (we check this by seeing if they are
// children of a DeclRefExpr that references a function template).		// children of a DeclRefExpr that references a function template).
// DeclRefExprs that fulfill these conditions should not be counted as a use or		// DeclRefExprs that fulfill these conditions should not be counted as a use or
// move.		// move.
▲ Show 20 Lines • Show All 348 Lines • Show Last 20 Lines

clang-tidy/utils/CMakeLists.txt

	set(LLVM_LINK_COMPONENTS support)			set(LLVM_LINK_COMPONENTS support)

	add_clang_library(clangTidyUtils			add_clang_library(clangTidyUtils
	ASTUtils.cpp			ASTUtils.cpp
	DeclRefExprUtils.cpp			DeclRefExprUtils.cpp
				ExprSequence.cpp
	FixItHintUtils.cpp			FixItHintUtils.cpp
	HeaderFileExtensionsUtils.cpp			HeaderFileExtensionsUtils.cpp
	HeaderGuard.cpp			HeaderGuard.cpp
	IncludeInserter.cpp			IncludeInserter.cpp
	IncludeSorter.cpp			IncludeSorter.cpp
	LexerUtils.cpp			LexerUtils.cpp
	NamespaceAliaser.cpp			NamespaceAliaser.cpp
	OptionsUtils.cpp			OptionsUtils.cpp
	Show All 10 Lines

clang-tidy/utils/ExprSequence.h

This file was added.

				//===------------- ExprSequence.h - clang-tidy ----------------------------===//
				//
				// The LLVM Compiler Infrastructure
				//
				// This file is distributed under the University of Illinois Open Source
				// License. See LICENSE.TXT for details.
				//
				//===----------------------------------------------------------------------===//

				#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_EXPRSEQUENCE_H
				#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_EXPRSEQUENCE_H

				#include "clang/Analysis/CFG.h"
				#include "clang/Lex/Lexer.h"
				#include "llvm/ADT/DenseMap.h"
				#include "llvm/ADT/SmallPtrSet.h"
				#include "llvm/ADT/SmallVector.h"

				#include "../ClangTidy.h"

				namespace clang {
				namespace tidy {
				namespace utils {

				/// Provides information about the evaluation order of (sub-)expressions within
				/// a `CFGBlock`.
				///
				/// While a `CFGBlock` does contain individual `CFGElement`s for some
				/// sub-expressions, the order in which those `CFGElement`s appear reflects
				/// only one possible order in which the sub-expressions may be evaluated.
				/// However, we want to warn if any of the potential evaluation orders can lead
				/// to a use-after-move, not just the one contained in the `CFGBlock`.
				///
				/// This class implements only a simplified version of the C++ sequencing
				/// rules. The main limitation is that we do not distinguish between value
				/// computation and side effect -- see the "Implementation" section for more
				/// details.
				///
				/// Note: `SequenceChecker` from SemaChecking.cpp does a similar job (and much
				/// more thoroughly), but using it would require
				/// - Pulling `SequenceChecker` out into a header file (i.e. making it part of
				/// the API),
				/// - Removing the dependency of `SequenceChecker` on `Sema`, and
				/// - (Probably) modifying `SequenceChecker` to make it suitable to be used in
				/// this context.
				/// For the moment, it seems preferable to re-implement our own version of
				/// sequence checking that is special-cased to what we need here.
				///
				/// Implementation
				/// --------------
				///
				/// `ExprSequence` uses two types of sequencing edges between nodes in the AST:
				///
				/// - Every `Stmt` is assumed to be sequenced after its children. This is
				/// overly optimistic because the standard only states that value computations
				/// of operands are sequenced before the value computation of the operator,
				/// making no guarantees about side effects (in general).
				///
				/// For our purposes, this rule is sufficient, however, because this check is
				/// interested in operations on objects, which are generally performed through
				/// function calls (whether explicit and implicit). Function calls guarantee
				/// that the value computations and side effects for all function arguments
				/// are sequenced before the execution of the function.
				///
				/// - In addition, some `Stmt`s are known to be sequenced before or after
				/// their siblings. For example, the `Stmt`s that make up a `CompoundStmt`are
				/// all sequenced relative to each other. The function
				/// `getSequenceSuccessor()` implements these sequencing rules.
				class ExprSequence {
				public:
				/// Initializes this `ExprSequence` with sequence information for the given
				/// `CFG`.
				ExprSequence(const CFG TheCFG, ASTContext TheContext);

				/// Returns whether \p Before is sequenced before \p After.
				bool inSequence(const Stmt Before, const Stmt After) const;

				/// Returns whether \p After can potentially be evaluated after \p Before.
				/// This is exactly equivalent to `!inSequence(After, Before)` but makes some
				/// conditions read more naturally.
				bool potentiallyAfter(const Stmt After, const Stmt Before) const;

				private:
				// Returns the sibling of \p S (if any) that is directly sequenced after \p S,
				// or nullptr if no such sibling exists. For example, if \p S is the child of
				// a `CompoundStmt`, this would return the Stmt that directly follows \p S in
				// the `CompoundStmt`.
				//
				// As the sequencing of many constructs that change control flow is already
				// encoded in the `CFG`, this function only implements the sequencing rules
				// for those constructs where sequencing cannot be inferred from the `CFG`.
				const Stmt getSequenceSuccessor(const Stmt S) const;

				const Stmt resolveSyntheticStmt(const Stmt S) const;

				ASTContext *Context;

				llvm::DenseMap<const Stmt , const Stmt > SyntheticStmtSourceMap;
				};

				/// Maps `Stmt`s to the `CFGBlock` that contains them. Some `Stmt`s may be
				/// contained in more than one `CFGBlock`; in this case, they are mapped to the
				/// innermost block (i.e. the one that is furthest from the root of the tree).
				class StmtToBlockMap {
				public:
				/// Initializes the map for the given `CFG`.
				StmtToBlockMap(const CFG TheCFG, ASTContext TheContext);

				/// Returns the block that \p S is contained in. Some `Stmt`s may be contained
				/// in more than one `CFGBlock`; in this case, this function returns the
				/// innermost block (i.e. the one that is furthest from the root of the tree).
				const CFGBlock blockContainingStmt(const Stmt S) const;

				private:
				ASTContext *Context;

				llvm::DenseMap<const Stmt , const CFGBlock > Map;
				};


				}
				mboehmeUnsubmitted Done Reply Inline Actions Double newline mboehme: Double newline
				}
				}

				PrazekUnsubmitted Done Reply Inline Actions Run clang-tidy llvm checks on this patch. These braces requires comments like // namespace clang Prazek: Run clang-tidy llvm checks on this patch. These braces requires comments like // namespace…

				#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_EXPRSEQUENCE_H

clang-tidy/utils/ExprSequence.cpp

This file was added.

				//===---------- ExprSequence.cpp - clang-tidy -----------------------------===//
				//
				// The LLVM Compiler Infrastructure
				//
				// This file is distributed under the University of Illinois Open Source
				// License. See LICENSE.TXT for details.
				//
				//===----------------------------------------------------------------------===//

				#include "ExprSequence.h"

				namespace clang {
				namespace tidy {
				namespace utils {

				// Returns the Stmt nodes that are parents of 'S', skipping any potential
				// intermediate non-Stmt nodes.
				//
				// In almost all cases, this function returns a single parent or no parents at
				// all.
				//
				// The case that a Stmt has multiple parents is rare but does actually occur in
				// the parts of the AST that we're interested in. Specifically, InitListExpr
				// nodes cause ASTContext::getParent() to return multiple parents for certain
				// nodes in their subtree because RecursiveASTVisitor visits both the syntactic
				// and semantic forms of InitListExpr, and the parent-child relationships are
				// different between the two forms.
				static SmallVector<const Stmt , 1> getParentStmts(const Stmt S,
				ASTContext *Context) {
				SmallVector<const Stmt *, 1> Result;

				ASTContext::DynTypedNodeList Parents = Context->getParents(*S);

				SmallVector<ast_type_traits::DynTypedNode, 1> NodesToProcess(Parents.begin(),
				Parents.end());

				while (!NodesToProcess.empty()) {
				ast_type_traits::DynTypedNode Node = NodesToProcess.back();
				NodesToProcess.pop_back();

				if (const auto *S = Node.get<Stmt>()) {
				Result.push_back(S);
				} else {
				Parents = Context->getParents(Node);
				NodesToProcess.append(Parents.begin(), Parents.end());
				}
				}

				return Result;
				}

				bool isDescendantOrEqual(const Stmt Descendant, const Stmt Ancestor,
				ASTContext *Context) {
				staronjUnsubmitted Done Reply Inline Actions Shouldn't isDescendantOrEqual be static or in inline namespace? staronj: Shouldn't isDescendantOrEqual be static or in inline namespace?
				PrazekUnsubmitted Done Reply Inline Actions Goot catch. I guess putting it with getParentStmts into anonymous namespace is the best solution. btw inline namespace is not the same as anonymous namespace :) Prazek: Goot catch. I guess putting it with getParentStmts into anonymous namespace is the best…
				mboehmeUnsubmitted Done Reply Inline Actions Thanks for the catch -- this was already a bug in the original code... mboehme: Thanks for the catch -- this was already a bug in the original code...
				if (Descendant == Ancestor)
				return true;
				for (const Stmt *Parent : getParentStmts(Descendant, Context)) {
				if (isDescendantOrEqual(Parent, Ancestor, Context))
				return true;
				}

				return false;
				}

				ExprSequence::ExprSequence(const CFG TheCFG, ASTContext TheContext)
				: Context(TheContext) {
				for (const auto &SyntheticStmt : TheCFG->synthetic_stmts()) {
				SyntheticStmtSourceMap[SyntheticStmt.first] = SyntheticStmt.second;
				}
				}

				bool ExprSequence::inSequence(const Stmt Before, const Stmt After) const {
				Before = resolveSyntheticStmt(Before);
				After = resolveSyntheticStmt(After);

				// If 'After' is in the subtree of the siblings that follow 'Before' in the
				// chain of successors, we know that 'After' is sequenced after 'Before'.
				for (const Stmt *Successor = getSequenceSuccessor(Before); Successor;
				Successor = getSequenceSuccessor(Successor)) {
				if (isDescendantOrEqual(After, Successor, Context))
				return true;
				}

				// If 'After' is a parent of 'Before' or is sequenced after one of these
				// parents, we know that it is sequenced after 'Before'.
				for (const Stmt *Parent : getParentStmts(Before, Context)) {
				if (Parent == After \|\| inSequence(Parent, After))
				return true;
				}

				return false;
				}

				bool ExprSequence::potentiallyAfter(const Stmt *After,
				const Stmt *Before) const {
				return !inSequence(After, Before);
				}

				const Stmt ExprSequence::getSequenceSuccessor(const Stmt S) const {
				for (const Stmt *Parent : getParentStmts(S, Context)) {
				if (const auto *BO = dyn_cast<BinaryOperator>(Parent)) {
				// Comma operator: Right-hand side is sequenced after the left-hand side.
				if (BO->getLHS() == S && BO->getOpcode() == BO_Comma)
				return BO->getRHS();
				} else if (const auto *InitList = dyn_cast<InitListExpr>(Parent)) {
				// Initializer list: Each initializer clause is sequenced after the
				// clauses that precede it.
				for (unsigned I = 1; I < InitList->getNumInits(); ++I) {
				if (InitList->getInit(I - 1) == S)
				return InitList->getInit(I);
				}
				} else if (const auto *Compound = dyn_cast<CompoundStmt>(Parent)) {
				// Compound statement: Each sub-statement is sequenced after the
				// statements that precede it.
				const Stmt *Previous = nullptr;
				for (const auto *Child : Compound->body()) {
				if (Previous == S)
				return Child;
				Previous = Child;
				}
				} else if (const auto *TheDeclStmt = dyn_cast<DeclStmt>(Parent)) {
				// Declaration: Every initializer expression is sequenced after the
				// initializer expressions that precede it.
				const Expr *PreviousInit = nullptr;
				for (const Decl *TheDecl : TheDeclStmt->decls()) {
				if (const auto *TheVarDecl = dyn_cast<VarDecl>(TheDecl)) {
				if (const Expr *Init = TheVarDecl->getInit()) {
				if (PreviousInit == S)
				return Init;
				PreviousInit = Init;
				}
				}
				}
				} else if (const auto *ForRange = dyn_cast<CXXForRangeStmt>(Parent)) {
				// Range-based for: Loop variable declaration is sequenced before the
				// body. (We need this rule because these get placed in the same
				// CFGBlock.)
				if (S == ForRange->getLoopVarStmt())
				return ForRange->getBody();
				} else if (const auto *TheIfStmt = dyn_cast<IfStmt>(Parent)) {
				// If statement: If a variable is declared inside the condition, the
				// expression used to initialize the variable is sequenced before the
				// evaluation of the condition.
				if (S == TheIfStmt->getConditionVariableDeclStmt())
				return TheIfStmt->getCond();
				}
				}

				return nullptr;
				}

				const Stmt ExprSequence::resolveSyntheticStmt(const Stmt S) const {
				if (SyntheticStmtSourceMap.count(S))
				return SyntheticStmtSourceMap.lookup(S);
				else
				return S;
				alexfhUnsubmitted Done Reply Inline Actions nit: No `else` after return, please. alexfh: nit: No `else` after return, please.
				PrazekUnsubmitted Done Reply Inline Actions Not sure if he should change it in this patch - it is just move of this class to different file, so I am not sure if it is good do introduce small changes to it now. I guess pushin NFC patch with this after would be good solution Prazek: Not sure if he should change it in this patch - it is just move of this class to different file…
				alexfhUnsubmitted Done Reply Inline Actions For me it's usually easier to fix than to postpone to a different patch. Feel free to do either. alexfh: For me it's usually easier to fix than to postpone to a different patch. Feel free to do either.
				}

				StmtToBlockMap::StmtToBlockMap(const CFG TheCFG, ASTContext TheContext)
				: Context(TheContext) {
				for (const auto B : TheCFG) {
				for (const auto &Elem : *B) {
				if (Optional<CFGStmt> S = Elem.getAs<CFGStmt>())
				Map[S->getStmt()] = B;
				}
				}
				}

				const CFGBlock StmtToBlockMap::blockContainingStmt(const Stmt S) const {
				while (!Map.count(S)) {
				SmallVector<const Stmt *, 1> Parents = getParentStmts(S, Context);
				if (Parents.empty())
				return nullptr;
				S = Parents[0];
				}

				return Map.lookup(S);
				}


				}
				mboehmeUnsubmitted Done Reply Inline Actions Double newline mboehme: Double newline
				}
				}
				No newline at end of file
				PrazekUnsubmitted Not Done Reply Inline Actions same here Prazek: same here

This is an archive of the discontinued LLVM Phabricator instance.

[clang-tidy] refactor ExprSequence out of misc-use-after-move check
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Diff 81188

clang-tidy/misc/UseAfterMoveCheck.cpp

clang-tidy/utils/CMakeLists.txt

clang-tidy/utils/ExprSequence.h

clang-tidy/utils/ExprSequence.cpp

This is an archive of the discontinued LLVM Phabricator instance.

[clang-tidy] refactor ExprSequence out of misc-use-after-move checkClosedPublic

Details

Diff Detail

Event Timeline

Revision Contents

Diff 81188

clang-tidy/misc/UseAfterMoveCheck.cpp

clang-tidy/utils/CMakeLists.txt

clang-tidy/utils/ExprSequence.h

clang-tidy/utils/ExprSequence.cpp

[clang-tidy] refactor ExprSequence out of misc-use-after-move check
ClosedPublic