| //===-- LoopConvert/LoopMatchers.cpp - Matchers for for loops -------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| /// |
| /// \file |
| /// \brief This file contains definitions of the matchers for use in migrating |
| /// C++ for loops. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #include "LoopMatchers.h" |
| |
| using namespace clang::ast_matchers; |
| using namespace clang; |
| |
| const char LoopName[] = "forLoop"; |
| const char ConditionBoundName[] = "conditionBound"; |
| const char ConditionVarName[] = "conditionVar"; |
| const char IncrementVarName[] = "incrementVar"; |
| const char InitVarName[] = "initVar"; |
| const char BeginCallName[] = "beginCall"; |
| const char EndCallName[] = "endCall"; |
| const char ConditionEndVarName[] = "conditionEndVar"; |
| const char EndVarName[] = "endVar"; |
| const char DerefByValueResultName[] = "derefByValueResult"; |
| const char DerefByRefResultName[] = "derefByRefResult"; |
| |
| // shared matchers |
| static const TypeMatcher AnyType = anything(); |
| |
| static const StatementMatcher IntegerComparisonMatcher = |
| expr(ignoringParenImpCasts(declRefExpr(to( |
| varDecl(hasType(isInteger())).bind(ConditionVarName))))); |
| |
| static const DeclarationMatcher InitToZeroMatcher = |
| varDecl(hasInitializer(ignoringParenImpCasts( |
| integerLiteral(equals(0))))).bind(InitVarName); |
| |
| static const StatementMatcher IncrementVarMatcher = |
| declRefExpr(to( |
| varDecl(hasType(isInteger())).bind(IncrementVarName))); |
| |
| // FIXME: How best to document complicated matcher expressions? They're fairly |
| // self-documenting...but there may be some unintuitive parts. |
| |
| /// \brief The matcher for loops over arrays. |
| /// |
| /// In this general example, assuming 'j' and 'k' are of integral type: |
| /// \code |
| /// for (int i = 0; j < 3 + 2; ++k) { ... } |
| /// \endcode |
| /// The following string identifiers are bound to these parts of the AST: |
| /// ConditionVarName: 'j' (as a VarDecl) |
| /// ConditionBoundName: '3 + 2' (as an Expr) |
| /// InitVarName: 'i' (as a VarDecl) |
| /// IncrementVarName: 'k' (as a VarDecl) |
| /// LoopName: The entire for loop (as a ForStmt) |
| /// |
| /// Client code will need to make sure that: |
| /// - The three index variables identified by the matcher are the same |
| /// VarDecl. |
| /// - The index variable is only used as an array index. |
| /// - All arrays indexed by the loop are the same. |
| StatementMatcher makeArrayLoopMatcher() { |
| StatementMatcher ArrayBoundMatcher = |
| expr(hasType(isInteger())).bind(ConditionBoundName); |
| |
| return forStmt( |
| hasLoopInit(declStmt(hasSingleDecl(InitToZeroMatcher))), |
| hasCondition(anyOf(binaryOperator(hasOperatorName("<"), |
| hasLHS(IntegerComparisonMatcher), |
| hasRHS(ArrayBoundMatcher)), |
| binaryOperator(hasOperatorName(">"), |
| hasLHS(ArrayBoundMatcher), |
| hasRHS(IntegerComparisonMatcher)))), |
| hasIncrement(unaryOperator(hasOperatorName("++"), |
| hasUnaryOperand(IncrementVarMatcher)))) |
| .bind(LoopName); |
| } |
| |
| /// \brief The matcher used for iterator-based for loops. |
| /// |
| /// This matcher is more flexible than array-based loops. It will match |
| /// catch loops of the following textual forms (regardless of whether the |
| /// iterator type is actually a pointer type or a class type): |
| /// |
| /// Assuming f, g, and h are of type containerType::iterator, |
| /// \code |
| /// for (containerType::iterator it = container.begin(), |
| /// e = createIterator(); f != g; ++h) { ... } |
| /// for (containerType::iterator it = container.begin(); |
| /// f != anotherContainer.end(); ++h) { ... } |
| /// \endcode |
| /// The following string identifiers are bound to the parts of the AST: |
| /// InitVarName: 'it' (as a VarDecl) |
| /// ConditionVarName: 'f' (as a VarDecl) |
| /// LoopName: The entire for loop (as a ForStmt) |
| /// In the first example only: |
| /// EndVarName: 'e' (as a VarDecl) |
| /// ConditionEndVarName: 'g' (as a VarDecl) |
| /// In the second example only: |
| /// EndCallName: 'container.end()' (as a CXXMemberCallExpr) |
| /// |
| /// Client code will need to make sure that: |
| /// - The iterator variables 'it', 'f', and 'h' are the same |
| /// - The two containers on which 'begin' and 'end' are called are the same |
| /// - If the end iterator variable 'g' is defined, it is the same as 'f' |
| StatementMatcher makeIteratorLoopMatcher() { |
| StatementMatcher BeginCallMatcher = |
| memberCallExpr( |
| argumentCountIs(0), |
| callee( |
| methodDecl(hasName("begin")) |
| ) |
| ).bind(BeginCallName); |
| |
| DeclarationMatcher InitDeclMatcher = |
| varDecl( |
| hasInitializer( |
| anyOf( |
| ignoringParenImpCasts(BeginCallMatcher), |
| materializeTemporaryExpr(ignoringParenImpCasts(BeginCallMatcher)), |
| hasDescendant(BeginCallMatcher) |
| ) |
| ) |
| ).bind(InitVarName); |
| |
| DeclarationMatcher EndDeclMatcher = |
| varDecl(hasInitializer(anything())).bind(EndVarName); |
| |
| StatementMatcher EndCallMatcher = |
| memberCallExpr(argumentCountIs(0), callee(methodDecl(hasName("end")))); |
| |
| StatementMatcher IteratorBoundMatcher = |
| expr(anyOf(ignoringParenImpCasts(declRefExpr(to( |
| varDecl().bind(ConditionEndVarName)))), |
| ignoringParenImpCasts( |
| expr(EndCallMatcher).bind(EndCallName)), |
| materializeTemporaryExpr(ignoringParenImpCasts( |
| expr(EndCallMatcher).bind(EndCallName))))); |
| |
| StatementMatcher IteratorComparisonMatcher = |
| expr(ignoringParenImpCasts(declRefExpr(to( |
| varDecl().bind(ConditionVarName))))); |
| |
| StatementMatcher OverloadedNEQMatcher = operatorCallExpr( |
| hasOverloadedOperatorName("!="), |
| argumentCountIs(2), |
| hasArgument(0, IteratorComparisonMatcher), |
| hasArgument(1, IteratorBoundMatcher)); |
| |
| // This matcher tests that a declaration is a CXXRecordDecl that has an |
| // overloaded operator*(). If the operator*() returns by value instead of by |
| // reference then the return type is tagged with DerefByValueResultName. |
| internal::Matcher<VarDecl> TestDerefReturnsByValue = |
| hasType( |
| recordDecl( |
| hasMethod( |
| allOf( |
| hasOverloadedOperatorName("*"), |
| anyOf( |
| // Tag the return type if it's by value. |
| returns( |
| qualType( |
| unless(hasCanonicalType(referenceType())) |
| ).bind(DerefByValueResultName) |
| ), |
| returns( |
| // Skip loops where the iterator's operator* returns an |
| // rvalue reference. This is just weird. |
| qualType( |
| unless( |
| hasCanonicalType(rValueReferenceType()) |
| ) |
| ).bind(DerefByRefResultName) |
| ) |
| ) |
| ) |
| ) |
| ) |
| ); |
| |
| |
| return |
| forStmt( |
| hasLoopInit(anyOf( |
| declStmt( |
| declCountIs(2), |
| containsDeclaration(0, InitDeclMatcher), |
| containsDeclaration(1, EndDeclMatcher) |
| ), |
| declStmt(hasSingleDecl(InitDeclMatcher)) |
| )), |
| hasCondition(anyOf( |
| binaryOperator( |
| hasOperatorName("!="), |
| hasLHS(IteratorComparisonMatcher), |
| hasRHS(IteratorBoundMatcher) |
| ), |
| binaryOperator( |
| hasOperatorName("!="), |
| hasLHS(IteratorBoundMatcher), |
| hasRHS(IteratorComparisonMatcher) |
| ), |
| OverloadedNEQMatcher |
| )), |
| hasIncrement(anyOf( |
| unaryOperator( |
| hasOperatorName("++"), |
| hasUnaryOperand( |
| declRefExpr(to( |
| varDecl(hasType(pointsTo(AnyType))).bind(IncrementVarName) |
| )) |
| ) |
| ), |
| operatorCallExpr( |
| hasOverloadedOperatorName("++"), |
| hasArgument(0, |
| declRefExpr(to( |
| varDecl(TestDerefReturnsByValue).bind(IncrementVarName) |
| )) |
| ) |
| ) |
| )) |
| ).bind(LoopName); |
| } |
| |
| /// \brief The matcher used for array-like containers (pseudoarrays). |
| /// |
| /// This matcher is more flexible than array-based loops. It will match |
| /// loops of the following textual forms (regardless of whether the |
| /// iterator type is actually a pointer type or a class type): |
| /// |
| /// Assuming f, g, and h are of type containerType::iterator, |
| /// \code |
| /// for (int i = 0, j = container.size(); f < g; ++h) { ... } |
| /// for (int i = 0; f < container.size(); ++h) { ... } |
| /// \endcode |
| /// The following string identifiers are bound to the parts of the AST: |
| /// InitVarName: 'i' (as a VarDecl) |
| /// ConditionVarName: 'f' (as a VarDecl) |
| /// LoopName: The entire for loop (as a ForStmt) |
| /// In the first example only: |
| /// EndVarName: 'j' (as a VarDecl) |
| /// ConditionEndVarName: 'g' (as a VarDecl) |
| /// In the second example only: |
| /// EndCallName: 'container.size()' (as a CXXMemberCallExpr) |
| /// |
| /// Client code will need to make sure that: |
| /// - The index variables 'i', 'f', and 'h' are the same |
| /// - The containers on which 'size()' is called is the container indexed |
| /// - The index variable is only used in overloaded operator[] or |
| /// container.at() |
| /// - If the end iterator variable 'g' is defined, it is the same as 'j' |
| /// - The container's iterators would not be invalidated during the loop |
| StatementMatcher makePseudoArrayLoopMatcher() { |
| // Test that the incoming type has a record declaration that has methods |
| // called 'begin' and 'end'. If the incoming type is const, then make sure |
| // these methods are also marked const. |
| // |
| // FIXME: To be completely thorough this matcher should also ensure the |
| // return type of begin/end is an iterator that dereferences to the same as |
| // what operator[] or at() returns. Such a test isn't likely to fail except |
| // for pathological cases. |
| // |
| // FIXME: Also, a record doesn't necessarily need begin() and end(). Free |
| // functions called begin() and end() taking the container as an argument |
| // are also allowed. |
| TypeMatcher RecordWithBeginEnd = |
| qualType(anyOf( |
| qualType( |
| isConstQualified(), |
| hasDeclaration( |
| recordDecl( |
| hasMethod( |
| methodDecl( |
| hasName("begin"), |
| isConst() |
| ) |
| ), |
| hasMethod( |
| methodDecl( |
| hasName("end"), |
| isConst() |
| ) |
| ) |
| ) |
| ) // hasDeclaration |
| ), // qualType |
| qualType( |
| unless(isConstQualified()), |
| hasDeclaration( |
| recordDecl( |
| hasMethod(hasName("begin")), |
| hasMethod(hasName("end")) |
| ) |
| ) |
| ) // qualType |
| ) |
| ); |
| |
| StatementMatcher SizeCallMatcher = |
| memberCallExpr(argumentCountIs(0), |
| callee(methodDecl(anyOf(hasName("size"), |
| hasName("length")))), |
| on(anyOf(hasType(pointsTo(RecordWithBeginEnd)), |
| hasType(RecordWithBeginEnd)))); |
| |
| StatementMatcher EndInitMatcher = |
| expr(anyOf( |
| ignoringParenImpCasts(expr(SizeCallMatcher).bind(EndCallName)), |
| explicitCastExpr(hasSourceExpression(ignoringParenImpCasts( |
| expr(SizeCallMatcher).bind(EndCallName)))))); |
| |
| DeclarationMatcher EndDeclMatcher = |
| varDecl(hasInitializer(EndInitMatcher)).bind(EndVarName); |
| |
| StatementMatcher IndexBoundMatcher = |
| expr(anyOf( |
| ignoringParenImpCasts(declRefExpr(to( |
| varDecl(hasType(isInteger())).bind(ConditionEndVarName)))), |
| EndInitMatcher)); |
| |
| return forStmt( |
| hasLoopInit(anyOf( |
| declStmt(declCountIs(2), |
| containsDeclaration(0, InitToZeroMatcher), |
| containsDeclaration(1, EndDeclMatcher)), |
| declStmt(hasSingleDecl(InitToZeroMatcher)))), |
| hasCondition(anyOf( |
| binaryOperator(hasOperatorName("<"), |
| hasLHS(IntegerComparisonMatcher), |
| hasRHS(IndexBoundMatcher)), |
| binaryOperator(hasOperatorName(">"), |
| hasLHS(IndexBoundMatcher), |
| hasRHS(IntegerComparisonMatcher)))), |
| hasIncrement(unaryOperator( |
| hasOperatorName("++"), |
| hasUnaryOperand(IncrementVarMatcher)))) |
| .bind(LoopName); |
| } |
