From 222e2a7620e6520ffaf4fc4e69d79c18da31542e Mon Sep 17 00:00:00 2001 From: "Zancanaro; Carlo" Date: Mon, 24 Sep 2012 09:58:17 +1000 Subject: Add the clang library to the repo (with some of my changes, too). --- clang/lib/Parse/ParseInit.cpp | 547 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 547 insertions(+) create mode 100644 clang/lib/Parse/ParseInit.cpp (limited to 'clang/lib/Parse/ParseInit.cpp') diff --git a/clang/lib/Parse/ParseInit.cpp b/clang/lib/Parse/ParseInit.cpp new file mode 100644 index 0000000..1c349fd --- /dev/null +++ b/clang/lib/Parse/ParseInit.cpp @@ -0,0 +1,547 @@ +//===--- ParseInit.cpp - Initializer Parsing ------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements initializer parsing as specified by C99 6.7.8. +// +//===----------------------------------------------------------------------===// + +#include "clang/Parse/Parser.h" +#include "clang/Parse/ParseDiagnostic.h" +#include "RAIIObjectsForParser.h" +#include "clang/Sema/Designator.h" +#include "clang/Sema/Scope.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/Support/raw_ostream.h" +using namespace clang; + + +/// MayBeDesignationStart - Return true if the current token might be the start +/// of a designator. If we can tell it is impossible that it is a designator, +/// return false. +bool Parser::MayBeDesignationStart() { + switch (Tok.getKind()) { + default: + return false; + + case tok::period: // designator: '.' identifier + return true; + + case tok::l_square: { // designator: array-designator + if (!PP.getLangOpts().CPlusPlus0x) + return true; + + // C++11 lambda expressions and C99 designators can be ambiguous all the + // way through the closing ']' and to the next character. Handle the easy + // cases here, and fall back to tentative parsing if those fail. + switch (PP.LookAhead(0).getKind()) { + case tok::equal: + case tok::r_square: + // Definitely starts a lambda expression. + return false; + + case tok::amp: + case tok::kw_this: + case tok::identifier: + // We have to do additional analysis, because these could be the + // start of a constant expression or a lambda capture list. + break; + + default: + // Anything not mentioned above cannot occur following a '[' in a + // lambda expression. + return true; + } + + // Handle the complicated case below. + break; + } + case tok::identifier: // designation: identifier ':' + return PP.LookAhead(0).is(tok::colon); + } + + // Parse up to (at most) the token after the closing ']' to determine + // whether this is a C99 designator or a lambda. + TentativeParsingAction Tentative(*this); + ConsumeBracket(); + while (true) { + switch (Tok.getKind()) { + case tok::equal: + case tok::amp: + case tok::identifier: + case tok::kw_this: + // These tokens can occur in a capture list or a constant-expression. + // Keep looking. + ConsumeToken(); + continue; + + case tok::comma: + // Since a comma cannot occur in a constant-expression, this must + // be a lambda. + Tentative.Revert(); + return false; + + case tok::r_square: { + // Once we hit the closing square bracket, we look at the next + // token. If it's an '=', this is a designator. Otherwise, it's a + // lambda expression. This decision favors lambdas over the older + // GNU designator syntax, which allows one to omit the '=', but is + // consistent with GCC. + ConsumeBracket(); + tok::TokenKind Kind = Tok.getKind(); + Tentative.Revert(); + return Kind == tok::equal; + } + + default: + // Anything else cannot occur in a lambda capture list, so it + // must be a designator. + Tentative.Revert(); + return true; + } + } + + return true; +} + +static void CheckArrayDesignatorSyntax(Parser &P, SourceLocation Loc, + Designation &Desig) { + // If we have exactly one array designator, this used the GNU + // 'designation: array-designator' extension, otherwise there should be no + // designators at all! + if (Desig.getNumDesignators() == 1 && + (Desig.getDesignator(0).isArrayDesignator() || + Desig.getDesignator(0).isArrayRangeDesignator())) + P.Diag(Loc, diag::ext_gnu_missing_equal_designator); + else if (Desig.getNumDesignators() > 0) + P.Diag(Loc, diag::err_expected_equal_designator); +} + +/// ParseInitializerWithPotentialDesignator - Parse the 'initializer' production +/// checking to see if the token stream starts with a designator. +/// +/// designation: +/// designator-list '=' +/// [GNU] array-designator +/// [GNU] identifier ':' +/// +/// designator-list: +/// designator +/// designator-list designator +/// +/// designator: +/// array-designator +/// '.' identifier +/// +/// array-designator: +/// '[' constant-expression ']' +/// [GNU] '[' constant-expression '...' constant-expression ']' +/// +/// NOTE: [OBC] allows '[ objc-receiver objc-message-args ]' as an +/// initializer (because it is an expression). We need to consider this case +/// when parsing array designators. +/// +ExprResult Parser::ParseInitializerWithPotentialDesignator() { + + // If this is the old-style GNU extension: + // designation ::= identifier ':' + // Handle it as a field designator. Otherwise, this must be the start of a + // normal expression. + if (Tok.is(tok::identifier)) { + const IdentifierInfo *FieldName = Tok.getIdentifierInfo(); + + SmallString<256> NewSyntax; + llvm::raw_svector_ostream(NewSyntax) << '.' << FieldName->getName() + << " = "; + + SourceLocation NameLoc = ConsumeToken(); // Eat the identifier. + + assert(Tok.is(tok::colon) && "MayBeDesignationStart not working properly!"); + SourceLocation ColonLoc = ConsumeToken(); + + Diag(NameLoc, diag::ext_gnu_old_style_field_designator) + << FixItHint::CreateReplacement(SourceRange(NameLoc, ColonLoc), + NewSyntax.str()); + + Designation D; + D.AddDesignator(Designator::getField(FieldName, SourceLocation(), NameLoc)); + return Actions.ActOnDesignatedInitializer(D, ColonLoc, true, + ParseInitializer()); + } + + // Desig - This is initialized when we see our first designator. We may have + // an objc message send with no designator, so we don't want to create this + // eagerly. + Designation Desig; + + // Parse each designator in the designator list until we find an initializer. + while (Tok.is(tok::period) || Tok.is(tok::l_square)) { + if (Tok.is(tok::period)) { + // designator: '.' identifier + SourceLocation DotLoc = ConsumeToken(); + + if (Tok.isNot(tok::identifier)) { + Diag(Tok.getLocation(), diag::err_expected_field_designator); + return ExprError(); + } + + Desig.AddDesignator(Designator::getField(Tok.getIdentifierInfo(), DotLoc, + Tok.getLocation())); + ConsumeToken(); // Eat the identifier. + continue; + } + + // We must have either an array designator now or an objc message send. + assert(Tok.is(tok::l_square) && "Unexpected token!"); + + // Handle the two forms of array designator: + // array-designator: '[' constant-expression ']' + // array-designator: '[' constant-expression '...' constant-expression ']' + // + // Also, we have to handle the case where the expression after the + // designator an an objc message send: '[' objc-message-expr ']'. + // Interesting cases are: + // [foo bar] -> objc message send + // [foo] -> array designator + // [foo ... bar] -> array designator + // [4][foo bar] -> obsolete GNU designation with objc message send. + // + // We do not need to check for an expression starting with [[ here. If it + // contains an Objective-C message send, then it is not an ill-formed + // attribute. If it is a lambda-expression within an array-designator, then + // it will be rejected because a constant-expression cannot begin with a + // lambda-expression. + InMessageExpressionRAIIObject InMessage(*this, true); + + BalancedDelimiterTracker T(*this, tok::l_square); + T.consumeOpen(); + SourceLocation StartLoc = T.getOpenLocation(); + + ExprResult Idx; + + // If Objective-C is enabled and this is a typename (class message + // send) or send to 'super', parse this as a message send + // expression. We handle C++ and C separately, since C++ requires + // much more complicated parsing. + if (getLangOpts().ObjC1 && getLangOpts().CPlusPlus) { + // Send to 'super'. + if (Tok.is(tok::identifier) && Tok.getIdentifierInfo() == Ident_super && + NextToken().isNot(tok::period) && + getCurScope()->isInObjcMethodScope()) { + CheckArrayDesignatorSyntax(*this, StartLoc, Desig); + return ParseAssignmentExprWithObjCMessageExprStart(StartLoc, + ConsumeToken(), + ParsedType(), + 0); + } + + // Parse the receiver, which is either a type or an expression. + bool IsExpr; + void *TypeOrExpr; + if (ParseObjCXXMessageReceiver(IsExpr, TypeOrExpr)) { + SkipUntil(tok::r_square); + return ExprError(); + } + + // If the receiver was a type, we have a class message; parse + // the rest of it. + if (!IsExpr) { + CheckArrayDesignatorSyntax(*this, StartLoc, Desig); + return ParseAssignmentExprWithObjCMessageExprStart(StartLoc, + SourceLocation(), + ParsedType::getFromOpaquePtr(TypeOrExpr), + 0); + } + + // If the receiver was an expression, we still don't know + // whether we have a message send or an array designator; just + // adopt the expression for further analysis below. + // FIXME: potentially-potentially evaluated expression above? + Idx = ExprResult(static_cast(TypeOrExpr)); + } else if (getLangOpts().ObjC1 && Tok.is(tok::identifier)) { + IdentifierInfo *II = Tok.getIdentifierInfo(); + SourceLocation IILoc = Tok.getLocation(); + ParsedType ReceiverType; + // Three cases. This is a message send to a type: [type foo] + // This is a message send to super: [super foo] + // This is a message sent to an expr: [super.bar foo] + switch (Sema::ObjCMessageKind Kind + = Actions.getObjCMessageKind(getCurScope(), II, IILoc, + II == Ident_super, + NextToken().is(tok::period), + ReceiverType)) { + case Sema::ObjCSuperMessage: + case Sema::ObjCClassMessage: + CheckArrayDesignatorSyntax(*this, StartLoc, Desig); + if (Kind == Sema::ObjCSuperMessage) + return ParseAssignmentExprWithObjCMessageExprStart(StartLoc, + ConsumeToken(), + ParsedType(), + 0); + ConsumeToken(); // the identifier + if (!ReceiverType) { + SkipUntil(tok::r_square); + return ExprError(); + } + + return ParseAssignmentExprWithObjCMessageExprStart(StartLoc, + SourceLocation(), + ReceiverType, + 0); + + case Sema::ObjCInstanceMessage: + // Fall through; we'll just parse the expression and + // (possibly) treat this like an Objective-C message send + // later. + break; + } + } + + // Parse the index expression, if we haven't already gotten one + // above (which can only happen in Objective-C++). + // Note that we parse this as an assignment expression, not a constant + // expression (allowing *=, =, etc) to handle the objc case. Sema needs + // to validate that the expression is a constant. + // FIXME: We also need to tell Sema that we're in a + // potentially-potentially evaluated context. + if (!Idx.get()) { + Idx = ParseAssignmentExpression(); + if (Idx.isInvalid()) { + SkipUntil(tok::r_square); + return move(Idx); + } + } + + // Given an expression, we could either have a designator (if the next + // tokens are '...' or ']' or an objc message send. If this is an objc + // message send, handle it now. An objc-message send is the start of + // an assignment-expression production. + if (getLangOpts().ObjC1 && Tok.isNot(tok::ellipsis) && + Tok.isNot(tok::r_square)) { + CheckArrayDesignatorSyntax(*this, Tok.getLocation(), Desig); + return ParseAssignmentExprWithObjCMessageExprStart(StartLoc, + SourceLocation(), + ParsedType(), + Idx.take()); + } + + // If this is a normal array designator, remember it. + if (Tok.isNot(tok::ellipsis)) { + Desig.AddDesignator(Designator::getArray(Idx.release(), StartLoc)); + } else { + // Handle the gnu array range extension. + Diag(Tok, diag::ext_gnu_array_range); + SourceLocation EllipsisLoc = ConsumeToken(); + + ExprResult RHS(ParseConstantExpression()); + if (RHS.isInvalid()) { + SkipUntil(tok::r_square); + return move(RHS); + } + Desig.AddDesignator(Designator::getArrayRange(Idx.release(), + RHS.release(), + StartLoc, EllipsisLoc)); + } + + T.consumeClose(); + Desig.getDesignator(Desig.getNumDesignators() - 1).setRBracketLoc( + T.getCloseLocation()); + } + + // Okay, we're done with the designator sequence. We know that there must be + // at least one designator, because the only case we can get into this method + // without a designator is when we have an objc message send. That case is + // handled and returned from above. + assert(!Desig.empty() && "Designator is empty?"); + + // Handle a normal designator sequence end, which is an equal. + if (Tok.is(tok::equal)) { + SourceLocation EqualLoc = ConsumeToken(); + return Actions.ActOnDesignatedInitializer(Desig, EqualLoc, false, + ParseInitializer()); + } + + // We read some number of designators and found something that isn't an = or + // an initializer. If we have exactly one array designator, this + // is the GNU 'designation: array-designator' extension. Otherwise, it is a + // parse error. + if (Desig.getNumDesignators() == 1 && + (Desig.getDesignator(0).isArrayDesignator() || + Desig.getDesignator(0).isArrayRangeDesignator())) { + Diag(Tok, diag::ext_gnu_missing_equal_designator) + << FixItHint::CreateInsertion(Tok.getLocation(), "= "); + return Actions.ActOnDesignatedInitializer(Desig, Tok.getLocation(), + true, ParseInitializer()); + } + + Diag(Tok, diag::err_expected_equal_designator); + return ExprError(); +} + + +/// ParseBraceInitializer - Called when parsing an initializer that has a +/// leading open brace. +/// +/// initializer: [C99 6.7.8] +/// '{' initializer-list '}' +/// '{' initializer-list ',' '}' +/// [GNU] '{' '}' +/// +/// initializer-list: +/// designation[opt] initializer ...[opt] +/// initializer-list ',' designation[opt] initializer ...[opt] +/// +ExprResult Parser::ParseBraceInitializer() { + InMessageExpressionRAIIObject InMessage(*this, false); + + BalancedDelimiterTracker T(*this, tok::l_brace); + T.consumeOpen(); + SourceLocation LBraceLoc = T.getOpenLocation(); + + /// InitExprs - This is the actual list of expressions contained in the + /// initializer. + ExprVector InitExprs(Actions); + + if (Tok.is(tok::r_brace)) { + // Empty initializers are a C++ feature and a GNU extension to C. + if (!getLangOpts().CPlusPlus) + Diag(LBraceLoc, diag::ext_gnu_empty_initializer); + // Match the '}'. + return Actions.ActOnInitList(LBraceLoc, MultiExprArg(Actions), + ConsumeBrace()); + } + + bool InitExprsOk = true; + + while (1) { + // Handle Microsoft __if_exists/if_not_exists if necessary. + if (getLangOpts().MicrosoftExt && (Tok.is(tok::kw___if_exists) || + Tok.is(tok::kw___if_not_exists))) { + if (ParseMicrosoftIfExistsBraceInitializer(InitExprs, InitExprsOk)) { + if (Tok.isNot(tok::comma)) break; + ConsumeToken(); + } + if (Tok.is(tok::r_brace)) break; + continue; + } + + // Parse: designation[opt] initializer + + // If we know that this cannot be a designation, just parse the nested + // initializer directly. + ExprResult SubElt; + if (MayBeDesignationStart()) + SubElt = ParseInitializerWithPotentialDesignator(); + else + SubElt = ParseInitializer(); + + if (Tok.is(tok::ellipsis)) + SubElt = Actions.ActOnPackExpansion(SubElt.get(), ConsumeToken()); + + // If we couldn't parse the subelement, bail out. + if (!SubElt.isInvalid()) { + InitExprs.push_back(SubElt.release()); + } else { + InitExprsOk = false; + + // We have two ways to try to recover from this error: if the code looks + // grammatically ok (i.e. we have a comma coming up) try to continue + // parsing the rest of the initializer. This allows us to emit + // diagnostics for later elements that we find. If we don't see a comma, + // assume there is a parse error, and just skip to recover. + // FIXME: This comment doesn't sound right. If there is a r_brace + // immediately, it can't be an error, since there is no other way of + // leaving this loop except through this if. + if (Tok.isNot(tok::comma)) { + SkipUntil(tok::r_brace, false, true); + break; + } + } + + // If we don't have a comma continued list, we're done. + if (Tok.isNot(tok::comma)) break; + + // TODO: save comma locations if some client cares. + ConsumeToken(); + + // Handle trailing comma. + if (Tok.is(tok::r_brace)) break; + } + + bool closed = !T.consumeClose(); + + if (InitExprsOk && closed) + return Actions.ActOnInitList(LBraceLoc, move_arg(InitExprs), + T.getCloseLocation()); + + return ExprError(); // an error occurred. +} + + +// Return true if a comma (or closing brace) is necessary after the +// __if_exists/if_not_exists statement. +bool Parser::ParseMicrosoftIfExistsBraceInitializer(ExprVector &InitExprs, + bool &InitExprsOk) { + bool trailingComma = false; + IfExistsCondition Result; + if (ParseMicrosoftIfExistsCondition(Result)) + return false; + + BalancedDelimiterTracker Braces(*this, tok::l_brace); + if (Braces.consumeOpen()) { + Diag(Tok, diag::err_expected_lbrace); + return false; + } + + switch (Result.Behavior) { + case IEB_Parse: + // Parse the declarations below. + break; + + case IEB_Dependent: + Diag(Result.KeywordLoc, diag::warn_microsoft_dependent_exists) + << Result.IsIfExists; + // Fall through to skip. + + case IEB_Skip: + Braces.skipToEnd(); + return false; + } + + while (Tok.isNot(tok::eof)) { + trailingComma = false; + // If we know that this cannot be a designation, just parse the nested + // initializer directly. + ExprResult SubElt; + if (MayBeDesignationStart()) + SubElt = ParseInitializerWithPotentialDesignator(); + else + SubElt = ParseInitializer(); + + if (Tok.is(tok::ellipsis)) + SubElt = Actions.ActOnPackExpansion(SubElt.get(), ConsumeToken()); + + // If we couldn't parse the subelement, bail out. + if (!SubElt.isInvalid()) + InitExprs.push_back(SubElt.release()); + else + InitExprsOk = false; + + if (Tok.is(tok::comma)) { + ConsumeToken(); + trailingComma = true; + } + + if (Tok.is(tok::r_brace)) + break; + } + + Braces.consumeClose(); + + return !trailingComma; +} -- cgit v1.2.3