Merge branch 'master' of ssh://bitbucket.org/czan/honours

1 files changed, 547 insertions, 0 deletions

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<Expr*>(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;
+}