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+//===--- 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/Basic/Diagnostic.h"
+#include "llvm/ADT/SmallString.h"
+using namespace clang;
+
+
+/// MayBeDesignationStart - Return true if this token might be the start of a
+/// designator.
+static bool MayBeDesignationStart(tok::TokenKind K) {
+ switch (K) {
+ default: return false;
+ case tok::period: // designator: '.' identifier
+ case tok::l_square: // designator: array-designator
+ case tok::identifier: // designation: identifier ':'
+ return true;
+ }
+}
+
+/// 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. We need to consider this case when parsing array designators.
+///
+Parser::ExprResult Parser::ParseInitializerWithPotentialDesignator() {
+ // Parse each designator in the designator list until we find an initializer.
+ while (1) {
+ switch (Tok.getKind()) {
+ case tok::equal:
+ // We read some number (at least one due to the grammar we implemented)
+ // of designators and found an '=' sign. The following tokens must be
+ // the initializer.
+ ConsumeToken();
+ return ParseInitializer();
+
+ default: {
+ // We read some number (at least one due to the grammar we implemented)
+ // of designators and found something that isn't an = or an initializer.
+ // If we have exactly one array designator [TODO CHECK], this is the GNU
+ // 'designation: array-designator' extension. Otherwise, it is a parse
+ // error.
+ SourceLocation Loc = Tok.getLocation();
+ ExprResult Init = ParseInitializer();
+ if (Init.isInvalid) return Init;
+
+ Diag(Tok, diag::ext_gnu_missing_equal_designator);
+ return Init;
+ }
+ case tok::period:
+ // designator: '.' identifier
+ ConsumeToken();
+ if (ExpectAndConsume(tok::identifier, diag::err_expected_ident))
+ return ExprResult(true);
+ break;
+
+ case tok::l_square: {
+ // array-designator: '[' constant-expression ']'
+ // array-designator: '[' constant-expression '...' constant-expression ']'
+ // When designation is empty, this can be '[' objc-message-expr ']'. Note
+ // that we also have the case of [4][foo bar], which is the gnu designator
+ // extension + objc message send.
+ SourceLocation StartLoc = ConsumeBracket();
+
+ // If Objective-C is enabled and this is a typename or other identifier
+ // receiver, parse this as a message send expression.
+ if (getLang().ObjC1 && isTokObjCMessageIdentifierReceiver()) {
+ // FIXME: Emit ext_gnu_missing_equal_designator for inits like
+ // [4][foo bar].
+ IdentifierInfo *Name = Tok.getIdentifierInfo();
+ ConsumeToken();
+ ExprResult R = ParseObjCMessageExpressionBody(StartLoc, Name, 0);
+ return ParsePostfixExpressionSuffix(R);
+ }
+
+ // 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.
+ ExprResult Idx = ParseAssignmentExpression();
+ if (Idx.isInvalid) {
+ SkipUntil(tok::r_square);
+ return 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.
+ if (getLang().ObjC1 && Tok.isNot(tok::ellipsis) &&
+ Tok.isNot(tok::r_square)) {
+ // FIXME: Emit ext_gnu_missing_equal_designator for inits like
+ // [4][foo bar].
+ ExprResult R = ParseObjCMessageExpressionBody(StartLoc, 0, Idx.Val);
+ return ParsePostfixExpressionSuffix(R);
+ }
+
+ // Handle the gnu array range extension.
+ if (Tok.is(tok::ellipsis)) {
+ Diag(Tok, diag::ext_gnu_array_range);
+ ConsumeToken();
+
+ ExprResult RHS = ParseConstantExpression();
+ if (RHS.isInvalid) {
+ SkipUntil(tok::r_square);
+ return RHS;
+ }
+ }
+
+ MatchRHSPunctuation(tok::r_square, StartLoc);
+ break;
+ }
+ case tok::identifier: {
+ // Due to the GNU "designation: identifier ':'" extension, we don't know
+ // whether something starting with an identifier is an
+ // assignment-expression or if it is an old-style structure field
+ // designator.
+ // TODO: Check that this is the first designator.
+ Token Ident = Tok;
+ ConsumeToken();
+
+ // If this is the gross GNU extension, handle it now.
+ if (Tok.is(tok::colon)) {
+ Diag(Ident, diag::ext_gnu_old_style_field_designator);
+ ConsumeToken();
+ return ParseInitializer();
+ }
+
+ // Otherwise, we just consumed the first token of an expression. Parse
+ // the rest of it now.
+ return ParseAssignmentExprWithLeadingIdentifier(Ident);
+ }
+ }
+ }
+}
+
+
+/// ParseInitializer
+/// initializer: [C99 6.7.8]
+/// assignment-expression
+/// '{' initializer-list '}'
+/// '{' initializer-list ',' '}'
+/// [GNU] '{' '}'
+///
+/// initializer-list:
+/// designation[opt] initializer
+/// initializer-list ',' designation[opt] initializer
+///
+Parser::ExprResult Parser::ParseInitializer() {
+ if (Tok.isNot(tok::l_brace))
+ return ParseAssignmentExpression();
+
+ SourceLocation LBraceLoc = ConsumeBrace();
+
+ // We support empty initializers, but tell the user that they aren't using
+ // C99-clean code.
+ if (Tok.is(tok::r_brace)) {
+ Diag(LBraceLoc, diag::ext_gnu_empty_initializer);
+ // Match the '}'.
+ return Actions.ActOnInitList(LBraceLoc, 0, 0, ConsumeBrace());
+ }
+ llvm::SmallVector<ExprTy*, 8> InitExprs;
+ bool InitExprsOk = true;
+
+ while (1) {
+ // Parse: designation[opt] initializer
+
+ // If we know that this cannot be a designation, just parse the nested
+ // initializer directly.
+ ExprResult SubElt;
+ if (!MayBeDesignationStart(Tok.getKind()))
+ SubElt = ParseInitializer();
+ else
+ SubElt = ParseInitializerWithPotentialDesignator();
+
+ // If we couldn't parse the subelement, bail out.
+ if (SubElt.isInvalid) {
+ InitExprsOk = false;
+ SkipUntil(tok::r_brace, false, true);
+ break;
+ } else
+ InitExprs.push_back(SubElt.Val);
+
+ // If we don't have a comma continued list, we're done.
+ if (Tok.isNot(tok::comma)) break;
+
+ // FIXME: save comma locations.
+ ConsumeToken();
+
+ // Handle trailing comma.
+ if (Tok.is(tok::r_brace)) break;
+ }
+ if (InitExprsOk && Tok.is(tok::r_brace))
+ return Actions.ActOnInitList(LBraceLoc, &InitExprs[0], InitExprs.size(),
+ ConsumeBrace());
+ // Match the '}'.
+ MatchRHSPunctuation(tok::r_brace, LBraceLoc);
+ return ExprResult(true); // an error occurred.
+}
+
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