Mojom parser: Compute and validate struct field ordinals.

mojom/mojom_parser/parser/parsing.go

 package parser
 
 import (
         "fmt"
         "math"
         "mojom/mojom_parser/lexer"
         "mojom/mojom_parser/mojom"
         "strconv"
 )
 
@@ skipping 636 matching lines @@
                         continue
                 case lexer.RParen:
                         continue
                 default:
                         p.unexpectedTokenError(nextToken, "comma or )")
                         return nil
                 }
         }
 
         if p.OK() {
-                paramStruct.ComputeFieldOrdinals()
+                if err := paramStruct.ComputeFieldOrdinals(); err != nil {
+                        p.err = err
+                        return nil
+                }
         }
         return
 }
 
 // STRUCT_DECL   -> struct name lbrace STRUCT_BODY rbrace semi
 func (p *Parser) parseStructDecl(attributes *mojom.Attributes) (mojomStruct *mojom.MojomStruct) {
         if !p.OK() {
                 return
         }
         p.pushChildNode("structDecl")
@@ skipping 75 matching lines @@
                 default:
                         p.unexpectedTokenError(nextToken, "field, enum or constant declaration")
                         return false
                 }
                 if p.OK() && duplicateNameError != nil {
                         p.err = duplicateNameError
                         return false
                 }
         }
         if p.OK() {
-                mojomStruct.ComputeFieldOrdinals()
+                if err := mojomStruct.ComputeFieldOrdinals(); err != nil {
+                        p.err = err
+                        return false
+                }
         }
+
         return p.OK()
 }
 
 // STRUCT_FIELD         -> TYPE name [ordinal] [equals DEFAULT_VALUE] semi
 // DEFAULT_VALUE        -> COMPATIBLE_VALUE_REF | default
 func (p *Parser) parseStructField(attributes *mojom.Attributes) *mojom.StructField {
         if !p.OK() {
                 return nil
         }
         p.pushChildNode("structField")
@@ skipping 983 matching lines @@
 func (p *Parser) unexpectedTokenError(token lexer.Token, expected string) {
         var message string
         switch token.Kind {
         case lexer.ErrorUnterminatedStringLiteral, lexer.ErrorUnterminatedComment:
                 message = fmt.Sprintf("%s", token)
         default:
                 message = fmt.Sprintf("Unexpected %s. Expecting %s.", token, expected)
         }
         p.parseErrorT(ParserErrorCodeUnexpectedToken, message, token)
 }