/* parse a statement */ enum ParseResult ParseStatement(struct ParseState *Parser, int CheckTrailingSemicolon) { struct Value *CValue; struct Value *LexerValue; struct Value *VarValue; int Condition; struct ParseState PreState; enum LexToken Token; /* if we're debugging, check for a breakpoint */ if (Parser->DebugMode && Parser->Mode == RunModeRun) DebugCheckStatement(Parser); /* take note of where we are and then grab a token to see what statement we have */ ParserCopy(&PreState, Parser); Token = LexGetToken(Parser, &LexerValue, TRUE); switch (Token) { case TokenEOF: return ParseResultEOF; case TokenIdentifier: /* might be a typedef-typed variable declaration or it might be an expression */ if (VariableDefined(Parser->pc, LexerValue->Val->Identifier)) { VariableGet(Parser->pc, Parser, LexerValue->Val->Identifier, &VarValue); if (VarValue->Typ->Base == Type_Type) { *Parser = PreState; ParseDeclaration(Parser, Token); break; } } else { /* it might be a goto label */ enum LexToken NextToken = LexGetToken(Parser, NULL, FALSE); if (NextToken == TokenColon) { /* declare the identifier as a goto label */ LexGetToken(Parser, NULL, TRUE); if (Parser->Mode == RunModeGoto && LexerValue->Val->Identifier == Parser->SearchGotoLabel) Parser->Mode = RunModeRun; CheckTrailingSemicolon = FALSE; break; } #ifdef FEATURE_AUTO_DECLARE_VARIABLES else /* new_identifier = something */ { /* try to guess type and declare the variable based on assigned value */ if (NextToken == TokenAssign && !VariableDefinedAndOutOfScope(Parser->pc, LexerValue->Val->Identifier)) { if (Parser->Mode == RunModeRun) { struct Value *CValue; char* Identifier = LexerValue->Val->Identifier; LexGetToken(Parser, NULL, TRUE); if (!ExpressionParse(Parser, &CValue)) { ProgramFail(Parser, "expected: expression"); } #if 0 PRINT_SOURCE_POS; PlatformPrintf(Parser->pc->CStdOut, "%t %s = %d;\n", CValue->Typ, Identifier, CValue->Val->Integer); printf("%d\n", VariableDefined(Parser->pc, Identifier)); #endif VariableDefine(Parser->pc, Parser, Identifier, CValue, CValue->Typ, TRUE); break; } } } #endif } /* else fallthrough to expression */ /* no break */ case TokenAsterisk: case TokenAmpersand: case TokenIncrement: case TokenDecrement: case TokenOpenBracket: *Parser = PreState; ExpressionParse(Parser, &CValue); if (Parser->Mode == RunModeRun) VariableStackPop(Parser, CValue); break; case TokenLeftBrace: ParseBlock(Parser, FALSE, TRUE); CheckTrailingSemicolon = FALSE; break; case TokenIf: if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); Condition = ExpressionParseInt(Parser) != 0; if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); if (ParseStatementMaybeRun(Parser, Condition, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); if (LexGetToken(Parser, NULL, FALSE) == TokenElse) { LexGetToken(Parser, NULL, TRUE); if (ParseStatementMaybeRun(Parser, !Condition, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); } CheckTrailingSemicolon = FALSE; break; case TokenWhile: { struct ParseState PreConditional; enum RunMode PreMode = Parser->Mode; if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); ParserCopyPos(&PreConditional, Parser); do { ParserCopyPos(Parser, &PreConditional); Condition = ExpressionParseInt(Parser) != 0; if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); if (ParseStatementMaybeRun(Parser, Condition, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); if (Parser->Mode == RunModeContinue) Parser->Mode = PreMode; } while (Parser->Mode == RunModeRun && Condition); if (Parser->Mode == RunModeBreak) Parser->Mode = PreMode; CheckTrailingSemicolon = FALSE; } break; case TokenDo: { struct ParseState PreStatement; enum RunMode PreMode = Parser->Mode; ParserCopyPos(&PreStatement, Parser); do { ParserCopyPos(Parser, &PreStatement); if (ParseStatement(Parser, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); if (Parser->Mode == RunModeContinue) Parser->Mode = PreMode; if (LexGetToken(Parser, NULL, TRUE) != TokenWhile) ProgramFail(Parser, "'while' expected"); if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); Condition = ExpressionParseInt(Parser) != 0; if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); } while (Condition && Parser->Mode == RunModeRun); if (Parser->Mode == RunModeBreak) Parser->Mode = PreMode; } break; case TokenFor: ParseFor(Parser); CheckTrailingSemicolon = FALSE; break; case TokenSemicolon: CheckTrailingSemicolon = FALSE; break; case TokenIntType: case TokenShortType: case TokenCharType: case TokenLongType: case TokenFloatType: case TokenDoubleType: case TokenVoidType: case TokenStructType: case TokenUnionType: case TokenEnumType: case TokenSignedType: case TokenUnsignedType: case TokenStaticType: case TokenAutoType: case TokenRegisterType: case TokenExternType: *Parser = PreState; CheckTrailingSemicolon = ParseDeclaration(Parser, Token); break; case TokenHashDefine: ParseMacroDefinition(Parser); CheckTrailingSemicolon = FALSE; break; #ifndef NO_HASH_INCLUDE case TokenHashInclude: if (LexGetToken(Parser, &LexerValue, TRUE) != TokenStringConstant) ProgramFail(Parser, "\"filename.h\" expected"); IncludeFile(Parser->pc, (char *)LexerValue->Val->Pointer); CheckTrailingSemicolon = FALSE; break; #endif case TokenSwitch: if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); Condition = (int) ExpressionParseInt(Parser); if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); if (LexGetToken(Parser, NULL, FALSE) != TokenLeftBrace) ProgramFail(Parser, "'{' expected"); { /* new block so we can store parser state */ enum RunMode OldMode = Parser->Mode; int64_t OldSearchLabel = Parser->SearchLabel; Parser->Mode = RunModeCaseSearch; Parser->SearchLabel = Condition; ParseBlock(Parser, TRUE, (OldMode != RunModeSkip) && (OldMode != RunModeReturn)); if (Parser->Mode != RunModeReturn) Parser->Mode = OldMode; Parser->SearchLabel = OldSearchLabel; } CheckTrailingSemicolon = FALSE; break; case TokenCase: if (Parser->Mode == RunModeCaseSearch) { Parser->Mode = RunModeRun; Condition = (int) ExpressionParseInt(Parser); Parser->Mode = RunModeCaseSearch; } else Condition = (int) ExpressionParseInt(Parser); if (LexGetToken(Parser, NULL, TRUE) != TokenColon) ProgramFail(Parser, "':' expected"); if (Parser->Mode == RunModeCaseSearch && Condition == Parser->SearchLabel) Parser->Mode = RunModeRun; CheckTrailingSemicolon = FALSE; break; case TokenDefault: if (LexGetToken(Parser, NULL, TRUE) != TokenColon) ProgramFail(Parser, "':' expected"); if (Parser->Mode == RunModeCaseSearch) Parser->Mode = RunModeRun; CheckTrailingSemicolon = FALSE; break; case TokenBreak: if (Parser->Mode == RunModeRun) Parser->Mode = RunModeBreak; break; case TokenContinue: if (Parser->Mode == RunModeRun) Parser->Mode = RunModeContinue; break; case TokenReturn: if (Parser->Mode == RunModeRun) { if (!Parser->pc->TopStackFrame || Parser->pc->TopStackFrame->ReturnValue->Typ->Base != TypeVoid) { if (!ExpressionParse(Parser, &CValue)) ProgramFail(Parser, "value required in return"); if (!Parser->pc->TopStackFrame) /* return from top-level program? */ PlatformExit(Parser->pc, (int)ExpressionCoerceLong(CValue)); else ExpressionAssign(Parser, Parser->pc->TopStackFrame->ReturnValue, CValue, TRUE, NULL, 0, FALSE); VariableStackPop(Parser, CValue); } else { if (ExpressionParse(Parser, &CValue)) ProgramFail(Parser, "value in return from a void function"); } Parser->Mode = RunModeReturn; } else ExpressionParse(Parser, &CValue); break; case TokenTypedef: ParseTypedef(Parser); break; case TokenGoto: if (LexGetToken(Parser, &LexerValue, TRUE) != TokenIdentifier) ProgramFail(Parser, "identifier expected"); if (Parser->Mode == RunModeRun) { /* start scanning for the goto label */ Parser->SearchGotoLabel = LexerValue->Val->Identifier; Parser->Mode = RunModeGoto; } break; case TokenDelete: { /* try it as a function or variable name to delete */ if (LexGetToken(Parser, &LexerValue, TRUE) != TokenIdentifier) ProgramFail(Parser, "identifier expected"); if (Parser->Mode == RunModeRun) { /* delete this variable or function */ CValue = TableDelete(Parser->pc, &Parser->pc->GlobalTable, LexerValue->Val->Identifier); if (CValue == NULL) ProgramFail(Parser, "'%s' is not defined", LexerValue->Val->Identifier); VariableFree(Parser->pc, CValue); } break; } default: *Parser = PreState; return ParseResultError; } if (CheckTrailingSemicolon) { if (LexGetToken(Parser, NULL, TRUE) != TokenSemicolon) ProgramFail(Parser, "';' expected"); } return ParseResultOk; }
/* parse a statement */ enum ParseResult ParseStatement(struct ParseState *Parser, int CheckTrailingSemicolon) { struct Value *CValue; struct Value *LexerValue; struct Value *VarValue; int Condition; struct ParseState PreState; enum LexToken Token; ParserCopy(&PreState, Parser); Token = LexGetToken(Parser, &LexerValue, TRUE); switch (Token) { case TokenEOF: return ParseResultEOF; case TokenIdentifier: /* might be a typedef-typed variable declaration or it might be an expression */ if (VariableDefined(LexerValue->Val->Identifier)) { VariableGet(Parser, LexerValue->Val->Identifier, &VarValue); if (VarValue->Typ->Base == Type_Type) { *Parser = PreState; ParseDeclaration(Parser, Token); break; } } else { /* it might be a goto label */ enum LexToken NextToken = LexGetToken(Parser, NULL, FALSE); if (NextToken == TokenColon) { /* declare the identifier as a goto label */ LexGetToken(Parser, NULL, TRUE); if (Parser->Mode == RunModeGoto && LexerValue->Val->Identifier == Parser->SearchGotoLabel) Parser->Mode = RunModeRun; CheckTrailingSemicolon = FALSE; break; } } /* else fallthrough to expression */ case TokenAsterisk: case TokenAmpersand: case TokenIncrement: case TokenDecrement: case TokenOpenBracket: *Parser = PreState; ExpressionParse(Parser, &CValue); if (Parser->Mode == RunModeRun) VariableStackPop(Parser, CValue); break; case TokenLeftBrace: ParseBlock(Parser, FALSE, TRUE); CheckTrailingSemicolon = FALSE; break; case TokenIf: if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); Condition = ExpressionParseInt(Parser); trace_state_print(Parser); if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); if (ParseStatementMaybeRun(Parser, Condition, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); if (LexGetToken(Parser, NULL, FALSE) == TokenElse) { LexGetToken(Parser, NULL, TRUE); if (ParseStatementMaybeRun(Parser, !Condition, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); } CheckTrailingSemicolon = FALSE; break; case TokenWhile: { struct ParseState PreConditional; enum RunMode PreMode = Parser->Mode; if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); ParserCopyPos(&PreConditional, Parser); do { ParserCopyPos(Parser, &PreConditional); Condition = ExpressionParseInt(Parser); if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); if (ParseStatementMaybeRun(Parser, Condition, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); if (Parser->Mode == RunModeContinue) Parser->Mode = PreMode; } while (Parser->Mode == RunModeRun && Condition); if (Parser->Mode == RunModeBreak) Parser->Mode = PreMode; CheckTrailingSemicolon = FALSE; } break; case TokenDo: { struct ParseState PreStatement; enum RunMode PreMode = Parser->Mode; ParserCopyPos(&PreStatement, Parser); do { ParserCopyPos(Parser, &PreStatement); if (ParseStatement(Parser, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); if (Parser->Mode == RunModeContinue) Parser->Mode = PreMode; if (LexGetToken(Parser, NULL, TRUE) != TokenWhile) ProgramFail(Parser, "'while' expected"); if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); Condition = ExpressionParseInt(Parser); if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); } while (Condition && Parser->Mode == RunModeRun); if (Parser->Mode == RunModeBreak) Parser->Mode = PreMode; } break; case TokenFor: ParseFor(Parser); //trace_state_print(Parser); CheckTrailingSemicolon = FALSE; break; case TokenSemicolon: CheckTrailingSemicolon = FALSE; break; case TokenIntType: case TokenShortType: case TokenCharType: case TokenLongType: case TokenFloatType: case TokenDoubleType: case TokenVoidType: case TokenStructType: case TokenUnionType: case TokenEnumType: case TokenSignedType: case TokenUnsignedType: case TokenStaticType: case TokenAutoType: case TokenRegisterType: case TokenExternType: *Parser = PreState; CheckTrailingSemicolon = ParseDeclaration(Parser, Token); break; case TokenHashDefine: ParseMacroDefinition(Parser); CheckTrailingSemicolon = FALSE; break; #ifndef NO_HASH_INCLUDE case TokenHashInclude: if (LexGetToken(Parser, &LexerValue, TRUE) != TokenStringConstant) ProgramFail(Parser, "\"filename.h\" expected"); IncludeFile((char *)LexerValue->Val->Pointer); CheckTrailingSemicolon = FALSE; break; #endif case TokenSwitch: if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); Condition = ExpressionParseInt(Parser); if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); if (LexGetToken(Parser, NULL, FALSE) != TokenLeftBrace) ProgramFail(Parser, "'{' expected"); { /* new block so we can store parser state */ enum RunMode OldMode = Parser->Mode; int OldSearchLabel = Parser->SearchLabel; Parser->Mode = RunModeCaseSearch; Parser->SearchLabel = Condition; ParseBlock(Parser, TRUE, OldMode != RunModeSkip); if (Parser->Mode != RunModeReturn) Parser->Mode = OldMode; Parser->SearchLabel = OldSearchLabel; } CheckTrailingSemicolon = FALSE; break; case TokenCase: if (Parser->Mode == RunModeCaseSearch) { Parser->Mode = RunModeRun; Condition = ExpressionParseInt(Parser); Parser->Mode = RunModeCaseSearch; } else Condition = ExpressionParseInt(Parser); if (LexGetToken(Parser, NULL, TRUE) != TokenColon) ProgramFail(Parser, "':' expected"); if (Parser->Mode == RunModeCaseSearch && Condition == Parser->SearchLabel) Parser->Mode = RunModeRun; CheckTrailingSemicolon = FALSE; break; case TokenDefault: if (LexGetToken(Parser, NULL, TRUE) != TokenColon) ProgramFail(Parser, "':' expected"); if (Parser->Mode == RunModeCaseSearch) Parser->Mode = RunModeRun; CheckTrailingSemicolon = FALSE; break; case TokenBreak: if (Parser->Mode == RunModeRun) Parser->Mode = RunModeBreak; break; case TokenContinue: if (Parser->Mode == RunModeRun) Parser->Mode = RunModeContinue; break; case TokenReturn: if (Parser->Mode == RunModeRun) { if (TopStackFrame->ReturnValue->Typ->Base != TypeVoid) { if (!ExpressionParse(Parser, &CValue)) ProgramFail(Parser, "value required in return"); ExpressionAssign(Parser, TopStackFrame->ReturnValue, CValue, TRUE, NULL, 0, FALSE); VariableStackPop(Parser, CValue); } else { if (ExpressionParse(Parser, &CValue)) ProgramFail(Parser, "value in return from a void function"); } Parser->Mode = RunModeReturn; } else ExpressionParse(Parser, &CValue); break; case TokenTypedef: ParseTypedef(Parser); break; case TokenGoto: if (LexGetToken(Parser, &LexerValue, TRUE) != TokenIdentifier) ProgramFail(Parser, "identifier expected"); if (Parser->Mode == RunModeRun) { /* start scanning for the goto label */ Parser->SearchGotoLabel = LexerValue->Val->Identifier; Parser->Mode = RunModeGoto; } break; case TokenDelete: { /* try it as a function or variable name to delete */ if (LexGetToken(Parser, &LexerValue, TRUE) != TokenIdentifier) ProgramFail(Parser, "identifier expected"); if (Parser->Mode == RunModeRun) { /* delete this variable or function */ CValue = TableDelete(&GlobalTable, LexerValue->Val->Identifier); if (CValue == NULL) ProgramFail(Parser, "'%s' is not defined", LexerValue->Val->Identifier); VariableFree(CValue); } break; } default: *Parser = PreState; return ParseResultError; } if (CheckTrailingSemicolon) { if (LexGetToken(Parser, NULL, TRUE) != TokenSemicolon) ProgramFail(Parser, "';' expected"); trace_state_print(Parser); } return ParseResultOk; }
/* parse a "for" statement */ void ParseFor(struct ParseState *Parser) { int Condition; struct ParseState PreConditional; struct ParseState PreIncrement; struct ParseState PreStatement; struct ParseState After; enum RunMode OldMode = Parser->Mode; int PrevScopeID = 0, ScopeID = VariableScopeBegin(Parser, &PrevScopeID); if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); if (ParseStatement(Parser, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); ParserCopyPos(&PreConditional, Parser); if (LexGetToken(Parser, NULL, FALSE) == TokenSemicolon) Condition = TRUE; else Condition = ExpressionParseInt(Parser) != 0; if (LexGetToken(Parser, NULL, TRUE) != TokenSemicolon) ProgramFail(Parser, "';' expected"); ParserCopyPos(&PreIncrement, Parser); ParseStatementMaybeRun(Parser, FALSE, FALSE); if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); ParserCopyPos(&PreStatement, Parser); if (ParseStatementMaybeRun(Parser, Condition, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); if (Parser->Mode == RunModeContinue && OldMode == RunModeRun) Parser->Mode = RunModeRun; ParserCopyPos(&After, Parser); while (Condition && Parser->Mode == RunModeRun) { ParserCopyPos(Parser, &PreIncrement); ParseStatement(Parser, FALSE); ParserCopyPos(Parser, &PreConditional); if (LexGetToken(Parser, NULL, FALSE) == TokenSemicolon) Condition = TRUE; else Condition = ExpressionParseInt(Parser) != 0; if (Condition) { ParserCopyPos(Parser, &PreStatement); ParseStatement(Parser, TRUE); if (Parser->Mode == RunModeContinue) Parser->Mode = RunModeRun; } } if (Parser->Mode == RunModeBreak && OldMode == RunModeRun) Parser->Mode = RunModeRun; VariableScopeEnd(Parser, ScopeID, PrevScopeID); ParserCopyPos(Parser, &After); }
/* parse a "for" statement */ void ParseFor(struct ParseState *Parser) { int Condition; struct ParseState PreConditional; struct ParseState PreIncrement; struct ParseState PreStatement; struct ParseState After; if (LexGetToken(Parser, NULL, TRUE) != TokenOpenBracket) ProgramFail(Parser, "'(' expected"); if (ParseStatement(Parser, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); ParserCopyPos(&PreConditional, Parser); if (LexGetToken(Parser, NULL, FALSE) == TokenSemicolon) Condition = TRUE; else Condition = ExpressionParseInt(Parser); if (LexGetToken(Parser, NULL, TRUE) != TokenSemicolon) ProgramFail(Parser, "';' expected"); ParserCopyPos(&PreIncrement, Parser); ParseStatementMaybeRun(Parser, FALSE, FALSE); if (LexGetToken(Parser, NULL, TRUE) != TokenCloseBracket) ProgramFail(Parser, "')' expected"); ParserCopyPos(&PreStatement, Parser); if (ParseStatementMaybeRun(Parser, Condition, TRUE) != ParseResultOk) ProgramFail(Parser, "statement expected"); if (Parser->Mode == RunModeContinue) Parser->Mode = RunModeRun; ParserCopyPos(&After, Parser); while (Condition && Parser->Mode == RunModeRun) { ParserCopyPos(Parser, &PreIncrement); ParseStatement(Parser, FALSE); ParserCopyPos(Parser, &PreConditional); if (LexGetToken(Parser, NULL, FALSE) == TokenSemicolon) Condition = TRUE; else Condition = ExpressionParseInt(Parser); if (Condition) { ParserCopyPos(Parser, &PreStatement); trace_state_print(Parser); ParseStatement(Parser, TRUE); if (Parser->Mode == RunModeContinue) Parser->Mode = RunModeRun; } } if (Parser->Mode == RunModeBreak) Parser->Mode = RunModeRun; ParserCopyPos(Parser, &After); }