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fcl-passrc: fixed parsing case statement without semicolon before else, added comments

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git-svn-id: trunk@45434 -
This commit is contained in:
Mattias Gaertner 2020-05-19 12:43:44 +00:00
parent 375cfbf25c
commit d9734aa533
1 changed files with 86 additions and 96 deletions
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182
packages/fcl-passrc/src/pparser.pp
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@ -453,7 +453,7 @@ type
procedure ParseInitialization;
procedure ParseFinalization;
procedure ParseDeclarations(Declarations: TPasDeclarations);
procedure ParseStatement(Parent: TPasImplBlock; out NewImplElement: TPasImplElement);
procedure ParseStatement(Parent: TPasImplBlock; out NewImplElement: TPasImplElement);
procedure ParseLabels(AParent: TPasElement);
procedure ParseProcBeginBlock(Parent: TProcedureBody);
procedure ParseProcAsmBlock(Parent: TProcedureBody);
@ -5809,7 +5809,7 @@ var
begin
if CurBlock=Parent then exit(true);
while CurBlock.CloseOnSemicolon
or (CloseIfs and (CurBlock is TPasImplIfElse)) do
or (CloseIfs and (CurBlock is TPasImplIfElse)) do
if CloseBlock then exit(true);
Result:=false;
end;
@ -5821,19 +5821,20 @@ var
if NewImplElement=nil then NewImplElement:=CurBlock;
end;
procedure CheckSemicolon;
procedure CheckStatementCanStart;
var
t: TToken;
begin
if (CurBlock.Elements.Count=0) then exit;
if (CurBlock.Elements.Count=0) then
exit; // at start of block
t:=GetPrevToken;
if t in [tkSemicolon,tkColon] then
exit;
if (CurBlock.ClassType=TPasImplIfElse) and (t=tkelse) then
exit;
case t of
tkSemicolon,tkColon,tkElse: exit;
end;
{$IFDEF VerbosePasParser}
writeln('TPasParser.ParseStatement.CheckSemicolon Prev=',GetPrevToken,' Cur=',CurToken,' ',CurBlock.ClassName,' ',CurBlock.Elements.Count,' ',TObject(CurBlock.Elements[0]).ClassName);
{$ENDIF}
// last statement not complete -> semicolon is missing
ParseExcTokenError('Semicolon');
end;
@ -5867,11 +5868,11 @@ begin
while True do
begin
NextToken;
//WriteLn({$IFDEF VerbosePasParser}i,{$ENDIF}' Token=',CurTokenText);
//WriteLn({$IFDEF VerbosePasParser}i,{$ENDIF}' Token=',CurTokenText,' CurBlock=',CurBlock.ClassName);
case CurToken of
tkasm:
begin
CheckSemicolon;
CheckStatementCanStart;
El:=TPasImplElement(CreateElement(TPasImplAsmStatement,'',CurBlock,CurTokenPos));
ParseAsmBlock(TPasImplAsmStatement(El));
CurBlock.AddElement(El);
@ -5882,98 +5883,84 @@ begin
end;
tkbegin:
begin
CheckSemicolon;
CheckStatementCanStart;
El:=TPasImplElement(CreateElement(TPasImplBeginBlock,'',CurBlock,CurTokenPos));
CreateBlock(TPasImplBeginBlock(El));
El:=nil;
end;
tkrepeat:
begin
CheckSemicolon;
CheckStatementCanStart;
El:=TPasImplRepeatUntil(CreateElement(TPasImplRepeatUntil,'',CurBlock,CurTokenPos));
CreateBlock(TPasImplRepeatUntil(El));
El:=nil;
end;
tkIf:
begin
CheckSemicolon;
SrcPos:=CurTokenPos;
NextToken;
Left:=DoParseExpression(CurBlock);
UngetToken;
El:=TPasImplIfElse(CreateElement(TPasImplIfElse,'',CurBlock,SrcPos));
TPasImplIfElse(El).ConditionExpr:=Left;
Left.Parent:=El;
Left:=nil;
//WriteLn(i,'IF Condition="',Condition,'" Token=',CurTokenText);
CreateBlock(TPasImplIfElse(El));
El:=nil;
ExpectToken(tkthen);
CheckStatementCanStart;
SrcPos:=CurTokenPos;
NextToken;
Left:=DoParseExpression(CurBlock);
UngetToken;
El:=TPasImplIfElse(CreateElement(TPasImplIfElse,'',CurBlock,SrcPos));
TPasImplIfElse(El).ConditionExpr:=Left;
Left.Parent:=El;
Left:=nil;
//WriteLn(i,'IF Condition="',Condition,'" Token=',CurTokenText);
CreateBlock(TPasImplIfElse(El));
El:=nil;
ExpectToken(tkthen);
end;
tkelse:
if (CurBlock is TPasImplIfElse) then
begin
if TPasImplIfElse(CurBlock).IfBranch=nil then
begin
// empty then statement e.g. if condition then else
El:=TPasImplCommand(CreateElement(TPasImplCommand,'', CurBlock,CurTokenPos));
CurBlock.AddElement(El);
El:=nil;
end;
if TPasImplIfElse(CurBlock).ElseBranch<>nil then
begin
// this and the following 3 may solve TPasImplIfElse.AddElement BUG
// ifs without begin end
// if .. then
// if .. then
// else
// else
// ELSE can close multiple blocks, similar to semicolon
repeat
{$IFDEF VerbosePasParser}
writeln('TPasParser.ParseStatement CurBlock=',CurBlock.ClassName);
{$ENDIF}
if CurBlock is TPasImplIfElse then
begin
if TPasImplIfElse(CurBlock).IfBranch=nil then
begin
// empty THEN statement e.g. if condition then else
El:=TPasImplCommand(CreateElement(TPasImplCommand,'', CurBlock,CurTokenPos));
CurBlock.AddElement(El); // this sets TPasImplIfElse(CurBlock).IfBranch:=El
El:=nil;
end;
if TPasImplIfElse(CurBlock).ElseBranch=nil then
break; // add next statement as ElseBranch
end
else if CurBlock is TPasImplTryExcept then
begin
// close TryExcept handler and open an TryExceptElse handler
CloseBlock;
CloseStatement(false);
end;
end else if (CurBlock is TPasImplCaseStatement) then
begin
// Case ... else without semicolon in front.
UngetToken;
CloseStatement(False);
break;
end else if (CurBlock is TPasImplWhileDo) then
begin
El:=TPasImplTryExceptElse(CreateElement(TPasImplTryExceptElse,'',CurBlock,CurTokenPos));
TPasImplTry(CurBlock).ElseBranch:=TPasImplTryExceptElse(El);
CurBlock:=TPasImplTryExceptElse(El);
El:=nil;
break;
end
else if (CurBlock is TPasImplCaseStatement) then
begin
UngetToken;
// Note: a TPasImplCaseStatement is parsed by a call of ParseStatement,
// so it must be the top level block
if CurBlock<>Parent then
CheckToken(tkSemicolon);
exit;
end
else if (CurBlock is TPasImplWhileDo)
or (CurBlock is TPasImplForLoop)
or (CurBlock is TPasImplWithDo)
or (CurBlock is TPasImplRaise) then
// simply close block
else
ParseExcSyntaxError;
CloseBlock;
UngetToken;
end else if (CurBlock is TPasImplForLoop) then
begin
//if .. then for .. do smt else ..
CloseBlock;
UngetToken;
end else if (CurBlock is TPasImplWithDo) then
begin
//if .. then with .. do smt else ..
CloseBlock;
UngetToken;
end else if (CurBlock is TPasImplRaise) then
begin
//if .. then Raise Exception else ..
CloseBlock;
UngetToken;
end else if (CurBlock is TPasImplAsmStatement) then
begin
//if .. then asm end else ..
CloseBlock;
UngetToken;
end else if (CurBlock is TPasImplTryExcept) then
begin
CloseBlock;
El:=TPasImplTryExceptElse(CreateElement(TPasImplTryExceptElse,'',CurBlock,CurTokenPos));
TPasImplTry(CurBlock).ElseBranch:=TPasImplTryExceptElse(El);
CurBlock:=TPasImplTryExceptElse(El);
El:=nil;
end else
ParseExcSyntaxError;
until false;
tkwhile:
begin
// while Condition do
CheckSemicolon;
CheckStatementCanStart;
SrcPos:=CurTokenPos;
NextToken;
Left:=DoParseExpression(CurBlock);
@ -5989,7 +5976,7 @@ begin
end;
tkgoto:
begin
CheckSemicolon;
CheckStatementCanStart;
NextToken;
CurBlock.AddCommand('goto '+curtokenstring);
// expecttoken(tkSemiColon);
@ -5998,7 +5985,7 @@ begin
begin
// for VarName := StartValue to EndValue do
// for VarName in Expression do
CheckSemicolon;
CheckStatementCanStart;
El:=TPasImplForLoop(CreateElement(TPasImplForLoop,'',CurBlock,CurTokenPos));
ExpectIdentifier;
Expr:=CreatePrimitiveExpr(El,pekIdent,CurTokenString);
@ -6051,7 +6038,7 @@ begin
begin
// with Expr do
// with Expr, Expr do
CheckSemicolon;
CheckStatementCanStart;
SrcPos:=CurTokenPos;
NextToken;
El:=TPasImplWithDo(CreateElement(TPasImplWithDo,'',CurBlock,SrcPos));
@ -6075,7 +6062,7 @@ begin
end;
tkcase:
begin
CheckSemicolon;
CheckStatementCanStart;
SrcPos:=CurTokenPos;
NextToken;
Left:=DoParseExpression(CurBlock);
@ -6144,15 +6131,14 @@ begin
until Curtoken=tkColon;
// read statement
ParseStatement(CurBlock,SubBlock);
// CurToken is now at last token of case-statement
CloseBlock;
if CurToken<>tkSemicolon then
begin
NextToken;
if not (CurToken in [tkSemicolon,tkelse,tkend]) then
ParseExcTokenError(TokenInfos[tkSemicolon]);
if CurToken<>tkSemicolon then
UngetToken;
end;
if not (CurToken in [tkSemicolon,tkelse,tkend]) then
ParseExcTokenError(TokenInfos[tkSemicolon]);
if CurToken<>tkSemicolon then
UngetToken;
end;
until false;
if CurToken=tkend then
@ -6163,7 +6149,7 @@ begin
end;
tktry:
begin
CheckSemicolon;
CheckStatementCanStart;
El:=TPasImplTry(CreateElement(TPasImplTry,'',CurBlock,CurTokenPos));
CreateBlock(TPasImplTry(El));
El:=nil;
@ -6203,7 +6189,7 @@ begin
end;
tkraise:
begin
CheckSemicolon;
CheckStatementCanStart;
ImplRaise:=TPasImplRaise(CreateElement(TPasImplRaise,'',CurBlock,CurTokenPos));
CreateBlock(ImplRaise);
NextToken;
@ -6223,13 +6209,17 @@ begin
end;
tkend:
begin
// Note: ParseStatement should return with CurToken at last token of the statement
if CloseStatement(true) then
begin
// there was none requiring an END
UngetToken;
break;
end;
// still a block left
if CurBlock is TPasImplBeginBlock then
begin
// close at END
if CloseBlock then break; // close end
if CloseStatement(false) then break;
end else if CurBlock is TPasImplCaseElse then
@ -6283,7 +6273,7 @@ begin
// Do not check this here:
// if (CurToken=tkAt) and not (msDelphi in CurrentModeswitches) then
// ParseExc;
CheckSemicolon;
CheckStatementCanStart;
// On is usable as an identifier
if lowerCase(CurTokenText)='on' then