[PATCH 0/1] MR10333: Draft: vbscript: Refactor ElseIf and Else grammar rules to avoid reduce/reduce conflicts.

[Francis De Brabandere (＠francisdb)]

Introduce StatementsBody, InlineStatements and InlineStatements_opt
non-terminals whose FIRST sets do not overlap with StSep. This allows
splitting ElseIf into multi-line (strict, requires statement separator)
and inline (lenient, allows trailing End If) forms, and splitting
Else_opt into separator and inline forms that naturally reject
"Else End If" without a semantic check.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10333

[PATCH 1/1] vbscript: Refactor ElseIf and Else grammar rules to avoid reduce/reduce conflicts.

[Francis De Brabandere]

From: Francis De Brabandere <[e-mail]>

Introduce StatementsBody, InlineStatements and InlineStatements_opt
non-terminals whose FIRST sets do not overlap with StSep. This allows
splitting ElseIf into multi-line (strict, requires statement separator)
and inline (lenient, allows trailing End If) forms, and splitting
Else_opt into separator and inline forms that naturally reject
"Else End If" without a semantic check.
---
 dlls/vbscript/parser.y | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/dlls/vbscript/parser.y b/dlls/vbscript/parser.y
index 20c30eed681..ca42fa758c4 100644
--- a/dlls/vbscript/parser.y
+++ b/dlls/vbscript/parser.y
@@ -137,7 +137,7 @@ static statement_t *link_statements(statement_t*,statement_t*);
 %token <date> tDate
 
 %type <statement> Statement SimpleStatement StatementNl StatementsNl StatementsNl_opt BodyStatements IfStatement Else_opt
-%type <statement> GlobalDimDeclaration
+%type <statement> GlobalDimDeclaration StatementsBody InlineStatements InlineStatements_opt
 %type <expression> Expression LiteralExpression PrimaryExpression EqualityExpression CallExpression ExpressionNl_opt
 %type <expression> ConcatExpression AdditiveExpression ModExpression IntdivExpression MultiplicativeExpression ExpExpression
 %type <expression> NotExpression UnaryExpression AndExpression OrExpression XorExpression EqvExpression SignExpression
@@ -325,12 +325,30 @@ ElseIfs
     | ElseIf ElseIfs                        { $1->next = $2; $$ = $1; }
 
 ElseIf
-    : tELSEIF Expression tTHEN StSep_opt StatementsNl_opt
-                                            { $$ = new_elseif_decl(ctx, @$, $2, $5); }
+    : tELSEIF Expression tTHEN StSep StatementsNl_opt
+                                             { $$ = new_elseif_decl(ctx, @$, $2, $5); }
+    | tELSEIF Expression tTHEN InlineStatements_opt
+                                             { $$ = new_elseif_decl(ctx, @$, $2, $4); }
 
 Else_opt
     : /* empty */                           { $$ = NULL; }
-    | tELSE StSep_opt StatementsNl_opt      { $$ = $3; }
+    | tELSE StSep StatementsBody           { $$ = $3; }
+    | tELSE InlineStatements                { $$ = $2; }
+
+StatementsBody
+    : /* empty */                                { $$ = NULL; }
+    | StSep StatementsBody                      { $$ = $2; }
+    | SimpleStatement                            { $$ = $1; }
+    | SimpleStatement StSep StatementsBody      { $1->next = $3; $$ = $1; }
+
+InlineStatements_opt
+    : /* empty */                                { $$ = NULL; }
+    | SimpleStatement                            { $$ = $1; }
+    | SimpleStatement StSep StatementsBody      { $1->next = $3; $$ = $1; }
+
+InlineStatements
+    : SimpleStatement                            { $$ = $1; }
+    | SimpleStatement StSep StatementsBody      { $1->next = $3; $$ = $1; }
 
 CaseClausules
     : /* empty */                                                      { $$ = NULL; }
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10333