[cparse.d] use early returns (#16809)

dlang · Aug 26, 2024 · b531a71 · b531a71
1 parent 0834c75
commit b531a71
Showing 1 changed file with 60 additions and 61 deletions.
diff --git a/compiler/src/dmd/cparse.d b/compiler/src/dmd/cparse.d
@@ -1120,75 +1120,74 @@ final class CParser(AST) : Parser!AST
  */
  private AST.Expression cparseCastExp()
  {
- if (token.value == TOK.leftParenthesis)
+ if (token.value != TOK.leftParenthesis)
+ return cparseUnaryExp();
+
+ //printf("cparseCastExp()\n");
+ auto tk = peek(&token);
+ bool iscast;
+ bool isexp;
+ if (tk.value == TOK.identifier)
  {
- //printf("cparseCastExp()\n");
- auto tk = peek(&token);
- bool iscast;
- bool isexp;
- if (tk.value == TOK.identifier)
- {
- iscast = isTypedef(tk.ident);
- isexp = !iscast;
- }
- if (isexp)
- {
- // ( identifier ) is an expression
- return cparseUnaryExp();
- }
+ iscast = isTypedef(tk.ident);
+ isexp = !iscast;
+ }
+ if (isexp)
+ {
+ // ( identifier ) is an expression
+ return cparseUnaryExp();
+ }
 
-  // If ( type-name )
-  auto pt = &token;
+ // If ( type-name )
+ auto pt = &token;
 
- if (isCastExpression(pt))
- {
- // Expression may be either a cast or a compound literal, which
- // requires checking whether the next token is leftCurly
- const loc = token.loc;
- nextToken();
- auto t = cparseTypeName();
- check(TOK.rightParenthesis);
- pt = &token;
+ if (!isCastExpression(pt))
+ return cparseUnaryExp();
 
-  if (token.value == TOK.leftCurly)
-  {
-  // C11 6.5.2.5 ( type-name ) { initializer-list }
-  auto ci = cparseInitializer();
-  auto ce = new AST.CompoundLiteralExp(loc, t, ci);
-  return cparsePostfixOperators(ce);
-  }
+ // Expression may be either a cast or a compound literal, which
+ // requires checking whether the next token is leftCurly
+ const loc = token.loc;
+ nextToken();
+ auto t = cparseTypeName();
+ check(TOK.rightParenthesis);
+ pt = &token;
 
- if (iscast)
- {
- // ( type-name ) cast-expression
- auto ce = cparseCastExp();
- return new AST.CastExp(loc, ce, t);
- }
+ if (token.value == TOK.leftCurly)
+ {
+ // C11 6.5.2.5 ( type-name ) { initializer-list }
+ auto ci = cparseInitializer();
+ auto ce = new AST.CompoundLiteralExp(loc, t, ci);
+ return cparsePostfixOperators(ce);
+ }
 
- if (t.isTypeIdentifier() &&
- isexp &&
- token.value == TOK.leftParenthesis &&
- !isCastExpression(pt))
- {
- /* (t)(...)... might be a cast expression or a function call,
- * with different grammars: a cast would be cparseCastExp(),
- * a function call would be cparsePostfixExp(CallExp(cparseArguments())).
- * We can't know until t is known. So, parse it as a function call
- * and let semantic() rewrite the AST as a CastExp if it turns out
- * to be a type.
- */
- auto ie = new AST.IdentifierExp(loc, t.isTypeIdentifier().ident);
- ie.parens = true; // let semantic know it might be a CastExp
- AST.Expression e = new AST.CallExp(loc, ie, cparseArguments());
- return cparsePostfixOperators(e);
- }
+ if (iscast)
+ {
+ // ( type-name ) cast-expression
+ auto ce = cparseCastExp();
+ return new AST.CastExp(loc, ce, t);
+ }
 
- // ( type-name ) cast-expression
- auto ce = cparseCastExp();
- return new AST.CastExp(loc, ce, t);
- }
+ if (t.isTypeIdentifier() &&
+ isexp &&
+ token.value == TOK.leftParenthesis &&
+ !isCastExpression(pt))
+ {
+ /* (t)(...)... might be a cast expression or a function call,
+ * with different grammars: a cast would be cparseCastExp(),
+ * a function call would be cparsePostfixExp(CallExp(cparseArguments())).
+ * We can't know until t is known. So, parse it as a function call
+ * and let semantic() rewrite the AST as a CastExp if it turns out
+ * to be a type.
+ */
+ auto ie = new AST.IdentifierExp(loc, t.isTypeIdentifier().ident);
+ ie.parens = true; // let semantic know it might be a CastExp
+ AST.Expression e = new AST.CallExp(loc, ie, cparseArguments());
+ return cparsePostfixOperators(e);
  }
- return cparseUnaryExp();
+
+ // ( type-name ) cast-expression
+ auto ce = cparseCastExp();
+ return new AST.CastExp(loc, ce, t);
  }
 
  /**************