This patch improves the synactic error recovery in the case where a ";"
is used instead of "," in a case expression. The following test should
get these errors:
case_exp_semi.ads:5:28: ";" should be ","
package Case_Exp_Semi is
X : Integer := 1;
Y : Integer :=
(case X is when 1 => 1; when 2 => 2, when others => 3);
end Case_Exp_Semi;
Tested on x86_64-pc-linux-gnu, committed on trunk
2017-04-25 Bob Duff <[email protected]>
* par-ch4.adb (P_Case_Expression): If a semicolon
is followed by "when", assume that ";" was meant to be ",".
Index: par-ch4.adb
===================================================================
--- par-ch4.adb (revision 247135)
+++ par-ch4.adb (working copy)
@@ -3199,6 +3199,20 @@
if Token = Tok_When then
T_Comma;
+ -- A semicolon followed by "when" is probably meant to be a comma
+
+ elsif Token = Tok_Semicolon then
+ Save_Scan_State (Save_State);
+ Scan; -- past the semicolon
+
+ if Token /= Tok_When then
+ Restore_Scan_State (Save_State);
+ exit;
+ end if;
+
+ Error_Msg_SP -- CODEFIX
+ ("|"";"" should be "",""");
+
-- If comma/WHEN, skip comma and we have another alternative
elsif Token = Tok_Comma then
