[Ada] INOX: prototype "when" constructs

gcc/ada/

	* doc/gnat_rm/implementation_defined_pragmas.rst: Document new
	feature under pragma Extensions_Allowed.
	* gnat_rm.texi: Regenerate.
	* errout.adb, errout.ads (Error_Msg_GNAT_Extension): Created to
	issue errors when parsing extension only constructs.
	* exp_ch11.adb, exp_ch11.ads (Expand_N_Raise_When_Statement):
	Created to expand raise ... when constucts.
	* exp_ch5.adb, exp_ch5.ads (Expand_N_Goto_When_Statement):
	Created to expand goto ... when constructs.
	* exp_ch6.adb, exp_ch6.ads (Expand_N_Return_When_Statement):
	Created to expand return ... when constructs.
	* expander.adb (Expand): Add case entries for "when" constructs.
	* gen_il-gen-gen_nodes.adb, gen_il-types.ads: Add entries for
	"when" constructs.
	* par-ch11.adb (P_Raise_Statement): Add processing for raise ...
	when.
	* par-ch5.adb (Missing_Semicolon_On_Exit): Renamed to
	Missing_Semicolon_On_When and moved to par-util.adb.
	* par-ch6.adb (Get_Return_Kind): Renamed from Is_Simple and
	processing added for "return ... when" return kind.
	(Is_Simple): Renamed to Get_Return_Kind.
	(P_Return_Statement): Add case for return ... when variant of
	return statement.
	* par-util.adb, par.adb (Missing_Semicolon_On_When): Added to
	centeralize parsing of "when" keywords in the context of "when"
	constructs.
	* sem.adb (Analyze): Add case for "when" constructs.
	* sem_ch11.adb, sem_ch11.ads (Analyze_Raise_When_Statement):
	Created to analyze raise ... when constructs.
	* sem_ch5.adb, sem_ch5.ads (Analyzed_Goto_When_Statement):
	Created to analyze goto ... when constructs.
	* sem_ch6.adb, sem_ch6.ads (Analyze_Return_When_Statement):
	Created to analyze return ... when constructs.
	* sprint.adb (Sprint_Node_Actual): Add entries for new "when"
	nodes.

1 files changed, 29 insertions, 0 deletions

diff --git a/gcc/ada/par-util.adb b/gcc/ada/par-util.adb
index 149b1a1..f4179b9 100644
--- a/gcc/ada/par-util.adb
+++ b/gcc/ada/par-util.adb
@@ -630,6 +630,35 @@ package body Util is
       Scan;
    end Merge_Identifier;
 
+   -------------------------------
+   -- Missing_Semicolon_On_When --
+   -------------------------------
+
+   function Missing_Semicolon_On_When return Boolean is
+      State : Saved_Scan_State;
+
+   begin
+      if not Token_Is_At_Start_Of_Line then
+         return False;
+
+      elsif Scopes (Scope.Last).Etyp /= E_Case then
+         return False;
+
+      else
+         Save_Scan_State (State);
+         Scan; -- past WHEN
+         Scan; -- past token after WHEN
+
+         if Token = Tok_Arrow then
+            Restore_Scan_State (State);
+            return True;
+         else
+            Restore_Scan_State (State);
+            return False;
+         end if;
+      end if;
+   end Missing_Semicolon_On_When;
+
    -------------------
    -- Next_Token_Is --
    -------------------