[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, 12 insertions, 0 deletions

diff --git a/gcc/ada/par.adb b/gcc/ada/par.adb
index 67339f1ca3f..649d2a08dc0 100644
--- a/gcc/ada/par.adb
+++ b/gcc/ada/par.adb
@@ -1351,6 +1351,18 @@ function Par (Configuration_Pragmas : Boolean) return List_Id is
       --  conditions are met, an error message is issued, and the merge is
       --  carried out, modifying the Chars field of Prev.
 
+      function Missing_Semicolon_On_When return Boolean;
+      --  This function deals with the following specialized situations
+      --
+      --    when 'x' =>
+      --       exit/return [identifier]
+      --    when 'y' =>
+      --
+      --  This looks like a messed up EXIT WHEN or RETURN WHEN, when in fact
+      --  the problem is a missing semicolon. It is called with Token pointing
+      --  to the WHEN token, and returns True if a semicolon is missing before
+      --  the WHEN as in the above example.
+
       function Next_Token_Is (Tok : Token_Type) return Boolean;
       --  Looks at token after current one and returns True if the token type
       --  matches Tok. The scan is unconditionally restored on return.