ada: Specialize syntax error on malformed Abstract_State contract

Syntax for the Abstract_State contract is the same as for extended aggregates,
but conceptually they are completely different. This patch specializes error
messages emitted on syntax errors for these constructs.

gcc/ada/ChangeLog:

	* par-ch13.adb (Get_Aspect_Specifications): Save and restore flag while
	parsing aspect Abstract_State.
	* par-ch2.adb (P_Pragma): Same while parsing pragma Abstract_State.
	* par-ch4.adb (P_Aggregate_Or_Paren_Expr): Specialize error message
	for contract Abstract_State and extended aggregate.
	* par.adb (Inside_Abstract_State): Add new context flag.

diff --git a/gcc/ada/par-ch13.adb b/gcc/ada/par-ch13.adb
index f52136c916a7681c203b0fd87c4e4bf291e92fa4..dbb894f79cd3926a48940183663bccefd6d82bc4 100644 (file)
--- a/gcc/ada/par-ch13.adb
+++ b/gcc/ada/par-ch13.adb
@@ -503,6 +503,8 @@ package body Ch13 is
                  or else A_Id = Aspect_Refined_Depends
                then
                   Inside_Depends := True;
+               elsif A_Id = Aspect_Abstract_State then
+                  Inside_Abstract_State := True;
                end if;
 
                --  Note that we have seen an Import aspect specification.
@@ -529,9 +531,10 @@ package body Ch13 is
                   Set_Expression (Aspect, P_Expression);
                end if;
 
-               --  Unconditionally reset flag for Inside_Depends
+               --  Unconditionally reset flag for being inside aspects
 
-               Inside_Depends := False;
+               Inside_Depends        := False;
+               Inside_Abstract_State := False;
             end if;
 
             --  Add the aspect to the resulting list only when it was properly

diff --git a/gcc/ada/par-ch2.adb b/gcc/ada/par-ch2.adb
index 20640d5547b8bc1a8a0be37d478e86eb9a9d95e4..11c9a8384df40d2dc9f66f4d97108c02c59472b5 100644 (file)
--- a/gcc/ada/par-ch2.adb
+++ b/gcc/ada/par-ch2.adb
@@ -385,6 +385,8 @@ package body Ch2 is
         or else Chars (Ident_Node) = Name_Refined_Depends
       then
          Inside_Depends := True;
+      elsif Chars (Ident_Node) = Name_Abstract_State then
+         Inside_Abstract_State := True;
       end if;
 
       --  Scan arguments. We assume that arguments are present if there is
@@ -441,11 +443,11 @@ package body Ch2 is
 
       Semicolon_Loc := Token_Ptr;
 
-      --  Cancel indication of being within a pragma or in particular a Depends
-      --  pragma.
+      --  Cancel indication of being within a pragma
 
-      Inside_Depends := False;
-      Inside_Pragma  := False;
+      Inside_Depends        := False;
+      Inside_Abstract_State := False;
+      Inside_Pragma         := False;
 
       --  Now we have two tasks left, we need to scan out the semicolon
       --  following the pragma, and we have to call Par.Prag to process
@@ -472,8 +474,9 @@ package body Ch2 is
    exception
       when Error_Resync =>
          Resync_Past_Semicolon;
-         Inside_Depends := False;
-         Inside_Pragma  := False;
+         Inside_Depends        := False;
+         Inside_Abstract_State := False;
+         Inside_Pragma         := False;
          return Error;
    end P_Pragma;
 

diff --git a/gcc/ada/par-ch4.adb b/gcc/ada/par-ch4.adb
index 8267a0c06d3b9efd483bc1cfec675ad2d0c3c72b..e6cf93ab38784b1df30256a19a76d8936d0eb3a5 100644 (file)
--- a/gcc/ada/par-ch4.adb
+++ b/gcc/ada/par-ch4.adb
@@ -1607,8 +1607,13 @@ package body Ch4 is
          --  Improper use of WITH
 
          elsif Token = Tok_With then
-            Error_Msg_SC ("WITH must be preceded by single expression in " &
-                          "extension aggregate");
+            if Inside_Abstract_State then
+               Error_Msg_SC ("state name with options must be enclosed in " &
+                             "parentheses");
+            else
+               Error_Msg_SC ("WITH must be preceded by single expression in " &
+                             "extension aggregate");
+            end if;
             raise Error_Resync;
 
          --  Range attribute can only appear as part of a discrete choice list

diff --git a/gcc/ada/par.adb b/gcc/ada/par.adb
index 5d61fac3c113eba5c548a9423ec353c7672ac57c..0003a332222eacfc1d7a38a9cd35395dc1345bb5 100644 (file)
--- a/gcc/ada/par.adb
+++ b/gcc/ada/par.adb
@@ -80,6 +80,11 @@ function Par (Configuration_Pragmas : Boolean) return List_Id is
    --  True within a delta aggregate (but only after the "delta" token has
    --  been scanned). Used to distinguish syntax errors from syntactically
    --  correct "deep" delta aggregates (enabled via -gnatX0).
+
+   Inside_Abstract_State : Boolean := False;
+   --  True within an Abstract_State contract. Used to distinguish syntax error
+   --  about extended aggregates and about a malformed contract.
+
    Save_Style_Checks : Style_Check_Options;
    Save_Style_Check  : Boolean;
    --  Variables for storing the original state of whether style checks should