[Ada] Use spans instead of locations for compiler diagnostics

gcc/ada/

	* errout.adb: (Error_Msg_Internal): Use span instead of
	location.
	(Error_Msg, Error_Msg_NEL): Add versions with span parameter.
	(Error_Msg_F, Error_Msg_FE, Error_Msg_N, Error_Msg_NE,
	Error_Msg_NW): Retrieve span from node.
	(First_Node): Use the new First_And_Last_Nodes.
	(First_And_Last_Nodes): Expand on previous First_Node. Apply to
	other nodes than expressions.
	(First_Sloc): Protect against inconsistent locations.
	(Last_Node): New function based on First_And_Last_Nodes.
	(Last_Sloc): New function similar to First_Sloc.
	(Output_Messages): Update output when -gnatdF is used. Use
	character ~ for making the span visible, similar to what is done
	in GCC and Clang.
	* errout.ads (Error_Msg, Error_Msg_NEL): Add versions with span
	parameter.
	(First_And_Last_Nodes, Last_Node, Last_Sloc): New subprograms.
	* erroutc.adb: Adapt to Sptr field being a span.
	* erroutc.ads (Error_Msg_Object): Change field Sptr from
	location to span.
	* errutil.adb: Adapt to Sptr field being a span.
	* freeze.adb: Use Errout reporting procedures for nodes to get
	spans.
	* par-ch3.adb: Likewise.
	* par-prag.adb: Likewise.
	* par-util.adb: Likewise.
	* sem_case.adb: Likewise.
	* sem_ch13.adb: Likewise.
	* sem_ch3.adb: Likewise.
	* sem_prag.adb: Likewise.
	* types.ads: (Source_Span): New type for spans.
	(To_Span): Basic constructors for spans.

1 files changed, 31 insertions, 7 deletions

diff --git a/gcc/ada/errout.ads b/gcc/ada/errout.ads
index 02cfdee..f9a8379 100644
--- a/gcc/ada/errout.ads
+++ b/gcc/ada/errout.ads
@@ -703,10 +703,15 @@ package Errout is
    procedure Error_Msg
      (Msg : String; Flag_Location : Source_Ptr);
    procedure Error_Msg
+     (Msg : String; Flag_Span : Source_Span);
+   procedure Error_Msg
      (Msg : String; Flag_Location : Source_Ptr; N : Node_Id);
+   procedure Error_Msg
+     (Msg : String; Flag_Span : Source_Span; N : Node_Id);
    --  Output a message at specified location. Can be called from the parser
    --  or the semantic analyzer. If N is set, points to the relevant node for
-   --  this message.
+   --  this message. The version with a span is preferred whenever possible,
+   --  in other cases the version with a location can still be used.
 
    procedure Error_Msg
      (Msg                    : String;
@@ -782,8 +787,13 @@ package Errout is
       N             : Node_Or_Entity_Id;
       E             : Node_Or_Entity_Id;
       Flag_Location : Source_Ptr);
+   procedure Error_Msg_NEL
+     (Msg       : String;
+      N         : Node_Or_Entity_Id;
+      E         : Node_Or_Entity_Id;
+      Flag_Span : Source_Span);
    --  Exactly the same as Error_Msg_NE, except that the flag is placed at
-   --  the specified Flag_Location instead of at Sloc (N).
+   --  the specified Flag_Location/Flag_Span instead of at Sloc (N).
 
    procedure Error_Msg_NW
      (Eflag : Boolean;
@@ -801,12 +811,17 @@ package Errout is
    --  the given text. This text may contain insertion characters in the
    --  usual manner, and need not be the same length as the original text.
 
+   procedure First_And_Last_Nodes
+     (C                     : Node_Id;
+      First_Node, Last_Node : out Node_Id);
+   --  Given a construct C, finds the first and last node in the construct,
+   --  i.e. the ones with the lowest and highest Sloc value. This is useful in
+   --  placing error msgs. Note that this procedure uses Original_Node to look
+   --  at the original source tree, since that's what we want for placing an
+   --  error message flag in the right place.
+
    function First_Node (C : Node_Id) return Node_Id;
-   --  Given a construct C, finds the first node in the construct, i.e. the one
-   --  with the lowest Sloc value. This is useful in placing error msgs. Note
-   --  that this procedure uses Original_Node to look at the original source
-   --  tree, since that's what we want for placing an error message flag in
-   --  the right place.
+   --  Return the first output of First_And_Last_Nodes
 
    function First_Sloc (N : Node_Id) return Source_Ptr;
    --  Given the node for an expression, return a source pointer value that
@@ -817,6 +832,15 @@ package Errout is
    function Get_Ignore_Errors return Boolean;
    --  Return True if all error calls are ignored.
 
+   function Last_Node (C : Node_Id) return Node_Id;
+   --  Return the last output of First_And_Last_Nodes
+
+   function Last_Sloc (N : Node_Id) return Source_Ptr;
+   --  Given the node for an expression, return a source pointer value that
+   --  points to the end of the last token in the expression. In the case
+   --  where the expression is parenthesized, an attempt is made to include
+   --  the parentheses (i.e. to return the location of the final paren).
+
    procedure Purge_Messages (From : Source_Ptr; To : Source_Ptr)
      renames Erroutc.Purge_Messages;
    --  All error messages whose location is in the range From .. To (not