U805-023: Filter the signatures using the previous designators

AdrienBoulanger · AdrienBoulanger · commit d34f141a73ce · 2021-09-08T17:32:13.000+02:00
Previously it was only using the current designator and the
active position.
diff --git a/source/ada/lsp-ada_handlers.adb b/source/ada/lsp-ada_handlers.adb
@@ -2508,6 +2508,7 @@ package body LSP.Ada_Handlers is
         Document.Get_Source_Location (Value.position);
 
       Name_Node        : Libadalang.Analysis.Name;
+      Prev_Designators : Laltools.Common.Node_Vectors.Vector;
       Designator       : Libadalang.Analysis.Ada_Node;
       Active_Position  : LSP.Types.LSP_Number;
       Active_Signature : LSP.Types.LSP_Number := 0;
@@ -2542,7 +2543,11 @@ package body LSP.Ada_Handlers is
       procedure Add_Signature (Decl_Node : Libadalang.Analysis.Basic_Decl)
       is
          Param_Index : constant LSP.Types.LSP_Number :=
-           Get_Active_Parameter (Decl_Node, Designator, Active_Position);
+           Get_Active_Parameter
+             (Node             => Decl_Node,
+              Designator       => Designator,
+              Prev_Designators => Prev_Designators,
+              Position         => Active_Position);
       begin
          if Param_Index = -1 then
             return;
@@ -2659,11 +2664,12 @@ package body LSP.Ada_Handlers is
 
       --  Check if we are inside a function call and get the caller name
       Get_Call_Expr_Name
-        (Node            => Node,
-         Cursor          => Sloc,
-         Active_Position => Active_Position,
-         Designator      => Designator,
-         Name_Node       => Name_Node);
+        (Node             => Node,
+         Cursor           => Sloc,
+         Active_Position  => Active_Position,
+         Designator       => Designator,
+         Prev_Designators => Prev_Designators,
+         Name_Node        => Name_Node);
 
       if Name_Node = Libadalang.Analysis.No_Name then
          return Response;
@@ -2675,10 +2681,9 @@ package body LSP.Ada_Handlers is
         and then
           (Value.context.Value.triggerKind /= TriggerCharacter
            or else
-           --  Check if the trigger character is a backspace
-             ((not Value.context.Value.triggerCharacter.Is_Set)
-              or else Value.context.Value.triggerCharacter.Value /=
-                (+(1 => Backspace))))
+           --  Adding a ',' will not add new results only filter the previous
+             (Value.context.Value.triggerCharacter.Is_Set
+              and then Value.context.Value.triggerCharacter.Value = (+",")))
       then
          --  At this point, we are filtering the previous signatures:
          --  * Don't recompute the list of signature
diff --git a/source/ada/lsp-lal_utils.adb b/source/ada/lsp-lal_utils.adb
@@ -386,11 +386,12 @@ package body LSP.Lal_Utils is
    ------------------------
 
    procedure Get_Call_Expr_Name
-     (Node            : Libadalang.Analysis.Ada_Node'Class;
-      Cursor          : Langkit_Support.Slocs.Source_Location;
-      Active_Position : out LSP.Types.LSP_Number;
-      Designator      : out Libadalang.Analysis.Ada_Node;
-      Name_Node       : out Libadalang.Analysis.Name)
+     (Node             : Libadalang.Analysis.Ada_Node'Class;
+      Cursor           : Langkit_Support.Slocs.Source_Location;
+      Active_Position  : out LSP.Types.LSP_Number;
+      Designator       : out Libadalang.Analysis.Ada_Node;
+      Prev_Designators : out Laltools.Common.Node_Vectors.Vector;
+      Name_Node        : out Libadalang.Analysis.Name)
    is
       use Langkit_Support.Slocs;
       Cur_Node      : Ada_Node := Node.As_Ada_Node;
@@ -453,6 +454,7 @@ package body LSP.Lal_Utils is
    begin
       Active_Position := 0;
       Designator := Libadalang.Analysis.No_Ada_Node;
+      Prev_Designators := Laltools.Common.Node_Vectors.Empty_Vector;
       Name_Node := Libadalang.Analysis.No_Name;
 
       if not Cur_Node.Is_Null
@@ -519,6 +521,9 @@ package body LSP.Lal_Utils is
                Designator := Assoc.As_Param_Assoc.F_Designator;
                Active_Position := Active_Position + 1;
                exit when Cursor_In_Node (Assoc.As_Ada_Node);
+               if Designator /= No_Ada_Node then
+                  Prev_Designators.Append (Designator);
+               end if;
             end loop;
          end if;
 
@@ -570,46 +575,101 @@ package body LSP.Lal_Utils is
    --------------------------
 
    function Get_Active_Parameter
-     (Node       : Libadalang.Analysis.Basic_Decl;
-      Designator : Libadalang.Analysis.Ada_Node;
-      Position   : LSP.Types.LSP_Number)
+     (Node             : Libadalang.Analysis.Basic_Decl;
+      Designator       : Libadalang.Analysis.Ada_Node;
+      Prev_Designators : Laltools.Common.Node_Vectors.Vector;
+      Position         : LSP.Types.LSP_Number)
       return LSP.Types.LSP_Number
    is
       Spec : constant Libadalang.Analysis.Base_Subp_Spec :=
         Node.P_Subp_Spec_Or_Null;
-      Index : LSP.Types.LSP_Number := 0;
-   begin
-      if Spec = Libadalang.Analysis.No_Base_Subp_Spec then
-         return -1;
+      Res  : LSP.Types.LSP_Number := -1;
+
+      function Find_Designator
+        (D      : Libadalang.Analysis.Ada_Node;
+         Params : Libadalang.Analysis.Param_Spec_Array)
+         return LSP.Types.LSP_Number;
+
+      function Count_Parameters
+        (Params : Libadalang.Analysis.Param_Spec_Array)
+         return LSP.Types.LSP_Number;
 
-      elsif Designator = Libadalang.Analysis.No_Ada_Node then
-         --  Check if the given position is a valid index for Node
-         for Param of Spec.P_Params loop
+      ---------------------
+      -- Find_Designator --
+      ---------------------
+
+      function Find_Designator
+        (D      : Libadalang.Analysis.Ada_Node;
+         Params : Libadalang.Analysis.Param_Spec_Array)
+         return LSP.Types.LSP_Number
+      is
+         Index : LSP.Types.LSP_Number := 0;
+      begin
+         for Param of Params loop
             for Id of Param.F_Ids loop
+               if Id.Text = D.Text then
+                  return Index;
+               end if;
                Index := Index + 1;
             end loop;
          end loop;
-         if Position > Index - 1 then
-            return -1;
-         else
-            return Position;
-         end if;
 
-      else
-         --  If we have a designator then try to find the position of a
-         --  parameter with the same name
-         for Param of Spec.P_Params loop
+         return -1;
+      end Find_Designator;
+
+      ----------------------
+      -- Count_Parameters --
+      ----------------------
+
+      function Count_Parameters
+        (Params : Libadalang.Analysis.Param_Spec_Array)
+         return LSP.Types.LSP_Number
+      is
+         Index : LSP.Types.LSP_Number := 0;
+      begin
+         for Param of Params loop
             for Id of Param.F_Ids loop
-               if Id.Text = Designator.Text then
-                  return Index;
-               end if;
                Index := Index + 1;
             end loop;
          end loop;
 
-         --  No matching designator
+         return Index;
+      end Count_Parameters;
+
+   begin
+      if Spec = Libadalang.Analysis.No_Base_Subp_Spec then
          return -1;
       end if;
+
+      declare
+         Params : constant Libadalang.Analysis.Param_Spec_Array :=
+           Spec.P_Params;
+      begin
+         if Designator = Libadalang.Analysis.No_Ada_Node then
+            --  Check if the given position is a valid index for Node
+
+            if Position >= Count_Parameters (Params) then
+               return -1;
+            else
+               Res := Position;
+            end if;
+
+         else
+            --  If we have a designator then try to find the position of a
+            --  parameter with the same name
+            Res := Find_Designator (Designator, Params);
+
+         end if;
+
+         --  Invalidate the result if it doesn't match the previous designators
+         for Prev_Designator of Prev_Designators loop
+            if Find_Designator (Prev_Designator, Params) = -1 then
+               return -1;
+            end if;
+         end loop;
+      end;
+
+      return Res;
    end Get_Active_Parameter;
 
    ------------------
diff --git a/source/ada/lsp-lal_utils.ads b/source/ada/lsp-lal_utils.ads
@@ -197,29 +197,33 @@ package LSP.Lal_Utils is
    --  variables.
 
    procedure Get_Call_Expr_Name
-     (Node            : Libadalang.Analysis.Ada_Node'Class;
-      Cursor          : Langkit_Support.Slocs.Source_Location;
-      Active_Position : out LSP.Types.LSP_Number;
-      Designator      : out Libadalang.Analysis.Ada_Node;
-      Name_Node       : out Libadalang.Analysis.Name);
+     (Node             : Libadalang.Analysis.Ada_Node'Class;
+      Cursor           : Langkit_Support.Slocs.Source_Location;
+      Active_Position  : out LSP.Types.LSP_Number;
+      Designator       : out Libadalang.Analysis.Ada_Node;
+      Prev_Designators : out Laltools.Common.Node_Vectors.Vector;
+      Name_Node        : out Libadalang.Analysis.Name);
    --  If Node is inside a Call_Expr returns the following:
    --  Active_Position: the index of the parameter in the Call_Expr
    --  Designator: the designator of the Active_Position
+   --  Prev_Designators: the designators found before the Active_Position
    --  Name_Node: the name of the Call_Expr
-   --  Cursor: the position of the cursor when the request was triggered.
+   --  Cursor: the position of the cursor when the request was triggered
 
    procedure Get_Parameters
      (Node : Libadalang.Analysis.Basic_Decl;
       Parameters : in out LSP.Messages.ParameterInformation_Vector);
    --  Append all the parameters of Node inside Parameters
 
    function Get_Active_Parameter
-     (Node       : Libadalang.Analysis.Basic_Decl;
-      Designator : Libadalang.Analysis.Ada_Node;
-      Position   : LSP.Types.LSP_Number)
+     (Node             : Libadalang.Analysis.Basic_Decl;
+      Designator       : Libadalang.Analysis.Ada_Node;
+      Prev_Designators : Laltools.Common.Node_Vectors.Vector;
+      Position         : LSP.Types.LSP_Number)
       return LSP.Types.LSP_Number;
    --  Return the position of Designator in the parameters of Node else -1
    --  If Designator is null try check if Position is a valid parameter index
+   --  Verify that Node parameters matches all the previous designators.
 
    function To_Call_Hierarchy_Item
      (Name : Libadalang.Analysis.Defining_Name)
diff --git a/testsuite/ada_lsp/U805-023.signatureHelp.designators/foo.adb b/testsuite/ada_lsp/U805-023.signatureHelp.designators/foo.adb
@@ -0,0 +1,10 @@
+procedure Foo is
+
+   procedure Bar (I, J, K : Integer);
+   procedure Bar (I, J : Integer; F : Float);
+   procedure Bar (F, H : Float; I : Integer);
+   procedure Bar (J : Integer; F : Float);
+
+begin
+   Bar (I => 1, J => 2
+end Foo;
diff --git a/testsuite/ada_lsp/U805-023.signatureHelp.designators/test.gpr b/testsuite/ada_lsp/U805-023.signatureHelp.designators/test.gpr
@@ -0,0 +1,3 @@
+project Test is
+  for Main use ("foo.adb"); 
+end Test;
diff --git a/testsuite/ada_lsp/U805-023.signatureHelp.designators/test.json b/testsuite/ada_lsp/U805-023.signatureHelp.designators/test.json
diff --git a/testsuite/ada_lsp/U805-023.signatureHelp.designators/test.yaml b/testsuite/ada_lsp/U805-023.signatureHelp.designators/test.yaml

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+project Test is`
	`2`	`+ for Main use ("foo.adb");`
	`3`	`+end Test;`