Fix bug18280, and add it.

5 files changed, 97 insertions, 7 deletions

diff --git a/sem_specs.adb b/sem_specs.adb
index 885a41abc..11a3711bd 100644
--- a/sem_specs.adb
+++ b/sem_specs.adb
@@ -331,7 +331,9 @@ package body Sem_Specs is
    is
       Res : Boolean;
 
-      procedure Sem_Named_Entity1 (Ent : Iir; Decl : Iir)
+      --  If declaration DECL matches then named entity ENT, apply attribute
+      --  specification and returns TRUE. Otherwise, return FALSE.
+      function Sem_Named_Entity1 (Ent : Iir; Decl : Iir) return Boolean
       is
          Ent_Id : Name_Id;
       begin
@@ -345,9 +347,10 @@ package body Sem_Specs is
             else
                Attribute_A_Decl
                  (Decl, Attr, Name, Is_Designators, Check_Defined);
-               Res := True;
+               return True;
             end if;
          end if;
+         return False;
       end Sem_Named_Entity1;
 
       procedure Sem_Named_Entity (Ent : Iir) is
@@ -366,7 +369,7 @@ package body Sem_Specs is
               | Iir_Kind_Unit_Declaration
               | Iir_Kind_Group_Template_Declaration
               | Iir_Kind_Group_Declaration =>
-               Sem_Named_Entity1 (Ent, Ent);
+               Res := Res or Sem_Named_Entity1 (Ent, Ent);
             when Iir_Kind_Object_Alias_Declaration =>
                --  LRM93 5.1
                --  An entity designator that denotes an alias of an object is
@@ -374,18 +377,19 @@ package body Sem_Specs is
                --  or slice thereof.
                declare
                   Decl : Iir;
+                  Applied : Boolean;
                begin
                   Decl := Get_Name (Ent);
-                  if Get_Base_Name (Decl) /= Decl then
+                  Applied := Sem_Named_Entity1 (Ent, Decl);
+                  if Applied and then Get_Base_Name (Decl) /= Decl then
                      Error_Msg_Sem
                        (Disp_Node (Ent) & " does not denote the entire object",
                         Attr);
-                     return;
                   end if;
-                  Sem_Named_Entity1 (Ent, Decl);
+                  Res := Res or Applied;
                end;
             when Iir_Kind_Non_Object_Alias_Declaration =>
-               Sem_Named_Entity1 (Ent, Get_Name (Ent));
+               Res := Res or Sem_Named_Entity1 (Ent, Get_Name (Ent));
             when Iir_Kind_Attribute_Declaration
               | Iir_Kind_Attribute_Specification
               | Iir_Kind_Configuration_Specification
diff --git a/testsuite/gna/bug18280/alias_bug.txt b/testsuite/gna/bug18280/alias_bug.txt
new file mode 100644
index 000000000..b86e47d8b
--- /dev/null
+++ b/testsuite/gna/bug18280/alias_bug.txt
@@ -0,0 +1,33 @@
+

+ The Windows 0.29.1 GHDL build errors at compile time when

+an attribute is placed on a signal for which an alias has 

+previously been created.

+

+--------

+

+Code snippet from attached <alias_bug.vhd> example:

+

+   signal processor_address : std_logic_vector(15 downto 0);

+

+   alias  address_ms       : std_logic_vector(3 downto 0)   is   processor_address(15 downto 12);

+

+   attribute keep : boolean;

+   attribute keep of processor_address: signal is TRUE;

+

+Resulting error message:

+

+ .\alias_bug.vhd:35:13: alias "address_ms" does not denote the entire object

+

+--------

+

+Workaround:

+

+ Moving the alias _after_ the attribute causes the error to go away.

+

+--------

+

+alias_bug.zip contents : 

+

+ alias_bug.txt              this file

+ alias_bug.vhd              test program to demonstrate alias bug

+ ghdc.bat                   batch file to invoke compiler

diff --git a/testsuite/gna/bug18280/alias_bug.vhd b/testsuite/gna/bug18280/alias_bug.vhd
new file mode 100644
index 000000000..c9e5caab6
--- /dev/null
+++ b/testsuite/gna/bug18280/alias_bug.vhd
@@ -0,0 +1,41 @@
+--

+-- <alias_bug.vhd>

+--

+--  Illustrates GHDL 0.29.1 WinXP problem with attributes and aliases 

+--

+--  Problem:

+--     A signal attribute, placed after an alias on the signal, causes errors like this:

+--

+--     .\alias_bug.vhd:35:13: alias "address_ms" does not denote the entire object

+--

+--

+--  Workaround: move the attribute before the alias

+--

+

+library ieee;

+  use ieee.std_logic_1164.all;

+  use ieee.numeric_std.all;

+

+entity alias_bug is

+end alias_bug;

+     

+architecture test of alias_bug is

+

+  signal processor_address : std_logic_vector(15 downto 0);

+

+  --

+  -- if alias is _NOT_ declared, error goes away

+  --

+  alias  address_ms       : std_logic_vector(3 downto 0)   is   processor_address(15 downto 12);

+

+  --

+  -- if the keep attribute is placed _BEFORE_ the alias, no error occurs

+  --

+  attribute keep : boolean;

+  attribute keep of processor_address: signal is TRUE;

+

+  begin

+

+    processor_address <= X"1234";

+

+  end test;

diff --git a/testsuite/gna/bug18280/ghdc.bat b/testsuite/gna/bug18280/ghdc.bat
new file mode 100644
index 000000000..aca169bb5
--- /dev/null
+++ b/testsuite/gna/bug18280/ghdc.bat
@@ -0,0 +1,2 @@
+ghdl -a alias_bug.vhd

+ghdl -r alias_bug.vhd
\ No newline at end of file
diff --git a/testsuite/gna/bug18280/testsuite.sh b/testsuite/gna/bug18280/testsuite.sh
new file mode 100755
index 000000000..8856ba53c
--- /dev/null
+++ b/testsuite/gna/bug18280/testsuite.sh
@@ -0,0 +1,10 @@
+#! /bin/sh
+
+. ../../testenv.sh
+
+analyze alias_bug.vhd
+elab_simulate alias_bug
+
+clean
+
+echo "Test successful"