[Ada] Fix wrong value of 'Size for slices of bit-packed arrays (2)

2019-12-12  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* exp_attr.adb (Expand_Size_Attribute): Look directly at the
	prefix to detect the bit-packed slices.  Apply the checks last
	in case the attribute needs to be processed by the back-end.
	* exp_ch4.adb (Expand_N_Slice): Do not create a temporary for
	a prefix of the Size attribute.

From-SVN: r279293

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index c2e4c36ab8951f62f7ba45ff60b632f17de23198..cf79c7d2a625a56326ca11e85be2e2b9f9170ed9 100644 (file)
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,11 @@
+2019-12-12  Eric Botcazou  <ebotcazou@adacore.com>
+
+       * exp_attr.adb (Expand_Size_Attribute): Look directly at the
+       prefix to detect the bit-packed slices.  Apply the checks last
+       in case the attribute needs to be processed by the back-end.
+       * exp_ch4.adb (Expand_N_Slice): Do not create a temporary for
+       a prefix of the Size attribute.
+
 2019-12-12  Steve Baird  <baird@adacore.com>
 
        * sem_ch12.adb

diff --git a/gcc/ada/exp_attr.adb b/gcc/ada/exp_attr.adb
index 1459cfcd04ffdb152a2bd78610ffd6a6f0d2f236..c7b6451430e72abd92bcf542fa7a429333e0c5ab 100644 (file)
--- a/gcc/ada/exp_attr.adb
+++ b/gcc/ada/exp_attr.adb
@@ -7455,8 +7455,6 @@ package body Exp_Attr is
       --  All other cases are handled by the back end
 
       else
-         Apply_Universal_Integer_Attribute_Checks (N);
-
          --  If Size is applied to a formal parameter that is of a packed
          --  array subtype, then apply Size to the actual subtype.
 
@@ -7489,9 +7487,7 @@ package body Exp_Attr is
          --  System.Unsigned_Types.Packed_Byte for code generation purposes so
          --  the size is always rounded up in the back end.
 
-         elsif Nkind (Original_Node (Pref)) = N_Slice
-           and then Is_Bit_Packed_Array (Ptyp)
-         then
+         elsif Nkind (Pref) = N_Slice and then Is_Bit_Packed_Array (Ptyp) then
             Rewrite (N,
               Make_Op_Multiply (Loc,
                 Make_Attribute_Reference (Loc,
@@ -7503,6 +7499,9 @@ package body Exp_Attr is
             Analyze_And_Resolve (N, Typ);
          end if;
 
+         --  Apply the required checks last, after rewriting has taken place
+
+         Apply_Universal_Integer_Attribute_Checks (N);
          return;
       end if;
 

diff --git a/gcc/ada/exp_ch4.adb b/gcc/ada/exp_ch4.adb
index 158dcb59cc5d632d2c6793270d192d66929235ba..20b3babdc3015ca85faf36bd31df96235c24bf9e 100644 (file)
--- a/gcc/ada/exp_ch4.adb
+++ b/gcc/ada/exp_ch4.adb
@@ -11013,7 +11013,8 @@ package body Exp_Ch4 is
 
       --    5. Prefix of an address attribute (this is an error which is caught
       --       elsewhere, and the expansion would interfere with generating the
-      --       error message).
+      --       error message) or of a size attribute (because 'Size may change
+      --       when applied to the temporary instead of the slice directly).
 
       if not Is_Packed (Typ) then
 
@@ -11039,7 +11040,8 @@ package body Exp_Ch4 is
          return;
 
       elsif Nkind (Parent (N)) = N_Attribute_Reference
-        and then Attribute_Name (Parent (N)) = Name_Address
+        and then (Attribute_Name (Parent (N)) = Name_Address
+                   or else Attribute_Name (Parent (N)) = Name_Size)
       then
          return;