public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: Pierre-Marie de Rodat <derodat@adacore.com>
To: gcc-patches@gcc.gnu.org
Subject: [Ada] Crash on limited array object with address clause
Date: Wed, 30 Jun 2021 05:30:46 -0400	[thread overview]
Message-ID: <20210630093046.GA2150@adacore.com> (raw)

[-- Attachment #1: Type: text/plain, Size: 982 bytes --]

Compiler aborts on an object declaration for a limited array type,
when declaration includes an aggregate that must be built in place,
and declaration carries an aspect specification for Address of object.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

	* exp_aggr.adb (Convert_Aggr_In_Object_Decl): After expansion of
	the aggregate, the expression can be removed from the
	declaration, except if the object is class-wide, in which case
	the aggregate provides the actual type. In other cases the
	presence of the expression may lead to spurious freezing issue.
	* exp_ch3.adb (Expand_N_Object_Declaration): If the expression
	in the declaration is an aggregate with delayed expansion (as is
	the case for objects of a limited type, or a subsequent address
	specification) the aggregate must be resolved at this point.
	This resolution must not include expansion, because the
	expansion of the enclosing declaration will construct the
	necessary aggregate expansion.

[-- Attachment #2: patch.diff --]
[-- Type: text/x-diff, Size: 1863 bytes --]

diff --git a/gcc/ada/exp_aggr.adb b/gcc/ada/exp_aggr.adb
--- a/gcc/ada/exp_aggr.adb
+++ b/gcc/ada/exp_aggr.adb
@@ -4437,6 +4437,15 @@ package body Exp_Aggr is
       end;
 
       Set_No_Initialization (N);
+
+      --  After expansion the expression can be removed from the declaration
+      --  except if the object is class-wide, in which case the aggregate
+      --  provides the actual type.
+
+      if not Is_Class_Wide_Type (Etype (Obj)) then
+         Set_Expression (N, Empty);
+      end if;
+
       Initialize_Discriminants (N, Typ);
    end Convert_Aggr_In_Object_Decl;
 


diff --git a/gcc/ada/exp_ch3.adb b/gcc/ada/exp_ch3.adb
--- a/gcc/ada/exp_ch3.adb
+++ b/gcc/ada/exp_ch3.adb
@@ -30,6 +30,7 @@ with Einfo;          use Einfo;
 with Einfo.Entities; use Einfo.Entities;
 with Einfo.Utils;    use Einfo.Utils;
 with Errout;         use Errout;
+with Expander;       use Expander;
 with Exp_Aggr;       use Exp_Aggr;
 with Exp_Atag;       use Exp_Atag;
 with Exp_Ch4;        use Exp_Ch4;
@@ -6985,12 +6986,16 @@ package body Exp_Ch3 is
             --  happen when the aggregate is limited and the declared object
             --  has a following address clause; it happens also when generating
             --  C code for an aggregate that has an alignment or address clause
-            --  (see Analyze_Object_Declaration).
+            --  (see Analyze_Object_Declaration). Resolution is done without
+            --  expansion because it will take place when the declaration
+            --  itself is expanded.
 
             if (Is_Limited_Type (Typ) or else Modify_Tree_For_C)
               and then not Analyzed (Expr)
             then
+               Expander_Mode_Save_And_Set (False);
                Resolve (Expr, Typ);
+               Expander_Mode_Restore;
             end if;
 
             Convert_Aggr_In_Object_Decl (N);



                 reply	other threads:[~2021-06-30  9:30 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210630093046.GA2150@adacore.com \
    --to=derodat@adacore.com \
    --cc=gcc-patches@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).