From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2153) id 3F3B6385BC23; Sun, 18 Jul 2021 23:28:41 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3F3B6385BC23 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jakub Jelinek To: gcc-cvs@gcc.gnu.org Subject: [gcc r11-8765] stor-layout: Avoid DECL_BIT_FIELD_REPRESENTATIVE with NULL TREE_TYPE [PR101172] X-Act-Checkin: gcc X-Git-Author: Jakub Jelinek X-Git-Refname: refs/heads/releases/gcc-11 X-Git-Oldrev: e9844603541d5585f778841afbdbf583a1b53412 X-Git-Newrev: 2b99794806d83e47249fd7c05bf521caee1fdcd4 Message-Id: <20210718232841.3F3B6385BC23@sourceware.org> Date: Sun, 18 Jul 2021 23:28:41 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 18 Jul 2021 23:28:41 -0000 https://gcc.gnu.org/g:2b99794806d83e47249fd7c05bf521caee1fdcd4 commit r11-8765-g2b99794806d83e47249fd7c05bf521caee1fdcd4 Author: Jakub Jelinek Date: Thu Jun 24 12:22:14 2021 +0200 stor-layout: Avoid DECL_BIT_FIELD_REPRESENTATIVE with NULL TREE_TYPE [PR101172] finish_bitfield_representative has an early out if the field after a bitfield has error_mark_node type, but that early out leads to TREE_TYPE of the DECL_BIT_FIELD_REPRESENTATIVE being NULL, which breaks assumptions on code that uses the DECL_BIT_FIELD_REPRESENTATIVE during error-recovery. The following patch instead sets TREE_TYPE of the representative to error_mark_node, something the users can deal with better. At this point the representative can be set as DECL_BIT_FIELD_REPRESENTATIVE for multiple bitfields, so making sure that we clear the DECL_BIT_FIELD_REPRESENTATIVE instead would be harder (but doable, e.g. with the error_mark_node TREE_TYPE set by this patch set some flag in the caller and if the flag is there, walk all the fields once again and clear all DECL_BIT_FIELD_REPRESENTATIVE that have error_mark_node TREE_TYPE). 2021-06-24 Jakub Jelinek PR middle-end/101172 * stor-layout.c (finish_bitfield_representative): If nextf has error_mark_node type, set repr type to error_mark_node too. * gcc.dg/pr101172.c: New test. (cherry picked from commit 65371066d8967560e3508af4a804e0ddb90acee7) Diff: --- gcc/stor-layout.c | 5 ++++- gcc/testsuite/gcc.dg/pr101172.c | 20 ++++++++++++++++++++ 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c index 9f850c3951e..242452f2acf 100644 --- a/gcc/stor-layout.c +++ b/gcc/stor-layout.c @@ -2086,7 +2086,10 @@ finish_bitfield_representative (tree repr, tree field) /* If there was an error, the field may be not laid out correctly. Don't bother to do anything. */ if (TREE_TYPE (nextf) == error_mark_node) - return; + { + TREE_TYPE (repr) = error_mark_node; + return; + } maxsize = size_diffop (DECL_FIELD_OFFSET (nextf), DECL_FIELD_OFFSET (repr)); if (tree_fits_uhwi_p (maxsize)) diff --git a/gcc/testsuite/gcc.dg/pr101172.c b/gcc/testsuite/gcc.dg/pr101172.c new file mode 100644 index 00000000000..b9d098bb644 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr101172.c @@ -0,0 +1,20 @@ +/* PR middle-end/101172 */ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ + +union U +{ + int a[3]; + struct + { + int a : 3; + struct this_struct var; /* { dg-error "field 'var' has incomplete type" } */ + } b; +}; + +const union U hello = {.a = {1, 2, 3}}; + +void foo() +{ + int x = hello.b.a; +}