Re: [PATCH] backends: Ignore GCC8 -Wpacked-not-aligned for m68k_corenote.c.

[Mark Wielaard <mark at klomp dot org>]

On Tue, 2017-10-24 at 14:35 +0200, Mark Wielaard wrote:
> The GCC8 -Wpacked-not-aligned warns if a structure field with explicit
> padding in a packed structure will be misaligned. m68k prstatus core
> notes are described by a packed structure which has such aligned structure
> fields.

Well, that worked, but only because of two typos canceling each other
out...

> +# m68k prstatus core notes are described by a packed structure
> +# which has not naturally aligned fields. Since we don't access
> +# these fields directly, but take their offset to be used later
> +# to extract the data through elfxx_xlatetom/memmove, this isn't
> +# an issue.
> +m68k_corenote_Wpacked_not_aligned = yes

Missing no_ ...

> +++ b/config/eu.am
> @@ -74,6 +74,7 @@ AM_CFLAGS = -std=gnu99 -Wall -Wshadow -Wformat=2 \
> >  	    $(if $($(*F)_no_Werror),,-Werror) \
> >  	    $(if $($(*F)_no_Wunused),,-Wunused -Wextra) \
> >  	    $(if $($(*F)_no_Wstack_usage),,$(STACK_USAGE_WARNING)) \
> > +	    $(if $($(*F)_no_Wpacked_not_aligned),,-Wno-packed-not-aligned) \

Double ,, causing everything to get -Wno-packaged-not-aligned.

Oops. Fixed patch attached.

From ab6b37ac32ddf2f2f11f800a770170814f5cbb8b Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mark@klomp.org>
Date: Tue, 24 Oct 2017 14:23:30 +0200
Subject: [PATCH] backends: Ignore GCC8 -Wpacked-not-aligned for
 m68k_corenote.c.

The GCC8 -Wpacked-not-aligned warns if a structure field with explicit
padding in a packed structure will be misaligned. m68k prstatus core
notes are described by a packed structure which has such aligned structure
fields.

Signed-off-by: Mark Wielaard <mark@klomp.org>
---
 backends/ChangeLog   | 4 ++++
 backends/Makefile.am | 7 +++++++
 config/ChangeLog     | 4 ++++
 config/eu.am         | 1 +
 4 files changed, 16 insertions(+)

diff --git a/backends/ChangeLog b/backends/ChangeLog
index 8c3f42c..190ae96 100644
--- a/backends/ChangeLog
+++ b/backends/ChangeLog
@@ -1,3 +1,7 @@
+2017-10-24  Mark Wielaard  <mark@klomp.org>
+
+	* Makefile.am (m68k_corenote_no_Wpacked_not_aligned): New variable.
+
 2017-08-18  Ulf Hermann <ulf.hermann@qt.io>
 
 	* linux-core-note.c: Use attribute_packed.
diff --git a/backends/Makefile.am b/backends/Makefile.am
index 0fde0cb..2c62add 100644
--- a/backends/Makefile.am
+++ b/backends/Makefile.am
@@ -119,6 +119,13 @@ m68k_SRCS = m68k_init.c m68k_symbol.c m68k_regs.c \
 libebl_m68k_pic_a_SOURCES = $(m68k_SRCS)
 am_libebl_m68k_pic_a_OBJECTS = $(m68k_SRCS:.c=.os)
 
+# m68k prstatus core notes are described by a packed structure
+# which has not naturally aligned fields. Since we don't access
+# these fields directly, but take their offset to be used later
+# to extract the data through elfxx_xlatetom/memmove, this isn't
+# an issue.
+m68k_corenote_no_Wpacked_not_aligned = yes
+
 bpf_SRCS = bpf_init.c bpf_regs.c
 cpu_bpf = ../libcpu/libcpu_bpf.a
 libebl_bpf_pic_a_SOURCES = $(bpf_SRCS)
diff --git a/config/ChangeLog b/config/ChangeLog
index 1ed3c4a..de0d890 100644
--- a/config/ChangeLog
+++ b/config/ChangeLog
@@ -1,3 +1,7 @@
+2017-10-24  Mark Wielaard  <mark@klomp.org>
+
+	* eu.am (AM_CFLAGS): Handle -Wno-packed-not-aligned.
+
 2017-04-27  Ulf Hermann  <ulf.hermann@qt.io>
 
 	* eu.am: Use fpic_CFLAGS.
diff --git a/config/eu.am b/config/eu.am
index 796f388..05c27f0 100644
--- a/config/eu.am
+++ b/config/eu.am
@@ -74,6 +74,7 @@ AM_CFLAGS = -std=gnu99 -Wall -Wshadow -Wformat=2 \
 	    $(if $($(*F)_no_Werror),,-Werror) \
 	    $(if $($(*F)_no_Wunused),,-Wunused -Wextra) \
 	    $(if $($(*F)_no_Wstack_usage),,$(STACK_USAGE_WARNING)) \
+	    $(if $($(*F)_no_Wpacked_not_aligned),-Wno-packed-not-aligned,) \
 	    $($(*F)_CFLAGS)
 
 COMPILE.os = $(filter-out -fprofile-arcs -ftest-coverage, $(COMPILE))
-- 
1.8.3.1