Bug #8007
closed
want sys/stddef.h for offsetof and container_of macros
100%
Description
The current uts/common/sys/sysmacros.h does attempt to protect offsetof() and container_of() macros from getting exposed to userland stddef.h by using construct:
#if (defined(_KERNEL) || defined(_FAKE_KERNEL)) && !defined(_KMEMUSER) .. #endif
However, the i86pc and i86xpv dboot is built with -D_BOOT -D_KMEMUSER -U_KERNEL and is therefore excluded from offsetof() and container_of() macros. To solve this issue, we need to update the conditional expression.
Updated by Toomas Soome about 6 years ago
Sample error case from building dboot bits:
+ /opt/gcc/4.4.4/bin/gcc -fident -finline -fno-inline-functions -fno-builtin -fno-asm -fdiagnostics-show-option -nodefaultlibs -D__sun -Wall -Wextra -std=gnu99 -Werror -Wno-missing-braces -Wno-sign-compare -Wno-unknown-pragmas -Wno-unused-parameter -Wno-missing-field-initializers -Wno-unused -Wno-empty-body -Wno-parentheses -Wno-uninitialized -Wno-char-subscripts -Wno-unused-variable -Wno-unused-function -Wno-unused-label -Wno-type-limits -Wno-clobbered -Wno-empty-body -Wno-unused-value -fno-inline-small-functions -fno-inline-functions-called-once -fno-ipa-cp -O -D_BOOT -ffreestanding -D_BOOT_TARGET_amd64 -D_MACHDEP -D_KMEMUSER -U_KERNEL -D_I32LPx -I/code/illumos-gate/usr/src/common -I/code/illumos-gate/usr/src/common/util -I../../i86pc -I/code/illumos-gate/usr/src/common -I../../i86xpv -I../../common/xen -I../../intel -nostdinc -I../../common -c -o dboot/obj64/dboot_multiboot2.o ../../i86pc/dboot/dboot_multiboot2.c cc1: warnings being treated as errors ../../i86pc/dboot/dboot_multiboot2.c: In function 'dboot_multiboot2_mmap_nentries': ../../i86pc/dboot/dboot_multiboot2.c:329: error: implicit declaration of function 'offsetof' [-Wimplicit-function-declaration] ../../i86pc/dboot/dboot_multiboot2.c:329: error: expected expression before 'multiboot_tag_mmap_t' *** Error code 1 dmake: Fatal error: Command failed for target `dboot/obj64/dboot_multiboot2.o' Current working directory /code/illumos-gate/usr/src/uts/i86pc/unix *** Error code 1
Updated by Toomas Soome about 6 years ago
- Subject changed from uts: sysmacros.h should allow offsetof for early boot to need sys/sysdef.h for offsetof and container_of macros
So far the idea has developed to:
Create sys/sysdef.h, move offsetof and container_of macros from sys/sysmacros.h to it, and remove offsetof from iso/stddef_iso.h. include sys/sysdef.h from both head/sysdef.h and sys/sysmacros.h.
Since we provide the same definition, in guarded header, we will not get into the conflicts, and we get a bit cleaned up headers in return.
Updated by Gordon Ross about 6 years ago
- Subject changed from need sys/sysdef.h for offsetof and container_of macros to want sys/stddef.h for offsetof and container_of macros
Updated by Andrew Stormont about 6 years ago
Why don't we put stuff in stddef.h like the spec says?
http://pubs.opengroup.org/onlinepubs/009695399/basedefs/stddef.h.html
Updated by Toomas Soome about 6 years ago
Andrew Stormont wrote:
Why don't we put stuff in stddef.h like the spec says?
http://pubs.opengroup.org/onlinepubs/009695399/basedefs/stddef.h.html
The #include <stddef.h> (usr/src/head/stddef.h) does provide many (all?) of them, however, if we should move some to sys/stddef.h or not - I think it is separate issue and entirely open for discussions.
Updated by Electric Monk about 6 years ago
- Status changed from In Progress to Closed
- % Done changed from 90 to 100
git commit ff7af0d3beb1bddf8bb93afc2e9042dc3828be3d
commit ff7af0d3beb1bddf8bb93afc2e9042dc3828be3d
Author: Toomas Soome <tsoome@me.com>
Date: 2017-04-24T08:36:11.000Z
8007 want sys/stddef.h for offsetof and container_of macros
Reviewed by: Gordon Ross <gordon.w.ross@gmail.com>
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Yuri Pankov <yuri.pankov@gmail.com>
Approved by: Hans Rosenfeld <hans.rosenfeld@joyent.com>
Updated by Electric Monk about 6 years ago
git commit 6175f5a92a3a312be8142de7390d92df1d05bd75
commit 6175f5a92a3a312be8142de7390d92df1d05bd75
Author: Toomas Soome <tsoome@me.com>
Date: 2017-04-26T10:44:35.000Z
8007 want sys/stddef.h for offsetof and container_of macros (fix container_of visibility)
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Reviewed by: Adam Stevko <adam.stevko@gmail.com>
Reviewed by: Joshua M. Clulow <josh@sysmgr.org>
Approved by: Joshua M. Clulow <josh@sysmgr.org>