| Message ID | 20150902013502.GT24814@bubble.grove.modra.org |
|---|---|
| State | New |
| Headers | show |
On Tue, Sep 1, 2015 at 9:35 PM, Alan Modra <amodra@gmail.com> wrote: > bugzilla.redhat.com/show_bug_cgi?id=1255946 shows that gcc built with > both powerpc64-linux and powerpc64le-linux support passes wrong linker > options when trying to link in the non-default endian. A --oformat > option coming from LINK_TARGET_SPEC is only correct for 32-bit. > > It turns out that GNU ld -m options select a particular ld emulation > (e*.c file in ld build dir) which provides compiled-in scripts or > selects a script from ldscripts/. Each of these has an OUTPUT_FORMAT > statement, which does the same thing as --oformat. --oformat is > therefore redundant when using GNU ld built this century, except > possibly when a user overrides the default ld script with -Wl,-T and > their script neglects OUTPUT_FORMAT, and it isn't the default output. > I don't think it's worth fixing this possible use case. > > Bootstrap and testing in progress. OK for mainline assuming all is > OK? > > * config/rs6000/sysv4le.h (LINK_TARGET_SPEC): Don't define. > * config/rs6000/sysv4.h (LINK_TARGET_SPEC): Likewise. > (LINK_SPEC, SUBTARGET_EXTRA_SPECS): Delete link_target. Okay. Thanks, David
On Wed, 2015-09-02 at 11:05 +0930, Alan Modra wrote: > bugzilla.redhat.com/show_bug_cgi?id=1255946 shows that gcc built with > both powerpc64-linux and powerpc64le-linux support passes wrong linker > options when trying to link in the non-default endian. A --oformat > option coming from LINK_TARGET_SPEC is only correct for 32-bit. > > It turns out that GNU ld -m options select a particular ld emulation > (e*.c file in ld build dir) which provides compiled-in scripts or > selects a script from ldscripts/. Each of these has an OUTPUT_FORMAT > statement, which does the same thing as --oformat. --oformat is > therefore redundant when using GNU ld built this century, except > possibly when a user overrides the default ld script with -Wl,-T and > their script neglects OUTPUT_FORMAT, and it isn't the default output. > I don't think it's worth fixing this possible use case. > > Bootstrap and testing in progress. OK for mainline assuming all is > OK? > > * config/rs6000/sysv4le.h (LINK_TARGET_SPEC): Don't define. > * config/rs6000/sysv4.h (LINK_TARGET_SPEC): Likewise. > (LINK_SPEC, SUBTARGET_EXTRA_SPECS): Delete link_target. Hi Alan, If you could please backport this to the gcc-5-branch, that would helpful for us (kernel folks). That way we can use the same toolchain for building big or little endian kernels. cheers
On Thu, Sep 24, 2015 at 02:24:25PM +1000, Michael Ellerman wrote: > On Wed, 2015-09-02 at 11:05 +0930, Alan Modra wrote: > > bugzilla.redhat.com/show_bug_cgi?id=1255946 shows that gcc built with > > both powerpc64-linux and powerpc64le-linux support passes wrong linker > > options when trying to link in the non-default endian. A --oformat > > option coming from LINK_TARGET_SPEC is only correct for 32-bit. > > > > It turns out that GNU ld -m options select a particular ld emulation > > (e*.c file in ld build dir) which provides compiled-in scripts or > > selects a script from ldscripts/. Each of these has an OUTPUT_FORMAT > > statement, which does the same thing as --oformat. --oformat is > > therefore redundant when using GNU ld built this century, except > > possibly when a user overrides the default ld script with -Wl,-T and > > their script neglects OUTPUT_FORMAT, and it isn't the default output. > > I don't think it's worth fixing this possible use case. > > > > Bootstrap and testing in progress. OK for mainline assuming all is > > OK? > > > > * config/rs6000/sysv4le.h (LINK_TARGET_SPEC): Don't define. > > * config/rs6000/sysv4.h (LINK_TARGET_SPEC): Likewise. > > (LINK_SPEC, SUBTARGET_EXTRA_SPECS): Delete link_target. > > Hi Alan, > > If you could please backport this to the gcc-5-branch, that would helpful for > us (kernel folks). Bootstrapped and regression tested powerpc64le-linux. Is this OK for the branch too, David?
On Thu, Sep 24, 2015 at 8:54 AM, Alan Modra <amodra@gmail.com> wrote: > On Thu, Sep 24, 2015 at 02:24:25PM +1000, Michael Ellerman wrote: >> On Wed, 2015-09-02 at 11:05 +0930, Alan Modra wrote: >> > bugzilla.redhat.com/show_bug_cgi?id=1255946 shows that gcc built with >> > both powerpc64-linux and powerpc64le-linux support passes wrong linker >> > options when trying to link in the non-default endian. A --oformat >> > option coming from LINK_TARGET_SPEC is only correct for 32-bit. >> > >> > It turns out that GNU ld -m options select a particular ld emulation >> > (e*.c file in ld build dir) which provides compiled-in scripts or >> > selects a script from ldscripts/. Each of these has an OUTPUT_FORMAT >> > statement, which does the same thing as --oformat. --oformat is >> > therefore redundant when using GNU ld built this century, except >> > possibly when a user overrides the default ld script with -Wl,-T and >> > their script neglects OUTPUT_FORMAT, and it isn't the default output. >> > I don't think it's worth fixing this possible use case. >> > >> > Bootstrap and testing in progress. OK for mainline assuming all is >> > OK? >> > >> > * config/rs6000/sysv4le.h (LINK_TARGET_SPEC): Don't define. >> > * config/rs6000/sysv4.h (LINK_TARGET_SPEC): Likewise. >> > (LINK_SPEC, SUBTARGET_EXTRA_SPECS): Delete link_target. >> >> Hi Alan, >> >> If you could please backport this to the gcc-5-branch, that would helpful for >> us (kernel folks). > > Bootstrapped and regression tested powerpc64le-linux. Is this OK for > the branch too, David? Backporting this bug fix is fine with me. Thanks! David
diff --git a/gcc/config/rs6000/sysv4.h b/gcc/config/rs6000/sysv4.h index 24618e3..f48af43 100644 --- a/gcc/config/rs6000/sysv4.h +++ b/gcc/config/rs6000/sysv4.h @@ -574,7 +574,6 @@ ENDIAN_SELECT(" -mbig", " -mlittle", DEFAULT_ASM_ENDIAN) %{R*} \ %(link_shlib) \ %{!T*: %(link_start) } \ -%(link_target) \ %(link_os)" /* Shared libraries are not default. */ @@ -584,10 +583,6 @@ ENDIAN_SELECT(" -mbig", " -mlittle", DEFAULT_ASM_ENDIAN) %{shared:-G -dy -z text } \ %{symbolic:-Bsymbolic -G -dy -z text }" -/* Override the default target of the linker. */ -#define LINK_TARGET_SPEC \ - ENDIAN_SELECT("", " --oformat elf32-powerpcle", "") - /* Any specific OS flags. */ #define LINK_OS_SPEC "\ %{mads : %(link_os_ads) ; \ @@ -873,7 +868,6 @@ ncrtn.o%s" { "endfile_openbsd", ENDFILE_OPENBSD_SPEC }, \ { "endfile_default", ENDFILE_DEFAULT_SPEC }, \ { "link_shlib", LINK_SHLIB_SPEC }, \ - { "link_target", LINK_TARGET_SPEC }, \ { "link_start", LINK_START_SPEC }, \ { "link_start_ads", LINK_START_ADS_SPEC }, \ { "link_start_yellowknife", LINK_START_YELLOWKNIFE_SPEC }, \ diff --git a/gcc/config/rs6000/sysv4le.h b/gcc/config/rs6000/sysv4le.h index 7b1d6a1..66ee7ca 100644 --- a/gcc/config/rs6000/sysv4le.h +++ b/gcc/config/rs6000/sysv4le.h @@ -25,10 +25,6 @@ #undef DEFAULT_ASM_ENDIAN #define DEFAULT_ASM_ENDIAN " -mlittle" -#undef LINK_TARGET_SPEC -#define LINK_TARGET_SPEC \ - ENDIAN_SELECT(" --oformat elf32-powerpc", "", "") - #undef MULTILIB_DEFAULTS #define MULTILIB_DEFAULTS { "mlittle", "mcall-sysv" }