| Message ID | 20111204190020.GA4873@bromo.med.uc.edu |
|---|---|
| State | New |
| Headers | show |
On Sun, Dec 04, 2011 at 02:00:20PM -0500, Jack Howarth wrote: > > > at -m32/-m64 on x86_64-apple-darwin11 due to the -pie linker default. Iain had wanted > > > to leave these in place to encourage boehm-gc to be fixed but I doubt that is a realistic > > > goal in the near/middle term. Perhaps we could patch boehm-gc/testsuite/lib/boehm-gc.exp > > > to pass -fno-pie on darwin (now that it is functional)? > > > > I think we should just find a way to add -fno-pie... Are there any > > flags that are added because we are doing gc that we can key off of? -f{pic,PIC,pie,PIE,no-pic} aren't option that should have any effect on how are binaries/shared libraries linked, these options control solely compilation. -shared, -pie or lack of these options determines how are things linked. So, either you should pass -no-pie or whatever linker option you need to generate position dependent binaries by default, unless -shared or -pie is specified, or you should add -no-pie or something similar, but IMHO it shouldn't be -fno-pie, that is a compilation option/too similar to them. Jakub
On Sun, Dec 04, 2011 at 08:18:32PM +0100, Jakub Jelinek wrote: > On Sun, Dec 04, 2011 at 02:00:20PM -0500, Jack Howarth wrote: > > > > at -m32/-m64 on x86_64-apple-darwin11 due to the -pie linker default. Iain had wanted > > > > to leave these in place to encourage boehm-gc to be fixed but I doubt that is a realistic > > > > goal in the near/middle term. Perhaps we could patch boehm-gc/testsuite/lib/boehm-gc.exp > > > > to pass -fno-pie on darwin (now that it is functional)? > > > > > > I think we should just find a way to add -fno-pie... Are there any > > > flags that are added because we are doing gc that we can key off of? > > -f{pic,PIC,pie,PIE,no-pic} aren't option that should have any effect on how > are binaries/shared libraries linked, these options control solely > compilation. -shared, -pie or lack of these options determines how are > things linked. So, either you should pass -no-pie or whatever linker option > you need to generate position dependent binaries by default, unless -shared > or -pie is specified, or you should add -no-pie or something similar, but > IMHO it shouldn't be -fno-pie, that is a compilation option/too similar to > them. Jakub, This isn't really an option on darwin11 and later since the linker defaults to -pie and this results in warnings from the linker of the form... ld: warning: PIE disabled. Absolute addressing (perhaps -mdynamic-no-pic) not allowed in code signed PIE, but used in _f from /var/tmp//ccVNy9V9.o. To fix this warning, don't compile with -mdynamic-no-pic or link with -Wl,-no_pie Author: mrs Date: Sun Dec 4 07:09:56 2011 New Revision: 181982 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181982 Log: 2011-12-03 Jack Howarth <howarth@bromo.med.uc.edu> * config/darwin10.h (LINK_GCC_C_SEQUENCE_SPEC): Pass -no_pie for non-PIC code when targeting 10.7 or later. Modified: trunk/gcc/ChangeLog trunk/gcc/config/darwin10.h is designed to inhibit this linker noise by explicitly disabling pie linkage. Also, FSF gcc previously wasn't honoring -fno-pie since this didn't inhibit the darwin11 linker from creating a PIE executable. Unfortunately the linker option -no_pie isn't recognized by earlier darwin linkers which makes -fno-pie preferred since it only passes -no_pie to the linker when targeting 10.7 or later. So we may have to make the change darwin-specific. Jack > > Jakub
On 4 Dec 2011, at 20:19, Jack Howarth wrote: > On Sun, Dec 04, 2011 at 08:18:32PM +0100, Jakub Jelinek wrote: >> On Sun, Dec 04, 2011 at 02:00:20PM -0500, Jack Howarth wrote: >>>>> at -m32/-m64 on x86_64-apple-darwin11 due to the -pie linker >>>>> default. Iain had wanted >>>>> to leave these in place to encourage boehm-gc to be fixed but I >>>>> doubt that is a realistic >>>>> goal in the near/middle term. Perhaps we could patch boehm-gc/ >>>>> testsuite/lib/boehm-gc.exp >>>>> to pass -fno-pie on darwin (now that it is functional)? >>>> >>>> I think we should just find a way to add -fno-pie... Are there any >>>> flags that are added because we are doing gc that we can key off >>>> of? >> >> -f{pic,PIC,pie,PIE,no-pic} aren't option that should have any >> effect on how >> are binaries/shared libraries linked, these options control solely >> compilation. -shared, -pie or lack of these options determines how >> are >> things linked. So, either you should pass -no-pie or whatever >> linker option >> you need to generate position dependent binaries by default, unless >> -shared >> or -pie is specified, or you should add -no-pie or something >> similar, but >> IMHO it shouldn't be -fno-pie, that is a compilation option/too >> similar to >> them. > > Jakub, > This isn't really an option on darwin11 and later since the linker > defaults to > -pie and this results in warnings from the linker of the form... > > ld: warning: PIE disabled. Absolute addressing (perhaps -mdynamic-no- > pic) not allowed in code signed PIE, but used in _f from /var/tmp// > ccVNy9V9.o. To fix this warning, don't compile with -mdynamic-no-pic > or link with -Wl,-no_pie perhaps the question should be "why is this particualr code being built with non-default options?". x86 darwin code should default to fPIC - so someone must be passing - mdynamic-no-pic or -fno-PIC etc. (perhaps derived from the bootstrap usage of the "-mdynamic-no-pic" option - which suggests that this should be disabled for Darwin >= 11). Iain
On Sun, Dec 04, 2011 at 08:35:07PM +0000, Iain Sandoe wrote: > > On 4 Dec 2011, at 20:19, Jack Howarth wrote: > >> On Sun, Dec 04, 2011 at 08:18:32PM +0100, Jakub Jelinek wrote: >>> On Sun, Dec 04, 2011 at 02:00:20PM -0500, Jack Howarth wrote: >>>>>> at -m32/-m64 on x86_64-apple-darwin11 due to the -pie linker >>>>>> default. Iain had wanted >>>>>> to leave these in place to encourage boehm-gc to be fixed but I >>>>>> doubt that is a realistic >>>>>> goal in the near/middle term. Perhaps we could patch boehm-gc/ >>>>>> testsuite/lib/boehm-gc.exp >>>>>> to pass -fno-pie on darwin (now that it is functional)? >>>>> >>>>> I think we should just find a way to add -fno-pie... Are there any >>>>> flags that are added because we are doing gc that we can key off >>>>> of? >>> >>> -f{pic,PIC,pie,PIE,no-pic} aren't option that should have any effect >>> on how >>> are binaries/shared libraries linked, these options control solely >>> compilation. -shared, -pie or lack of these options determines how >>> are >>> things linked. So, either you should pass -no-pie or whatever >>> linker option >>> you need to generate position dependent binaries by default, unless >>> -shared >>> or -pie is specified, or you should add -no-pie or something >>> similar, but >>> IMHO it shouldn't be -fno-pie, that is a compilation option/too >>> similar to >>> them. >> >> Jakub, >> This isn't really an option on darwin11 and later since the linker >> defaults to >> -pie and this results in warnings from the linker of the form... >> >> ld: warning: PIE disabled. Absolute addressing (perhaps -mdynamic-no- >> pic) not allowed in code signed PIE, but used in _f from /var/tmp// >> ccVNy9V9.o. To fix this warning, don't compile with -mdynamic-no-pic >> or link with -Wl,-no_pie > > perhaps the question should be "why is this particualr code being built > with non-default options?". > x86 darwin code should default to fPIC - so someone must be passing - > mdynamic-no-pic or -fno-PIC etc. Iain, I was only pointing out that we are in a unique situation when targeting darwin11 and later since we are the only target currently creating PIE by default. However unlike linux, darwin doesn't require or even encourage the use of -fpie/-fPIE to do this but silently relies on the default -fPIC. Also, the warning cited above was from gcc.dg/20020312-2.c which previously failed its excessive error test since it passed -fno-pic which triggered the warning. Jack > > (perhaps derived from the bootstrap usage of the "-mdynamic-no-pic" > option - which suggests that this should be disabled for Darwin >= 11). > > Iain
Index: boehm-gc/testsuite/boehm-gc.c/c.exp =================================================================== --- boehm-gc/testsuite/boehm-gc.c/c.exp (revision 181993) +++ boehm-gc/testsuite/boehm-gc.c/c.exp (working copy) @@ -17,6 +17,6 @@ dg-init boehm-gc-init -boehm-gc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.c]] "-O2" "" +boehm-gc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.c]] "-O2 -fno-pie" "" dg-finish Index: boehm-gc/testsuite/boehm-gc.lib/lib.exp =================================================================== --- boehm-gc/testsuite/boehm-gc.lib/lib.exp (revision 181993) +++ boehm-gc/testsuite/boehm-gc.lib/lib.exp (working copy) @@ -21,6 +21,6 @@ boehm-gc-init set tests [lsort [glob -nocomplain $srcdir/$subdir/*.c]] set tests [prune $tests $srcdir/$subdir/*lib.c] -boehm-gc-dg-runtest $tests "-O2" "" +boehm-gc-dg-runtest $tests "-O2 -fno-pie" "" dg-finish