On Thu, Jun 22, 2017 at 8:28 AM, Alan Modra <amo...@gmail.com> wrote: > PR80044 notes that -static and -pie together behave differently when > gcc is configured with --enable-default-pie as compared to configuring > without (or --disable-default-pie). This patch removes that > difference. In both cases you now will have -static completely > overriding -pie. > > Fixing this wasn't quite as simple as you'd expect, due to poor > separation of functionality. PIE_SPEC didn't just mean that -pie was > on explicitly or by default, but also -r and -shared were *not* on. > Fortunately the three files touched by this patch are the only places > PIE_SPEC and NO_PIE_SPEC are used, so it isn't too hard to see that > the reason PIE_SPEC and NO_PIE_SPEC are not inverses is the use of > PIE_SPEC in LINK_PIE_SPEC. So, move the inelegant symmetry breaking > addition, to LINK_PIE_SPEC where it belongs. Doing that showed > another problem in gnu-user.h, with PIE_SPEC and NO_PIE_SPEC selection > of crtbegin*.o not properly hooked into a chain of if .. elseif .. > conditions, which required both PIE_SPEC and NO_PIE_SPEC to exclude > -static and -shared. Fixing that particular problem finally allows > PIE_SPEC to serve just one purpose, and NO_PIE_SPEC to disappear. > > Bootstrapped and regression tested powerpc64le-linux c,c++. No > regressions and a bunch of --enable-default-pie failures squashed. > OK mainline and active branches? > > Incidentally, there is a fairly strong case to be made for adding > -static to the -shared, -pie, -no-pie chain of RejectNegative's in > common.opt. Since git 0d6378a9e (svn r48039) 2001-11-15, -static has > done more than just the traditional "prevent linking with dynamic > libraries", as -static selects crtbeginT.o rather than crtbegin.o > on GNU systems. Realizing this is what led me to close pr80044, which > I'd opened with the aim of making -pie -static work together (with the > traditional meaning of -static). I don't that is worth doing, but > mention pr80044 in the changelog due to fixing the insane output > produced by -pie -static with --disable-default-pie. >
On x86-64, without --enable-default-pie, "-static -pie" and "-pie -static" never worked since both -static and -pie are passed to linker, which uses libc.a to build PIE. With --enable-default-pie, -static and -pie override each other. What does your patch do on x86-64? Make with and without --enable-default-pie behave the same? Does it mean that both fail to create executable? -- H.J.
