On 7/14/21 2:47 PM, Tamar Christina wrote: > Hi, > > Ever since this commit > > commit c9114f2804b91690e030383de15a24e0b738e856 > Author: Bernd Edlinger <bernd.edlin...@hotmail.de> > Date: Fri May 28 06:27:27 2021 +0200 > > Various tools have been having trouble with cross compilation resulting in > > make[2]: *** No rule to make target > '../build-x86_64-build_pc-linux-gnu/libcpp/libcpp.a', needed by > 'build/genmatch'. > > (took a while to track down). I don't understand this part of the build > system well enough to know how to fix this. > It looks like `libcpp.a` has special handling for cross compilers which now > seems to be broken. > > I can't reproduce it with our normal cross compiler scripts. Which handles > the stages on its own, but e.g. > https://github.com/crosstool-ng/crosstool-ng does reproduce the failure. >
Sorry for the breakage! I do not know this tool at all, but this here looks suspicious, as it it by-passes the dependencies in the top-level Makefile: https://github.com/crosstool-ng/crosstool-ng/blob/755850d07ec4e8dc44787d1a0e35fe19507f17f6/scripts/build/cc/gcc.sh#L682-L683 CT_DoExecLog CFG make ${CT_JOBSFLAGS} configure-gcc configure-libcpp configure-build-libiberty CT_DoExecLog ALL make ${CT_JOBSFLAGS} all-libcpp all-build-libiberty ... https://github.com/crosstool-ng/crosstool-ng/blob/755850d07ec4e8dc44787d1a0e35fe19507f17f6/scripts/build/cc/gcc.sh#L711-L712 CT_DoExecLog ALL make ${CT_JOBSFLAGS} -C gcc ${libgcc_rule} \ ${repair_cc} but the top-level Makefile has also a dependency to all-build-libcpp: dependencies = { module=all-gcc; on=all-build-libcpp; }; dependencies = { module=all-gcc; on=all-libcpp; hard=true; }; Maybe this just worked by chance, when building with "make -j" started a parallel build, might build the build-libcpp dependency eventually, but due to the patch it is needed earlier? Bernd. > Any ideas what's going on? > > Kind Regards, > Tamar > >> -----Original Message----- >> From: Gcc-patches <gcc-patches-boun...@gcc.gnu.org> On Behalf Of >> Michael Matz >> Sent: Friday, May 28, 2021 4:33 PM >> To: Bernd Edlinger <bernd.edlin...@hotmail.de> >> Cc: gcc-patches@gcc.gnu.org; Richard Biener <rguent...@suse.de> >> Subject: Re: [PATCH] Generate gimple-match.c and generic-match.c earlier >> >> Hello, >> >> On Fri, 28 May 2021, Bernd Edlinger wrote: >> >>>>> I was wondering, why gimple-match.c and generic-match.c are not >>>>> built early but always last, which slows down parallel makes >>>>> significantly. >>>>> >>>>> The reason seems to be that generated_files does not mention >>>>> gimple-match.c and generic-match.c. >>>>> >>>>> This comment in Makefile.in says it all: >>>>> >>>>> $(ALL_HOST_OBJS) : | $(generated_files) >>>>> >>>>> So this patch adds gimple-match.c generic-match.c to generated_files. >>>>> >>>>> >>>>> Tested on x86_64-pc-linux-gnu. >>>>> Is it OK for trunk? >>>> >>>> This should help for what I was complaining about in >>>> https://gcc.gnu.org/pipermail/gcc/2021-May/235963.html . I build >>>> with >>>> -j24 and it was stalling on compiling gimple-match.c for me. >>>> Looks like insn-attrtab.c is missed too; I saw genattrtab was running last >> too. >>>> >>> >>> Yeah, probably insn-automata.c as well, sometimes it is picked up >>> early sometimes not. maybe $(simple_generated_c) should be added to >>> generated_files, but insn-attrtab.c is yet another exception. >> >> You can't put files in there that are sometimes slow to generate (which insn- >> {attrtab,automata}.c are on some targets), as _everything_ then waits for >> them to be created first. >> >> Ideally there would be a way for gnumake to mark some targets as "ugh- >> slow" and back-propagate this to all dependencies so that those are put in >> front of the work queue in a parallel make. Alas, something like that never >> came into existence :-/ (When order-only deps were introduced I got >> excited, but then came to realize that that wasn't what was really needed for >> this case, a "weak" version of it would be required at least, or better yet a >> specific facility to impose a cost with a target) >> >> >> Ciao, >> Michael. >> >>> >>> >>> Bernd. >>> >>>> Thanks, >>>> Andrew >>>> >>>>> >>>>> >>>>> Thanks >>>>> Bernd. >>>>> >>>>> >>>>> 2021-05-28 Bernd Edlinger <bernd.edlin...@hotmail.de> >>>>> >>>>> * Makefile.in (generated_files): Add gimple-match.c and >>>>> generic-match.c >>>
