Hhvm: full_fidelity_syntax_type.ml no longer builds on Aarch64 hosts

[swalk-cavium]

HHVM Version

First noticed at this commit
swalk@lab-7:~/extra/play.031919a/hhvm$ git branch -v

• master d9c334e Rename Local_helpers.scope_with_handler to Scope.with_unnamed_locals

Operating System and Version

swalk@lab-7:~/extra/play.031919a/hhvm$ uname -a
Linux lab-7 4.4.0-138-generic #164-Ubuntu SMP Tue Oct 2 17:15:48 UTC 2018 aarch64 aarch64 aarch64 GNU/Linux

Standalone code, or other way to reproduce the problem

Part of the build log

17308 gcc.compile.c++ bin.v2/libs/wave/build/gcc-5.4.0/release/link-static/threading-multi/instantiate_defined_grammar.o
17309 + ocamlfind ocamlopt -c -ccopt '-DUSE_UNISTD=1' -g -w A -package core_kernel -package visitors.ppx -package visitors.runtime -package pcre -package l wt -package lwt.unix -package lwt_ppx -package lwt_log -w -3-4-6-29-35-44-48-50-52 -package unix -package str -package bigarray -package ppx_deriving .std -I src/parser -I src/search -I src/dfind -I src/typing -I src/annotated_ast -I src/deps -I src/naming -I src/diff -I src/globals -I src/decl -I src/pocket_universes -I src/facts -I src/server -I src/hackfmt -I src/watchman -I src/fsnotify_linux -I src/errors -I src/find -I src/monitor -I src/ config -I src/procs -I src/utils -I src/heap -I src/options -I src/libancillary -I src/ast -I src/hhbc -I src/ide_rpc -I src/stubs -I src/socket -I s rc/common -I src/watchman_event_watcher -I src/hhi -I src/client -I src/search/signatures -I src/typing/tast_check -I src/typing/nast_check -I src/ha ckfmt/debug -I src/hackfmt/error -I src/utils/config_file -I src/utils/process -I src/utils/collections -I src/utils/sys -I src/utils/parent -I src/u tils/hashlib -I src/utils/hg -I src/utils/lint -I src/utils/disk -I src/utils/hh_json -I src/injection/default_injector -I src/stubs/logging -I src/t hird-party/avl -I src/third-party/inotify -I src/third-party/core -I src/parser/ppl -I src/parser/smart_constructors -I src/parser/coroutine -I src/p arser/schema -o src/parser/full_fidelity_syntax_type.cmx src/parser/full_fidelity_syntax_type.ml
17310 ocamlfind: [WARNING] Package `threads': Linking problems may arise because of the missing -thread or -vmthread switch
17311 /tmp/camlasmfb4f89.s: Assembler messages:
17312 /tmp/camlasmfb4f89.s:8150: Error: immediate out of range //<<--- HERE
17313 File "src/parser/full_fidelity_syntax_type.ml", line 1:
17314 Error: Assembler error, input left in file /tmp/camlasmfb4f89.s
17315 Command exited with code 2.

Shows immediate out of range

8146 movz x7, #3, lsl #0
8147 str x7, [x5, #8]
8148 ldr x12, [sp, #8]
8149 str x12, [x5, #16]
8150 .L232: sub x27, x27, #5688 //<<--- HERE (only 12-bits in encoding - unsigned)
8151 cmp x27, x28
8152 add x1, x27, #8
8153 b.lo .L233
8154 movz x8, #11, lsl #16

Actual result

Build fails

Expected result

Build pass.

[fredemmott]

Is there an issue filed with ocaml, or a more recent version that works?

[swalk-cavium]

@fredemmott - I haven't looked yet. This looks similar to the issue from last year when we had to make a patch to the ocaml code gen.

[swalk-cavium]

Some recent change is downloading a newer version of the ocaml language,
but the patching infrastructure built in the cmake scripts wasn't considered.

swalk@lab-7:~/extra/play.032219a/hhvm$ find . -type f -print |& grep arm64 | grep emit | xargs /usr/bin/sum
25012 37 ./third-party/ocaml/src/asmcomp/arm64/emit.mlp
26280 37 ./hphp/hack/_build/.opam/hack-switch/.opam-switch/sources/ocaml-base-compiler.4.05.0/asmcomp/arm64/emit.mlp

[fredemmott]

cc @vsiles

[vsiles]

Indeed that rings a bell. I'll check on a way to patch ocaml during the opam switch installation (or directly bundle a patched version, it might even be easier)

[vsiles]

@fredemmott the patch seems to be in more recent ocaml version. Out of curiosity while I read opam's doc, are there hard reasons not to update the ocaml version ?

[fredemmott]

It should be the same as the internal version - if updating the internal version is fine, go ahead :)

[vsiles]

@vassilmladenov I'll write about that next week :)

[vsiles]

@swalk-cavium I don't have an arm64 to test this, so if you have the opportunity, could you test the build after changing https://github.com/facebook/hhvm/blob/master/hphp/hack/opam_setup.sh#L56 to 4.07.0 ? I just want to know if upgrading is a viable option.

[swalk-cavium]

@vsiles - A different problem is exposed with this change. The numbers on the left are
line numbers into the build output.

17437 boot/ocamlrun ./ocamlopt -g -nostdlib -I stdlib -I otherlibs/dynlink -strict-sequence -principal -absname -w +a-4-9-41-42-44-45-48 -warn-error A -bin-annot -safe-string -strict-formats -I utils -I parsing -I typing -I byte comp -I middle_end -I middle_end/base_types -I asmcomp -I driver -I toplevel -c asmcomp/compilenv.ml
17438 File "/mnt/diskb/swalk/play.032519a/hhvm/third-party/ocaml/src/_none_", line 1:
17439 Warning 58: no cmx file was found in path for module Compilenv, and its interface was not compiled with -opaque
17440 File "/mnt/diskb/swalk/play.032519a/hhvm/third-party/ocaml/src/asmcomp/selection.ml", line 1:
17441 Error: Some fatal warnings were triggered (1 occurrences)
17442 Makefile:1270: recipe for target 'asmcomp/selection.cmx' failed
17443 make[5]: * [asmcomp/selection.cmx] Error 2

It appears that there is some other fix in the 4.07.0 version for GOT related symbols.

[vsiles]

Thank you for that. I'd make a PR to fix the 4.05.0 asap

[swalk-cavium]

@vsiles - I'm not sure how to interpret your comment. Are you making the fix? If not,
how are patches to be applied after the opam has pulled in new packages?

[vsiles]

It's because my english sucks :D I have a fix in mind: it is possible to apply some patch using opam before it builds the package, so I'll be able to run the patched version + opam

[vsiles]

@swalk-cavium See https://github.com/facebook/hhvm/pull/8474 . As I don't have ARM64 hw to effectively test it, could you give it a go ?

[swalk-cavium]

@vsiles - Yes. I can do that.

[swalk-cavium]

swalk@lab-7:~/extra/play.032819a/hhvm$ hphp/hhvm/hhvm --version
HipHop VM 4.1.0-dev (rel)
Compiler: heads/master-0-gd715738b7db0870c3d1b1daafd0980a84064af54
Repo schema: b172210ccdac82abf293712173af6e3080a14365

swalk@lab-7:~/extra/play.032819a/hhvm$ uname -a
Linux lab-7 4.4.0-138-generic #164-Ubuntu SMP Tue Oct 2 17:15:48 UTC 2018 aarch64 aarch64 aarch64 GNU/Linux

@vsiles - This issue can be closed as soon as your PR lands. Thanks for the fix.

[vsiles]

@swalk-cavium the PR has landed, can you recheck that everything's alright ? If that's fixed, please close the issue.

[swalk-cavium]

@vsiles - aarch64 builds again without having to merge your PR. This issue is resolved. Thanks.