V8 build fails on //third_party/zlib dependency

[Dirk Becker]

Hi,

my OSX build of V8 failed with an error

ERROR at //BUILD.gn:3584:5: Unable to load "/Volumes/Disk2/v8/third_party/zlib/BUILD.gn".

correctly so, as there is no zlib in v8/third_party .





I commented out the matching dependency lines, introduced in https://chromium.googlesource.com/v8/v8.git/+/858e3c7ef7bc80ea1767737853971e4e6a4633af

Along the suggestion there, I also added v8_disable_snapshot_compression = true to my args.gn




After the warning

> Did you mean "v8_enable_snapshot_compression"?

I then used an v8_enable_snapshot_compression = false

Next is a compile error:

[939/1601] CXX obj/v8_base_without_compiler/snapshot-compression.o

FAILED: obj/v8_base_without_compiler/snapshot-compression.o 

../../src/snapshot/snapshot-compression.cc:10:10: fatal error: 'third_party/zlib/google/compression_utils_portable.h' file not found


v8_enable_snapshot_compression takes me to a define V8_SNAPSHOT_COMPRESSION


Next attempt: add several #ifdef V8_SNAPSHOT_COMPRESSION in snapshot-compression.cc, snapshot-utils.cc and so forth.

A dead end, more and more dependencies - snapshot compression is to stay, IMO that argument / option is toast.


Therefor maybe it is easier to add "third_party/zlib" .

Next problem though: Considering that reference to … "google/compression_utils_portable.h" this is likely to be a special build.

As I am pretty new to V8, how should I continue?

Thanks,

Dirk

[Ben Noordhuis]

It sounds like you did a regular `git clone`? See the instruction at
[0], you need to use the fetch command from depot_tools. That will
also check out dependencies, among other things.

I maintain a fork[1] of V8 that uses cmake as the build tool. It lets
you use the regular cmake workflow but it doesn't support every option
that GN supports (yet - pull requests welcome.)

[0] https://v8.dev/docs/source-code
[1] https://github.com/bnoordhuis/v8-cmake

[Dirk Becker]

Back in early 2019 I had used fetch for the initial checkout, later on succeeded once with git pull origin / gclient sync as suggested by https://chromium.googlesource.com/v8/v8.git .

Apparently since then I have broken something so past week's turn the same steps failed.

Now, with a fresh VM v8/third_party looks better, it has far more entries than https://chromium.googlesource.com/v8/v8.git/+/refs/heads/master/third_party/ that I took as the full thing.

Also thanks for suggesting your cmake based fork, but I'll stay with the ninjas for now.