In bug 1412952 I was surprised to discover that we use a 32-bit clang-cl.exe for 32-bit static analysis builds (in contrast to all other Win32 builds where we use a 64-bit toolchain). I landed an ugly hack to let 32-bit clang-cl.exe find 64-bit link.exe in our releng package. I think it would be better to use a 64-bit compiler with -m32. Nathan says this ought to be easy, see bug 1412952 comment 14. Then we can remove my Hostx64 hack.

And ThinLTO builds will need this too. They OOM left and right with a 32-bit toolchain.

Nathan, do you have any time to share advice on how to implement this?

We add the -m32 flag (or --target for clang) here: https://dxr.mozilla.org/mozilla-central/source/build/moz.configure/toolchain.configure#518 Adding a clang-cl case somewhere in there (I think in the `not info.cpu or info.cpu != target.cpu` case) should let configure figure out the right flags to pass to clang-cl? Does that seem sufficient?

I assume there are some automation files that need to be touched too, to tell the 32-bit builders to pull the 64-bit package?

Indeed.

I was hoping you'd tell me which files those would be. :p

(In reply to David Major [:dmajor] from comment #6) > I was hoping you'd tell me which files those would be. :p taskcluster/ci/ build/windows.yml searchfox/kind.yml static-analysis/kind.yml The win32-clang-cl in those files should be changed to win64-clang-cl. Once everything works, you can remove the win32-clang-cl job from taskcluster/ci/toolchain/windows.yml.

Following comment 3 + comment 7 gets me: 17:35:24 INFO - thread '<unnamed>' panicked at 'Unable to find libclang: "the `libclang` shared library could not be opened: z:/build\\build\\src\\clang\\bin\\libclang.dll"', src\libcore\result.rs:906:4 Presumably due to wrong bitness of libclang.dll.

libclang should only be loaded by bindgen from build scripts, which are host binaries. I suppose that since we don't have a `--host=...` in our win32 mozconfigs we're building 32-bit host binaries: https://dxr.mozilla.org/mozilla-central/source/build/win32/mozconfig.vs2017 Looking at a random win32 opt build on inbound does show: 19:05:42 INFO - checking for host system type... i686-pc-mingw32 I don't know how much of a PITA it would be to change that to x86_64, though, since: a) we'd have to set HOST_{CC,CXX} appropriately and the LIB/INCLUDE nonsense might be hard to get right b) we might wind up with a reoccurrence of bug 1377157 because rustc and cargo build scripts don't have a sensible way to set the host compiler

Ok, so to achieve the goal of this bug title ("Use a 64-bit clang-cl.exe for 32-bit static analysis builds"), these things are needed: * Some preparatory build changes that were already done in bug 1401647. * Pass the -m32 flag to 64-bit clang-cl. I've split this off into bug 1429128. * Fix the clang-plugin build. Right now we can't just flip the switch on the "S" builds to use the "win64-clang-cl" toolchain because then clang-plugin fails to build because of wrong-bitness libs. This should probably be its own bug once we know what the change needs to be. * Then, we _can_ flip the switch on "S" builds to use the "win64-clang-cl" toolchain * Nail in the coffin: delete the win32-clang-cl toolchain definition.

> * Fix the clang-plugin build. Right now we can't just flip the switch on the > "S" builds to use the "win64-clang-cl" toolchain because then clang-plugin > fails to build because of wrong-bitness libs. This should probably be its > own bug once we know what the change needs to be. I broke this out into bug 1429549, though I still don't know what the fix should be.

(In reply to David Major [:dmajor] from comment #1) > And ThinLTO builds will need this too. They OOM left and right with a 32-bit toolchain. This is no longer the case after bug 1443827 made the st-an builders use their own toolchain.

This also requires the 64-bits rust compiler and some build system tweaks.

Depends on D7845

Depends on D7846

Pushed by mh@glandium.org: https://hg.mozilla.org/integration/autoland/rev/73dcff37f846 Use a 64-bits clang-cl for 32-bits static analysis builds r=dmajor https://hg.mozilla.org/integration/autoland/rev/98bb6d9eb63c Remove now unused win32-clang-cl-st-an toolchain r=dmajor https://hg.mozilla.org/integration/autoland/rev/5cc491e4d9cb Remove now unused win32-rust-1.29 toolchain r=dmajor

Backed out 3 changesets (bug 1414287) for build bustages module machine type 'x64' conflicts with target machine type 'x86 push that caused the backout: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&classifiedState=unclassified&selectedJob=203766661&revision=5cc491e4d9cb991d8e14b3710b83ff29d9562a8a failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&classifiedState=unclassified&fromchange=b26a70a0fe8f22ee4a5118c7c563ab98a115e692&selectedJob=203766661&searchStr=windows%2C2012%2Cpgo%2Cbuild-win32%2Fpgo%2C%28b%29 backout: https://hg.mozilla.org/integration/autoland/rev/ca3b9c38e8e5af2a405353c2eb41f354f5e5f5ba

Pushed by mh@glandium.org: https://hg.mozilla.org/integration/mozilla-inbound/rev/76fafdaa9216 Use a 64-bits clang-cl for 32-bits static analysis builds r=dmajor https://hg.mozilla.org/integration/mozilla-inbound/rev/273e84414434 Remove now unused win32-clang-cl-st-an toolchain r=dmajor https://hg.mozilla.org/integration/mozilla-inbound/rev/b8da3d4e6da0 Remove now unused win32-rust-1.29 toolchain r=dmajor

https://hg.mozilla.org/mozilla-central/rev/76fafdaa9216 https://hg.mozilla.org/mozilla-central/rev/273e84414434 https://hg.mozilla.org/mozilla-central/rev/b8da3d4e6da0

Backed out 3 changesets (Bug 1414287) for causing Bug 1497029 a=backout Backout: https://hg.mozilla.org/mozilla-central/rev/f95186d58bfaad221b599e284b57d980ade32468

Pushed by mh@glandium.org: https://hg.mozilla.org/integration/autoland/rev/ce3b1b7b826f Use a 64-bits clang-cl for 32-bits static analysis builds r=dmajor https://hg.mozilla.org/integration/autoland/rev/0a7a9e17c1ea Remove now unused win32-clang-cl-st-an toolchain r=dmajor https://hg.mozilla.org/integration/autoland/rev/a5fe00a3b116 Remove now unused win32-rust-1.29 toolchain r=dmajor

https://hg.mozilla.org/mozilla-central/rev/ce3b1b7b826f https://hg.mozilla.org/mozilla-central/rev/0a7a9e17c1ea https://hg.mozilla.org/mozilla-central/rev/a5fe00a3b116