Rework go bindings so that binding tests work fine

[serge-sans-paille]

Summary

Since llvm-go is no longer part of the distribution, the binding testing have started to fail.

This is a straight forward attempt at fixing that. Note that I'm by no mean a go developer, which is probably reflected by the commit.

[teemperor]

So this is just using the system go compiler instead of llvm-go and all the files move to src/ because that's how the normal go compiler expects the workspace to look like?

[serge-sans-paille]

In D74540#1874011, @teemperor wrote:

So this is just using the system go compiler instead of llvm-go and all the files move to src/ because that's how the normal go compiler expects the workspace to look like?

yeah, that's basically it. Plus a few lit config stuff to make sure everything works. Which is not settled yet per the validation :-)

[serge-sans-paille]

@teemperor validation is ok now .

[teemperor]

Also works on my machine now, so LGTM. Thanks!

[pcc]

This broke users of the go bindings who were using build.sh, and changed the import path for the bindings unnecessarily. Can we please just bring back llvm-go as I requested before?

[MaskRay]

In D74540#1874534, @pcc wrote:

This broke users of the go bindings who were using build.sh, and changed the import path for the bindings unnecessarily. Can we please just bring back llvm-go as I requested before?

@pcc Are you the best one fixing this issue properly :) ?

I guess this patch fixed the /mnt/disks/ssd0/agent/workspace/amd64_debian_testing_clang8/build/test/Bindings/Go/Output/go.test.script: line 1: llvm-go: command not found diagnostic we continuously get from the premerge bot, so I still appreciate Serge's work.... https://reviews.llvm.org/harbormaster/unit/view/3381/

[pcc]

Now that llvm-go has been brought back, I've reverted this change.

[serge-sans-paille]

llvm-go is still a thing, this patch is no longer needed

llvm/bindings/go/build.sh

-#!/bin/sh -xe
-
-gollvmdir=$(dirname "$0")/llvm
-
-workdir=$gollvmdir/workdir
-llvmdir=$gollvmdir/../../..
-llvm_builddir=$workdir/llvm_build
-
-mkdir -p $llvm_builddir
-
-cmake_flags="../../../../.. $@"
-llvm_config="$llvm_builddir/bin/llvm-config"
-llvm_go="$llvm_builddir/bin/llvm-go"
-
-if test -n "`which ninja`" ; then
-  # If Ninja is available, we can speed up the build by building only the
-  # required subset of LLVM.
-  (cd $llvm_builddir && cmake -G Ninja $cmake_flags)
-  ninja -C $llvm_builddir llvm-config llvm-go
-  llvm_components="$($llvm_go print-components)"
-  llvm_buildtargets="$($llvm_config --libs $llvm_components | sed -e 's/-l//g')"
-  ninja -C $llvm_builddir $llvm_buildtargets FileCheck
-else
-  (cd $llvm_builddir && cmake $cmake_flags)
-  make -C $llvm_builddir -j4
-fi
-
-$llvm_go print-config > $gollvmdir/llvm_config.go

llvm/bindings/go/src/llvm/llvm_dep.go

 //===- llvm_dep.go - creates LLVM dependency ------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file ensures that the LLVM libraries are built before using the
 // bindings.
 //
 //===----------------------------------------------------------------------===//
 
 // +build !byollvm
 
 package llvm
-
-var _ run_build_sh

llvm/test/Bindings/Go/go.test

-; RUN: llvm-go test llvm.org/llvm/bindings/go/llvm
+; RUN: CGO_CPPFLAGS="`llvm-config --cppflags`" CGO_CXXFLAGS=-std=c++14 CGO_LDFLAGS="`llvm-config --ldflags --libs --system-libs all`" go test llvm
 
 ; REQUIRES: shell
 ; UNSUPPORTED: asan, ubsan, msan

llvm/test/Bindings/Go/lit.local.cfg

try:
             args[0] = path[:len(path)-3] + 'clang++'
     except (AttributeError, OSError):
         pass
 
     return ' '.join([pipes.quote(arg) for arg in args])
 
 config.environment['CC'] = fixup_compiler_path(config.host_cc)
 config.environment['CXX'] = fixup_compiler_path(config.host_cxx)
-config.environment['CGO_LDFLAGS'] = config.host_ldflags
+config.environment['LD_LIBRARY_PATH'] = config.llvm_shlib_dir
+config.environment['GOPATH'] = os.path.join(config.llvm_src_root, 'bindings', 'go')

llvm/test/lit.cfg.py

tools.extend([
     'llvm-pdbutil', 'llvm-profdata', 'llvm-ranlib', 'llvm-rc', 'llvm-readelf',
     'llvm-readobj', 'llvm-rtdyld', 'llvm-size', 'llvm-split', 'llvm-strings',
     'llvm-strip', 'llvm-tblgen', 'llvm-undname', 'llvm-c-test', 'llvm-cxxfilt',
     'llvm-xray', 'yaml2obj', 'obj2yaml', 'yaml-bench', 'verify-uselistorder',
     'bugpoint', 'llc', 'llvm-symbolizer', 'opt', 'sancov', 'sanstats'])
 
 # The following tools are optional
 tools.extend([
-    ToolSubst('llvm-go', unresolved='ignore'),
+    ToolSubst('go', unresolved='ignore'),
     ToolSubst('llvm-mt', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch3', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch4', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch5', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch6', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch7', unresolved='ignore'),
     ToolSubst('Kaleidoscope-Ch8', unresolved='ignore')])
 

llvm/utils/lit/lit/llvm/subst.py

def resolve(self, config, dirs):
         if command is None:
             # Then check out search paths.
             command = lit.util.which(self.name, dirs)
             if not command:
                 return None
 
         if self.name == 'llc' and os.environ.get('LLVM_ENABLE_MACHINE_VERIFIER') == '1':
             command += ' -verify-machineinstrs'
-        elif self.name == 'llvm-go':
+        elif self.name == 'go':
             exe = getattr(config.config, 'go_executable', None)
             if exe:
                 command += ' go=' + exe
         return command
 
 
 class ToolSubst(object):
     """String-like class used to build regex substitution patterns for llvm