environment: Replace LD with <LANG>LD

The rust code is ugly, because rust is annoying. It doesn't invoke a
linker directly (unless that linker is link.exe or lld-link.exe),
instead it invokes the C compiler (gcc or clang usually) to do it's
linking. Meson doesn't have good abstractions for this, though we
probably should because some of the D compilers do the same thing.
Either that or we should just call the c compiler directly, like vala
does.

This changes the public interface for meson, which we don't do unless we
absolutely have to. In this case I think we need to do it. A fair number
of projects have already been using 'ld' in their cross/native files to
get the ld binary and call it directly in custom_targets or generators,
and we broke that. While we could hit this problem again names like
`c_ld` and `cpp_ld` are far less likely to cause collisions than `ld`.
Additionally this gives a way to set the linker on a per-compiler basis,
which is probably in itself very useful.

Fixes #6442

1 files changed, 5 insertions, 2 deletions

diff --git a/run_unittests.py b/run_unittests.py
index b034773..d8c3a1c 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -44,6 +44,7 @@ from distutils.dir_util import copy_tree
 import mesonbuild.mlog
 import mesonbuild.depfile
 import mesonbuild.compilers
+import mesonbuild.envconfig
 import mesonbuild.environment
 import mesonbuild.mesonlib
 import mesonbuild.coredata
@@ -4663,7 +4664,8 @@ class WindowsTests(BasePlatformTests):
     def _check_ld(self, name: str, lang: str, expected: str) -> None:
         if not shutil.which(name):
             raise unittest.SkipTest('Could not find {}.'.format(name))
-        with mock.patch.dict(os.environ, {'LD': name}):
+        envvar = mesonbuild.envconfig.BinaryTable.evarMap['{}ld'.format(lang)]
+        with mock.patch.dict(os.environ, {envvar: name}):
             env = get_fake_env()
             try:
                 comp = getattr(env, 'detect_{}_compiler'.format(lang))(MachineChoice.HOST)
@@ -5943,7 +5945,8 @@ c = ['{0}']
             raise unittest.SkipTest('Solaris currently cannot override the linker.')
         if not shutil.which(check):
             raise unittest.SkipTest('Could not find {}.'.format(check))
-        with mock.patch.dict(os.environ, {'LD': name}):
+        envvar = mesonbuild.envconfig.BinaryTable.evarMap['{}ld'.format(lang)]
+        with mock.patch.dict(os.environ, {envvar: name}):
             env = get_fake_env()
             comp = getattr(env, 'detect_{}_compiler'.format(lang))(MachineChoice.HOST)
             if lang != 'rust' and comp.use_linker_args('foo') == []: