[lld] Add a feature for each lld variant when use_lld is called

[jhenderson]

Summary

This allows tests to detect whether to run or not, dependent on which LLD version is required for the test.

[thopre]

llvm/utils/lit/tests/Inputs/lld-features/lit.cfg

13–16

This seems to be leaking from https://reviews.llvm.org/D101995

[jhenderson]

llvm/utils/lit/tests/Inputs/lld-features/lit.cfg

13–16

Not entirely sure what you mean by "leaking" here. I'm making use of the environment variable to ensure there's a real file being pointed at so that the features are enabled. Strictly, it's not required as there's no check for existence of the file specified by the environment variable, but that might change in the future.

[thopre]

llvm/utils/lit/tests/Inputs/lld-features/lit.cfg

13–16

My bad, I stupidly thought it was the same test as in the other patch and the rest of my thought process was even more broken. All good.

[jhenderson]

As D101995 has been abandoned, I'll need to update the testing for this patch.

[jhenderson]

Update test to not depend on D101995.

[jhenderson]

@thopre, could you confirm you're happy with the latest version of the test, please?

[thopre]

LGTM

[jhenderson]

llvm/utils/lit/tests/Inputs/lld-features/lit.cfg

17

Depending on whether I land this patch or D102630 first, this line somewhere will need to change to use_lld(use_installed=True).

llvm/utils/lit/lit/llvm/config.py

def use_lld(self, additional_tool_dirs=[], required=True):
         lld_link = self.use_llvm_tool('lld-link', required=required)
         ld64_lld = self.use_llvm_tool('ld64.lld', required=required)
         wasm_ld = self.use_llvm_tool('wasm-ld', required=required)
 
         was_found = ld_lld and lld_link and ld64_lld and wasm_ld
         tool_substitutions = []
         if ld_lld:
             tool_substitutions.append(ToolSubst(r'ld\.lld', command=ld_lld))
+            self.config.available_features.add('ld.lld')
         if lld_link:
             tool_substitutions.append(ToolSubst('lld-link', command=lld_link))
+            self.config.available_features.add('lld-link')
         if ld64_lld:
             tool_substitutions.append(ToolSubst(r'ld64\.lld', command=ld64_lld))
+            self.config.available_features.add('ld64.lld')
         if wasm_ld:
             tool_substitutions.append(ToolSubst('wasm-ld', command=wasm_ld))
+            self.config.available_features.add('wasm-ld')
         self.add_tool_substitutions(tool_substitutions)
+
         return was_found

llvm/utils/lit/tests/Inputs/lld-features/ld.lld.txt

+# REQUIRES: ld.lld
+# RUN: true

llvm/utils/lit/tests/Inputs/lld-features/ld64.lld.txt

+# REQUIRES: ld64.lld
+# RUN: true

llvm/utils/lit/tests/Inputs/lld-features/lit.cfg

+import lit.formats
+config.name = 'search-env'
+config.suffixes = ['.txt']
+config.test_format = lit.formats.ShTest()
+config.test_source_root = None
+config.test_exec_root = None
+config.llvm_tools_dir = ''
+import lit.llvm
+lit.llvm.initialize(lit_config, config)
+import os.path
+curdir = os.path.dirname(__file__)
+# The current directory contains files for each version of LLD, both with and
+# without a .exe extension. The .exe versions will be found on Windows and the
+# ones without will be found on Linux. Note that all files are just empty files,
+# since the test doesn't actually use them.
+lit.llvm.llvm_config.with_environment('PATH', curdir, append_path=True)
+lit.llvm.llvm_config.use_lld()

llvm/utils/lit/tests/Inputs/lld-features/lld-link.txt

+# REQUIRES: lld-link
+# RUN: true

llvm/utils/lit/tests/Inputs/lld-features/wasm-ld.txt

+# REQUIRES: wasm-ld
+# RUN: true

llvm/utils/lit/tests/lld-features.py

+## Show that each of the LLD variants detected by use_lld comes with its own
+## feature.
+
+# RUN: %{lit} %{inputs}/lld-features 2>&1 | FileCheck %s -DDIR=%p
+
+# CHECK: Passed: 4