[mac/lld] Run tests with -fatal_warnings by default

[thakis]

Summary

This helps us catch cases where we add support for a flag but forget to
remove HelpHidden from Options.td.

More explicit alternative to D92455

[MaskRay]

I don't think we should add -fatal_warnings to %lld. We should test that whether a diagnostic is a warning or error.

[thakis]

The tests that check for warnings (there's currently just one) all use %no_fatal_warnings_lld. That's still testable with this patch.

The motivation here is that lld/MachO warns on options that are marked HelpHidden and there were several instances were someone implemented a flag but forgot to remove HelpHidden, and then lld still warned about the flag not being implemented even though it is. This prevents that type of error. Also see discussion on D92455 -- I strongly prefer this patch here over that other one.

[compnerd]

Interesting, I expected a large fallout. I think I agree with @thakis that this is preferable to D92455.

[int3]

lgtm with the test changes from D92455. Thanks!

lld/test/MachO/fatal-warnings.s

 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t1.o
 
-# RUN: %lld %t1.o -o /dev/null -single_module 2>&1 \
+# RUN: %no_fatal_warnings_lld %t1.o -o /dev/null -single_module 2>&1 \
 # RUN:     | FileCheck -check-prefix=WARNING %s
-# RUN: not %lld %t1.o -fatal_warnings -o /dev/null -single_module 2>&1 \
-# RUN:     | FileCheck -check-prefix=ERROR %s
+# RUN: not %no_fatal_warnings_lld %t1.o -fatal_warnings -o /dev/null \
+# RUN:     -single_module 2>&1 | FileCheck -check-prefix=ERROR %s
 
 # ERROR: error: Option `-single_module' is deprecated
 # WARNING: warning: Option `-single_module' is deprecated
 
 .globl _main
 _main:

lld/test/MachO/lit.local.cfg

 # -*- Python -*-
 
 import os
 
-config.substitutions.append(('%lld', 'lld -flavor darwinnew -syslibroot ' +
-  os.path.join(config.test_source_root, "MachO", "Inputs", "MacOSX.sdk")))
+lld = ('lld -flavor darwinnew -syslibroot ' +
+    os.path.join(config.test_source_root, "MachO", "Inputs", "MacOSX.sdk"))
+config.substitutions.append(('%lld', lld + ' -fatal_warnings'))
+config.substitutions.append(('%no_fatal_warnings_lld', lld))

lld/test/MachO/load-commands.s

 # REQUIRES: x86
 # RUN: rm -rf %t && mkdir -p %t
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t/test.o
 # RUN: %lld -o %t/executable %t/test.o
-# RUN: %lld -fatal_warnings -execute -o %t/explicit-executable %t/test.o
-# RUN: %lld -fatal_warnings -bundle -o %t/bundle %t/test.o
-# RUN: %lld -fatal_warnings -dylib -o %t/dylib %t/test.o
+# RUN: %lld -execute -o %t/explicit-executable %t/test.o
+# RUN: %lld -bundle -o %t/bundle %t/test.o
+# RUN: %lld -dylib -o %t/dylib %t/test.o
 
 ## These load commands should be in every final output binary.
 # COMMON-DAG: cmd LC_DYLD_INFO_ONLY
 # COMMON-DAG: cmd LC_SYMTAB
 # COMMON-DAG: cmd LC_DYSYMTAB
 # COMMON-DAG: cmd LC_UUID
 
 ## Check for the presence of load commands that are essential for a working

lld/test/MachO/x86-64-reloc-unsigned.s

 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
 # RUN: %lld -o %t %t.o
 # RUN: llvm-objdump --macho --rebase --full-contents %t | FileCheck %s
 
-# RUN: %lld -fatal_warnings -pie -o %t-pie %t.o
+# RUN: %lld -pie -o %t-pie %t.o
 # RUN: llvm-objdump --macho --rebase %t-pie | FileCheck %s --check-prefix=PIE
-# RUN: %lld -fatal_warnings -pie -no_pie -o %t-no-pie %t.o
+# RUN: %lld -pie -no_pie -o %t-no-pie %t.o
 # RUN: llvm-objdump --macho --rebase %t-no-pie | FileCheck %s --check-prefix=NO-PIE
-# RUN: %lld -fatal_warnings -no_pie -pie -o %t-no-pie %t.o
+# RUN: %lld -no_pie -pie -o %t-no-pie %t.o
 # RUN: llvm-objdump --macho --rebase %t-no-pie | FileCheck %s --check-prefix=NO-PIE
 
 # RUN: %lld -platform_version macos 10.6.0 11.0 -o %t-pie %t.o
 # RUN: llvm-objdump --macho --rebase %t-pie | FileCheck %s --check-prefix=PIE
 # RUN: %lld -platform_version macos 10.5.0 11.0 -o %t-no-pie %t.o
 # RUN: llvm-objdump --macho --rebase %t-no-pie | FileCheck %s --check-prefix=NO-PIE
 
 # CHECK:       Contents of section __DATA,foo: