Read LTO archives with the compiler's own llvm-nmHEADmain

The symbols test ran the system nm on the static library. Under LTO the
archive holds bitcode. Xcode's nm cannot read bitcode from a newer
Homebrew LLVM, so the test failed on macOS. With clang, the test now
asks the compiler for its llvm-nm and falls back to nm.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/tests/meson.build b/tests/meson.build
index f176a6e..f42a1de 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -1,3 +1,4 @@
+fs = import('fs')
 dl_dep = cc.find_library('dl', required: false)
 python = find_program('python3', native: true, version: '>=3.10')
 bash = find_program('bash', native: true)
@@ -9,7 +10,17 @@ test_c_args = ['-UNDEBUG']
 test_env = environment()
 test_env.set('LD_PRELOAD', '')
 test_env.set('DYLD_INSERT_LIBRARIES', '')
-test_env.set('NM', find_program('nm', native: true).full_path())
+# An LTO archive holds the compiler's bitcode. A system nm from another
+# LLVM cannot read it, so clang uses the llvm-nm of its own toolchain.
+nm = find_program('nm', native: true)
+if cc.get_id() == 'clang'
+  llvm_nm = run_command(cc.cmd_array() + ['-print-prog-name=llvm-nm'],
+                        check: false).stdout().strip()
+  if fs.is_absolute(llvm_nm) and fs.is_file(llvm_nm)
+    nm = find_program(llvm_nm)
+  endif
+endif
+test_env.set('NM', nm.full_path())
 
 # [name, sources, dependencies, suites]
 wsap_vtcore_tests = [