Improve brand detection for ld

Author: jimporter

bfg9000/platforms/core.py

@@ -1,4 +1,5 @@
 import importlib_metadata as metadata
+import os
 import platform
 import re
 import subprocess
@@ -49,6 +50,8 @@ def _result(arch, vendor_sys, abi=None):
 
 @memoize
 def platform_name():
+    if 'BFG_FORCE_PLATFORM' in os.environ:
+        return os.environ['BFG_FORCE_PLATFORM']
     system = platform.system().lower()
     if system.startswith('cygwin'):
         return 'cygwin'

bfg9000/tools/cc/__init__.py

@@ -58,21 +58,26 @@ def __init__(self, env, langinfo, command, found, version_output):
         arflags_name = arinfo.var('flags').lower()
         arflags = shell.split(env.getvar(arinfo.var('flags'), 'cr'))
 
-        # macOS's ld doesn't support --version, but we can still try it out and
-        # grab the command line.
         ld_command = None
         try:
-            stdout, stderr = env.execute(
-                command + ldflags + ['-v', '-Wl,--version'],
-                stdout=shell.Mode.pipe, stderr=shell.Mode.pipe,
+            # Pass a sentinel flag to the linker so we can examine the verbose
+            # compiler output and try to determine which linker we're using.
+            output = env.execute(
+                command + ldflags + ['-v', '-Wl,-v', '-Wl,--not-a-real-flag'],
+                stdout=shell.Mode.pipe, stderr=shell.Mode.stdout,
                 returncode='any'
             )
 
-            for line in stderr.split('\n'):
-                if '--version' in line:
-                    ld_command = shell.split(line)[0:1]
-                    if os.path.basename(ld_command[0]) != 'collect2':
-                        break
+            for line in output.split('\n'):
+                if '--not-a-real-flag' in line:
+                    args = shell.split(line)
+                    if os.path.basename(args[0]) != 'collect2':
+                        try:
+                            shell.which(args[0])
+                            ld_command = args[0:1]
+                            break
+                        except FileNotFoundError:
+                            pass
         except (OSError, shell.CalledProcessError):
             pass
 
@@ -96,7 +101,7 @@ def __init__(self, env, langinfo, command, found, version_output):
             ),
         }
         if ld_command:
-            self._linkers['raw'] = LdLinker(self, env, ld_command, stdout)
+            self._linkers['raw'] = LdLinker(self, env, ld_command)
 
         self.packages = CcPackageResolver(self, env, command, ldflags)
         self.runner = None

bfg9000/tools/ld.py

@@ -6,25 +6,40 @@
 
 
 class LdLinker:
-    def __init__(self, builder, env, command, version_output):
+    def __init__(self, builder, env, command):
         self.builder = builder
         self.env = env
         self.command = command
         # Currently, if we're constructing this object, we know the command has
         # been found.
         self.found = True
 
+        version_output = self.check_command(env, command)
         if 'GNU ld' in version_output:
             self.brand = 'bfd'
             self.version = detect_version(version_output)
         elif 'GNU gold' in version_output:
             self.brand = 'gold'
-            self.version = detect_version(version_output, post='$',
-                                          flags=re.MULTILINE)
+            self.version = detect_version(version_output, post='$', flags=re.M)
+        elif 'LLD' in version_output:
+            self.brand = 'lld'
+            self.version = detect_version(version_output)
+        elif '@(#)PROGRAM:ld' in version_output:
+            self.brand = 'apple'
+            self.version = detect_version(version_output)
         else:
             self.brand = 'unknown'
             self.version = None
 
+    @staticmethod
+    def check_command(env, command):
+        try:
+            return env.execute(command + ['--version'], stdout=shell.Mode.pipe,
+                               stderr=shell.Mode.devnull)
+        except shell.CalledProcessError:
+            return env.execute(command + ['-v'], stdout=shell.Mode.pipe,
+                               stderr=shell.Mode.devnull)
+
     @property
     def lang(self):
         return self.builder.lang

bfg9000/tools/yacc.py

@@ -40,7 +40,7 @@ def __init__(self, env, langinfo, command, found, version_output):
 
     @staticmethod
     def _parse_brand(version_output):
-        if 'bison' in version_output:
+        if 'GNU Bison' in version_output:
             return 'bison', detect_version(version_output)
         return 'unknown', None
 

test/unit/tools/test_ld.py

@@ -47,6 +47,20 @@ def test_gnu_gold(self):
         self.assertEqual(ld.brand, 'gold')
         self.assertEqual(ld.version, Version('1.11'))
 
+    def test_lld(self):
+        version = 'LLD 10.0.0 (compatible with GNU linkers)'
+        ld = LdLinker(None, self.env, ['ld'], version)
+
+        self.assertEqual(ld.brand, 'lld')
+        self.assertEqual(ld.version, Version('10.0.0'))
+
+    def test_apple(self):
+        version = '@(#)PROGRAM:ld PROJECT:ld-1167.5'
+        ld = LdLinker(None, self.env, ['ld'], version)
+
+        self.assertEqual(ld.brand, 'apple')
+        self.assertEqual(ld.version, Version('1167.5'))
+
     def test_unknown_brand(self):
         version = 'unknown'
         ld = LdLinker(None, self.env, ['ld'], version)