From 878eb0ad9837997247ce08479df080a06b035637 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ciro=20Santilli=20=E5=85=AD=E5=9B=9B=E4=BA=8B=E4=BB=B6=20?=
 =?UTF-8?q?=E6=B3=95=E8=BD=AE=E5=8A=9F?= <ciro.santilli@gmail.com>
Date: Tue, 21 May 2019 00:00:00 +0000
Subject: [PATCH] build: use just gcc instead of x86_64-linux-gnu-gcc when host
 arch == target arch and --gcc-which host

This is particularly important to easily build userland content on host,
as different distros will have different prefixes as mentioned at:
https://github.com/cirosantilli/linux-kernel-module-cheat/issues/66
---
 build-linux   |  2 +-
 build-modules |  2 +-
 common.py     | 11 +++++++++--
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/build-linux b/build-linux
index a49f6f6..773775f 100755
--- a/build-linux
+++ b/build-linux
@@ -102,7 +102,7 @@ Run `make modules_install` after `make`.
             'make', LF,
             '-j', str(self.env['nproc']), LF,
             'ARCH={}'.format(self.env['linux_arch']), LF,
-            'CROSS_COMPILE={}-'.format(self.env['toolchain_prefix']), LF,
+            'CROSS_COMPILE={}'.format(self.env['toolchain_prefix_dash']), LF,
             'CC={}'.format(cc), LF,
             'O={}'.format(build_dir), LF,
         ] + verbose
diff --git a/build-modules b/build-modules
index 6f1b344..bef0bfb 100755
--- a/build-modules
+++ b/build-modules
@@ -102,7 +102,7 @@ Place the modules on a separate magic directory from non --host builds.
                     'ARCH={}'.format(self.env['linux_arch']), LF,
                     'CC={}'.format(cc), LF,
                     'CCFLAGS={}'.format(self.sh.cmd_to_string(ccflags)), LF,
-                    'CROSS_COMPILE={}-'.format(self.env['toolchain_prefix']), LF,
+                    'CROSS_COMPILE={}'.format(self.env['toolchain_prefix_dash']), LF,
                     'LINUX_DIR={}'.format(linux_dir), LF,
                     'M={}'.format(build_subdir), LF,
                     'OBJECT_FILES={}'.format(' '.join(object_files)), LF,
diff --git a/common.py b/common.py
index 94f011b..dcb5b27 100644
--- a/common.py
+++ b/common.py
@@ -949,7 +949,10 @@ lunch aosp_{}-eng
                 env['crosstool_ng_toolchain_prefix']
             )
         elif env['gcc_which'] == 'host':
-            env['toolchain_prefix'] = env['ubuntu_toolchain_prefix']
+            if env['arch'] == env['host_arch']:
+                env['toolchain_prefix'] = ''
+            else:
+                env['toolchain_prefix'] = env['ubuntu_toolchain_prefix']
             if env['arch'] == 'x86_64':
                 env['userland_library_dir'] = '/'
             elif env['arch'] == 'arm':
@@ -964,6 +967,10 @@ lunch aosp_{}-eng
                 raise Exception('There is no host baremetal chain for arch: ' + env['arch'])
         else:
             raise Exception('Unknown toolchain: ' + env['gcc_which'])
+        if env['toolchain_prefix'] == '':
+            env['toolchain_prefix_dash'] = ''
+        else:
+            env['toolchain_prefix_dash'] = '{}-'.format(env['toolchain_prefix'])
         env['gcc_path'] = self.get_toolchain_tool('gcc')
         env['gxx_path'] = self.get_toolchain_tool('g++')
         env['ld_path'] = self.get_toolchain_tool('ld')
@@ -1062,7 +1069,7 @@ lunch aosp_{}-eng
         return ret
 
     def get_toolchain_tool(self, tool):
-        return '{}-{}'.format(self.env['toolchain_prefix'], tool)
+        return '{}{}'.format(self.env['toolchain_prefix_dash'], tool)
 
     def github_make_request(
             self,