tools: moveconfig: check compilers before starting defconfig walk

Since commit 25400090b1e2 ("moveconfig: Print a message for
missing compiler"), this tool parses an error message every time an
error occurs during the process in order to detect missing compiler.

Instead of that, we can look for compilers in the PATH environment
only once before starting the defconfig walk.  If a desired compiler
is missing, "make include/config/auto.conf" will apparently fail for
that architecture.  So, the tool can just skip those board, showing
"Compiler is missing.  Do nothing.".

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>

tools/moveconfig.py

@@ -82,7 +82,12 @@ It looks like one of the followings:
    This config option was not found in the config header.
    Nothing to do.
 
- - Failed to process.  Skip.
+ - Compiler is missing.  Do nothing.
+   The compiler specified for this architecture was not found
+   in your PATH environment.
+   (If -e option is passed, the tool exits immediately.)
+
+ - Failed to process.
    An error occurred during processing this defconfig.  Skipped.
    (If -e option is passed, the tool exits immediately on error.)
 
@@ -272,7 +277,7 @@ def log_msg(color_enabled, color, defconfig, msg):
     return defconfig[:-len('_defconfig')].ljust(37) + ': ' + \
         color_text(color_enabled, color, msg) + '\n'
 
-def update_cross_compile():
+def update_cross_compile(color_enabled):
     """Update per-arch CROSS_COMPILE via environment variables
 
     The default CROSS_COMPILE values are available
@@ -286,6 +291,9 @@ def update_cross_compile():
 
     export CROSS_COMPILE_ARM=...
     export CROSS_COMPILE_POWERPC=...
+
+    Then, this function checks if specified compilers really exist in your
+    PATH environment.
     """
     archs = []
 
@@ -299,8 +307,20 @@ def update_cross_compile():
     for arch in archs:
         env = 'CROSS_COMPILE_' + arch.upper()
         cross_compile = os.environ.get(env)
-        if cross_compile:
-            CROSS_COMPILE[arch] = cross_compile
+        if not cross_compile:
+            cross_compile = CROSS_COMPILE.get(arch, '')
+
+        for path in os.environ["PATH"].split(os.pathsep):
+            gcc_path = os.path.join(path, cross_compile + 'gcc')
+            if os.path.isfile(gcc_path) and os.access(gcc_path, os.X_OK):
+                break
+        else:
+            print >> sys.stderr, color_text(color_enabled, COLOR_YELLOW,
+                 'warning: %sgcc: not found in PATH.  %s architecture boards will be skipped'
+                                            % (cross_compile, arch))
+            cross_compile = None
+
+        CROSS_COMPILE[arch] = cross_compile
 
 def cleanup_one_header(header_path, patterns, dry_run):
     """Clean regex-matched lines away from a file.
@@ -387,6 +407,10 @@ class KconfigParser:
 
         Returns:
           A string storing the compiler prefix for the architecture.
+          Return a NULL string for architectures that do not require
+          compiler prefix (Sandbox and native build is the case).
+          Return None if the specified compiler is missing in your PATH.
+          Caller should distinguish '' and None.
         """
         arch = ''
         cpu = ''
@@ -400,13 +424,14 @@ class KconfigParser:
             if m:
                 cpu = m.group(1)
 
-        assert arch, 'Error: arch is not defined in %s' % defconfig
+        if not arch:
+            return None
 
         # fix-up for aarch64
         if arch == 'arm' and cpu == 'armv8':
             arch = 'aarch64'
 
-        return CROSS_COMPILE.get(arch, '')
+        return CROSS_COMPILE.get(arch, None)
 
     def parse_one_config(self, config_attr, defconfig_lines, autoconf_lines):
         """Parse .config, defconfig, include/autoconf.mk for one config.
@@ -606,21 +631,12 @@ class Slot:
             return False
 
         if self.ps.poll() != 0:
-            errmsg = 'Failed to process.'
-            errout = self.ps.stderr.read()
-            if errout.find('gcc: command not found') != -1:
-                errmsg = 'Compiler not found ('
-                errmsg += color_text(self.options.color, COLOR_YELLOW,
-                                     self.cross_compile)
-                errmsg += color_text(self.options.color, COLOR_LIGHT_RED,
-                                     ')')
-            print >> sys.stderr, log_msg(self.options.color,
-                                         COLOR_LIGHT_RED,
-                                         self.defconfig,
-                                         errmsg),
+            print >> sys.stderr, log_msg(self.options.color, COLOR_LIGHT_RED,
+                                         self.defconfig, "Failed to process."),
             if self.options.verbose:
                 print >> sys.stderr, color_text(self.options.color,
-                                                COLOR_LIGHT_CYAN, errout)
+                                                COLOR_LIGHT_CYAN,
+                                                self.ps.stderr.read())
             if self.options.exit_on_error:
                 sys.exit("Exit on error.")
             # If --exit-on-error flag is not set, skip this board and continue.
@@ -651,15 +667,24 @@ class Slot:
             return True
 
         self.cross_compile = self.parser.get_cross_compile()
+        if self.cross_compile is None:
+            print >> sys.stderr, log_msg(self.options.color, COLOR_YELLOW,
+                                         self.defconfig,
+                                         "Compiler is missing.  Do nothing."),
+            if self.options.exit_on_error:
+                sys.exit("Exit on error.")
+            # If --exit-on-error flag is not set, skip this board and continue.
+            # Record the failed board.
+            self.failed_boards.append(self.defconfig)
+            self.state = STATE_IDLE
+            return True
+
         cmd = list(self.make_cmd)
         if self.cross_compile:
             cmd.append('CROSS_COMPILE=%s' % self.cross_compile)
         cmd.append('KCONFIG_IGNORE_DUPLICATES=1')
         cmd.append('include/config/auto.conf')
-        """This will be screen-scraped, so be sure the expected text will be
-        returned consistently on every machine by setting LANG=C"""
         self.ps = subprocess.Popen(cmd, stdout=self.devnull,
-                                   env=dict(os.environ, LANG='C'),
                                    stderr=subprocess.PIPE)
         self.state = STATE_AUTOCONF
         return False
@@ -907,7 +932,7 @@ def main():
 
     check_top_directory()
 
-    update_cross_compile()
+    update_cross_compile(options.color)
 
     if not options.cleanup_headers_only:
         move_config(config_attrs, options)