tcmode: add compilation toolchain sanity test

It's not ideal to do this for every build, but it's not terrible, either, and
is worth the cost to get an error up front if there's a configuration or
licensing problem. master deals with this more cleanly.

JIRA: SB-8257

Signed-off-by: Christopher Larson <chris_larson@mentor.com>

conf/distro/include/tcmode-external-sourcery.inc

@@ -258,7 +258,10 @@ def set_vars_from_toolchains(codebench_path, d):
 
 
 python toolchain_sanity_check () {
-    d = e.data
+    import shlex
+    import subprocess
+    import tempfile
+
     external_toolchain = d.getVar('EXTERNAL_TOOLCHAIN', True)
     if not external_toolchain or external_toolchain == 'UNDEFINED':
         bb.fatal("EXTERNAL_TOOLCHAIN must be set to the path to your sourcery toolchain")
@@ -275,6 +278,24 @@ python toolchain_sanity_check () {
 
     if d.getVar('GCC_VERSION', True) == 'UNKNOWN':
         bb.warn("EXTERNAL_TOOLCHAIN gcc version extraction failed, see debug messages for details")
+
+    with tempfile.TemporaryDirectory() as tmpdir:
+        with open(os.path.join(tmpdir, 'test.c'), 'w') as f:
+            f.write('int main() {}')
+
+        # The external toolchain recipes haven't necessarily been built, so we
+        # need to drop --sysroot= and --no-sysroot-suffix and use the bits in
+        # the external toolchain sysroots for this test
+        l = d.createCopy()
+        l.setVar('TOOLCHAIN_OPTIONS', '')
+        l.setVar('HOST_CC_ARCH_remove', '--no-sysroot-suffix')
+        cmd = l.expand('${EXTERNAL_TOOLCHAIN}/bin/${CC} ${CFLAGS} ${LDFLAGS} test.c -o test')
+        try:
+            subprocess.check_output(shlex.split(cmd), cwd=tmpdir, stderr=subprocess.STDOUT)
+        except subprocess.CalledProcessError as exc:
+            output = exc.output.decode()
+            output_indented = ''.join('    ' + l for l in output.splitlines(keepends=True))
+            bb.fatal("Toolchain sanity test failed:\n  Command: %s\n  Output:\n%s" % (cmd, output_indented))
 }
 
 # This runs at TreeDataPreparationStarted time, as we want bitbake -e to work,