oeqa/poisoning: fix gcc include poisoning test

The test code in poison was flawed: as long as one CPP/CC/CXX has fatal
poisoning enabled then the test passes.  However, at the moment due to
a bad rebase only CPP has fatal poisoning and CC/CXX do not.

Rewrite the do_compile() task to more carefully check the output so the
test harness itself just has to bitbake the recipe.

Note that this results in the test failing:

  ERROR: poison-1.0-r0 do_compile: C Compiler is not poisoned.
  Exit status 0, output:  cc1: warning: include location "/usr/include" is unsafe for cross-compilation [-Wpoison-system-directories]
  ERROR: poison-1.0-r0 do_compile: C++ Compiler is not poisoned.
  Exit status 0, output:  cc1plus: warning: include location "/usr/include" is unsafe for cross-compilation [-Wpoison-system-directories]

(From OE-Core rev: 5b413d1fdb4bdbaec86d630bb52c3ccf68aae789)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-selftest/recipes-test/poison/poison.bb

@@ -8,13 +8,25 @@ inherit nopackages
 # This test confirms that compiling code that searches /usr/include for headers
 # will result in compiler errors.  This recipe should will fail to build and
 # oe-selftest has a test that verifies that.
-do_compile() {
-    bbnote Testing preprocessor
-    echo "int main(int argc, char** argv) {}" | ${CPP} -I/usr/include -
-    bbnote Testing C compiler
-    echo "int main(int argc, char** argv) {}" | ${CC} -x c -I/usr/include -
-    bbnote Testing C++ compiler
-    echo "int main(int argc, char** argv) {}" | ${CC} -x c++ -I/usr/include -
+python do_compile() {
+    import subprocess
+
+    tests = {
+        "Preprocessor": "${CPP} -I/usr/include -",
+        "C Compiler": "${CC} -I/usr/include -x c -",
+        "C++ Compiler": "${CXX} -I/usr/include -x c++ -",
+    }
+
+    for name, cmd in tests.items():
+        cmd = d.expand(cmd)
+        bb.note("Test command: " + cmd)
+        testcode = "int main(int argc, char** argv) {}"
+        proc = subprocess.run(cmd, shell=True, input=testcode, capture_output=True, text=True)
+
+        if proc.returncode != 0 and "is unsafe for cross-compilation" in proc.stderr:
+            bb.note(f"{name} passed: {proc.stderr}")
+        else:
+            bb.error(f"{name} is not poisoned. Exit status {proc.returncode}, output: {proc.stdout} {proc.stderr}")
 }
 
 EXCLUDE_FROM_WORLD = "1"

meta/lib/oeqa/selftest/cases/buildoptions.py

@@ -234,6 +234,5 @@ PREMIRRORS = "\\
 
 class Poisoning(OESelftestTestCase):
     def test_poisoning(self):
-        res = bitbake("poison", ignore_status=True)
-        self.assertNotEqual(res.status, 0)
-        self.assertTrue("is unsafe for cross-compilation" in res.output)
+        # The poison recipe fails if the poisoning didn't work
+        bitbake("poison")