check_compliance.py: Detect refs to undef. symbols in samples and tests

Extend the check for references to undefined Kconfig symbols to also
detect undefined symbols in samples and tests.

Samples and tests were skipped due to using separate Kconfig trees,
which hid the symbols defined in them. Work around it by grepping for
Kconfig symbol definitions in them instead.

Keep properly parsing the main Kconfig tree, as it's needed to see
symbol names that are stitched together with the Kconfig preprocessor.

Signed-off-by: Ulf Magnusson <[email protected]>

Author: ulfalizer

scripts/check_compliance.py

@@ -366,18 +366,14 @@ def check_no_undef_outside_kconfig(self, kconf):
         #
         #  - *, meant for comments like '#endif /* CONFIG_FOO_* */
         #
-        # We skip the samples/ and tests/ directories for now. They often
-        # contain Kconfig files that are not part of the main Kconfig tree,
-        # which will trigger false positives until we do something fancier.
-        #
-        # We also skip doc/releases, which often references removed symbols.
+        # We skip doc/releases, which often references removed symbols.
 
         # Warning: Needs to work with both --perl-regexp and the 're' module
         regex = r"\bCONFIG_[A-Z0-9_]+\b(?!\s*##|[$@{*])"
 
         grep_cmd = ["git", "grep", "--line-number", "-I", "--null",
                     "--perl-regexp", regex,
-                    "--", ":!samples", ":!tests", ":!doc/releases"]
+                    "--", ":!doc/releases"]
 
         grep_process = subprocess.Popen(grep_cmd,
                                         stdout=subprocess.PIPE,
@@ -393,7 +389,7 @@ def check_no_undef_outside_kconfig(self, kconf):
                        .format(" ".join(grep_cmd), grep_process.returncode,
                                grep_stdout, grep_stderr))
 
-        defined_syms = set(sym.name for sym in kconf.unique_defined_syms)
+        defined_syms = get_defined_syms(kconf)
         undef_to_locs = collections.defaultdict(list)
 
         # splitlines() supports various line terminators
@@ -436,6 +432,41 @@ def check_no_undef_outside_kconfig(self, kconf):
 {}""".format(os.path.basename(__file__), undef_desc))
 
 
+def get_defined_syms(kconf):
+    # Returns all defined Kconfig symbols. This is complicated by samples and
+    # tests defining their own Kconfig trees. For those, just grep for
+    # 'config FOO' to find definitions. Doing it "properly" with Kconfiglib is
+    # still useful for the main tree, because some symbols are defined using
+    # preprocessor macros.
+
+    # Warning: Needs to work with both --extended-regexp and the 're' module
+    regex = "^\s*(menu)?config\s*([A-Z0-9_]+)\s*(#|$)"
+
+    grep_cmd = ["git", "grep", "-I", "-h", "--extended-regexp", regex,
+                "--", ":samples", ":tests"]
+
+    grep_process = subprocess.Popen(grep_cmd,
+                                    stdout=subprocess.PIPE,
+                                    stderr=subprocess.PIPE,
+                                    cwd=ZEPHYR_BASE)
+
+    grep_stdout, grep_stderr = grep_process.communicate()
+    # Fail if there's anything on stderr too, so that it doesn't get missed
+    if grep_process.returncode or grep_stderr:
+        self.error("'{}' failed with exit code {} (while searching for "
+                   "Kconfig symbol definitions)\n\nstdout:\n{}\n\n"
+                   "stderr:\n{}"
+                   .format(" ".join(grep_cmd), grep_process.returncode,
+                           grep_stdout, grep_stderr))
+
+    res = set(sym.name for sym in kconf.unique_defined_syms)
+
+    for def_line in grep_stdout.decode("utf-8").splitlines():
+        res.add(re.match(regex, def_line).group(2))
+
+    return res
+
+
 # Many of these are symbols used as examples. Note that the list is sorted
 # alphabetically, and skips the CONFIG_ prefix.
 UNDEF_KCONFIG_WHITELIST = {
@@ -444,6 +475,7 @@ def check_no_undef_outside_kconfig(self, kconf):
     "CDC_ACM_PORT_NAME_",
     "CLOCK_STM32_SYSCLK_SRC_",
     "CMU",
+    "BT_6LOWPAN",  # Defined in Linux, mentioned in docs
     "COUNTER_RTC_STM32_CLOCK_SRC",
     "CRC",  # Used in TI CC13x2 / CC26x2 SDK comment
     "DEEP_SLEEP",  # #defined by RV32M1 in ext/
@@ -469,13 +501,15 @@ def check_no_undef_outside_kconfig(self, kconf):
     "PEDO_THS_MIN",
     "REG1",
     "REG2",
+    "SAMPLE_MODULE_LOG_LEVEL",  # Used as an example in samples/subsys/logging
     "SEL",
     "SHIFT",
     "SOC_WATCH",  # Issue 13749
     "SOME_BOOL",
     "SOME_INT",
     "SOME_OTHER_BOOL",
     "SOME_STRING",
+    "SRAM2",  # Referenced in a comment in samples/application_development
     "STACK_SIZE",  # Used as an example in the Kconfig docs
     "STD_CPP",  # Referenced in CMake comment
     "TEST1",