[Buildroot] [PATCH v2 9/9] check-package: check *.mk for typo in variable

[Ricardo Martincoski <ricardo.martincoski@gmail.com>]

Warn when a variable is defined in a .mk file and it don't start with
the package name.

This function generates false warnings and the maintenance of the
whitelist can be an extra burden, but it catches some typos really hard
to see:
- POPLER_CONF_OPTS [1]
- BALELD_LICENSE [2]
- DRDB_UTILS_DEPENDENCIES [3]
- PERL_LIBWWW_LICENSE_FILES [4]
- AVRDUDR_LICENSE_FILES [5]
- GST1_PLUGINS_ULGY_HAS_GPL_LICENSE [6]
- ON2_8170_LICENSE [7]
- LIBFDTI_CONF_OPTS [8][9]
- IPSEC_DEPENDENCIES [10]

[1] http://patchwork.ozlabs.org/patch/681533
[2] http://patchwork.ozlabs.org/patch/643293
[3] http://patchwork.ozlabs.org/patch/449589
[4] http://patchwork.ozlabs.org/patch/464545
[5] http://patchwork.ozlabs.org/patch/305060
[6] http://patchwork.ozlabs.org/patch/253089
[7] http://patchwork.ozlabs.org/patch/250523
[8] http://patchwork.ozlabs.org/patch/394125
[9] https://github.com/buildroot/buildroot/commit/fe7a4b524b72bcb448f7e723873d8244620cb2f1
[10] https://github.com/buildroot/buildroot/commit/dff1d590b2a0fadf58b6eed60029b2ecbab7c710

Signed-off-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
Cc: Romain Naour <romain.naour@gmail.com>
---
Changes v1 -> v2:
  - avoid false positive for variable of virtual package the package
    under analysis provides (e.g. MYSQL_SOCKET) (Romain);
  - use classes instead of functions to declare each check (Thomas DS);
  - I kept the examples of typos it catches, but Peter Korsgaard already
    fixed the typos listed above;
---

Notes:
    $ time support/scripts/check-package $(find package -type f) >/dev/null 2>/dev/null
    
    real	0m3.205s
    user	0m3.140s
    sys	0m0.064s
    
    TypoInPackageVariable:
     support/scripts/check-package --include-only TypoInPackageVariable \
     $(find package -name '*.mk') 2>/dev/null | wc -l
      3
     (cd support/scripts/check-package-example && \
     ../check-package --include-only TypoInPackageVariable -vv package/*/*)
      package/package1/package1.mk:33: possible typo: LINUX_DEPENDENCIES -> *PACKAGE1*
      LINUX_DEPENDENCIES = messing with others
      package/package1/package1.mk:34: possible typo: PACKACE1_DEPENDENCIES -> *PACKAGE1*
      PACKACE1_DEPENDENCIES = typo
      package/package1/package1.mk:39: possible typo: NOT_PROVIDED4_LOCK -> *PACKAGE1*
      NOT_PROVIDED4_LOCK = lock4
      180 lines processed
      3 warnings generated

 support/scripts/checkpackagelib_mk.py | 52 +++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/support/scripts/checkpackagelib_mk.py b/support/scripts/checkpackagelib_mk.py
index f66888d21..0740a37f7 100644
--- a/support/scripts/checkpackagelib_mk.py
+++ b/support/scripts/checkpackagelib_mk.py
@@ -131,6 +131,58 @@ class TrailingBackslash(_CheckFunction):
                     self.lastline]
 
 
+class TypoInPackageVariable(_CheckFunction):
+    ALLOWED = re.compile("|".join([
+        "ACLOCAL_DIR",
+        "ACLOCAL_HOST_DIR",
+        "BR_CCACHE_INITIAL_SETUP",
+        "BR_NO_CHECK_HASH_FOR",
+        "LINUX_POST_PATCH_HOOKS",
+        "LINUX_TOOLS",
+        "LUA_RUN",
+        "MKFS_JFFS2",
+        "MKIMAGE_ARCH",
+        "PKG_CONFIG_HOST_BINARY",
+        "TARGET_FINALIZE_HOOKS",
+        "XTENSA_CORE_NAME"]))
+    PACKAGE_NAME = re.compile("/([^/]+)\.mk")
+    VARIABLE = re.compile("^([A-Z0-9_]+_[A-Z0-9_]+)\s*(\+|)=")
+
+    def before(self):
+        package = self.PACKAGE_NAME.search(self.filename).group(1)
+        package = package.replace("-", "_").upper()
+        # linux tools do not use LINUX_TOOL_ prefix for variables
+        package = package.replace("LINUX_TOOL_", "")
+        self.package = package
+        self.REGEX = re.compile("^(HOST_)?({}_[A-Z0-9_]+)".format(package))
+        self.FIND_VIRTUAL = re.compile(
+            "^{}_PROVIDES\s*(\+|)=\s*(.*)".format(package))
+        self.virtual = []
+
+    def check_line(self, lineno, text):
+        m = self.VARIABLE.search(text)
+        if m is None:
+            return
+
+        variable = m.group(1)
+
+        # allow to set variables for virtual package this package provides
+        v = self.FIND_VIRTUAL.search(text)
+        if v:
+            self.virtual += v.group(2).upper().split()
+            return
+        for virtual in self.virtual:
+            if variable.startswith("{}_".format(virtual)):
+                return
+
+        if self.ALLOWED.match(variable):
+            return
+        if self.REGEX.search(text) is None:
+            return ["{}:{}: possible typo: {} -> *{}*"
+                    .format(self.filename, lineno, variable, self.package),
+                    text]
+
+
 class UselessFlag(_CheckFunction):
     DEFAULT_AUTOTOOLS_FLAG = re.compile("^.*{}".format("|".join([
         "_AUTORECONF\s*=\s*NO",
-- 
2.11.0