Re: Toolchain library whitelisting: A first pass (preliminary patch/RFC)

[Peter Seebach <peter.seebach@windriver.com>]

On Wed, 25 Apr 2012 20:38:05 -0500
Peter Seebach <peter.seebach@windriver.com> wrote:
> This is a followup from some chat in #yocto and elsewhere.

Okay, some more followup.

While testing this, I kept burning myself on perfectly reasonable
things to get wrong while defining and using multilibs, so I wrote a
bunch of sanity checks for that.

The intent of this is to validate that tunings (including multilibs)
are configured in a reasonable way that we would expect to work.  This
includes:

1.  Verifying that no multilib's tuning is the same as DEFAULTTUNE.
2.  Verifying that no multilib's library name is 'lib', because that
causes really cryptic error messages parsing recipes.
3.  For each tuning, verify:
3a.  The tuning has features.
3b.  Every feature has a TUNEVALID[x] entry.
3c.  If the feature has a TUNECONFLICTS[x] entry, no feature listed in
it is included in the feature list.
3d.  If the value TUNEABI_WHITELIST exists, the tuning's
TUNEABI_tune-foo value, or the tuning's name if that doesn't exist, is
in TUNEABI_WHITELIST, or alternatively, TUNEABI_OVERRIDE is defined.

The whitelist feature is optional, and my intent would be not to define
any TUNEABI_tune values in oe-core, but just to maintain the hooks so
that people with custom (and often prebuilt-binary) toolchains can use
it without all of us writing our own.

I am totally aware that my Python is a little rough, and would be happy
to improve the legibility or idiom.

Separately, I propose also the following fix:

     # Check TARGET_ARCH is set correctly
-    if data.getVar('TARGE_ARCH', e.data, False) == '${TUNE_ARCH}':
+    if data.getVar('TARGET_ARCH', e.data, False) == '${TUNE_ARCH}':

Anyway, the patch:

diff --git a/meta/classes/sanity.bbclass b/meta/classes/sanity.bbclass
index 687ddeb..b7f93b5 100644
--- a/meta/classes/sanity.bbclass
+++ b/meta/classes/sanity.bbclass
@@ -11,6 +11,70 @@ def raise_sanity_error(msg):
     
     %s""" % msg)
 
+# Check a single tune for validity.
+def check_toolchain_tune(data, tune, multilib):
+    tune_errors = []
+    bb.note("Sanity-checking tuning '%s' (%s) features:" % (tune, multilib))
+    features = data.getVar("TUNE_FEATURES_tune-%s" % tune, True) or ""
+    if features == '':
+        return "Tuning '%s' has no defined features, and cannot be used." % tune
+    features = features.split(' ')
+    validities = data.getVarFlags('TUNEVALID') or ""
+    conflicts = data.getVarFlags('TUNECONFLICTS') or ""
+    split_conflicts = {}
+    for feature in features:
+       if feature in conflicts:
+	   if feature not in split_conflicts:
+	       split_conflicts[feature] = conflicts[feature].split(' ')
+	   for other in features:
+	       if other in split_conflicts[feature]:
+		   tune_errors.append("Feature '%s' conflicts with '%s'." %
+		       ( feature, other ))
+       if feature in validities:
+	   bb.note("  %s: %s" % (feature, validities[feature]))
+       else:
+	   tune_errors.append("Feature '%s' is not defined." % feature)
+    whitelist = data.getVar("TUNEABI_WHITELIST", True) or ''
+    if whitelist != '':
+	override = data.getVar("TUNEABI_OVERRIDE", True) or ''
+	if not override:
+	    tuneabi = data.getVar("TUNEABI", True) or ""
+	    if tuneabi == "" or tuneabi.startswith('$'):
+		tuneabi = tune
+	    if True not in [x in whitelist.split(' ') for x in tuneabi.split(' ')]:
+		tune_errors.append("Tuning '%s' (%s) cannot be used with any supported tuning/ABI." %
+		    (tune, tuneabi))
+    if tune_errors:
+        return "Tuning '%s' has the following errors:\n" + '\n'.join(tune_errors)
+
+def check_toolchain(data):
+    tune_error_set = []
+    deftune = data.getVar("DEFAULTTUNE", True)
+    tune_errors = check_toolchain_tune(data, deftune, 'default')
+    if tune_errors:
+        tune_error_set.append(tune_errors)
+
+    multilibs = data.getVar("MULTILIBS", True) or ""
+    if multilibs != "":
+        for pairs in [x.split(':') for x in multilibs.split(' ')]:
+	    if pairs[0] != 'multilib':
+	        bb.warn("Got an unexpected '%s' in MULTILIBS." % pairs[0])
+	    else:
+		if pairs[1] == 'lib':
+		    tune_error_set.append("The multilib 'lib' was specified, but that doesn't work. You need lib32 or lib64.")
+		else:
+		    tune = data.getVar("DEFAULTTUNE_virtclass-multilib-%s" % pairs[1], True)
+		    if tune == deftune:
+		        tune_error_set.append("Multilib '%s' (%s) is also the default tuning." % (pairs[1], deftune))
+		    else:
+		        tune_errors = check_toolchain_tune(data, tune, pairs[1])
+		    if tune_errors:
+		        tune_error_set.append(tune_errors)
+    if tune_error_set:
+        return "Toolchain tunings invalid:\n" + '\n'.join(tune_error_set)
+
+    return ""
+
 def check_conf_exists(fn, data):
     bbpath = []
     fn = data.expand(fn)
@@ -327,6 +391,9 @@ def check_sanity(e):
         messages = messages + pseudo_msg + '\n'
 
     check_supported_distro(e)
+    toolchain_msg = check_toolchain(e.data)
+    if toolchain_msg != "":
+        messages = messages + toolchain_msg + '\n'
 
     # Check if DISPLAY is set if IMAGETEST is set
     if not data.getVar( 'DISPLAY', e.data, True ) and data.getVar( 'IMAGETEST', e.data, True ) == 'qemu':
-- 
Listen, get this.  Nobody with a good compiler needs to be justified.