Let emerge fix .la files

Triggered by FEATURES="lafilefixing" (enabled by default)
Includes a QA warning for invalid .la files.

1 files changed, 176 insertions, 0 deletions

diff --git a/pym/portage/util/lafilefixer.py b/pym/portage/util/lafilefixer.py
new file mode 100644
index 000000000..90cc43541
--- /dev/null
+++ b/pym/portage/util/lafilefixer.py
@@ -0,0 +1,176 @@
+# Copyright 2010 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+import re
+
+from portage import os
+from portage.exception import InvalidData
+
+#########################################################
+#	This an re-implementaion of dev-util/lafilefixer-0.5.
+#	rewrite_lafile() takes the contents of an lafile as a string
+#	It then parses the dependency_libs and inherited_linker_flags
+#	entries. 
+#	We insist on dependency_libs being present. inherited_linker_flags
+#	is optional.
+#	There are strict rules about the syntax imposed by libtool's libltdl.
+#	See 'parse_dotla_file' and 'trim' functions in libltdl/ltdl.c.
+#	Note that duplicated entries of dependency_libs and inherited_linker_flags
+#	are ignored by libtool (last one wins), but we treat it as error (like
+#	lafilefixer does).
+#	What it does:
+#		* Replaces all .la files with absolut paths in dependency_libs with
+#		  corresponding -l* and -L* entries 
+#		  (/usr/lib64/libfoo.la -> -L/usr/lib64 -lfoo)
+#		* Moves various flags (see flag_re below) to inherited_linker_flags,
+#		  if such an entry was present.
+#		* Reorders dependency_libs such that all -R* entries precede -L* entries
+#		  and these precede all other entries.
+#		* Remove duplicated entries from dependency_libs
+#		* Takes care that no entry to inherited_linker_flags is added that is
+#		  already there.
+#########################################################
+
+#These regexes are used to parse the interesting entries in the la file
+dep_libs_re = re.compile("dependency_libs='(?P<value>[^']*)'$")
+inh_link_flags_re = re.compile("inherited_linker_flags='(?P<value>[^']*)'$")
+
+#regexes for replacing stuff in -L entries. 
+#replace 'X11R6/lib' and 'local/lib' with 'lib', no idea what's this about.
+X11_local_sub = re.compile("X11R6/lib|local/lib")
+#get rid of the '..'
+pkgconfig_sub1 = re.compile("usr/lib[^/]*/pkgconfig/\.\./\.\.")
+pkgconfig_sub2 = re.compile("(?P<usrlib>usr/lib[^/]*)/pkgconfig/\.\.")
+
+#detect flags that should go into inherited_linker_flags instead of dependency_libs
+flag_re = re.compile("-mt|-mthreads|-kthread|-Kthread|-pthread|-pthreads|--thread-safe|-threads")
+
+def _parse_lafile_contents(contents):
+	"""
+	Parses 'dependency_libs' and 'inherited_linker_flags' lines.
+	"""
+
+	dep_libs = None
+	inh_link_flags = None
+
+	for line in contents.split("\n"):
+		m = dep_libs_re.match(line)
+		if m:
+			if dep_libs is not None:
+				raise InvalidData("duplicated dependency_libs entry")
+			dep_libs = m.group("value")
+			continue
+
+		m = inh_link_flags_re.match(line)
+		if m:
+			if inh_link_flags is not None:
+				raise InvalidData("duplicated inherited_linker_flags entry")
+			inh_link_flags = m.group("value")
+			continue
+
+	return dep_libs, inh_link_flags
+
+def rewrite_lafile(contents):
+	"""
+	Given the contents of an .la file, parse and fix it.
+	Returns a bool, string tuple. 
+	The bool indicates if the file needs fixing.
+	The string contains the fixed contents if the file needs fixing.
+	Raises 'InvalidData' if the .la file is invalid.
+	"""
+	#Parse the 'dependency_libs' and 'inherited_linker_flags' lines.
+	dep_libs, inh_link_flags = \
+		_parse_lafile_contents(contents)
+
+	if dep_libs is None:
+		raise InvalidData("missing or invalid dependency_libs")
+
+	new_dep_libs = []
+	new_inh_link_flags = []
+	librpath = []
+	libladir = []
+
+	if inh_link_flags is not None:
+		new_inh_link_flags = inh_link_flags.split()
+
+	#Check entries in 'dependency_libs'.
+	for dep_libs_entry in dep_libs.split():
+		if dep_libs_entry.startswith("-l"):
+			#-lfoo, keep it
+			if dep_libs_entry not in new_dep_libs:
+				new_dep_libs.append(dep_libs_entry)
+
+		elif dep_libs_entry.endswith(".la"):
+			#Two cases:
+			#1) /usr/lib64/libfoo.la, turn it into -lfoo and append -L/usr/lib64 to libladir
+			#2) libfoo.la, keep it
+			dir, file = os.path.split(dep_libs_entry)
+
+			if not dir or not file.startswith("lib"):
+				if dep_libs_entry not in new_dep_libs:
+					new_dep_libs.append(dep_libs_entry)
+			else:
+				#/usr/lib64/libfoo.la -> -lfoo
+				lib = "-l" + file[3:-3]
+				if lib not in new_dep_libs:
+					new_dep_libs.append(lib)
+				#/usr/lib64/libfoo.la -> -L/usr/lib64
+				ladir = "-L" + dir
+				if ladir not in libladir:
+					libladir.append(ladir)
+
+		elif dep_libs_entry.startswith("-L"):
+			#Do some replacement magic and store them in 'libladir'.
+			#This allows us to place all -L entries at the beginning
+			#of 'dependency_libs'.
+			ladir = dep_libs_entry
+			
+			ladir = X11_local_sub.sub("lib", ladir)
+			ladir = pkgconfig_sub1.sub("usr", ladir)
+			ladir = pkgconfig_sub2.sub("\g<usrlib>", ladir)
+			
+			if ladir not in libladir:
+				libladir.append(ladir)
+
+		elif dep_libs_entry.startswith("-R"):
+			if dep_libs_entry not in librpath:
+				librpath.append(dep_libs_entry)
+
+		elif flag_re.match(dep_libs_entry):
+			#All this stuff goes into inh_link_flags, if the la file has such an entry.
+			#If it doesn't, they stay in 'dependency_libs'.
+			if inh_link_flags is not None:
+				if dep_libs_entry not in new_inh_link_flags:
+					new_inh_link_flags.append(dep_libs_entry)
+			else:
+				if dep_libs_entry not in new_dep_libs:
+					new_dep_libs.append(dep_libs_entry)
+
+		else:
+			raise InvalidData("Error: Unexpected entry '%s' in 'dependency_libs'" \
+				% dep_libs_entry)
+
+	#What should 'dependency_libs' and 'inherited_linker_flags' look like?
+	expected_dep_libs = ""
+	for x in (librpath, libladir, new_dep_libs):
+		if x:
+			expected_dep_libs += " " + " ".join(x)
+
+	expected_inh_link_flags = ""
+	if new_inh_link_flags:
+		expected_inh_link_flags += " " + " ".join(new_inh_link_flags)
+
+	#Don't touch the file if we don't need to, otherwise put the expected values into
+	#'contents' and write it into the la file.
+	if dep_libs == expected_dep_libs and \
+		(inh_link_flags is None or expected_inh_link_flags == inh_link_flags):
+		return False, None
+
+	contents = re.sub("dependency_libs='" + dep_libs + "'", \
+		"dependency_libs='" + expected_dep_libs + "'" , contents)
+
+	if inh_link_flags is not None:
+		contents = re.sub("inherited_linker_flags='" + inh_link_flags + "'", \
+			"inherited_linker_flags='" + expected_inh_link_flags + "'" , contents)
+
+	return True, contents