update-alternatives.bbclass: Add function to get metadata

This adds update_alternatives_alt_targets function to get the metadata
for a package. This is for code reuse because the metadata would help
other classes that needs to be aware of how update-alternatives modify
the final package.

[YOCTO #12597]
[YOCTO #13238]

(From OE-Core rev: 04d966c0a91c5e16555bba827969a0a2fd96bb96)

Signed-off-by: Mariano Lopez <just.another.mariano@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 45 insertions, 25 deletions

diff --git a/meta/classes/update-alternatives.bbclass b/meta/classes/update-alternatives.bbclass
index 537e85d9a3..b702e77ee5 100644
--- a/meta/classes/update-alternatives.bbclass
+++ b/meta/classes/update-alternatives.bbclass
@@ -216,42 +216,62 @@ python apply_update_alternative_renames () {
             update_files(alt_target, alt_target_rename, pkg, d)
 }
 
+def update_alternatives_alt_targets(d, pkg):
+    """
+    Returns the update-alternatives metadata for a package.
+
+    The returned format is a list of tuples where the tuple contains:
+    alt_name:     The binary name
+    alt_link:     The path for the binary (Shared by different packages)
+    alt_target:   The path for the renamed binary (Unique per package)
+    alt_priority: The priority of the alt_target
+
+    All the alt_targets will be installed into the sysroot. The alt_link is
+    a symlink pointing to the alt_target with the highest priority.
+    """
+
+    pn = d.getVar('BPN')
+    pkgdest = d.getVar('PKGD')
+    updates = list()
+    for alt_name in (d.getVar('ALTERNATIVE_%s' % pkg) or "").split():
+        alt_link     = d.getVarFlag('ALTERNATIVE_LINK_NAME', alt_name)
+        alt_target   = d.getVarFlag('ALTERNATIVE_TARGET_%s' % pkg, alt_name) or \
+                       d.getVarFlag('ALTERNATIVE_TARGET', alt_name) or \
+                       d.getVar('ALTERNATIVE_TARGET_%s' % pkg) or \
+                       d.getVar('ALTERNATIVE_TARGET') or \
+                       alt_link
+        alt_priority = d.getVarFlag('ALTERNATIVE_PRIORITY_%s' % pkg,  alt_name) or \
+                       d.getVarFlag('ALTERNATIVE_PRIORITY',  alt_name) or \
+                       d.getVar('ALTERNATIVE_PRIORITY_%s' % pkg) or  \
+                       d.getVar('ALTERNATIVE_PRIORITY')
+
+        # This shouldn't trigger, as it should have been resolved earlier!
+        if alt_link == alt_target:
+            bb.note('alt_link == alt_target: %s == %s -- correcting, this should not happen!' % (alt_link, alt_target))
+            alt_target = '%s.%s' % (alt_target, pn)
+
+        if not os.path.lexists('%s/%s' % (pkgdest, alt_target)):
+            bb.warn('%s: NOT adding alternative provide %s: %s does not exist' % (pn, alt_link, alt_target))
+            continue
+
+        alt_target = os.path.normpath(alt_target)
+        updates.append( (alt_name, alt_link, alt_target, alt_priority) )
+
+    return updates
+
 PACKAGESPLITFUNCS_prepend = "populate_packages_updatealternatives "
 
 python populate_packages_updatealternatives () {
     if not update_alternatives_enabled(d):
         return
 
-    pn = d.getVar('BPN')
-
     # Do actual update alternatives processing
-    pkgdest = d.getVar('PKGD')
     for pkg in (d.getVar('PACKAGES') or "").split():
         # Create post install/removal scripts
         alt_setup_links = ""
         alt_remove_links = ""
-        for alt_name in (d.getVar('ALTERNATIVE_%s' % pkg) or "").split():
-            alt_link     = d.getVarFlag('ALTERNATIVE_LINK_NAME', alt_name)
-            alt_target   = d.getVarFlag('ALTERNATIVE_TARGET_%s' % pkg, alt_name) or d.getVarFlag('ALTERNATIVE_TARGET', alt_name)
-            alt_target   = alt_target or d.getVar('ALTERNATIVE_TARGET_%s' % pkg) or d.getVar('ALTERNATIVE_TARGET') or alt_link
-            # Sometimes alt_target is specified as relative to the link name.
-            alt_target   = os.path.join(os.path.dirname(alt_link), alt_target)
-
-            alt_priority = d.getVarFlag('ALTERNATIVE_PRIORITY_%s' % pkg,  alt_name) or d.getVarFlag('ALTERNATIVE_PRIORITY',  alt_name)
-            alt_priority = alt_priority or d.getVar('ALTERNATIVE_PRIORITY_%s' % pkg) or d.getVar('ALTERNATIVE_PRIORITY')
-
-            # This shouldn't trigger, as it should have been resolved earlier!
-            if alt_link == alt_target:
-                bb.note('alt_link == alt_target: %s == %s -- correcting, this should not happen!' % (alt_link, alt_target))
-                alt_target = '%s.%s' % (alt_target, pn)
-
-            if not os.path.lexists('%s/%s' % (pkgdest, alt_target)):
-                bb.warn('%s: NOT adding alternative provide %s: %s does not exist' % (pn, alt_link, alt_target))
-                continue
-
-            # Default to generate shell script.. eventually we may want to change this...
-            alt_target = os.path.normpath(alt_target)
-
+        updates = update_alternatives_alt_targets(d, pkg)
+        for alt_name, alt_link, alt_target, alt_priority in updates:
             alt_setup_links  += '\tupdate-alternatives --install %s %s %s %s\n' % (alt_link, alt_name, alt_target, alt_priority)
             alt_remove_links += '\tupdate-alternatives --remove  %s %s\n' % (alt_name, alt_target)