oeqa/utils/command: fast-path get_bb_var()

get_bb_var() currently end up calling 'bitbake -e' and parsing the whole
output. However if postconfig isn't set then we can speed this up by
just calling bitbake-getvar.

The complication with failing bitbake-getvar calls is because we need to
be careful to return None instead of the empty string when the variable
doesn't exist.

(From OE-Core rev: fafe77879aa6225aa8b5187ff590bb4998cbf987)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/meta/lib/oeqa/utils/commands.py b/meta/lib/oeqa/utils/commands.py
index 2a47f90e32..b60a6e6c38 100644
--- a/meta/lib/oeqa/utils/commands.py
+++ b/meta/lib/oeqa/utils/commands.py
@@ -285,7 +285,20 @@ def get_bb_vars(variables=None, target=None, postconfig=None):
     return values
 
 def get_bb_var(var, target=None, postconfig=None):
-    return get_bb_vars([var], target, postconfig)[var]
+    if postconfig:
+        return bitbake("-e %s" % target or "", postconfig=postconfig).output
+    else:
+        # Fast-path for the non-postconfig case
+        cmd = ["bitbake-getvar", "--quiet", "--value", var]
+        if target:
+            cmd.extend(["--recipe", target])
+        try:
+            return subprocess.run(cmd, check=True, text=True, stdout=subprocess.PIPE).stdout.strip()
+        except subprocess.CalledProcessError as e:
+            # We need to return None not the empty string if the variable hasn't been set.
+            if e.returncode == 1:
+                return None
+            raise
 
 def get_test_layer(bblayers=None):
     if bblayers is None: