Use traceback module to specify CODE_{LINE,FUNC,FILE}

$python3 -c 'import journald; x = lambda: journald.send("tescik"); x()'

gives a message like:

MESSAGE=tescik
CODE_FILE=<string>
CODE_LINE=1
CODE_FUNC=<lambda>
_TRANSPORT=journal
...

This makes the CODE_* fields much more useful: before they would
always give the location of the sd_journald_sendv() call in the module
source, and now they specify the location of the caller of
journald.send().

When using the low-level journald.sendv() is becomes the
responsibility of the caller to specify the CODE_* fields.

2 files changed, 18 insertions, 4 deletions

diff --git a/journald/__init__.py b/journald/__init__.py
index b892faf..23941a6 100644
--- a/journald/__init__.py
+++ b/journald/__init__.py
@@ -1,6 +1,9 @@
+import traceback
 from ._journald import sendv
 
-def send(MESSAGE, MESSAGE_ID=None, **kwargs):
+def send(MESSAGE, MESSAGE_ID=None,
+         CODE_FILE=None, CODE_LINE=None, CODE_FUNC=None,
+         **kwargs):
     """Send a message to journald.
 
     >>> journald.send('Hello world')
@@ -16,15 +19,25 @@ def send(MESSAGE, MESSAGE_ID=None, **kwargs):
     CODE_LINE, CODE_FILE, and CODE_FUNC can be specified to identify
     the caller. Unless at least on of the three is given, values are
     extracted from the stack frame of the caller of send(). CODE_FILE
-    and CODE_FUNC should be strings, CODE_LINE should be an integer.
+    and CODE_FUNC must be strings, CODE_LINE must be an integer.
 
     Other useful fields include PRIORITY, SYSLOG_FACILITY,
     SYSLOG_IDENTIFIER, SYSLOG_PID.
     """
 
     args = ['MESSAGE=' + MESSAGE]
+
     if MESSAGE_ID is not None:
         args.append('MESSAGE_ID=' + MESSAGE_ID)
-    for key, val in kwargs.items():
-        args.append(key + '=' + val)
+
+    if CODE_LINE == CODE_FILE == CODE_FUNC == None:
+        CODE_FILE, CODE_LINE, CODE_FUNC = traceback.extract_stack(limit=2)[0][:3]
+    if CODE_FILE is not None:
+        args.append('CODE_FILE=' + CODE_FILE)
+    if CODE_LINE is not None:
+        args.append('CODE_LINE={:d}'.format(CODE_LINE))
+    if CODE_FUNC is not None:
+        args.append('CODE_FUNC=' + CODE_FUNC)
+
+    args.extend(key + '=' + val for key, val in kwargs.items())
     return sendv(*args)
diff --git a/journald/_journald.c b/journald/_journald.c
index 024ebc6..a289255 100644
--- a/journald/_journald.c
+++ b/journald/_journald.c
@@ -1,4 +1,5 @@
 #include <Python.h>
+#define SD_JOURNAL_SUPPRESS_LOCATION
 #include <systemd/sd-journal.h>
 
 static PyObject *