[meta-virtualization] [PATCH] lxc: logs: use base filenames when reporting src files

[Jim Somerville]

Problem:  Logs are nice in that they report the source file,
routine, and line number where an issue occurs.  But the
file is printed as the absolute filename.  Users do not
need to see a long spew of path directory names where the package
just happened to have been built on some host somewhere.  It
can be confusing to anyone other than the developer.

Solution:  Introduce a configure option to chop off all leading
directories so that just the source filename ie. basename is printed.

[ Upstream status:  Not needed.  These absolute filenames are a
  consequence of poky/bitbake feeding the absolute filenames to
  the compiler.  If you build lxc outside of poky/bitbake, just
  the basenames are fed to the compiler. ]

Signed-off-by: Jim Somerville <Jim.Somerville at windriver.com>
---
 ...ally-use-base-filenames-to-report-src-fil.patch | 70 ++++++++++++++++++++++
 recipes-containers/lxc/lxc_1.1.3.bb                |  3 +
 2 files changed, 73 insertions(+)
 create mode 100644 recipes-containers/lxc/files/logs-optionally-use-base-filenames-to-report-src-fil.patch

diff --git a/recipes-containers/lxc/files/logs-optionally-use-base-filenames-to-report-src-fil.patch b/recipes-containers/lxc/files/logs-optionally-use-base-filenames-to-report-src-fil.patch
new file mode 100644
index 0000000..583b6f1
--- /dev/null
+++ b/recipes-containers/lxc/files/logs-optionally-use-base-filenames-to-report-src-fil.patch
@@ -0,0 +1,70 @@
+From 4729d0f4c4d1dacd150ddfd7061dda875eb94e34 Mon Sep 17 00:00:00 2001
+Message-Id: <4729d0f4c4d1dacd150ddfd7061dda875eb94e34.1443216870.git.Jim.Somerville at windriver.com>
+From: Jim Somerville <Jim.Somerville at windriver.com>
+Date: Fri, 25 Sep 2015 15:08:17 -0400
+Subject: [PATCH 1/1] logs: optionally use base filenames to report src files
+
+Problem:  Logs are nice in that they report the source file,
+routine, and line number where an issue occurs.  But the
+file is printed as the absolute filename.  Users do not
+need to see a long spew of path directory names where the package
+was built.  It just confuses things.
+
+Solution:  Optionally chop off all leading directories so that just
+the source filename ie. basename is printed.  This is done by
+setting a #ifdef LXC_LOG_USE_BASENAME check in the code.  That
+define is done via the optional --enable-log-src-basename provided
+at configure time.
+
+Using __BASE_FILE__ instead of __FILE__ did not work.  It
+refers to the file name as presented to the compile
+machinery, and that may still be the absolute pathname to
+the file.
+
+Signed-off-by: Jim Somerville <Jim.Somerville at windriver.com>
+---
+ configure.ac  | 9 +++++++++
+ src/lxc/log.h | 5 +++++
+ 2 files changed, 14 insertions(+)
+
+diff --git a/configure.ac b/configure.ac
+index deba90b..c1ed67b 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -357,6 +357,15 @@ AM_COND_IF([ENABLE_PYTHON],
+ 	PKG_CHECK_MODULES([PYTHONDEV], [python3 >= 3.2],[],[AC_MSG_ERROR([You must install python3-dev])])
+ 	AC_DEFINE_UNQUOTED([ENABLE_PYTHON], 1, [Python3 is available])])
+ 
++# Enable basenames in the logs for source files
++AC_ARG_ENABLE([log-src-basename],
++	[AC_HELP_STRING([--enable-log-src-basename], [Use the shorter source file basename in the logs [default=no]])],
++	[], [enable_log_src_basename=no])
++
++if test "x$enable_log_src_basename" = "xyes"; then
++	AC_DEFINE([LXC_LOG_USE_BASENAME], 1, [Enabling shorter src filenames in the logs])
++fi
++
+ # Enable dumping stack traces
+ AC_ARG_ENABLE([mutex-debugging],
+ 	[AC_HELP_STRING([--enable-mutex-debugging], [Makes mutexes to report error and provide stack trace [default=no]])],
+diff --git a/src/lxc/log.h b/src/lxc/log.h
+index 76bd4df..4365977 100644
+--- a/src/lxc/log.h
++++ b/src/lxc/log.h
+@@ -74,8 +74,13 @@ struct lxc_log_locinfo {
+ 	int		line;
+ };
+ 
++#ifdef LXC_LOG_USE_BASENAME
++#define LXC_LOG_LOCINFO_INIT						\
++	{ .file = (strrchr(__FILE__, '/') ? strrchr(__FILE__, '/') + 1 : __FILE__), .func = __func__, .line = __LINE__	}
++#else
+ #define LXC_LOG_LOCINFO_INIT						\
+ 	{ .file = __FILE__, .func = __func__, .line = __LINE__	}
++#endif
+ 
+ /* brief logging event object */
+ struct lxc_log_event {
+-- 
+1.8.3.2
+
diff --git a/recipes-containers/lxc/lxc_1.1.3.bb b/recipes-containers/lxc/lxc_1.1.3.bb
index d1e80c4..e61aa6d 100644
--- a/recipes-containers/lxc/lxc_1.1.3.bb
+++ b/recipes-containers/lxc/lxc_1.1.3.bb
@@ -33,6 +33,7 @@ SRC_URI = "http://linuxcontainers.org/downloads/${BPN}-${PV}.tar.gz \
 	file://lxc-busybox-add-OpenSSH-support.patch \
 	file://make-some-OpenSSH-tools-optional.patch \
 	file://lxc-doc-upgrade-to-use-docbook-3.1-DTD.patch \
+	file://logs-optionally-use-base-filenames-to-report-src-fil.patch \
 	"
 
 SRC_URI[md5sum] = "197abb5a28ab0b689c737eb1951023fb"
@@ -49,6 +50,8 @@ EXTRA_OECONF += "--with-init-script=\
 ${@bb.utils.contains('DISTRO_FEATURES', 'sysvinit', 'sysvinit,', '', d)}\
 ${@bb.utils.contains('DISTRO_FEATURES', 'systemd', 'systemd', '', d)}"
 
+EXTRA_OECONF += "--enable-log-src-basename"
+
 PACKAGECONFIG ??= "templates \
     ${@base_contains('DISTRO_FEATURES', 'selinux', 'selinux', '', d)} \
 "
-- 
1.8.3.2