Revise stripping and splitting of debug information

We now support two styles of debug information generation, the '.debug' style,
which is the same as previously implemented.  This style simply splits the
debug information and makes it available in the same general directory.

  /bin/foo -> /bin/.debug/foo

The new 'debug-file-directory' style splits the debug information and places
it into the single debug-file-directory, /usr/lib/debug:

  /bin/foo -> /usr/lib/debug/bin/foo.debug

Both also find and copy all referenced source code to a new /usr/src/debug
directory.  This allows the -dbg files to be used for stand-a-lone debugging
on or off the target device.

File stripping is now handled as a seperate operation from file splitting.
This allows us to split the debug information, but also leave it in the
original file -- or prevent the debug information from being split.

Also enhance the comments within local.conf.sample to provide a better
understanding of the control the user has over debug file generation.

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>

2 files changed, 38 insertions, 2 deletions

diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index cba918e1e..cf99a8124 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -242,9 +242,14 @@ SECTION_${PN}-dev = "devel"
 ALLOW_EMPTY_${PN}-dev = "1"
 RDEPENDS_${PN}-dev = "${PN} (= ${EXTENDPV})"
 
-FILES_${PN}-dbg = "${bindir}/.debug ${sbindir}/.debug ${libexecdir}/.debug ${libdir}/.debug \
+DOTDEBUG-dbg = "${bindir}/.debug ${sbindir}/.debug ${libexecdir}/.debug ${libdir}/.debug \
             ${base_bindir}/.debug ${base_sbindir}/.debug ${base_libdir}/.debug ${libdir}/${PN}/.debug \
-            ${libdir}/matchbox-panel/.debug"
+            ${libdir}/matchbox-panel/.debug /usr/src/debug"
+
+DEBUGFILEDIRECTORY-dbg = "/usr/lib/debug /usr/src/debug"
+
+FILES_${PN}-dbg = "${@bb.data.getVar(['DOTDEBUG-dbg', 'DEBUGFILEDIRECTORY-dbg'][bb.data.getVar('PACKAGE_DEBUG_SPLIT_STYLE', d, 1) == 'debug-file-directory'], d, 1)}"
+
 SECTION_${PN}-dbg = "devel"
 ALLOW_EMPTY_${PN}-dbg = "1"
 RRECOMMENDS_${PN}-dbg = "${PN} (= ${EXTENDPV})"
diff --git a/meta/conf/local.conf.sample b/meta/conf/local.conf.sample
index 65b508717..434c6841b 100644
--- a/meta/conf/local.conf.sample
+++ b/meta/conf/local.conf.sample
@@ -104,6 +104,37 @@ USER_CLASSES ?= "image-mklibs image-prelink"
 # <build directory>/tmp
 #TMPDIR = "${POKYBASE}/build/tmp"
 
+# The following are used to control options related to debugging.
+#
+# Uncomment this to change the optimization to make debugging easer, at the 
+# possible cost of performance.
+# DEBUG_BUILD = "1"
+#
+# Uncomment this to disable the stripping of the installed binaries
+# INHIBIT_PACKAGE_STRIP = "1"
+#
+# Uncomment this to disable the split of the debug information into -dbg files
+# INHIBIT_PACKAGE_DEBUG_SPLIT = "1"
+#
+# When splitting debug information, the following controls the results of the
+# file splitting.
+#
+#  .debug (default):
+#    When splitting the debug information will be placed into
+#    a .debug directory in the same dirname of the binary produced:
+#      /bin/foo -> /bin/.debug/foo
+#
+#  debug-file-directory:
+#    When splitting the debug information will be placed into
+#    a central debug-file-directory, /usr/lib/debug:
+#      /bin/foo -> /usr/lib/debug/bin/foo.debug
+#
+#    Any source code referenced in the debug symbols will be copied
+#    and made available within the /usr/src/debug directory
+#
+PACKAGE_DEBUG_SPLIT_STYLE = '.debug'
+# PACKAGE_DEBUG_SPLIT_STYLE = 'debug-file-directory'
+
 # Uncomment these to build a package such that you can use gprof to profile it.
 # NOTE: This will only work with 'linux' targets, not
 # 'linux-uclibc', as uClibc doesn't provide the necessary