unwind non-PC registers using elfutils

[Jacob Burkholder via Elfutils-devel]

Hi, I'm trying to figure out how to unwind registers other than the PC
using elfutils.  I can use dwfl_module_register_names to get the register
names, and then I'm trying to use dwarf_frame_register to get the register
values for a given frame.  I looked at the code in __libdwfl_frame_unwind
and there's another example in addrcfi.c.   dwarf_frame_register seems
quite a low level dwarf API, I'm not sure how to use the ops that are
returned, also the code used by __libdwfl_frame_unwind to evaluate the ops
is all static or internal so not callable.  Any guidance?  Do I need to
basically interpret the dwarf atoms in the ops returned by
dwarf_frame_register?  Any plans to make code like
frame_unwind.c:expr_eval() used by frame_unwind.c:handle_cfi externally
accessible?

[patch] PR27783: default debuginfod-urls profile rework

[Frank Ch. Eigler via Elfutils-devel]

commit 0c634f243d266ce8841fd311433d5d79555fabf9
Author: Frank Ch. Eigler 
Date:   Sun Oct 3 17:04:24 2021 -0400

PR27783: switch default debuginfod-urls to drop-in style files

Rewrote and commented the /etc/profile.d csh and sh script fragments
to take the default $DEBUGINFOD_URLS from the union of drop-in files:
/etc/debuginfod/*.urls.  Hand-tested with csh and bash, with
conditions including no prior $DEBUGINFOD_URLS, nonexistent .urls
files, multiple entries in .urls files.

Signed-off-by: Frank Ch. Eigler 

diff --git a/config/ChangeLog b/config/ChangeLog
index b2c0af8ac816..bd41654f5492 100644
--- a/config/ChangeLog
+++ b/config/ChangeLog
@@ -1,3 +1,11 @@
+2021-10-03  Frank Ch. Eigler  
+
+   PR27783
+   * profile.sh, profile.csh: Rewrite to document and set DEBUGINFOD_URLS
+   from /etc/debuginfod/*.urls files.
+   * Makefile.am: Install the configury-specified .urls file.
+   * elfutils.spec: Package it.
+
 2021-09-05  Dmitry V. Levin  
 
* eu.am (STACK_USAGE_NO_ERROR): New variable.
diff --git a/config/Makefile.am b/config/Makefile.am
index a66f54904991..0d3ba164ee3a 100644
--- a/config/Makefile.am
+++ b/config/Makefile.am
@@ -40,9 +40,16 @@ pkgconfig_DATA += libdebuginfod.pc
 install-data-local:
$(INSTALL_DATA) profile.sh -D 
$(DESTDIR)$(sysconfdir)/profile.d/debuginfod.sh
$(INSTALL_DATA) profile.csh -D 
$(DESTDIR)$(sysconfdir)/profile.d/debuginfod.csh
+   mkdir -p $(DESTDIR)$(sysconfdir)/debuginfod
+   if [ -n "@DEBUGINFOD_URLS@" ]; then \
+   echo "@DEBUGINFOD_URLS@" > 
$(DESTDIR)$(sysconfdir)/debuginfod/elfutils.urls; \
+   fi
 
 uninstall-local:
-   rm -f $(DESTDIR)$(sysconfdir)/profile.d/debuginfod.sh 
$(DESTDIR)$(sysconfdir)/profile.d/debuginfod.csh
+   rm -f $(DESTDIR)$(sysconfdir)/profile.d/debuginfod.sh
+   rm -f $(DESTDIR)$(sysconfdir)/profile.d/debuginfod.csh
+   rm -f $(DESTDIR)$(sysconfdir)/debuginfod/elfutils.urls
+   -rmdir $(DESTDIR)$(sysconfdir)/debuginfod
 endif
 
 if MAINTAINER_MODE
diff --git a/config/elfutils.spec.in b/config/elfutils.spec.in
index 043762653c90..8f6a8e03202f 100644
--- a/config/elfutils.spec.in
+++ b/config/elfutils.spec.in
@@ -301,6 +301,7 @@ fi
 %{_mandir}/man1/debuginfod-find.1*
 %{_mandir}/man7/debuginfod*.7*
 %config(noreplace) %{_sysconfdir}/profile.d/*
+%config(noreplace) %{_sysconfdir}/debuginfod/*
   
 %files debuginfod-client-devel
 %defattr(-,root,root)
diff --git a/config/profile.csh.in b/config/profile.csh.in
index 0a2d6d162019..29e59a709450 100644
--- a/config/profile.csh.in
+++ b/config/profile.csh.in
@@ -1,11 +1,16 @@
-if ("@DEBUGINFOD_URLS@" != "") then
-   if ($?DEBUGINFOD_URLS) then
-   if ($%DEBUGINFOD_URLS) then
-   setenv DEBUGINFOD_URLS "$DEBUGINFOD_URLS 
@DEBUGINFOD_URLS@"
-   else
-   setenv DEBUGINFOD_URLS "@DEBUGINFOD_URLS@"
-   endif
-   else
-   setenv DEBUGINFOD_URLS "@DEBUGINFOD_URLS@"
-   endif
+
+# $HOME/.login* or similar files may first set $DEBUGINFOD_URLS.
+# If $DEBUGINFOD_URLS is not set there, we set it from system *.url files.
+# $HOME/.*rc or similar files may then amend $DEBUGINFOD_URLS.
+# See also [man debuginfod-client-config] for other environment variables
+# such as $DEBUGINFOD_MAXSIZE, $DEBUGINFOD_MAXTIME, $DEBUGINFOD_PROGRESS.
+
+if (! $?DEBUGINFOD_URLS) then
+set prefix="@prefix@"
+set debuginfod_urls=`find "@sysconfdir@/debuginfod/" -name '*.urls' | 
xargs cat | tr '\n' ' '`
+if ( "$debuginfod_urls" != "" ) then
+setenv DEBUGINFOD_URLS "$debuginfod_urls"
+endif
+unset debuginfod_urls
+unset prefix
 endif
diff --git a/config/profile.sh.in b/config/profile.sh.in
index aa228a0dcd16..94b2983b9f90 100644
--- a/config/profile.sh.in
+++ b/config/profile.sh.in
@@ -1,4 +1,17 @@
-if [ -n "@DEBUGINFOD_URLS@" ]; then
-   DEBUGINFOD_URLS="${DEBUGINFOD_URLS-}${DEBUGINFOD_URLS:+ 
}@DEBUGINFOD_URLS@"
-   export DEBUGINFOD_URLS
+
+# $HOME/.profile* or similar files may first set $DEBUGINFOD_URLS.
+# If $DEBUGINFOD_URLS is not set there, we set it from system *.url files.
+# $HOME/.*rc or similar files may then amend $DEBUGINFOD_URLS.
+# See also [man debuginfod-client-config] for other environment variables
+# such as $DEBUGINFOD_MAXSIZE, $DEBUGINFOD_MAXTIME, $DEBUGINFOD_PROGRESS.
+
+if [ -z "$DEBUGINFOD_URLS" ]; then
+prefix="@prefix@"
+debuginfod_urls=`find "@sysconfdir@/debuginfod/" -name '*.urls' | xargs 
cat | tr '\n' ' '`
+if [ -n "$debuginfod_urls" ]; then
+DEBUGINFOD_URLS="$debuginfod_urls"
+export DEBUGINFOD_URLS
+fi
+unset debuginfod_urls
+unset prefix
 fi