[PATCH] Make ftrace tests work with remote targets

[Simon Marchi <simon dot marchi at ericsson dot com>]

When we build a shared library for testing, it is built differently
whether it is meant for the local system or a remote one.  When it is
for the local system, the library is built with no SONAME.  So when the
executable is built, roughly in this way:

  $ gcc testfile.c /path/to/library.so

the executable will contain an absolute reference to the library.  For
example:

  $ readelf -a testsuite/gdb.python/py-shared | grep NEEDED
   0x0000000000000001 (NEEDED)             Shared library: [/home/emaisin/build/binutils-gdb/gdb/testsuite/gdb.python/py-shared-sl.sl]

When testing is done remotely, the absolute path obviously doesn't work.
Therefore, we build the library with an SONAME:

  $ readelf -a testsuite/gdb.python/py-shared-sl.sl | grep SONAME
   0x000000000000000e (SONAME)             Library soname: [py-shared-sl.sl]

which ends up in the executable's NEEDED field:

  $ readelf -a testsuite/gdb.python/py-shared | grep NEEDED
   0x0000000000000001 (NEEDED)             Shared library: [py-shared-sl.sl]

The executable and the library are then uploaded side-by-side on the
remote system.  To allow the dynamic linker to find the shared library,
we have to add the special RPATH value $ORIGIN, which tells it to search
in the executable's directory:

  $ readelf -a testsuite/gdb.python/py-shared | grep ORIGIN
   0x000000000000000f (RPATH)              Library rpath: [$ORIGIN]

The problem with the IPA library is that it doesn't have an SONAME,
making it very difficult to do testing on a remote board.  When a
test executable is linked with it, it contains an absolute reference to
the library path.  Therefore, unless the paths on the target are the
same as on the build system, it won't work.

To make it possible for tests using the IPA library to run test on
remote boards, I suggest adding dding an SONAME to libinproctrace.so.  I
don't think it should be a big problem for users.  All the libraries
installed on my system have an SONAME, so it should be fine if
libinproctrace.so does too.

As a consequence, native testing does not work anymore, since
executables do not contain the absolute path to the library anymore.  To
keep them working, we can have gdb_load_shlibs copy the library to the
test directory when testing natively.  That's done by modifying
gdb_load_shlibs.  We also have to add RPATH=$ORIGIN to executables, even
when testing natively.

I think it's a good change in general, as it reduces the differences
between testing a native and a remote target.  To further reduce those
differences, we can also always build test shared libraries with an
SONAME.

ftrace.exp and ftrace-lock.exp need to be modified slightly.  The code
checks that the IPA library is loaded using the absolute path on the
build machine.  That obviously doesn't work if the test is done
remotely, as the path will be different.  I changed the tests to only
search for the library basename (e.g. libinproctrace.so).

gdb/gdbserver/ChangeLog:

	* Makefile.in ($(IPA_LIB)): Set SONAME of the IPA lib.

gdb/testsuite/ChangeLog:

	* gdb.trace/ftrace-lock.exp: Check for IPA basename instead of
	absolute.
	* gdb.trace/ftrace.exp: Likewise.
	* lib/gdb.exp (gdb_compile): Set rpath $ORIGIN for non-remote
	targets as well.
	(gdb_compile_shlib): Set SONAME for non-remote targets as well.
	(gdb_load_shlibs): Copy libraries to test directory when testing
	natively.
---
 gdb/gdbserver/Makefile.in               |  2 +-
 gdb/testsuite/gdb.trace/ftrace-lock.exp |  2 +-
 gdb/testsuite/gdb.trace/ftrace.exp      |  2 +-
 gdb/testsuite/lib/gdb.exp               | 27 ++++++++++++++++++++-------
 4 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/gdb/gdbserver/Makefile.in b/gdb/gdbserver/Makefile.in
index 1e874e3..c4324e3 100644
--- a/gdb/gdbserver/Makefile.in
+++ b/gdb/gdbserver/Makefile.in
@@ -327,7 +327,7 @@ IPA_LIB=libinproctrace.so
 
 $(IPA_LIB): $(IPA_OBJS) ${ADD_DEPS} ${CDEPS}
 	rm -f $(IPA_LIB)
-	$(CC_LD) -shared -fPIC -Wl,--no-undefined $(INTERNAL_CFLAGS) \
+	$(CC_LD) -shared -fPIC -Wl,--soname=$(IPA_LIB) -Wl,--no-undefined $(INTERNAL_CFLAGS) \
 	$(INTERNAL_LDFLAGS) -o $(IPA_LIB) ${IPA_OBJS} -ldl -pthread
 
 # Put the proper machine-specific files first, so M-. on a machine
diff --git a/gdb/testsuite/gdb.trace/ftrace-lock.exp b/gdb/testsuite/gdb.trace/ftrace-lock.exp
index 0b73086..077a261 100644
--- a/gdb/testsuite/gdb.trace/ftrace-lock.exp
+++ b/gdb/testsuite/gdb.trace/ftrace-lock.exp
@@ -64,7 +64,7 @@ if ![runto_main] {
     return -1
 }
 
-if { [gdb_test "info sharedlibrary" ".*${libipa}.*" "IPA loaded"] != 0 } {
+if { [gdb_test "info sharedlibrary" ".*[file tail ${libipa}].*" "IPA loaded"] != 0 } {
     untested "Could not find IPA lib loaded"
     return 1
 }
diff --git a/gdb/testsuite/gdb.trace/ftrace.exp b/gdb/testsuite/gdb.trace/ftrace.exp
index 15ad7e7..ce6ac27 100644
--- a/gdb/testsuite/gdb.trace/ftrace.exp
+++ b/gdb/testsuite/gdb.trace/ftrace.exp
@@ -217,7 +217,7 @@ proc test_ftrace_condition { condexp var list } \
 
 gdb_reinitialize_dir $srcdir/$subdir
 
-if { [gdb_test "info sharedlibrary" ".*${libipa}.*" "IPA loaded"] != 0 } {
+if { [gdb_test "info sharedlibrary" ".*[file tail ${libipa}].*" "IPA loaded"] != 0 } {
     untested "Could not find IPA lib loaded"
     return 1
 }
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 1fb05c4..d6a9ead 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -3374,7 +3374,7 @@ proc gdb_compile {source dest type options} {
     # dynamically load one by basename, we must specify rpath.  If we
     # are using a remote host, DejaGNU will link to the shared library
     # using a relative path, so again we must specify an rpath.
-    if { $shlib_load || ($shlib_found && [is_remote target]) } {
+    if { $shlib_load || $shlib_found } {
 	if { ([istarget "*-*-mingw*"]
 	      || [istarget *-*-cygwin*]
 	      || [istarget *-*-pe*]) } {
@@ -3585,7 +3585,7 @@ proc gdb_compile_shlib {sources dest options} {
 		set name ${dest}
 	    }
 	    lappend link_options "additional_flags=-Wl,--out-implib,${name}.a"
-	} elseif [is_remote target] {
+	} else {
 	    # By default, we do not set the soname.  This causes the linker
 	    # on ELF systems to create a DT_NEEDED entry in the executable
 	    # refering to the full path name of the library.  This is a
@@ -4218,14 +4218,27 @@ proc gdb_download { filename } {
 # Copy the listed libraries to the target.
 
 proc gdb_load_shlibs { args } {
-    if {![is_remote target]} {
-	return
-    }
+    if {[is_remote target]} {
+	foreach file $args {
+	    # When the target is remote, we simply send the file to the target.
+	    gdb_download [shlib_target_file $file]
+	}
+    } else {
+	foreach from $args {
+	    # When the target is native, we copy the files to the test directory
+	    # (next to the executable), except if that's already where it is.
+	    set to [standard_output_file [file tail $from]]
 
-    foreach file $args {
-	gdb_download [shlib_target_file $file]
+	    set from [file normalize $from]
+	    set to [file normalize $to]
+
+	    if {"$from" != "$to"} {
+		file copy -force $from $to
+	    }
+	}
     }
 
+
     # Even if the target supplies full paths for shared libraries,
     # they may not be paths for this system.
     gdb_test "set solib-search-path [file dirname [lindex $args 0]]" "" ""
-- 
2.5.1