Date: Mon, 15 Apr 2013 11:04:10 -0700

  Message-ID: <CADPb22TTQCsFsuNtjTiUUQU_FN8R6cxfPeCRvNp_Ad2XS6XUag@mail.gmail.com>

  Subject: Re: [RFA] Fix solib-precsave.exp,solib-reverse.exp

  From: Doug Evans <dje at google dot com>

  To: Pedro Alves <palves at redhat dot com>

  Cc: gdb-patches <gdb-patches at sourceware dot org>

  On Mon, Apr 15, 2013 at 10:33 AM, Pedro Alves <palves@redhat.com> wrote:

  > On 04/13/2013 12:13 AM, Doug Evans wrote:

  >> Hi.

  >>

  >> These two tests are failing for me.

  >> They make the assumption that debug info for libc isn't installed.

  >>

  >> To fix this I've created a library of wrappers for the affected libc

  >> functions and compiled it without debug info.

  >>

  >> Ok to check in?

  >

  > This the certainly the right idea for fixing the problem, but it took me a

  > while to realize that the fact that the functions currently called are

  > printf and sleep, and that the new library has wrappers for those has no

  > importance.  They really are just used as proxy for "functions in library

  > with no debug info".  Not even the output of printf is used.  I think that

  > calling the library a syscall wrapper makes it prone to causing such doubt

  > and confusion in other readers (of either the patch or the resulting code

  > in the tree), as it has caused me.

  >

  > How about we just call it "shr1", and have it export some non-libc related

  > functions like e.g., "shr1_foo" and "shr1_bar"?

  Blech.  That's how I originally had it.

  The original code used printf and sleep and I figured someone would

  want to keep them.

  I don't have a preference for either way.  Anyone else?

  In any case we need to document that one cannot call libc functions

  (or similar) as is.

  >>  int main ()

  >> @@ -27,16 +31,25 @@ int main ()

  >>    char* cptr = "String 1";

  >>    int b[2] = {5,8};

  >>

  >> +  /* Call these functions once before we start testing so that they get

  >> +     resolved by the dynamic loader.  If the system has debug info for

  >> +     the dynamic loader installed, reverse-stepping for the first call

  >> +     will otherwise record being in the dynamic loader, which is not what

  >

  > reverse-stepping doesn't record.  Did you mean "report", or even

  > "reverse-stepping the first call will otherwise stop in the

  > dynamic loader", perhaps?

  Yeah.

commit c2a96e8cafeeda6132399e9ea94dafad6366ccc5

Author: Doug Evans <dje@google.com>

Date:   Mon May 6 22:07:13 2013 +0000

    	* gdb.reverse/shr.h: New file.

    	* gdb.reverse/shr1.c: New file.

    	* gdb.reverse/shr2.c: #include "shr.h".

    	* gdb.reverse/solib-reverse.c: Remove #include <stdio.h>.

    	#include "shr.h".  Replace calls to printf,sleep to call shr1 instead.

    	* gdb.reverse/solib-precsave.exp: Build shr2.sl.

    	Update tests using sleep/printf to use shr2.sl instead.

    	* gdb.reverse/solib-reverse.exp: Ditt.o

Index: gdb-7.6.1/gdb/testsuite/gdb.reverse/shr1.c

===================================================================

--- /dev/null

+++ gdb-7.6.1/gdb/testsuite/gdb.reverse/shr1.c

@@ -0,0 +1,24 @@

+/* This testcase is part of GDB, the GNU debugger.

+

+   Copyright 2013 Free Software Foundation, Inc.

+

+   This program is free software; you can redistribute it and/or modify

+   it under the terms of the GNU General Public License as published by

+   the Free Software Foundation; either version 3 of the License, or

+   (at your option) any later version.

+

+   This program is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+   GNU General Public License for more details.

+

+   You should have received a copy of the GNU General Public License

+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

+

+#include "shr.h"

+

+void

+shr1 (const char *s)

+{

+  /* nothing to do */

+}

Index: gdb-7.6.1/gdb/testsuite/gdb.reverse/shr2.c

===================================================================

--- gdb-7.6.1.orig/gdb/testsuite/gdb.reverse/shr2.c

+++ gdb-7.6.1/gdb/testsuite/gdb.reverse/shr2.c

@@ -15,6 +15,8 @@

    You should have received a copy of the GNU General Public License

    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

+#include "shr.h"

+

 #ifdef PROTOTYPES

 int shr2(int x)

 #else

Index: gdb-7.6.1/gdb/testsuite/gdb.reverse/shr.h

===================================================================

--- /dev/null

+++ gdb-7.6.1/gdb/testsuite/gdb.reverse/shr.h

@@ -0,0 +1,24 @@

+/* This testcase is part of GDB, the GNU debugger.

+

+   Copyright 2013 Free Software Foundation, Inc.

+

+   This program is free software; you can redistribute it and/or modify

+   it under the terms of the GNU General Public License as published by

+   the Free Software Foundation; either version 3 of the License, or

+   (at your option) any later version.

+

+   This program is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+   GNU General Public License for more details.

+

+   You should have received a copy of the GNU General Public License

+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

+

+#ifndef GDB_REVERSE_SHR_H

+#define GDB_REVERSE_SHR_H

+

+extern void shr1 (const char *);

+extern int shr2 (int);

+

+#endif /* GDB_REVERSE_SHR_H */

Index: gdb-7.6.1/gdb/testsuite/gdb.reverse/solib-precsave.exp

===================================================================

--- gdb-7.6.1.orig/gdb/testsuite/gdb.reverse/solib-precsave.exp

+++ gdb-7.6.1/gdb/testsuite/gdb.reverse/solib-precsave.exp

@@ -26,20 +26,30 @@ if {[skip_shlib_tests]} {

 standard_testfile solib-reverse.c

 set precsave [standard_output_file solib.precsave]

-set libfile  "shr2"

-set libsrc   ${libfile}.c

-set library  [standard_output_file ${libfile}.sl]

+set lib1file "shr1"

+set lib1src  ${lib1file}.c

+set library1 [standard_output_file ${lib1file}.sl]

+set lib2file "shr2"

+set lib2src  ${lib2file}.c

+set library2 [standard_output_file ${lib2file}.sl]

 if [get_compiler_info] {

     return -1

 }

-if { [gdb_compile_shlib ${srcdir}/${subdir}/${libsrc} ${library} "debug"] != "" } {

-    untested "Could not compile shared library."

+# Compile the first without debug info so that

+# stepping and reverse stepping doesn't end up inside them.

+if { [gdb_compile_shlib ${srcdir}/${subdir}/${lib1src} ${library1} ""] != "" } {

+    untested "Could not compile shared library1."

     return -1

 }

-set exec_opts [list debug shlib=${library}]

+if { [gdb_compile_shlib ${srcdir}/${subdir}/${lib2src} ${library2} "debug"] != "" } {

+    untested "Could not compile shared library2."

+    return -1

+}

+

+set exec_opts [list debug shlib=${library1} shlib=${library2}]

 # Attempt to prevent -Wl,-z,relro which may happen by default with some

 # toolchain configurations.  Due to PR corefiles/11804 GDB will then produce

@@ -57,12 +67,17 @@ if { [gdb_compile ${srcdir}/${subdir}/${

 gdb_exit

 gdb_start

-# Clear it to never find any separate system debug infos.

-gdb_test_no_output "set debug-file-directory"

+# Note: The test previously did "set debug-file-directory" to (try to)

+# ensure the debug info for the dynamic loader and libc weren't found.

+# This doesn't work if the debug info is in the .debug subdirectory.

+# Avoiding debug info for system libraries is not germaine to this test

+# and is no longer attempted.  Instead, the test does not make assumptions

+# about whether the debug info is present or not.

 gdb_reinitialize_dir $srcdir/$subdir

 gdb_load ${binfile}

-gdb_load_shlibs $library

+gdb_load_shlibs $library1

+gdb_load_shlibs $library2

 runto main

@@ -99,15 +114,10 @@ set end_part_one [gdb_get_line_number "

 set end_part_two [gdb_get_line_number " end part two" "$srcfile"]

 gdb_test "until $end_part_one" " end part one.*" "run until end part one"

-gdb_test "reverse-step" " sleep three .*" "reverse-step third sleep"

-gdb_test "reverse-step" " sleep two .*"   "reverse-step second sleep"

-gdb_test "reverse-step" " sleep one .*"   \

-		    "reverse-step first sleep, dynsym resolve"

-

-gdb_test "reverse-step" " printf three .*" "reverse-step third printf"

-gdb_test "reverse-step" " printf two .*"   "reverse-step second printf"

-gdb_test "reverse-step" " printf one .*"   \

-		    "reverse-step first printf, dynsym resolve"

+gdb_test "reverse-step" " shr1 three .*" "reverse-step third shr1"

+gdb_test "reverse-step" " shr1 two .*"   "reverse-step second shr1"

+gdb_test "reverse-step" " shr1 one .*"   "reverse-step first shr1"

+

 gdb_test "reverse-step" " generic statement.*" "reverse-step generic"

@@ -119,15 +129,10 @@ gdb_test "reverse-step" " generic statem

 gdb_test "until $end_part_one" " end part one.*" "forward to end part one"

-gdb_test "reverse-next" " sleep three .*" "reverse-next third sleep"

-gdb_test "reverse-next" " sleep two .*"   "reverse-next second sleep"

-gdb_test "reverse-next" " sleep one .*"   \

-		    "reverse-next first sleep, dynsym resolve"

-

-gdb_test "reverse-next" " printf three .*" "reverse-next third printf"

-gdb_test "reverse-next" " printf two .*"   "reverse-next second printf"

-gdb_test "reverse-next" " printf one .*"   \

-		    "reverse-next first printf, dynsym resolve"

+gdb_test "reverse-next" " shr1 three .*" "reverse-next third shr1"

+gdb_test "reverse-next" " shr1 two .*"   "reverse-next second shr1"

+gdb_test "reverse-next" " shr1 one .*"   "reverse-next first shr1"

+

 gdb_test "reverse-next" " generic statement.*" "reverse-next generic"

@@ -135,11 +140,11 @@ gdb_test "reverse-next" " generic statem

 # Test reverse-step into debuggable solib function

 #

-gdb_test "reverse-step" "${libsrc}.*" "reverse-step into solib function one"

+gdb_test "reverse-step" "${lib2src}.*" "reverse-step into solib function one"

 gdb_test "reverse-step" "return 2.x.*" "reverse-step within solib function one"

 gdb_test "reverse-step" " middle part two.*" "reverse-step back to main one"

-gdb_test "reverse-step" "${libsrc}.*" "reverse-step into solib function two"

+gdb_test "reverse-step" "${lib2src}.*" "reverse-step into solib function two"

 gdb_test "reverse-step" "return 2.x.*" "reverse-step within solib function two"

 gdb_test "reverse-step" " begin part two.*" "reverse-step back to main two"

Index: gdb-7.6.1/gdb/testsuite/gdb.reverse/solib-reverse.c

===================================================================

--- gdb-7.6.1.orig/gdb/testsuite/gdb.reverse/solib-reverse.c

+++ gdb-7.6.1/gdb/testsuite/gdb.reverse/solib-reverse.c

@@ -15,28 +15,33 @@

    You should have received a copy of the GNU General Public License

    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

-/* Test reverse debugging of shared libraries.  */

+/* Test reverse debugging of shared libraries.

-#include <stdio.h>

+   N.B. Do not call system routines here, we don't want to have to deal with

+   whether or not there is debug info present for them.  */

-/* Shared library function */

-extern int shr2(int);

+#include "shr.h"

 int main ()

 {

   char* cptr = "String 1";

   int b[2] = {5,8};

+  /* Call these functions once before we start testing so that they get

+     resolved by the dynamic loader.  If the system has debug info for

+     the dynamic loader installed, reverse-stepping for the first call

+     will otherwise stop in the dynamic loader, which is not what we want.  */

+  shr1 ("");

+  shr2 (0);

+

   b[0] = shr2(12);		/* begin part two */

   b[1] = shr2(17);		/* middle part two */

   b[0] = 6;   b[1] = 9;		/* generic statement, end part two */

-  printf ("message 1\n");	/* printf one */

-  printf ("message 2\n");	/* printf two */

-  printf ("message 3\n");	/* printf three */

-  sleep (0);			/* sleep one */

-  sleep (0);			/* sleep two */

-  sleep (0);			/* sleep three */

+

+  shr1 ("message 1\n");		/* shr1 one */

+  shr1 ("message 2\n");		/* shr1 two */

+  shr1 ("message 3\n");		/* shr1 three */

   return 0;			/* end part one */

 } /* end of main */

Index: gdb-7.6.1/gdb/testsuite/gdb.reverse/solib-reverse.exp

===================================================================

--- gdb-7.6.1.orig/gdb/testsuite/gdb.reverse/solib-reverse.exp

+++ gdb-7.6.1/gdb/testsuite/gdb.reverse/solib-reverse.exp

@@ -24,20 +24,30 @@ if {[skip_shlib_tests]} {

 }

 standard_testfile

-set libfile  "shr2"

-set libsrc   ${libfile}.c

-set library  [standard_output_file ${libfile}.sl]

+set lib1file "shr1"

+set lib1src  ${lib1file}.c

+set library1 [standard_output_file ${lib1file}.sl]

+set lib2file "shr2"

+set lib2src  ${lib2file}.c

+set library2 [standard_output_file ${lib2file}.sl]

 if [get_compiler_info] {

     return -1

 }

-if { [gdb_compile_shlib ${srcdir}/${subdir}/${libsrc} ${library} "debug"] != "" } {

-    untested "Could not compile shared library."

+# Compile the first without debug info so that

+# stepping and reverse stepping doesn't end up inside them.

+if { [gdb_compile_shlib ${srcdir}/${subdir}/${lib1src} ${library1} ""] != "" } {

+    untested "Could not compile shared library1."

     return -1

 }

-set exec_opts [list debug shlib=${library}]

+if { [gdb_compile_shlib ${srcdir}/${subdir}/${lib2src} ${library2} "debug"] != "" } {

+    untested "Could not compile shared library2."

+    return -1

+}

+

+set exec_opts [list debug shlib=${library1} shlib=${library2}]

 if { [gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile} executable $exec_opts] != "" } {

     untested "Could not compile $binfile."

@@ -49,12 +59,17 @@ if { [gdb_compile ${srcdir}/${subdir}/${

 gdb_exit

 gdb_start

-# Clear it to never find any separate system debug infos.

-gdb_test_no_output "set debug-file-directory"

+# Note: The test previously did "set debug-file-directory" to (try to)

+# ensure the debug info for the dynamic loader and libc weren't found.

+# This doesn't work if the debug info is in the .debug subdirectory.

+# Avoiding debug info for system libraries is not germaine to this test

+# and is no longer attempted.  Instead, the test does not make assumptions

+# about whether the debug info is present or not.

 gdb_reinitialize_dir $srcdir/$subdir

 gdb_load ${binfile}

-gdb_load_shlibs $library

+gdb_load_shlibs $library1

+gdb_load_shlibs $library2

 runto main

@@ -73,15 +88,10 @@ set end_part_one [gdb_get_line_number "

 set end_part_two [gdb_get_line_number " end part two" "$srcfile"]

 gdb_test "until $end_part_one" " end part one.*" "run until end part one"

-gdb_test "reverse-step" " sleep three .*" "reverse-step third sleep"

-gdb_test "reverse-step" " sleep two .*"   "reverse-step second sleep"

-gdb_test "reverse-step" " sleep one .*"   \

-		    "reverse-step first sleep, dynsym resolve"

-

-gdb_test "reverse-step" " printf three .*" "reverse-step third printf"

-gdb_test "reverse-step" " printf two .*"   "reverse-step second printf"

-gdb_test "reverse-step" " printf one .*"   \

-		    "reverse-step first printf, dynsym resolve"

+gdb_test "reverse-step" " shr1 three .*" "reverse-step third shr1"

+gdb_test "reverse-step" " shr1 two .*"   "reverse-step second shr1"

+gdb_test "reverse-step" " shr1 one .*"   "reverse-step first shr1"

+

 gdb_test "reverse-step" " generic statement.*" "reverse-step generic"

@@ -93,15 +103,10 @@ gdb_test "reverse-step" " generic statem

 gdb_test "until $end_part_one" " end part one.*" "forward to end part one"

-gdb_test "reverse-next" " sleep three .*" "reverse-next third sleep"

-gdb_test "reverse-next" " sleep two .*"   "reverse-next second sleep"

-gdb_test "reverse-next" " sleep one .*"   \

-		    "reverse-next first sleep, dynsym resolve"

-

-gdb_test "reverse-next" " printf three .*" "reverse-next third printf"

-gdb_test "reverse-next" " printf two .*"   "reverse-next second printf"

-gdb_test "reverse-next" " printf one .*"   \

-		    "reverse-next first printf, dynsym resolve"

+gdb_test "reverse-next" " shr1 three .*" "reverse-next third shr1"

+gdb_test "reverse-next" " shr1 two .*"   "reverse-next second shr1"

+gdb_test "reverse-next" " shr1 one .*"   "reverse-next first shr1"

+

 gdb_test "reverse-next" " generic statement.*" "reverse-next generic"

@@ -109,11 +114,11 @@ gdb_test "reverse-next" " generic statem

 # Test reverse-step into debuggable solib function

 #

-gdb_test "reverse-step" "${libsrc}.*" "reverse-step into solib function one"

+gdb_test "reverse-step" "${lib2src}.*" "reverse-step into solib function one"

 gdb_test "reverse-step" "return 2.x.*" "reverse-step within solib function one"

 gdb_test "reverse-step" " middle part two.*" "reverse-step back to main one"

-gdb_test "reverse-step" "${libsrc}.*" "reverse-step into solib function two"

+gdb_test "reverse-step" "${lib2src}.*" "reverse-step into solib function two"

 gdb_test "reverse-step" "return 2.x.*" "reverse-step within solib function two"

 gdb_test "reverse-step" " begin part two.*" "reverse-step back to main two"