[patch 7/7] STT_GNU_IFUNC testcase

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

Hi,

No regressions on {x86_64,x86_64-m32,i686}-fedora15-linux-gnu.

The new testfile has been also tested on
{ppc64,ppc64-to-ppc,s390x}-rhel61pre-linux-gnu.

Some of the testcases no longer make much sense with the current code but they
come from the previous very different variants of the patchset.


Thanks,
Jan


gdb/testsuite/
2011-03-19  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Test STT_GNU_IFUNC support.
	* gdb.base/gnu-ifunc-lib.c: New file.
	* gdb.base/gnu-ifunc.c: New file.
	* gdb.base/gnu-ifunc.exp: New file.

--- /dev/null
+++ b/gdb/testsuite/gdb.base/gnu-ifunc-lib.c
@@ -0,0 +1,33 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2009, 2010, 2011 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/>.  */
+
+extern volatile int gnu_ifunc_initialized;
+extern int init_stub (int arg);
+extern int final (int arg);
+
+typedef int (*final_t) (int arg);
+
+asm (".type gnu_ifunc, @gnu_indirect_function");
+
+final_t
+gnu_ifunc (void)
+{
+  if (! gnu_ifunc_initialized)
+    return init_stub;
+  else
+    return final;
+}
--- /dev/null
+++ b/gdb/testsuite/gdb.base/gnu-ifunc.c
@@ -0,0 +1,61 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2009, 2010, 2011 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 <assert.h>
+
+int
+init_stub (int arg)
+{
+  return 0;
+}
+
+int
+final (int arg)
+{
+  return arg + 1;
+}
+
+/* Make differentiation of how the gnu_ifunc call resolves before and after
+   calling gnu_ifunc_pre.  This ensures the resolved function address is not
+   being cached anywhere for the debugging purposes.  */
+
+volatile int gnu_ifunc_initialized;
+
+static void
+gnu_ifunc_pre (void)
+{
+  assert (!gnu_ifunc_initialized);
+
+  gnu_ifunc_initialized = 1;
+}
+
+extern int gnu_ifunc (int arg);
+
+int
+main (void)
+{
+  int i;
+
+  gnu_ifunc_pre ();
+  
+  i = gnu_ifunc (1);	/* break-at-call */
+  assert (i == 2);
+
+  gnu_ifunc (2);	/* break-at-nextcall */
+
+  return 0;	/* break-at-exit */
+}
--- /dev/null
+++ b/gdb/testsuite/gdb.base/gnu-ifunc.exp
@@ -0,0 +1,146 @@
+# Copyright (C) 2009, 2010, 2011 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/>.
+
+if {[skip_shlib_tests]} {
+    return 0
+}
+
+set testfile "gnu-ifunc"
+set executable ${testfile}
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${executable}
+set staticexecutable ${executable}-static
+set staticbinfile ${objdir}/${subdir}/${staticexecutable}
+
+set libfile "${testfile}-lib"
+set libsrc ${libfile}.c
+set lib_so ${objdir}/${subdir}/${libfile}.so
+# $lib_o must not have {debug}, it would override the STT_GNU_IFUNC ELF markers.
+set lib_o ${objdir}/${subdir}/${libfile}.o
+
+# We need DWARF for the "final" function as we "step" into the function and GDB
+# would step-over the "final" function if there would be no line number debug
+# information (DWARF) available.
+#
+# We must not have DWARF for the "gnu_ifunc" function as DWARF has no way to
+# express the STT_GNU_IFUNC type and it would be considered as a regular
+# function due to DWARF by GDB.  In ELF gnu-ifunc is expressed by the
+# STT_GNU_IFUNC type.
+#
+# Both functions need to be in the same shared library file but
+# gdb_compile_shlib has no way to specify source-specific compilation options.
+#
+# Therefore $libfile contains only the STT_GNU_IFUNC function with no DWARF
+# referencing all the other parts from the main executable with DWARF.
+
+set lib_opts {}
+set exec_opts [list debug shlib=$lib_so]
+
+if [get_compiler_info ${binfile}] {
+    return -1
+}
+
+if { [gdb_compile_shlib ${srcdir}/${subdir}/$libsrc $lib_so $lib_opts] != ""
+     || [gdb_compile ${srcdir}/${subdir}/$srcfile $binfile executable $exec_opts] != ""} {
+    untested "Could not compile dynamic executable $binfile."
+    return -1
+}
+
+# Start with a fresh gdb.
+
+clean_restart $executable
+gdb_load_shlibs ${lib_so}
+
+if ![runto_main] then {
+    fail "Can't run to main"
+    return 1;
+}
+
+# The "if" condition is artifical to test regression of a former patch.
+gdb_breakpoint "[gdb_get_line_number "break-at-nextcall"] if i && gnu_ifunc (i) != 42"
+
+gdb_breakpoint [gdb_get_line_number "break-at-call"]
+gdb_continue_to_breakpoint "break-at-call" ".*break-at-call.*"
+
+# Test GDB will automatically indirect the call.
+
+gdb_test "p gnu_ifunc (3)" " = 4"
+
+# Test GDB will skip the gnu_ifunc resolver on first call.
+
+gdb_test "step" "\r\nfinal .*"
+
+# Test GDB will not break before the final chosen implementation.
+
+# Also test a former patch regression:
+# Continuing.
+# Error in testing breakpoint condition:
+# Attempt to take address of value not located in memory.
+# 
+# Breakpoint 2, main () at ./gdb.base/gnu-ifunc.c:33
+
+gdb_test "continue" "Continuing.\r\n\r\nBreakpoint .* (at|in) .*break-at-nextcall.*" \
+	 "continue to break-at-nextcall"
+
+gdb_breakpoint "gnu_ifunc"
+
+gdb_continue_to_breakpoint "nextcall gnu_ifunc"
+
+gdb_test "frame" "#0 +(0x\[0-9a-f\]+ in +)?final \\(.*" "nextcall gnu_ifunc skipped"
+
+
+# Check any commands not doing an inferior call access the address of the
+# STT_GNU_IFUNC resolver, not the target function.
+
+if {[istarget powerpc64-*] && [is_lp64_target]} {
+    # With only minimal symbols GDB provides the function descriptors.  With
+    # full debug info the function code would be displayed.
+    set func_prefix {\.}
+} else {
+    set func_prefix {}
+}
+
+gdb_test "p gnu_ifunc" " = {<text gnu-indirect-function variable, no debug info>} 0x\[0-9a-f\]+ <${func_prefix}gnu_ifunc>" "p gnu_ifunc executing"
+gdb_test "info sym gnu_ifunc" "gnu_ifunc in section .*" "info sym gnu_ifunc executing"
+
+set test "info addr gnu_ifunc"
+gdb_test_multiple $test $test {
+    -re "Symbol \"gnu_ifunc\" is at (0x\[0-9a-f\]+) in .*$gdb_prompt $" {
+	pass $test
+    }
+}
+gdb_test "info sym $expect_out(1,string)" "gnu_ifunc in section .*" "info sym <gnu_ifunc-address>"
+
+
+# Test statically linked ifunc resolving during inferior start.
+# https://bugzilla.redhat.com/show_bug.cgi?id=624967
+
+if ![target_info exists gdb_stub] {
+
+    # Compile $staticbinfile separately as it may exit on error (ld/12595).
+
+    if { [gdb_compile ${srcdir}/${subdir}/$libsrc $lib_o object {}] != ""
+	 || [gdb_compile "${srcdir}/${subdir}/$srcfile $lib_o" $staticbinfile executable {debug}] != "" } {
+	untested "Could not compile static executable $staticbinfile."
+	return -1
+    }
+
+    clean_restart $staticexecutable
+
+    gdb_breakpoint "gnu_ifunc"
+    gdb_breakpoint "main"
+    gdb_run_cmd
+    gdb_test "" "Breakpoint \[0-9\]*, main .*" "static gnu_ifunc"
+}