[patch 2/2] Displaced stepping across fork/vfork : test case

[Yao Qi <yao@codesourcery.com>]

[-- Attachment #1: Type: text/plain, Size: 880 bytes --]

Hi,
These test cases are to expose the problems I mentioned in patch #1. 
Without patch #1 applied, there are three new failures,

+FAIL: gdb.base/disp-step-fork.exp: single step over fork (timeout)
+FAIL: gdb.base/disp-step-vfork.exp: continue to marker (the program is 
no longer running)
+FAIL: gdb.base/disp-step-vfork.exp: print global

After patch #1 applied, these three failures are fixed,

+PASS: gdb.base/disp-step-fork.exp: single step over fork
+PASS: gdb.base/disp-step-vfork.exp: continue to marker
+PASS: gdb.base/disp-step-vfork.exp: print global

In short, these two test cases do something similar.  First, they will 
look for syscall instruction in vfork () or fork (), and set breakpoint 
on it.  Then, continue to syscall insn, turn displaced stepping on, and 
step over that breakpoint.

Regression tested on x86_64-unknow-linux-gnu.

-- 
Yao (齐尧)

[-- Attachment #2: 0015-disp-step-fork-testcase.patch --]
[-- Type: text/x-patch, Size: 9654 bytes --]

	gdb/testsuite/
	* gdb.base/disp-step-fork.c: New.
	* gdb.base/disp-step-fork.exp: New.
	* gdb.base/disp-step-vfork.c: New.
	* gdb.base/disp-step-vfork.exp: New.
---
 gdb/testsuite/gdb.base/disp-step-fork.c    |   42 ++++++++++
 gdb/testsuite/gdb.base/disp-step-fork.exp  |  115 ++++++++++++++++++++++++++++
 gdb/testsuite/gdb.base/disp-step-vfork.c   |   47 +++++++++++
 gdb/testsuite/gdb.base/disp-step-vfork.exp |   81 +++++++++++++++++++
 4 files changed, 285 insertions(+), 0 deletions(-)
 create mode 100644 gdb/testsuite/gdb.base/disp-step-fork.c
 create mode 100644 gdb/testsuite/gdb.base/disp-step-fork.exp
 create mode 100644 gdb/testsuite/gdb.base/disp-step-vfork.c
 create mode 100644 gdb/testsuite/gdb.base/disp-step-vfork.exp

diff --git a/gdb/testsuite/gdb.base/disp-step-fork.c b/gdb/testsuite/gdb.base/disp-step-fork.c
new file mode 100644
index 0000000..38df3b8
--- /dev/null
+++ b/gdb/testsuite/gdb.base/disp-step-fork.c
@@ -0,0 +1,42 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 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 <stdlib.h>
+int
+main (void)
+{
+  int  pid;
+
+  pid = fork ();
+  if (pid == 0) /* child */
+    {
+      exit (0); /* at exit */
+    }
+  else
+    {
+    }
+
+  pid = fork ();
+  if (pid == 0) /* child */
+    {
+      exit (0); /* at exit */
+    }
+  else
+    {
+    }
+
+}
diff --git a/gdb/testsuite/gdb.base/disp-step-fork.exp b/gdb/testsuite/gdb.base/disp-step-fork.exp
new file mode 100644
index 0000000..a044d3e
--- /dev/null
+++ b/gdb/testsuite/gdb.base/disp-step-fork.exp
@@ -0,0 +1,115 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 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 { ![support_displaced_stepping] } {
+    unsupported "displaced stepping"
+    return -1
+}
+
+global srcfile
+set testfile "disp-step-fork"
+
+if [prepare_for_testing ${testfile}.exp ${testfile} ${testfile}.c {debug}] {
+    untested ${testfile}.exp
+    return -1
+}
+
+set syscall_insn ""
+
+# Define the syscall instruction for each target.
+
+if { [istarget "i\[34567\]86-*-linux*"] } {
+    set syscall_insn "int"
+} elseif { [istarget "x86_64-*-linux*"] } {
+    set syscall_insn "syscall"
+} else {
+    return -1
+}
+
+if { ![runto main] } then {
+    fail "run to main ($teststr)"
+    return
+}
+
+gdb_test "break fork" "Breakpoint.*at.*"
+gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, .* in fork ().*" \
+    "continue to fork (1st time)"
+
+# Hit the breakpoint on fork for the first time.  In this time, the address
+# of syscall insn and next insn of syscall are recorded.
+
+gdb_test "display/i \$pc" ".*"
+
+set see_syscall_insn 0
+
+# Single step until we see sysall insn.
+while { $see_syscall_insn == 0 } {
+    send_gdb "stepi\n"
+    gdb_expect {
+	-re ".*$syscall_insn.*$gdb_prompt $" {
+	    set see_syscall_insn 1
+	}
+	-re ".*$gdb_prompt $" {}
+    }
+}
+
+set syscall_insn_addr ""
+set test "extract syscall insn address"
+
+send_gdb "print \$pc\n"
+gdb_expect {
+    -re "\\$\[0-9\]+ = (\[^\r\n\]+).*$gdb_prompt $" {
+	if [regexp "0x\[0-9a-fA-F\]+" $expect_out(0,string) syscall_insn_addr] {
+	    pass "$test"
+	} else {
+	    fail "$test"
+	}
+    }
+    -re ".*$gdb_prompt $" {
+	fail "$test"
+    }
+}
+
+set syscall_insn_next_addr ""
+set test "extract syscall insn address"
+
+send_gdb "stepi\n"
+gdb_expect {
+    -re "0x\[0-9a-fA-F\]+ in .*$gdb_prompt $" {
+	if [regexp "0x\[0-9a-fA-F\]+" $expect_out(0,string) syscall_insn_next_addr] {
+	    pass "$test"
+	} else {
+	    fail "$test"
+	}
+    }
+}
+
+gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, .* in fork ().*" \
+    "continue to fork (2nd time)"
+
+# Hit the breakpoint on fork for the second time.  In this time, we'll set breakpoint
+# on the syscall insn we recorded previously, and single step over it.
+
+gdb_test "break \*$syscall_insn_addr" "Breakpoint \[0-9\]+ at.*" \
+    "break on syscall insn"
+
+gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, .*" \
+    "continue to syscall insn"
+
+gdb_test_no_output "set displaced-stepping on"
+# Check the address of next instruction of syscall.
+gdb_test "stepi" ".*$syscall_insn_next_addr.*" "single step over fork"
\ No newline at end of file
diff --git a/gdb/testsuite/gdb.base/disp-step-vfork.c b/gdb/testsuite/gdb.base/disp-step-vfork.c
new file mode 100644
index 0000000..84e79b0
--- /dev/null
+++ b/gdb/testsuite/gdb.base/disp-step-vfork.c
@@ -0,0 +1,47 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 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 <unistd.h>
+
+int global = 0;
+
+static void
+marker () {}
+
+int
+main (void)
+{
+  int pid;
+
+  pid = vfork ();
+  if (pid == -1)
+    {
+      return 1;
+    }
+  else if (pid != 0)
+    {
+    }
+  else
+    {
+      global = 1;
+      _exit (0);
+    }
+
+  marker ();
+  return 0;
+
+}
diff --git a/gdb/testsuite/gdb.base/disp-step-vfork.exp b/gdb/testsuite/gdb.base/disp-step-vfork.exp
new file mode 100644
index 0000000..65b7bdc
--- /dev/null
+++ b/gdb/testsuite/gdb.base/disp-step-vfork.exp
@@ -0,0 +1,81 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 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 { ![support_displaced_stepping] } {
+    unsupported "displaced stepping"
+    return -1
+}
+
+global srcfile
+set testfile "disp-step-vfork"
+
+if [prepare_for_testing ${testfile}.exp ${testfile} ${testfile}.c {debug}] {
+    untested ${testfile}.exp
+    return -1
+}
+
+set syscall_insn ""
+
+# Define the syscall instruction for each target.
+
+if { [istarget "i\[34567\]86-*-linux*"] } {
+    set syscall_insn "int"
+} elseif { [istarget "x86_64-*-linux*"] } {
+    set syscall_insn "syscall"
+} else {
+    return -1
+}
+
+if { ![runto main] } then {
+    fail "run to main ($teststr)"
+    return
+}
+
+gdb_test "break marker" "Breakpoint.*at.* file .*${testfile}.c, line.*"
+
+set syscall_insn_line ""
+set syscall_insn_addr ""
+
+# Disassemble vfork to extract the address of syscall instruction.
+gdb_test_multiple "disassemble vfork" "disassemble vfork" {
+    -re "Dump of assembler code for function vfork.*$gdb_prompt $" {
+	pass "disassemble vfork"
+	if [regexp "0x\[0-9a-fA-F\]+\[ \t\]<\\+\[0-9\]+>:\[ \t\]$syscall_insn" $expect_out(0,string) syscall_insn_line] {
+	    pass "find syscall insn address"
+
+	    regexp "0x\[0-9a-fA-F\]+" $syscall_insn_line syscall_insn_addr
+	} else {
+	    fail "find syscall insn address"
+	    return -1
+	}
+    }
+    -re ".*$gdb_prompt $" {
+	fail "disassemble vfork"
+	return -1
+    }
+}
+
+gdb_test "break \*$syscall_insn_addr" "Breakpoint \[0-9\]+ at .*" "break on syscall insn"
+gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, .* in vfork ().*" \
+    "continue to vfork"
+
+gdb_test_no_output "set displaced-stepping on"
+gdb_test "stepi" ".*" "single step over vfork"
+gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, marker \\(\\) at.*" \
+    "continue to marker"
+# Make sure child process is executed correctly
+gdb_test "print global" ".* = 1"
\ No newline at end of file
-- 
1.7.0.4