Reviewed and approved by Jim Blandy

[deliverable/binutils-gdb.git] / gdb / testsuite / gdb.base / recurse.exp

diff --git a/gdb/testsuite/gdb.base/recurse.exp b/gdb/testsuite/gdb.base/recurse.exp
index 88e1b30ee96d9b7a54b2809bcd269970c2351b90..bd1ecee60d95f1a7cc40e22128c0a6eb7af57aaa 100644 (file)
--- a/gdb/testsuite/gdb.base/recurse.exp
+++ b/gdb/testsuite/gdb.base/recurse.exp
@@ -1,4 +1,5 @@
-# Copyright (C) 1992, 1996, 1997 Free Software Foundation, Inc.
+# Copyright 1992, 1994, 1995, 1996, 1997, 1999, 2000
+# 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
@@ -42,6 +43,11 @@ gdb_load ${binfile}
 
 proc recurse_tests {} {
 
+    # Disable hardware watchpoints if necessary.
+    if [target_info exists gdb,no_hardware_watchpoints] {
+       gdb_test "set can-use-hw-watchpoints 0" "" ""
+    }
+
     if [runto recurse] then {
        # First we need to step over the assignment of b, so it has a known
        # value.
@@ -117,9 +123,30 @@ proc recurse_tests {} {
            gdb_suppress_tests
        }
 
-       # Continue again.  We should have a watchpoint go out of scope now
+       # Continue again.  We should have a watchpoint go out of scope now.
+       #
+       # The former version expected the test to return to main().
+       # Now it expects the test to return to main or to stop in the
+       # function's epilogue.
+       # 
+       # The problem is that gdb needs to (but doesn't) understand
+       # function epilogues in the same way as for prologues.
+       # 
+       # If there is no hardware watchpoint (such as a x86 debug register),
+       # then watchpoints are done "the hard way" by single-stepping the
+       # target until the value of the watched variable changes.  If you
+       # are single-stepping, you will eventually step into an epilogue.
+       # When you do that, the "top" stack frame may become partially
+       # deconstructed (as when you pop the frame pointer, for instance),
+       # and from that point on, GDB can no longer make sense of the stack.
+       # 
+       # A test which stops in the epilogue is trying to determine when GDB
+       # leaves the stack frame in which the watchpoint was created.  It does
+       # this basically by watching for the frame pointer to change.  When
+       # the frame pointer changes, the test expects to be back in main, but
+       # instead it is still in the epilogue of the callee.
        if [gdb_test "continue" \
-           "Continuing.*\[Ww\]atchpoint.*deleted.*main \\(\\) .*" \
+           "Continuing.*\[Ww\]atchpoint.*deleted.*\(main \\(\\) \|21.*\}\).*" \
            "first instance watchpoint deleted when leaving scope"] then {
            gdb_suppress_tests;
        }
@@ -127,19 +154,15 @@ proc recurse_tests {} {
     gdb_stop_suppressing_tests;
 }
 
-# Only enabled for some targets merely because it has not been tested 
-# elsewhere.
-if {[istarget "sparc*-*-sunos4*"] || [istarget "hppa*-*-bsd*"] || [istarget "hppa*-*-hpux*"] || [istarget "sparclet-*-*"] || [istarget "m32r-*-elf"] || [istarget "mn10200-*-*"] || [istarget "mn10300-*-*"]} then {
+# Preserve the old timeout, and set a new one that should be
+# sufficient to avoid timing out during this test.
+set oldtimeout $timeout
+set timeout [expr "$timeout + 60"]
+verbose "Timeout is now $timeout seconds" 2
 
-    # Preserve the old timeout, and set a new one that should be
-    # sufficient to avoid timing out during this test.
-    set oldtimeout $timeout
-    set timeout [expr "$timeout + 60"]
-    verbose "Timeout is now $timeout seconds" 2
+recurse_tests
 
-    recurse_tests
+# Restore the preserved old timeout value.
+set timeout $oldtimeout
+verbose "Timeout is now $timeout seconds" 2
 
-    # Restore the preserved old timeout value.
-    set timeout $oldtimeout
-    verbose "Timeout is now $timeout seconds" 2
-}