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authorPedro Alves <palves@redhat.com>2013-04-19 14:13:30 +0000
committerPedro Alves <palves@redhat.com>2013-04-19 14:13:30 +0000
commit433730c97306608f78fc8de0a319c9a5c6758db2 (patch)
tree3c091949746367cefae0e6dde17a45d643c9d65d
parentcb948fc00e2e37d0eb00fe0a822fbc38394759f4 (diff)
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Fix the x87 FP register printout when issuing the “info float” command.
Consider the following simple program: .globl _start .text _start: fldt val .data val: .byte 0x00,0x00,0x45,0x07,0x11,0x19,0x22,0xe9,0xfe,0xbf With current GDB on x86-64 GNU/Linux hosts, after the moment the fldt command has been executed the register st(0) looks like this, according to the “info regs” output (TOP=7): R7: Valid 0xffffffbffffffffeffffffe922191107450000 -0.910676542908976927 which is clearly wrong (just count its length). The problem is due to the printf statement (see patch) printing a promoted integer value of a char argument "raw[i]", and, since char is signed on x86-64 GNU/Linux, the erroneous “ffffff” are printed for the first three bytes which turn out to be "negative". The fix is to use gdb_byte instead which is unsigned (and is the type of value_contents(), the type to be used for raw target bytes anyway). After the fix the value will be printed correctly: R7: Valid 0xbffee922191107450000 -0.910676542908976927 gdb/ 2013-04-19 Vladimir Kargov <kargov@gmail.com> Pedro Alves <palves@redhat.com> * i387-tdep.c (i387_print_float_info): Use gdb_byte for pointer to value contents. gdb/testsuite/ 2013-04-19 Vladimir Kargov <kargov@gmail.com> Pedro Alves <palves@redhat.com> * gdb.arch/i386-float.S: New file. * gdb.arch/i386-float.exp: New file.
-rw-r--r--gdb/ChangeLog6
-rw-r--r--gdb/i387-tdep.c2
-rw-r--r--gdb/testsuite/ChangeLog6
-rw-r--r--gdb/testsuite/gdb.arch/i386-float.S34
-rw-r--r--gdb/testsuite/gdb.arch/i386-float.exp43
5 files changed, 90 insertions, 1 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 85c3245..80fb6de 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2013-04-19 Vladimir Kargov <kargov@gmail.com>
+ Pedro Alves <palves@redhat.com>
+
+ * i387-tdep.c (i387_print_float_info): Use gdb_byte for pointer to
+ value contents.
+
2013-04-17 Doug Evans <dje@google.com>
* dwarf2read.c (struct signatured_type): New member type.
diff --git a/gdb/i387-tdep.c b/gdb/i387-tdep.c
index 65bb103..48a00c3 100644
--- a/gdb/i387-tdep.c
+++ b/gdb/i387-tdep.c
@@ -298,7 +298,7 @@ i387_print_float_info (struct gdbarch *gdbarch, struct ui_file *file,
if (value_entirely_available (regval))
{
- const char *raw = value_contents (regval);
+ const gdb_byte *raw = value_contents (regval);
fputs_filtered ("0x", file);
for (i = 9; i >= 0; i--)
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 4d69f41..d262b81 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2013-04-19 Vladimir Kargov <kargov@gmail.com>
+ Pedro Alves <palves@redhat.com>
+
+ * gdb.arch/i386-float.S: New file.
+ * gdb.arch/i386-float.exp: New file.
+
2013-04-18 Luis Machado <lgustavo@codesourcery.com>
* gdb.mi/mi-var-create-rtti.exp: Create a variable of
diff --git a/gdb/testsuite/gdb.arch/i386-float.S b/gdb/testsuite/gdb.arch/i386-float.S
new file mode 100644
index 0000000..c4f6391
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/i386-float.S
@@ -0,0 +1,34 @@
+/* Copyright 2009-2013 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/>.
+
+ This file is part of the gdb testsuite. */
+
+#define CONCAT1(a, b) CONCAT2(a, b)
+#define CONCAT2(a, b) a ## b
+
+#ifdef SYMBOL_PREFIX
+# define SYMBOL(str) CONCAT1(SYMBOL_PREFIX, str)
+#else
+# define SYMBOL(str) str
+#endif
+
+ .text
+ .globl SYMBOL(main)
+SYMBOL(main):
+ fninit
+ fldt val
+ ret
+.data
+ val: .byte 0x00,0x00,0x45,0x07,0x11,0x19,0x22,0xe9,0xfe,0xbf
diff --git a/gdb/testsuite/gdb.arch/i386-float.exp b/gdb/testsuite/gdb.arch/i386-float.exp
new file mode 100644
index 0000000..c417532
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/i386-float.exp
@@ -0,0 +1,43 @@
+# Copyright (C) 2009-2013 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/>.
+
+
+# This file is part of the gdb testsuite.
+
+# Test the x87 floating point information printout.
+
+if { ![istarget "i?86-*-*"] && ![istarget "x86_64-*-*"] } then {
+ verbose "Skipping i386 tests for x87 floating point support."
+ return
+}
+
+standard_testfile .S
+
+# some targets have leading underscores on assembly symbols.
+set additional_flags [gdb_target_symbol_prefix_flags]
+
+if { [prepare_for_testing break.exp $testfile $srcfile [list debug $additional_flags]] } {
+ return -1
+}
+
+if ![runto_main] then {
+ fail "Can't run to main"
+ return 0
+}
+
+gdb_test "stepi" ".*fldt.*" "first stepi"
+gdb_test "info float" ".*R7: Empty 0x00000000000000000000\r\n.*"
+gdb_test "stepi" ".*ret.*" "second stepi"
+gdb_test "info float" ".*=>R7: Valid 0xbffee922191107450000 .*"