Compute the function length instead of hard coding it
Commit Message
On 04/24/2014 10:04 PM, Pedro Alves wrote:
> if { $main_length == "" } {
> return -1
> }
>
> after gdb_test_multiple, as $main_length is unknown on e.g., internal
> error or timeout too.
OK, let's do the check like this.
>
>> > +}
>> > +# Calculate the size of the last instruction. Single instruction
>> > +# shouldn't be longer than 10 bytes.
> x86 has instructions longer than that, though it's not likely
> we'll see them as last instruction. You want to disassemble two
> instructions. So instead of having to hard code some number and
> having to explain it in a comment, how about just asking GDB what
> we want, with x/i ? That is:
>
> (gdb) x /2i main+72
> 0x45d854 <main+72>: retq
> 0x45d855: nopl (%rax)
>
"x /2i" is good to me. Here is the updated patch.
Comments
On 04/25/2014 02:33 AM, Yao Qi wrote:
> * gdb.dwarf2/dwz.exp: Compile main.c to object. Restart GDB
> and compute the length of function main. Save it in
> $main_length.
> (Dwarf::assemble): Use $main_length instead of hard-coded 10.
> (top-level): Use gdb_compile to compile objects into
> executable and restart GDB. Remove invocation to
> prepare_for_testing.
OK, with ...
> +# Start GDB and load object file, compute the function length which is
> +# needed in the Dwarf Assembler below.
> +
> +gdb_exit
> +gdb_start
> +gdb_reinitialize_dir $srcdir/$subdir
> +gdb_load ${binfile}1.o
I think this instead should work:
clean_restart ${testfile}1.o
On 04/25/2014 06:37 PM, Pedro Alves wrote:
> I think this instead should work:
>
> clean_restart ${testfile}1.o
Fixed.
Thanks, Pedro. Patch is pushed in.
@@ -22,10 +22,60 @@ if {![dwarf2_support]} {
standard_testfile main.c dwz.S
+if {[gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile}1.o \
+ object {nodebug}] != ""} {
+ return -1
+}
+
+# Start GDB and load object file, compute the function length which is
+# needed in the Dwarf Assembler below.
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}1.o
+
+set main_length ""
+set test "disassemble main"
+gdb_test_multiple $test $test {
+ -re ".*$hex <\\+($decimal)>:\[^\r\n\]+\r\nEnd of assembler dump\.\r\n$gdb_prompt $" {
+ set main_length $expect_out(1,string)
+ pass $test
+ }
+}
+
+if { $main_length == "" } {
+ # Bail out here, because we can't do the following tests if
+ # $main_length is unknown.
+ return -1
+}
+
+# Compute the size of the last instruction.
+
+set test "x/2i main+$main_length"
+gdb_test_multiple $test $test {
+ -re ".*($hex) <main\\+$main_length>:\[^\r\n\]+\r\n\[ \]+($hex).*\.\r\n$gdb_prompt $" {
+ set start $expect_out(1,string)
+ set end $expect_out(2,string)
+
+ set main_length [expr $main_length + $end - $start]
+ pass $test
+ }
+}
+
+if { $main_length == "" } {
+ # Bail out here, because we can't do the following tests if
+ # $main_length is unknown.
+ return -1
+}
+
+gdb_exit
+
# Create the DWARF.
set asm_file [standard_output_file $srcfile2]
Dwarf::assemble $asm_file {
declare_labels partial_label int_label int_label2
+ global main_length
extern main
@@ -34,7 +84,7 @@ Dwarf::assemble $asm_file {
subprogram {
{name main}
{low_pc main addr}
- {high_pc "main + 10" addr}
+ {high_pc "main + $main_length" addr}
}
}
}
@@ -82,11 +132,17 @@ Dwarf::assemble $asm_file {
}
}
-if { [prepare_for_testing ${testfile}.exp ${testfile} \
- [list $srcfile $asm_file] {nodebug}] } {
+if {[gdb_compile $asm_file ${binfile}2.o object {nodebug}] != ""} {
+ return -1
+}
+
+if {[gdb_compile [list ${binfile}1.o ${binfile}2.o] \
+ "${binfile}" executable {}] != ""} {
return -1
}
+clean_restart ${testfile}
+
if ![runto_main] {
return -1
}