| Message ID | 87r3zd2hr3.fsf@codesourcery.com |
|---|---|
| State | New |
| Headers | show |
On 09/15/2014 08:25 PM, Yao Qi wrote: > Subject: [PATCH] Fix gdb.dwarf2/dwz.exp for thumb mode > > We see the fail in gdb.dwarf2/dwz.exp in thumb mode, > > p the_int^M > $2 = 99^M > (gdb) FAIL: gdb.dwarf2/dwz.exp: p the_int > > In thumb mode, the lsb of references to 'main' in the assembly > (produced by dwarf assember) is set, so the generated debug > information is incorrect. > > in this patch, we add a label main_label inside function main. Linker > doesn't set its lsb in thumb mode, and we can get function main's > address by 'main_label - $main_label_offset'. This label isn't moved > out of function main in both gcc and clang. > > gdb/testsuite: > > 2014-09-15 Yao Qi <yao@codesourcery.com> > > * gdb.dwarf2/main.c (main): New lable main_label. > * gdb.dwarf2/dwz.exp: Get the offset of main_label to main. > Return early if $main_label_offset is unknown. Get address > of main by "main_label - $main_label_offset". Ping. https://sourceware.org/ml/gdb-patches/2014-09/msg00497.html
On 09/22/2014 09:47 PM, Yao Qi wrote: > On 09/15/2014 08:25 PM, Yao Qi wrote: >> Subject: [PATCH] Fix gdb.dwarf2/dwz.exp for thumb mode >> >> We see the fail in gdb.dwarf2/dwz.exp in thumb mode, >> >> p the_int^M >> $2 = 99^M >> (gdb) FAIL: gdb.dwarf2/dwz.exp: p the_int >> >> In thumb mode, the lsb of references to 'main' in the assembly >> (produced by dwarf assember) is set, so the generated debug >> information is incorrect. >> >> in this patch, we add a label main_label inside function main. Linker >> doesn't set its lsb in thumb mode, and we can get function main's >> address by 'main_label - $main_label_offset'. This label isn't moved >> out of function main in both gcc and clang. >> >> gdb/testsuite: >> >> 2014-09-15 Yao Qi <yao@codesourcery.com> >> >> * gdb.dwarf2/main.c (main): New lable main_label. >> * gdb.dwarf2/dwz.exp: Get the offset of main_label to main. >> Return early if $main_label_offset is unknown. Get address >> of main by "main_label - $main_label_offset". > > Ping. https://sourceware.org/ml/gdb-patches/2014-09/msg00497.html > Ping.
Yao Qi <yao@codesourcery.com> writes: > On 09/22/2014 09:47 PM, Yao Qi wrote: >> On 09/15/2014 08:25 PM, Yao Qi wrote: >>> Subject: [PATCH] Fix gdb.dwarf2/dwz.exp for thumb mode >>> >>> We see the fail in gdb.dwarf2/dwz.exp in thumb mode, >>> >>> p the_int^M >>> $2 = 99^M >>> (gdb) FAIL: gdb.dwarf2/dwz.exp: p the_int >>> >>> In thumb mode, the lsb of references to 'main' in the assembly >>> (produced by dwarf assember) is set, so the generated debug >>> information is incorrect. >>> >>> in this patch, we add a label main_label inside function main. Linker >>> doesn't set its lsb in thumb mode, and we can get function main's >>> address by 'main_label - $main_label_offset'. This label isn't moved >>> out of function main in both gcc and clang. >>> >>> gdb/testsuite: >>> >>> 2014-09-15 Yao Qi <yao@codesourcery.com> >>> >>> * gdb.dwarf2/main.c (main): New lable main_label. >>> * gdb.dwarf2/dwz.exp: Get the offset of main_label to main. >>> Return early if $main_label_offset is unknown. Get address >>> of main by "main_label - $main_label_offset". >> >> Ping. https://sourceware.org/ml/gdb-patches/2014-09/msg00497.html >> > > Ping. Ping.
On Mon, Sep 15, 2014 at 8:25 AM, Yao Qi <yao@codesourcery.com> wrote: > Yao Qi <yao@codesourcery.com> writes: > >> -if { $main_length == "" } { >> +set main_label_offset "" >> +set test "p main_label" >> +gdb_test_multiple $test $test { >> + -re ".* = {.*} $hex <main\\+($decimal)>.*\r\n$gdb_prompt $" { >> + set main_label_offset $expect_out(1,string) >> + } >> +} > > Here is the V3 of this patch, to address Andreas's comments about > getting the offset of main_label to main. > > -- > Yao (齐尧) > From: Yao Qi <yao@codesourcery.com> > Date: Sat, 13 Sep 2014 14:51:04 +0800 > Subject: [PATCH] Fix gdb.dwarf2/dwz.exp for thumb mode > > We see the fail in gdb.dwarf2/dwz.exp in thumb mode, > > p the_int^M > $2 = 99^M > (gdb) FAIL: gdb.dwarf2/dwz.exp: p the_int > > In thumb mode, the lsb of references to 'main' in the assembly > (produced by dwarf assember) is set, so the generated debug > information is incorrect. > > in this patch, we add a label main_label inside function main. Linker > doesn't set its lsb in thumb mode, and we can get function main's > address by 'main_label - $main_label_offset'. This label isn't moved > out of function main in both gcc and clang. > > gdb/testsuite: > > 2014-09-15 Yao Qi <yao@codesourcery.com> > > * gdb.dwarf2/main.c (main): New lable main_label. Typo: label > * gdb.dwarf2/dwz.exp: Get the offset of main_label to main. > Return early if $main_label_offset is unknown. Get address > of main by "main_label - $main_label_offset". > > diff --git a/gdb/testsuite/gdb.dwarf2/dwz.exp b/gdb/testsuite/gdb.dwarf2/dwz.exp > index 9175f9e..3cf4e4f 100644 > --- a/gdb/testsuite/gdb.dwarf2/dwz.exp > +++ b/gdb/testsuite/gdb.dwarf2/dwz.exp > @@ -27,8 +27,9 @@ if {[gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile}1.o \ > return -1 > } > > -# Start GDB and load object file, compute the function length which is > -# needed in the Dwarf Assembler below. > +# Start GDB and load object file, compute the function length and the > +# offset from main to main_label which are needed in the Dwarf Assembler > +# below. > clean_restart ${testfile}1.o > > set main_length "" > @@ -59,9 +60,17 @@ gdb_test_multiple $test $test { > } > } > > -if { $main_length == "" } { > +set main_label_offset "" > +set test "p main_label - main" > +gdb_test_multiple $test $test { > + -re ".* = ($decimal)\r\n$gdb_prompt $" { > + set main_label_offset $expect_out(1,string) > + } > +} > + > +if { $main_length == "" || $main_label_offset == "" } { > # Bail out here, because we can't do the following tests if > - # $main_length is unknown. > + # $main_length or $main_label_offset is unknown. > return -1 > } > > @@ -71,7 +80,7 @@ gdb_exit > set asm_file [standard_output_file $srcfile2] > Dwarf::assemble $asm_file { > declare_labels partial_label int_label int_label2 > - global main_length > + global main_length main_label_offset > > extern main > > @@ -79,8 +88,8 @@ Dwarf::assemble $asm_file { > partial_label: partial_unit {} { > subprogram { > {name main} > - {low_pc main addr} > - {high_pc "main + $main_length" addr} > + {low_pc "main_label - $main_label_offset" addr} > + {high_pc "main_label - $main_label_offset + $main_length" addr} > } > } > } > diff --git a/gdb/testsuite/gdb.dwarf2/main.c b/gdb/testsuite/gdb.dwarf2/main.c > index 3ddd194..e6d4715 100644 > --- a/gdb/testsuite/gdb.dwarf2/main.c > +++ b/gdb/testsuite/gdb.dwarf2/main.c > @@ -20,5 +20,6 @@ > int > main() > { > + asm ("main_label: .globl main_label"); > return 0; > } Hi. I'd like to see comments in the code explaining why main_label exists (thumb) and why we can't put labels outside the function (clang). I shouldn't have to grind through commit logs or emails to answer these questions.
diff --git a/gdb/testsuite/gdb.dwarf2/dwz.exp b/gdb/testsuite/gdb.dwarf2/dwz.exp index 9175f9e..3cf4e4f 100644 --- a/gdb/testsuite/gdb.dwarf2/dwz.exp +++ b/gdb/testsuite/gdb.dwarf2/dwz.exp @@ -27,8 +27,9 @@ if {[gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile}1.o \ return -1 } -# Start GDB and load object file, compute the function length which is -# needed in the Dwarf Assembler below. +# Start GDB and load object file, compute the function length and the +# offset from main to main_label which are needed in the Dwarf Assembler +# below. clean_restart ${testfile}1.o set main_length "" @@ -59,9 +60,17 @@ gdb_test_multiple $test $test { } } -if { $main_length == "" } { +set main_label_offset "" +set test "p main_label - main" +gdb_test_multiple $test $test { + -re ".* = ($decimal)\r\n$gdb_prompt $" { + set main_label_offset $expect_out(1,string) + } +} + +if { $main_length == "" || $main_label_offset == "" } { # Bail out here, because we can't do the following tests if - # $main_length is unknown. + # $main_length or $main_label_offset is unknown. return -1 } @@ -71,7 +80,7 @@ gdb_exit set asm_file [standard_output_file $srcfile2] Dwarf::assemble $asm_file { declare_labels partial_label int_label int_label2 - global main_length + global main_length main_label_offset extern main @@ -79,8 +88,8 @@ Dwarf::assemble $asm_file { partial_label: partial_unit {} { subprogram { {name main} - {low_pc main addr} - {high_pc "main + $main_length" addr} + {low_pc "main_label - $main_label_offset" addr} + {high_pc "main_label - $main_label_offset + $main_length" addr} } } } diff --git a/gdb/testsuite/gdb.dwarf2/main.c b/gdb/testsuite/gdb.dwarf2/main.c index 3ddd194..e6d4715 100644 --- a/gdb/testsuite/gdb.dwarf2/main.c +++ b/gdb/testsuite/gdb.dwarf2/main.c @@ -20,5 +20,6 @@ int main() { + asm ("main_label: .globl main_label"); return 0; }