* Re: [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute [not found] <8830.7035308846$1273670829@news.gmane.org> @ 2010-05-13 17:51 ` Tom Tromey 2010-05-17 17:34 ` Joel Brobecker 0 siblings, 1 reply; 16+ messages in thread From: Tom Tromey @ 2010-05-13 17:51 UTC (permalink / raw) To: Pierre Muller; +Cc: gdb-patches >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr> writes: Pierre> Free Pascal compiler has support for Pierre> DW_AT_variable_parameter attribute, but this is disabled because Pierre> GDB does not support it yet. Pierre> The value of the attribute must be a flag according to Pierre> DWARF specs. The only point I am unsure about is Pierre> what does a zero value of this flag mean: Pierre> Should zero be considered as FALSE and Pierre> thus the should say that this parameter is NOT a variable parameter, Pierre> or does the simple presence of this attribute condfirm Pierre> this it is a variable parameter, no matter the value of the flag. Pierre> I took the first approach here, but have the impression Pierre> that it is not always the case inside dwarf2read.c code. I think you made the correct choice. Pierre> Is this OK? I wonder whether it is possible for such a parameter to be marked as LOC_COMPUTED or LOC_OPTIMIZED_OUT by var_decode_location. If so then changing the class to LOC_REF_ARG seems incorrect. Tom ^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute 2010-05-13 17:51 ` [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute Tom Tromey @ 2010-05-17 17:34 ` Joel Brobecker 2010-05-17 17:34 ` Pierre Muller 0 siblings, 1 reply; 16+ messages in thread From: Joel Brobecker @ 2010-05-17 17:34 UTC (permalink / raw) To: Tom Tromey; +Cc: Pierre Muller, gdb-patches > Pierre> Should zero be considered as FALSE and > Pierre> thus the should say that this parameter is NOT a variable parameter, > Pierre> or does the simple presence of this attribute condfirm > Pierre> this it is a variable parameter, no matter the value of the flag. > Pierre> I took the first approach here, but have the impression > Pierre> that it is not always the case inside dwarf2read.c code. > > I think you made the correct choice. FWIW: I also double-checked the DWARF3 standard, and it says that the value of this attribute is a flag, and following the hyperlinks in the PDF, one gets to: flag A flag is represented as a single byte of data (DW_FORM_flag). If the flag has value zero, it indicates the absence of the attribute. If the flag has a non-zero value, it indicates the presence of the attribute. -- Joel ^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute 2010-05-17 17:34 ` Joel Brobecker @ 2010-05-17 17:34 ` Pierre Muller 2010-05-17 18:54 ` Joel Brobecker 0 siblings, 1 reply; 16+ messages in thread From: Pierre Muller @ 2010-05-17 17:34 UTC (permalink / raw) To: 'Joel Brobecker', 'Tom Tromey'; +Cc: gdb-patches > -----Message d'origine----- > De : gdb-patches-owner@sourceware.org [mailto:gdb-patches- > owner@sourceware.org] De la part de Joel Brobecker > Envoyé : Monday, May 17, 2010 7:28 PM > À : Tom Tromey > Cc : Pierre Muller; gdb-patches@sourceware.org > Objet : Re: [RFA] dwarf debug format: Support DW_AT_variable_parameter > attribute > > > Pierre> Should zero be considered as FALSE and > > Pierre> thus the should say that this parameter is NOT a variable > parameter, > > Pierre> or does the simple presence of this attribute condfirm > > Pierre> this it is a variable parameter, no matter the value of the > flag. > > Pierre> I took the first approach here, but have the impression > > Pierre> that it is not always the case inside dwarf2read.c code. > > > > I think you made the correct choice. > > FWIW: I also double-checked the DWARF3 standard, and it says that the > value of this attribute is a flag, and following the hyperlinks in > the PDF, one gets to: > > flag > A flag is represented as a single byte of data (DW_FORM_flag). > If the flag has value zero, it indicates the absence of the > attribute. If the flag has a non-zero value, it indicates the > presence of the attribute. So, may I commit this patch? Pierre ^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute 2010-05-17 17:34 ` Pierre Muller @ 2010-05-17 18:54 ` Joel Brobecker 2010-05-17 21:48 ` Pierre Muller [not found] ` <44296.7587885962$1274132782@news.gmane.org> 0 siblings, 2 replies; 16+ messages in thread From: Joel Brobecker @ 2010-05-17 18:54 UTC (permalink / raw) To: Pierre Muller; +Cc: 'Tom Tromey', gdb-patches > So, may I commit this patch? As far as I can tell, there was a question from Tom that is still unanswered... -- Joel ^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute 2010-05-17 18:54 ` Joel Brobecker @ 2010-05-17 21:48 ` Pierre Muller [not found] ` <44296.7587885962$1274132782@news.gmane.org> 1 sibling, 0 replies; 16+ messages in thread From: Pierre Muller @ 2010-05-17 21:48 UTC (permalink / raw) To: 'Joel Brobecker' Cc: 'Tom Tromey', gdb-patches, 'FPC Core Developer List' Whoops, you are right: this was Tom's question: >I wonder whether it is possible for such a parameter to be marked as >LOC_COMPUTED or LOC_OPTIMIZED_OUT by var_decode_location. If so then >changing the class to LOC_REF_ARG seems incorrect. I looked a little more into the sources and now understand that my patch is indeed wrong :( I hoped that simple case like variables in registers or at a fixed offset relative to stack would simply be treated as in stabs and assign a LOC_REGISTER or LOC_ARG SYMBOL_CLASS, but there is no such conversion ... See note line 8459 from dwarf2read.c source. /* NOTE drow/2002-01-30: It might be worthwhile to have a static expression evaluator, and use LOC_COMPUTED only when necessary (i.e. when the value of a register or memory location is referenced, or a thread-local block, etc.). Then again, it might not be worthwhile. I'm assuming that it isn't unless performance or memory numbers show me otherwise. */ I fear that my patch will have to wait until this static expression evaluator is implemented... Let's drop this patch for now. Thanks for the clever question, Tom! Pierre > -----Message d'origine----- > De : gdb-patches-owner@sourceware.org [mailto:gdb-patches- > owner@sourceware.org] De la part de Joel Brobecker > Envoyé : Monday, May 17, 2010 7:47 PM > À : Pierre Muller > Cc : 'Tom Tromey'; gdb-patches@sourceware.org > Objet : Re: [RFA] dwarf debug format: Support DW_AT_variable_parameter > attribute > > > So, may I commit this patch? > > As far as I can tell, there was a question from Tom that is still > unanswered... > > -- > Joel ^ permalink raw reply [flat|nested] 16+ messages in thread
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* Re: [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute [not found] ` <44296.7587885962$1274132782@news.gmane.org> @ 2010-05-19 19:43 ` Tom Tromey 2010-05-19 21:45 ` Pierre Muller [not found] ` <28559.2589797036$1274302480@news.gmane.org> 0 siblings, 2 replies; 16+ messages in thread From: Tom Tromey @ 2010-05-19 19:43 UTC (permalink / raw) To: Pierre Muller Cc: 'Joel Brobecker', gdb-patches, 'FPC Core Developer List' >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr> writes: Pierre> I looked a little more into the sources Pierre> and now understand that my patch is indeed Pierre> wrong :( [...] Pierre> See note line 8459 from dwarf2read.c source. Pierre> /* NOTE drow/2002-01-30: It might be worthwhile to have a static Pierre> expression evaluator, and use LOC_COMPUTED only when necessary Pierre> (i.e. when the value of a register or memory location is Pierre> referenced, or a thread-local block, etc.). Then again, it might Pierre> not be worthwhile. I'm assuming that it isn't unless performance Pierre> or memory numbers show me otherwise. */ Pierre> I fear that my patch will have to wait until Pierre> this static expression evaluator is implemented... I'm not totally convinced that we would want such an evaluator. Could you change the type of a parameter marked with DW_AT_variable_parameter to be a reference type instead? It seems to me that this would give the same result, or nearly so. Tom ^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute 2010-05-19 19:43 ` Tom Tromey @ 2010-05-19 21:45 ` Pierre Muller [not found] ` <28559.2589797036$1274302480@news.gmane.org> 1 sibling, 0 replies; 16+ messages in thread From: Pierre Muller @ 2010-05-19 21:45 UTC (permalink / raw) To: tromey Cc: 'Joel Brobecker', gdb-patches, 'FPC Core Developer List' > Pierre> I fear that my patch will have to wait until > Pierre> this static expression evaluator is implemented... > > I'm not totally convinced that we would want such an evaluator. > > Could you change the type of a parameter marked with > DW_AT_variable_parameter to be a reference type instead? It seems to > me > that this would give the same result, or nearly so. That is what is done for now on Free Pascal, i.e. the debug information generates a reference_type for parameters passed by var. It's not ideal yet, but this is just a matter of twicks inside p-* files... The following patch does make the same as if the reference_type is created by Free Pascal. I am unsure about the type allocation procedure, could you just tell me if this looks OK before I resubmit an RFA. Pierre $ cvs diff -u -p dwarf2read.c Index: dwarf2read.c =================================================================== RCS file: /cvs/src/src/gdb/dwarf2read.c,v retrieving revision 1.386 diff -u -p -r1.386 dwarf2read.c --- dwarf2read.c 17 May 2010 15:55:01 -0000 1.386 +++ dwarf2read.c 19 May 2010 20:52:42 -0000 @@ -8662,6 +8662,20 @@ new_symbol (struct die_info *die, struct { dwarf2_const_value (attr, sym, cu); } + attr = dwarf2_attr (die, DW_AT_variable_parameter, cu); + if (attr && DW_UNSND (attr)) + { + struct type *ref_type; + + ref_type = TYPE_REFERENCE_TYPE (SYMBOL_TYPE (sym)); + if (!ref_type) + { + ref_type = alloc_type (objfile); + ref_type = make_reference_type (SYMBOL_TYPE (sym), &ref_type); + } + SYMBOL_TYPE (sym) = ref_type; + } + add_symbol_to_list (sym, cu->list_in_scope); break; case DW_TAG_unspecified_parameters: ^ permalink raw reply [flat|nested] 16+ messages in thread
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* Re: [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute [not found] ` <28559.2589797036$1274302480@news.gmane.org> @ 2010-05-19 22:34 ` Tom Tromey 2010-05-19 23:34 ` [RFA-v2] " Pierre Muller [not found] ` <27418.1569614031$1274308493@news.gmane.org> 0 siblings, 2 replies; 16+ messages in thread From: Tom Tromey @ 2010-05-19 22:34 UTC (permalink / raw) To: Pierre Muller Cc: 'Joel Brobecker', gdb-patches, 'FPC Core Developer List' >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr> writes: Pierre> That is what is done for now on Free Pascal, Pierre> i.e. the debug information generates a reference_type for Pierre> parameters passed by var. Pierre> It's not ideal yet, but this is just a matter of Pierre> twicks inside p-* files... I suppose it is less than ideal in that the type is exposed to the user. Another idea would be to augment the DWARF expression evaluator to do an additional indirection when this bit is set. Though then one must wonder why the compiler does not simply emit an expression to that effect. Pierre> I am unsure about the type allocation procedure, Pierre> could you just tell me if this looks OK Pierre> before I resubmit an RFA. Pierre> + struct type *ref_type; Pierre> + Pierre> + ref_type = TYPE_REFERENCE_TYPE (SYMBOL_TYPE (sym)); Pierre> + if (!ref_type) Pierre> + { Pierre> + ref_type = alloc_type (objfile); Pierre> + ref_type = make_reference_type (SYMBOL_TYPE (sym), Pierre> &ref_type); Pierre> + } Just use 'lookup_reference_type (SYMBOL_TYPE (sym))'. That will handle the details for you. Tom ^ permalink raw reply [flat|nested] 16+ messages in thread
* [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute 2010-05-19 22:34 ` Tom Tromey @ 2010-05-19 23:34 ` Pierre Muller [not found] ` <27418.1569614031$1274308493@news.gmane.org> 1 sibling, 0 replies; 16+ messages in thread From: Pierre Muller @ 2010-05-19 23:34 UTC (permalink / raw) To: tromey Cc: 'Joel Brobecker', gdb-patches, 'FPC Core Developer List' So, here is a new version of this patch. I will try to improve reference type handling inside the pascal specific sources later. Does that look OK? Pierre 2010-05-20 Pierre Muller <muller@ics.u-strasbg.fr> * dwarf2read.c (new_symbol): Handle DW_AT_variable_parameter attribute. Index: dwarf2read.c =================================================================== RCS file: /cvs/src/src/gdb/dwarf2read.c,v retrieving revision 1.386 diff -u -p -r1.386 dwarf2read.c --- dwarf2read.c 17 May 2010 15:55:01 -0000 1.386 +++ dwarf2read.c 19 May 2010 22:29:04 -0000 @@ -8662,6 +8662,15 @@ new_symbol (struct die_info *die, struct { dwarf2_const_value (attr, sym, cu); } + attr = dwarf2_attr (die, DW_AT_variable_parameter, cu); + if (attr && DW_UNSND (attr)) + { + struct type *ref_type; + + ref_type = lookup_reference_type (SYMBOL_TYPE (sym)); + SYMBOL_TYPE (sym) = ref_type; + } + add_symbol_to_list (sym, cu->list_in_scope); break; case DW_TAG_unspecified_parameters: > -----Message d'origine----- > De : gdb-patches-owner@sourceware.org [mailto:gdb-patches- > owner@sourceware.org] De la part de Tom Tromey > Envoyé : Thursday, May 20, 2010 12:09 AM > À : Pierre Muller > Cc : 'Joel Brobecker'; gdb-patches@sourceware.org; 'FPC Core Developer > List' > Objet : Re: [RFA] dwarf debug format: Support DW_AT_variable_parameter > attribute > > >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr> > writes: > > Pierre> That is what is done for now on Free Pascal, > Pierre> i.e. the debug information generates a reference_type for > Pierre> parameters passed by var. > Pierre> It's not ideal yet, but this is just a matter of > Pierre> twicks inside p-* files... > > I suppose it is less than ideal in that the type is exposed to the > user. > > Another idea would be to augment the DWARF expression evaluator to do > an > additional indirection when this bit is set. Though then one must > wonder why the compiler does not simply emit an expression to that > effect. > > Pierre> I am unsure about the type allocation procedure, > Pierre> could you just tell me if this looks OK > Pierre> before I resubmit an RFA. > > Pierre> + struct type *ref_type; > Pierre> + > Pierre> + ref_type = TYPE_REFERENCE_TYPE (SYMBOL_TYPE > (sym)); > Pierre> + if (!ref_type) > Pierre> + { > Pierre> + ref_type = alloc_type (objfile); > Pierre> + ref_type = make_reference_type (SYMBOL_TYPE > (sym), > Pierre> &ref_type); > Pierre> + } > > Just use 'lookup_reference_type (SYMBOL_TYPE (sym))'. > That will handle the details for you. > > Tom ^ permalink raw reply [flat|nested] 16+ messages in thread
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* Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute [not found] ` <27418.1569614031$1274308493@news.gmane.org> @ 2010-05-21 17:44 ` Tom Tromey 2010-05-21 20:50 ` Pierre Muller 0 siblings, 1 reply; 16+ messages in thread From: Tom Tromey @ 2010-05-21 17:44 UTC (permalink / raw) To: Pierre Muller Cc: 'Joel Brobecker', gdb-patches, 'FPC Core Developer List' >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr> writes: Pierre> Does that look OK? Pierre> 2010-05-20 Pierre Muller <muller@ics.u-strasbg.fr> Pierre> * dwarf2read.c (new_symbol): Handle DW_AT_variable_parameter Pierre> attribute. This is ok. I think it would be improved by a test case, but that is up to you. Tom ^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute 2010-05-21 17:44 ` Tom Tromey @ 2010-05-21 20:50 ` Pierre Muller 2010-11-04 5:32 ` [new testcase] Regression 7.1->7.2 for iFort [Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute] Jan Kratochvil 0 siblings, 1 reply; 16+ messages in thread From: Pierre Muller @ 2010-05-21 20:50 UTC (permalink / raw) To: tromey Cc: 'Joel Brobecker', gdb-patches, 'FPC Core Developer List' > -----Message d'origine----- > De : gdb-patches-owner@sourceware.org [mailto:gdb-patches- > owner@sourceware.org] De la part de Tom Tromey > Envoyé : Friday, May 21, 2010 7:20 PM > À : Pierre Muller > Cc : 'Joel Brobecker'; gdb-patches@sourceware.org; 'FPC Core Developer > List' > Objet : Re: [RFA-v2] dwarf debug format: Support > DW_AT_variable_parameter attribute > > >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr> > writes: > > Pierre> Does that look OK? > > Pierre> 2010-05-20 Pierre Muller <muller@ics.u-strasbg.fr> > Pierre> * dwarf2read.c (new_symbol): Handle > DW_AT_variable_parameter > Pierre> attribute. > > This is ok. Thanks, I committed the patch. > I think it would be improved by a test case, but that is up to you. This test would be pascal specific anyhow, I will try to write one later. Pierre ^ permalink raw reply [flat|nested] 16+ messages in thread
* [new testcase] Regression 7.1->7.2 for iFort [Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute] 2010-05-21 20:50 ` Pierre Muller @ 2010-11-04 5:32 ` Jan Kratochvil 2010-11-04 8:47 ` [Core] " Pierre Free Pascal 0 siblings, 1 reply; 16+ messages in thread From: Jan Kratochvil @ 2010-11-04 5:32 UTC (permalink / raw) To: Pierre Muller Cc: tromey, 'Joel Brobecker', gdb-patches, 'FPC Core Developer List' On Fri, 21 May 2010 22:45:35 +0200, Pierre Muller wrote: > Thanks, I committed the patch. commit 570d5d01de35effada277a69552c0903a4928241 Author: Pierre Muller <muller@ics.u-strasbg.fr> Date: Fri May 21 20:45:18 2010 +0000 * dwarf2read.c (new_symbol): Handle DW_AT_variable_parameter attribute. Please revert this patch. From the DWARF-4 description of DW_AT_variable_parameter I do not think it changes the data structures meaning in any way. It just states which data can be modified by whom. I do not think this is useful for GDB in any way. > > I think it would be improved by a test case, but that is up to you. > > This test would be pascal specific anyhow, I believe the Pascal compiler should generate different debug info. For the `var' keyword you can either (a) use DW_TAG_reference_type and point DW_AT_location at the pointer or (b) use DW_OP_deref (as iFort does) on the passed pointer and point DW_AT_location at the value itself. DW_AT_variable_parameter would be true only for the (a) choice. 1 subroutine f (i) 2 integer i 3 i = 2 4 end 5 program varparam 6 integer m 7 m = 1 8 call f (m) 9 write(*,*) m 10 end for iFort 11.1 20100806 it regressed this code, GDB-7.1 displayed: Breakpoint 1, f (i=1) at varparam.f90:3 3 i = 2 (gdb) p i $1 = 1 while GDB-7.2 displays: Breakpoint 2, f (i=@0x1) at varparam.f90:3 3 i = 2 (gdb) p i $1 = (REF TO -> ( INTEGER(4) )) @0x1: <error reading variable> (note that `0x1' GDB considers as an address here) A new testcase for the iFort usage case is attached. No regressions on {x86_64,x86_64-m32,i686}-fedora14snapshot-linux-gnu. I will then check-in the testcase or you can or so. Regards, Jan gdb/ 2010-11-04 Jan Kratochvil <jan.kratochvil@redhat.com> Revert: 2010-05-21 Pierre Muller <muller@ics.u-strasbg.fr> * dwarf2read.c (new_symbol): Handle DW_AT_variable_parameter attribute. gdb/testsuite/ 2010-11-04 Jan Kratochvil <jan.kratochvil@redhat.com> * dw2-ifort-parameter-debug.S: New file. * dw2-ifort-parameter.c: New file. * dw2-ifort-parameter.exp: New file. --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -10801,14 +10801,6 @@ new_symbol_full (struct die_info *die, struct type *type, struct dwarf2_cu *cu, { dwarf2_const_value (attr, sym, cu); } - attr = dwarf2_attr (die, DW_AT_variable_parameter, cu); - if (attr && DW_UNSND (attr)) - { - struct type *ref_type; - - ref_type = lookup_reference_type (SYMBOL_TYPE (sym)); - SYMBOL_TYPE (sym) = ref_type; - } list_to_add = cu->list_in_scope; break; --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-ifort-parameter-debug.S @@ -0,0 +1,122 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2010 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/>. */ + + .section .debug_info +.Lcu1_begin: + /* CU header */ + .4byte .Lcu1_end - .Lcu1_start /* Length of Compilation Unit */ +.Lcu1_start: + .2byte 2 /* DWARF Version */ + .4byte .Labbrev1_begin /* Offset into abbrev section */ + .byte 4 /* Pointer size */ + + /* CU die */ + .uleb128 1 /* Abbrev: DW_TAG_compile_unit */ + .ascii "file1.txt\0" /* DW_AT_name */ + .ascii "GNU C 3.3.3\0" /* DW_AT_producer */ + .byte 1 /* DW_AT_language (C) */ + .4byte func /* DW_AT_low_pc */ + .4byte main /* DW_AT_high_pc */ + + .uleb128 2 /* Abbrev: DW_TAG_subprogram */ + .byte 1 /* DW_AT_external */ + .ascii "func\0" /* DW_AT_name */ + .4byte func /* DW_AT_low_pc */ + .4byte main /* DW_AT_high_pc */ + + .uleb128 3 /* Abbrev: DW_TAG_formal_parameter */ + .ascii "param\0" /* DW_AT_name */ + .byte 1 /* DW_AT_variable_parameter */ + .4byte .Ltype_int - .Lcu1_begin /* DW_AT_type */ + .byte 2f - 1f /* DW_AT_location */ +1: .byte 3 /* DW_OP_addr */ + .4byte ptr /* <addr> */ + .byte 0x6 /* DW_OP_deref */ +2: + + .byte 0 /* End of children of func */ + +.Ltype_int: + .uleb128 4 /* Abbrev: DW_TAG_base_type */ + .ascii "int\0" /* DW_AT_name */ + .byte 4 /* DW_AT_byte_size */ + .byte 5 /* DW_AT_encoding */ + + .byte 0 /* End of children of CU */ +.Lcu1_end: + +/* Abbrev table */ + .section .debug_abbrev +.Labbrev1_begin: + .uleb128 1 /* Abbrev code */ + .uleb128 0x11 /* DW_TAG_compile_unit */ + .byte 1 /* has_children */ + .uleb128 0x3 /* DW_AT_name */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0x25 /* DW_AT_producer */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0x13 /* DW_AT_language */ + .uleb128 0xb /* DW_FORM_data1 */ + .uleb128 0x11 /* DW_AT_low_pc */ + .uleb128 0x1 /* DW_FORM_addr */ + .uleb128 0x12 /* DW_AT_high_pc */ + .uleb128 0x1 /* DW_FORM_addr */ + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ + + .uleb128 2 /* Abbrev code */ + .uleb128 0x2e /* DW_TAG_subprogram */ + .byte 1 /* has_children */ + .uleb128 0x3f /* DW_AT_external */ + .uleb128 0xc /* DW_FORM_flag */ + .uleb128 0x3 /* DW_AT_name */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0x11 /* DW_AT_low_pc */ + .uleb128 0x1 /* DW_FORM_addr */ + .uleb128 0x12 /* DW_AT_high_pc */ + .uleb128 0x1 /* DW_FORM_addr */ + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ + + .uleb128 3 /* Abbrev code */ + .uleb128 0x05 /* DW_TAG_formal_parameter */ + .byte 0 /* has_children */ + .uleb128 0x3 /* DW_AT_name */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0x4b /* DW_AT_variable_parameter */ + .uleb128 0xb /* DW_FORM_data1 */ + .uleb128 0x49 /* DW_AT_type */ + .uleb128 0x13 /* DW_FORM_ref4 */ + .uleb128 0x2 /* DW_AT_location */ + .uleb128 0xa /* DW_FORM_block1 */ + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ + + .uleb128 4 /* Abbrev code */ + .uleb128 0x24 /* DW_TAG_base_type */ + .byte 0 /* has_children */ + .uleb128 0x3 /* DW_AT_name */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0xb /* DW_AT_byte_size */ + .uleb128 0xb /* DW_FORM_data1 */ + .uleb128 0x3e /* DW_AT_encoding */ + .uleb128 0xb /* DW_FORM_data1 */ + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ + + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-ifort-parameter.c @@ -0,0 +1,31 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2010 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/>. */ + +int value = 0xdeadf00d; +int *ptr = &value; + +void +func (void) +{ +} + +int +main (void) +{ + func (); + return 0; +} --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-ifort-parameter.exp @@ -0,0 +1,40 @@ +# Copyright 2010 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/>. + +# Verify DW_AT_variable_parameter does not modify the data structures meaning +# for GDB, as being used by iFort. + +# This test can only be run on targets which support DWARF-2 and use gas. +# For now pick a sampling of likely targets. +if {![istarget *-*-linux*] + && ![istarget *-*-gnu*] + && ![istarget *-*-elf*] + && ![istarget *-*-openbsd*] + && ![istarget arm-*-eabi*] + && ![istarget powerpc-*-eabi*]} { + return 0 +} + +set testfile "dw2-ifort-parameter" + +if { [prepare_for_testing ${testfile}.exp ${testfile} [list ${testfile}.c ${testfile}-debug.S] {nodebug}] } { + return -1 +} + +if ![runto func] { + return -1 +} + +gdb_test "p/x param" " = 0xdeadf00d" ^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: [Core] [new testcase] Regression 7.1->7.2 for iFort [Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute] 2010-11-04 5:32 ` [new testcase] Regression 7.1->7.2 for iFort [Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute] Jan Kratochvil @ 2010-11-04 8:47 ` Pierre Free Pascal 2010-11-04 18:01 ` Joel Brobecker 2011-09-01 7:20 ` Jan Kratochvil 0 siblings, 2 replies; 16+ messages in thread From: Pierre Free Pascal @ 2010-11-04 8:47 UTC (permalink / raw) To: 'FPC Core Developer List', gdb-patches Cc: tromey, 'Joel Brobecker' Rereading the dwarf4 specifications, I agree with Jan that I misinterpreted this TAG and that it is only an information tag, that could possibly be used as a warning notice that we might modify caller variables. Please apply this patch, I will try to correct Free Pascal code generation to cope for this issue. Pierre Muller Pascal language maintainer of GDB and core team member of Free Pascal Compiler. -----Message d'origine----- De : core-bounces@freepascal.org [mailto:core-bounces@freepascal.org] De la part de Jan Kratochvil Envoyé : jeudi 4 novembre 2010 06:32 À : Pierre Muller Cc : tromey@redhat.com; 'FPC Core Developer List'; gdb-patches@sourceware.org; 'Joel Brobecker' Objet : [Core] [new testcase] Regression 7.1->7.2 for iFort [Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute] On Fri, 21 May 2010 22:45:35 +0200, Pierre Muller wrote: > Thanks, I committed the patch. commit 570d5d01de35effada277a69552c0903a4928241 Author: Pierre Muller <muller@ics.u-strasbg.fr> Date: Fri May 21 20:45:18 2010 +0000 * dwarf2read.c (new_symbol): Handle DW_AT_variable_parameter attribute. Please revert this patch. From the DWARF-4 description of DW_AT_variable_parameter I do not think it changes the data structures meaning in any way. It just states which data can be modified by whom. I do not think this is useful for GDB in any way. > > I think it would be improved by a test case, but that is up to you. > > This test would be pascal specific anyhow, I believe the Pascal compiler should generate different debug info. For the `var' keyword you can either (a) use DW_TAG_reference_type and point DW_AT_location at the pointer or (b) use DW_OP_deref (as iFort does) on the passed pointer and point DW_AT_location at the value itself. DW_AT_variable_parameter would be true only for the (a) choice. 1 subroutine f (i) 2 integer i 3 i = 2 4 end 5 program varparam 6 integer m 7 m = 1 8 call f (m) 9 write(*,*) m 10 end for iFort 11.1 20100806 it regressed this code, GDB-7.1 displayed: Breakpoint 1, f (i=1) at varparam.f90:3 3 i = 2 (gdb) p i $1 = 1 while GDB-7.2 displays: Breakpoint 2, f (i=@0x1) at varparam.f90:3 3 i = 2 (gdb) p i $1 = (REF TO -> ( INTEGER(4) )) @0x1: <error reading variable> (note that `0x1' GDB considers as an address here) A new testcase for the iFort usage case is attached. No regressions on {x86_64,x86_64-m32,i686}-fedora14snapshot-linux-gnu. I will then check-in the testcase or you can or so. Regards, Jan gdb/ 2010-11-04 Jan Kratochvil <jan.kratochvil@redhat.com> Revert: 2010-05-21 Pierre Muller <muller@ics.u-strasbg.fr> * dwarf2read.c (new_symbol): Handle DW_AT_variable_parameter attribute. gdb/testsuite/ 2010-11-04 Jan Kratochvil <jan.kratochvil@redhat.com> * dw2-ifort-parameter-debug.S: New file. * dw2-ifort-parameter.c: New file. * dw2-ifort-parameter.exp: New file. --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -10801,14 +10801,6 @@ new_symbol_full (struct die_info *die, struct type *type, struct dwarf2_cu *cu, { dwarf2_const_value (attr, sym, cu); } - attr = dwarf2_attr (die, DW_AT_variable_parameter, cu); - if (attr && DW_UNSND (attr)) - { - struct type *ref_type; - - ref_type = lookup_reference_type (SYMBOL_TYPE (sym)); - SYMBOL_TYPE (sym) = ref_type; - } list_to_add = cu->list_in_scope; break; --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-ifort-parameter-debug.S @@ -0,0 +1,122 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2010 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/>. */ + + .section .debug_info +.Lcu1_begin: + /* CU header */ + .4byte .Lcu1_end - .Lcu1_start /* Length of Compilation Unit */ +.Lcu1_start: + .2byte 2 /* DWARF Version */ + .4byte .Labbrev1_begin /* Offset into abbrev section */ + .byte 4 /* Pointer size */ + + /* CU die */ + .uleb128 1 /* Abbrev: DW_TAG_compile_unit */ + .ascii "file1.txt\0" /* DW_AT_name */ + .ascii "GNU C 3.3.3\0" /* DW_AT_producer */ + .byte 1 /* DW_AT_language (C) */ + .4byte func /* DW_AT_low_pc */ + .4byte main /* DW_AT_high_pc */ + + .uleb128 2 /* Abbrev: DW_TAG_subprogram */ + .byte 1 /* DW_AT_external */ + .ascii "func\0" /* DW_AT_name */ + .4byte func /* DW_AT_low_pc */ + .4byte main /* DW_AT_high_pc */ + + .uleb128 3 /* Abbrev: DW_TAG_formal_parameter */ + .ascii "param\0" /* DW_AT_name */ + .byte 1 /* DW_AT_variable_parameter */ + .4byte .Ltype_int - .Lcu1_begin /* DW_AT_type */ + .byte 2f - 1f /* DW_AT_location */ +1: .byte 3 /* DW_OP_addr */ + .4byte ptr /* <addr> */ + .byte 0x6 /* DW_OP_deref */ +2: + + .byte 0 /* End of children of func */ + +.Ltype_int: + .uleb128 4 /* Abbrev: DW_TAG_base_type */ + .ascii "int\0" /* DW_AT_name */ + .byte 4 /* DW_AT_byte_size */ + .byte 5 /* DW_AT_encoding */ + + .byte 0 /* End of children of CU */ +.Lcu1_end: + +/* Abbrev table */ + .section .debug_abbrev +.Labbrev1_begin: + .uleb128 1 /* Abbrev code */ + .uleb128 0x11 /* DW_TAG_compile_unit */ + .byte 1 /* has_children */ + .uleb128 0x3 /* DW_AT_name */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0x25 /* DW_AT_producer */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0x13 /* DW_AT_language */ + .uleb128 0xb /* DW_FORM_data1 */ + .uleb128 0x11 /* DW_AT_low_pc */ + .uleb128 0x1 /* DW_FORM_addr */ + .uleb128 0x12 /* DW_AT_high_pc */ + .uleb128 0x1 /* DW_FORM_addr */ + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ + + .uleb128 2 /* Abbrev code */ + .uleb128 0x2e /* DW_TAG_subprogram */ + .byte 1 /* has_children */ + .uleb128 0x3f /* DW_AT_external */ + .uleb128 0xc /* DW_FORM_flag */ + .uleb128 0x3 /* DW_AT_name */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0x11 /* DW_AT_low_pc */ + .uleb128 0x1 /* DW_FORM_addr */ + .uleb128 0x12 /* DW_AT_high_pc */ + .uleb128 0x1 /* DW_FORM_addr */ + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ + + .uleb128 3 /* Abbrev code */ + .uleb128 0x05 /* DW_TAG_formal_parameter */ + .byte 0 /* has_children */ + .uleb128 0x3 /* DW_AT_name */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0x4b /* DW_AT_variable_parameter */ + .uleb128 0xb /* DW_FORM_data1 */ + .uleb128 0x49 /* DW_AT_type */ + .uleb128 0x13 /* DW_FORM_ref4 */ + .uleb128 0x2 /* DW_AT_location */ + .uleb128 0xa /* DW_FORM_block1 */ + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ + + .uleb128 4 /* Abbrev code */ + .uleb128 0x24 /* DW_TAG_base_type */ + .byte 0 /* has_children */ + .uleb128 0x3 /* DW_AT_name */ + .uleb128 0x8 /* DW_FORM_string */ + .uleb128 0xb /* DW_AT_byte_size */ + .uleb128 0xb /* DW_FORM_data1 */ + .uleb128 0x3e /* DW_AT_encoding */ + .uleb128 0xb /* DW_FORM_data1 */ + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ + + .byte 0x0 /* Terminator */ + .byte 0x0 /* Terminator */ --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-ifort-parameter.c @@ -0,0 +1,31 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2010 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/>. */ + +int value = 0xdeadf00d; +int *ptr = &value; + +void +func (void) +{ +} + +int +main (void) +{ + func (); + return 0; +} --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-ifort-parameter.exp @@ -0,0 +1,40 @@ +# Copyright 2010 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/>. + +# Verify DW_AT_variable_parameter does not modify the data structures meaning +# for GDB, as being used by iFort. + +# This test can only be run on targets which support DWARF-2 and use gas. +# For now pick a sampling of likely targets. +if {![istarget *-*-linux*] + && ![istarget *-*-gnu*] + && ![istarget *-*-elf*] + && ![istarget *-*-openbsd*] + && ![istarget arm-*-eabi*] + && ![istarget powerpc-*-eabi*]} { + return 0 +} + +set testfile "dw2-ifort-parameter" + +if { [prepare_for_testing ${testfile}.exp ${testfile} [list ${testfile}.c ${testfile}-debug.S] {nodebug}] } { + return -1 +} + +if ![runto func] { + return -1 +} + +gdb_test "p/x param" " = 0xdeadf00d" _______________________________________________ core site list core@freepascal.org http://idefix.wisa.be/mailman/listinfo/core ^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [Core] [new testcase] Regression 7.1->7.2 for iFort [Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute] 2010-11-04 8:47 ` [Core] " Pierre Free Pascal @ 2010-11-04 18:01 ` Joel Brobecker 2010-11-05 8:04 ` Pierre Free Pascal 2011-09-01 7:20 ` Jan Kratochvil 1 sibling, 1 reply; 16+ messages in thread From: Joel Brobecker @ 2010-11-04 18:01 UTC (permalink / raw) To: Pierre Free Pascal; +Cc: 'FPC Core Developer List', gdb-patches, tromey > Please apply this patch, > I will try to correct Free Pascal code generation > to cope for this issue. Should it be applied on 7.2 as well? -- Joel ^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: [Core] [new testcase] Regression 7.1->7.2 for iFort [Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute] 2010-11-04 18:01 ` Joel Brobecker @ 2010-11-05 8:04 ` Pierre Free Pascal 0 siblings, 0 replies; 16+ messages in thread From: Pierre Free Pascal @ 2010-11-05 8:04 UTC (permalink / raw) To: 'Joel Brobecker' Cc: 'FPC Core Developer List', gdb-patches, tromey Yes, if it affect badly fortran debugging, it should probably be applied to 7.2 branch as well. Pierre > -----Message d'origine----- > De : Joel Brobecker [mailto:brobecker@adacore.com] > Envoyé : jeudi 4 novembre 2010 19:01 > À : Pierre Free Pascal > Cc : 'FPC Core Developer List'; gdb-patches@sourceware.org; > tromey@redhat.com > Objet : Re: [Core] [new testcase] Regression 7.1->7.2 for iFort [Re: > [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter > attribute] > > > Please apply this patch, > > I will try to correct Free Pascal code generation > > to cope for this issue. > > Should it be applied on 7.2 as well? > > -- > Joel ^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [Core] [new testcase] Regression 7.1->7.2 for iFort [Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute] 2010-11-04 8:47 ` [Core] " Pierre Free Pascal 2010-11-04 18:01 ` Joel Brobecker @ 2011-09-01 7:20 ` Jan Kratochvil 1 sibling, 0 replies; 16+ messages in thread From: Jan Kratochvil @ 2011-09-01 7:20 UTC (permalink / raw) To: Pierre Free Pascal Cc: 'FPC Core Developer List', gdb-patches, tromey, 'Joel Brobecker' On Thu, 04 Nov 2010 09:46:22 +0100, Pierre Free Pascal wrote: > Rereading the dwarf4 specifications, > I agree with Jan that I misinterpreted > this TAG and that it is only an information tag, > that could possibly be used as a warning notice > that we might modify caller variables. > > Please apply this patch, > I will try to correct Free Pascal code generation > to cope for this issue. Checked in: http://sourceware.org/ml/gdb-cvs/2011-09/msg00003.html http://sourceware.org/ml/gdb-cvs/2011-09/msg00004.html Somehow it got forgotten and referenced now by: Question about DW_AT_variable_parameter in dwarf2read.c http://sourceware.org/ml/gdb/2011-08/msg00138.html Jan ^ permalink raw reply [flat|nested] 16+ messages in thread
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2010-05-13 17:51 ` [RFA] dwarf debug format: Support DW_AT_variable_parameter attribute Tom Tromey
2010-05-17 17:34 ` Joel Brobecker
2010-05-17 17:34 ` Pierre Muller
2010-05-17 18:54 ` Joel Brobecker
2010-05-17 21:48 ` Pierre Muller
[not found] ` <44296.7587885962$1274132782@news.gmane.org>
2010-05-19 19:43 ` Tom Tromey
2010-05-19 21:45 ` Pierre Muller
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2010-05-19 22:34 ` Tom Tromey
2010-05-19 23:34 ` [RFA-v2] " Pierre Muller
[not found] ` <27418.1569614031$1274308493@news.gmane.org>
2010-05-21 17:44 ` Tom Tromey
2010-05-21 20:50 ` Pierre Muller
2010-11-04 5:32 ` [new testcase] Regression 7.1->7.2 for iFort [Re: [RFA-v2] dwarf debug format: Support DW_AT_variable_parameter attribute] Jan Kratochvil
2010-11-04 8:47 ` [Core] " Pierre Free Pascal
2010-11-04 18:01 ` Joel Brobecker
2010-11-05 8:04 ` Pierre Free Pascal
2011-09-01 7:20 ` Jan Kratochvil
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