From patchwork Fri Jun 26 08:36:44 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kratochvil X-Patchwork-Id: 7357 Received: (qmail 15801 invoked by alias); 26 Jun 2015 08:36:53 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 15788 invoked by uid 89); 26 Jun 2015 08:36:52 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.2 required=5.0 tests=AWL, BAYES_00, KAM_LAZY_DOMAIN_SECURITY, KAM_STOCKGEN, RP_MATCHES_RCVD, SPF_HELO_PASS autolearn=no version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Fri, 26 Jun 2015 08:36:50 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 68847319831; Fri, 26 Jun 2015 08:36:49 +0000 (UTC) Received: from host1.jankratochvil.net (ovpn-116-41.ams2.redhat.com [10.36.116.41]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t5Q8aiLo004424 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 26 Jun 2015 04:36:47 -0400 Date: Fri, 26 Jun 2015 10:36:44 +0200 From: Jan Kratochvil To: Doug Evans Cc: gdb-patches , Sergio Durigan Junior Subject: Re: [patchv2] Do not skip prologue for asm (.S) files Message-ID: <20150626083644.GA11136@host1.jankratochvil.net> References: <047d7b5d4b7a98ad1505195daa4a@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <047d7b5d4b7a98ad1505195daa4a@google.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-IsSubscribed: yes On Thu, 25 Jun 2015 22:42:48 +0200, Doug Evans wrote: > Hmmm, so there's an undocumented requirement that minsym_found > and find_function_start_sal work compatibly? > [Which is actually not surprising if you know how linespecs and > breakpoints: we find all the matching minsyms and fullsyms > and then throw away the duplicates. But if these two functions > behave differently then the search for duplicates fails. At least > I'm guessing that's what happened here.] Yes: # (gdb) file /root/jkratoch/redhat/gdb-clean/gdb/testsuite/gdb.base/breako2 # Reading symbols from /root/jkratoch/redhat/gdb-clean/gdb/testsuite/gdb.base/breako2...done. # (gdb) break main #-Breakpoint 1 at 0x10000644: file ./gdb.base/break.c, line 43. #-(gdb) PASS: gdb.base/break.exp: breakpoint function, optimized file #+Breakpoint 1 at 0x10000640: main. (2 locations) #### Num Type Disp Enb Address What #### 1 breakpoint keep y #### 1.1 y 0x0000000010000640 in main at ./gdb.base/break.c:42 #### 1.2 y 0x0000000010000644 in main at ./gdb.base/break.c:43 #+(gdb) FAIL: gdb.base/break.exp: breakpoint function, optimized file # break marker4 # Breakpoint 2 at 0x10000aa0: file ./gdb.base/break1.c, line 59. # (gdb) PASS: gdb.base/break.exp: breakpoint small function, optimized file #[...] # Continuing. #-720 #-Breakpoint 2, marker4 (d=177601976) at ./gdb.base/break1.c:59 #-59 void marker4 (long d) { values[0].a_field = d; } /* set breakpoint 14 here */ #-(gdb) PASS: gdb.base/break.exp: run until breakpoint set at small function, optimized file (line bp_location14) #+Breakpoint 1, main (argc=1, argv=0x3fffffffec48, envp=0x3fffffffec58) at ./gdb.base/break.c:43 #+43 if (argc == 12345) { /* an unlikely value < 2^16, in case uninited */ /* set breakpoint 6 here */ #+(gdb) FAIL: gdb.base/break.exp: run until breakpoint set at small function, optimized file > Can you do that, plus add a comment to both minsym_found > and find_function_start_sal stating that we rely on them > working compatibly. Done. Providing for review the final patch given all the changes. Thanks, Jan gdb/ChangeLog 2015-06-26 Jan Kratochvil * linespec.c (minsym_found): Reset sal.PC for COMPUNIT_LOCATIONS_VALID and language_asm.. * symtab.c (find_function_start_sal): Likewise. gdb/testsuite/ChangeLog 2015-06-20 Jan Kratochvil * gdb.arch/amd64-prologue-skip.S: New file. * gdb.arch/amd64-prologue-skip.exp: New file. diff --git a/gdb/linespec.c b/gdb/linespec.c index d2089b5..65155d9 100644 --- a/gdb/linespec.c +++ b/gdb/linespec.c @@ -3432,7 +3432,9 @@ collect_symbols (struct symbol *sym, void *data) } /* We've found a minimal symbol MSYMBOL in OBJFILE to associate with our - linespec; return the SAL in RESULT. */ + linespec; return the SAL in RESULT. This function should return SALs + matching those from find_function_start_sal, otherwise false + multiple-locations breakpoints could be placed. */ static void minsym_found (struct linespec_state *self, struct objfile *objfile, @@ -3454,7 +3456,23 @@ minsym_found (struct linespec_state *self, struct objfile *objfile, sal = find_pc_sect_line (pc, NULL, 0); if (self->funfirstline) - skip_prologue_sal (&sal); + { + if (sal.symtab != NULL + && (COMPUNIT_LOCATIONS_VALID (SYMTAB_COMPUNIT (sal.symtab)) + || SYMTAB_LANGUAGE (sal.symtab) == language_asm)) + { + /* If gdbarch_convert_from_func_ptr_addr does not apply then + sal.SECTION, sal.LINE&co. will stay correct from above. + If gdbarch_convert_from_func_ptr_addr applies then + sal.SECTION is cleared from above and sal.LINE&co. will + stay correct from the last find_pc_sect_line above. */ + sal.pc = MSYMBOL_VALUE_ADDRESS (objfile, msymbol); + sal.pc = gdbarch_convert_from_func_ptr_addr (gdbarch, sal.pc, + ¤t_target); + } + else + skip_prologue_sal (&sal); + } if (maybe_add_address (self->addr_set, objfile->pspace, sal.pc)) add_sal_to_sals (self, result, &sal, MSYMBOL_NATURAL_NAME (msymbol), 0); diff --git a/gdb/symtab.c b/gdb/symtab.c index 6693930..2b6af6c 100644 --- a/gdb/symtab.c +++ b/gdb/symtab.c @@ -3605,7 +3605,9 @@ find_pc_line_pc_range (CORE_ADDR pc, CORE_ADDR *startptr, CORE_ADDR *endptr) /* Given a function symbol SYM, find the symtab and line for the start of the function. If the argument FUNFIRSTLINE is nonzero, we want the first line - of real code inside the function. */ + of real code inside the function. + This function should return SALs matching those from minsym_found, + otherwise false multiple-locations breakpoints could be placed. */ struct symtab_and_line find_function_start_sal (struct symbol *sym, int funfirstline) @@ -3617,6 +3619,14 @@ find_function_start_sal (struct symbol *sym, int funfirstline) section = SYMBOL_OBJ_SECTION (symbol_objfile (sym), sym); sal = find_pc_sect_line (BLOCK_START (SYMBOL_BLOCK_VALUE (sym)), section, 0); + if (funfirstline && sal.symtab != NULL + && (COMPUNIT_LOCATIONS_VALID (SYMTAB_COMPUNIT (sal.symtab)) + || SYMTAB_LANGUAGE (sal.symtab) == language_asm)) + { + sal.pc = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); + return sal; + } + /* We always should have a line for the function start address. If we don't, something is odd. Create a plain SAL refering just the PC and hope that skip_prologue_sal (if requested) diff --git a/gdb/testsuite/gdb.arch/amd64-prologue-skip.S b/gdb/testsuite/gdb.arch/amd64-prologue-skip.S new file mode 100644 index 0000000..66b806a --- /dev/null +++ b/gdb/testsuite/gdb.arch/amd64-prologue-skip.S @@ -0,0 +1,28 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2015 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 . */ + + .text +/*0*/ hlt +pushrbp: .globl pushrbp +#define PUSHRBP push %rbp; mov %rsp, %rbp; nop +/*1*/ PUSHRBP +/*6*/ hlt + +/*7*/ hlt +#define MINSYM nop; .globl minsym; minsym: nop +/*8*/ MINSYM +/*a*/ hlt diff --git a/gdb/testsuite/gdb.arch/amd64-prologue-skip.exp b/gdb/testsuite/gdb.arch/amd64-prologue-skip.exp new file mode 100644 index 0000000..015cd69 --- /dev/null +++ b/gdb/testsuite/gdb.arch/amd64-prologue-skip.exp @@ -0,0 +1,35 @@ +# Copyright 2010-2015 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 . + +standard_testfile .S +set binfile ${binfile}.o + +if { ![istarget x86_64-*-* ] || ![is_lp64_target] } { + verbose "Skipping ${testfile}." + return +} + +if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" object {debug}] != "" } { + untested ${testfile} + return +} + +clean_restart ${binfile} + +gdb_test "break *pushrbp" " at 0x1: file .*" +gdb_test "break pushrbp" " at 0x1: file .*" + +gdb_test "break *minsym" " at 0x9: file .*" +gdb_test "break minsym" " at 0x9: file .*"