From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 90496 invoked by alias); 1 Aug 2019 18:58:58 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 90447 invoked by uid 89); 1 Aug 2019 18:58:57 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-32.3 required=5.0 tests=AWL,BAYES_00,ENV_AND_HDR_SPF_MATCH,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,RCVD_IN_DNSWL_NONE,SPF_PASS,USER_IN_DEF_SPF_WL autolearn=ham version=3.3.1 spammy=HX-Spam-Relays-External:209.85.210.68, H*r:ip*209.85.210.68, H*RU:209.85.210.68 X-HELO: mail-ot1-f68.google.com Received: from mail-ot1-f68.google.com (HELO mail-ot1-f68.google.com) (209.85.210.68) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 01 Aug 2019 18:58:55 +0000 Received: by mail-ot1-f68.google.com with SMTP id j11so18128783otp.10 for ; Thu, 01 Aug 2019 11:58:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=ElzB29xuL+9vqhPg9FTB9nDoL7t2DmSEMMUdnD87hT8=; b=ogtlrQthUNYlbZudK+vK9o3W2TdX7EFW/9weMYb2MCnrWojW5CxDREKG58OSIdmjq7 vfvUWedHvLzHx9srIskeC/h9EmHDBEzeSEdz2N66QnZ4sdboFvbV4/R5pQT8IDp2XIiq J/aa/Qgc/zWuQeB2pKEtb/jKIM79xigr+VRSUzTWaH9Xx++PF1jk2naMrIieCMUnIElS Lzkr4EnXpRkAbNeeC0T6E/CHdeUoeUrmtc49T2Xna0o/6fVk/vXFWHo86B7KSv9d45bI qXuaf2AcQ37V3eFGLLh/+dq9Jt0BVBpr265imm57Id0IQhYbAAZrXN8CHFpLAdXBlHrp 0Wwg== MIME-Version: 1.0 References: <20190801184341.113641-1-cbiesinger@google.com> In-Reply-To: <20190801184341.113641-1-cbiesinger@google.com> From: "Christian Biesinger via gdb-patches" Reply-To: Christian Biesinger Date: Thu, 01 Aug 2019 18:58:00 -0000 Message-ID: Subject: Re: [RFC][PATCH] Replace solib_global_lookup with gdbarch_iterate_over_objfiles_in_search_order To: Christian Biesinger via gdb-patches Content-Type: text/plain; charset="UTF-8" X-SW-Source: 2019-08/txt/msg00031.txt.bz2 On a different note, given __attribute__((visibility("hidden))), we may just want to always start the search in the current objfile? On Thu, Aug 1, 2019 at 1:43 PM Christian Biesinger wrote: > > Thoughts on this change? It does not compile (_initialize_svr4_solib does > not have a gdbarch; comments welcome on the best way to handle this). But > it this worthwhile? > > All implementations of either function use it for the same purpose (except > Darwin, which is a no-op): to prefer a symbol in the current objfile over > symbols with the same name in other objfiles. There does not seem to be a > reason to have both mechanisms for that purpose. > --- > gdb/solib-darwin.c | 9 -------- > gdb/solib-spu.c | 27 ++++++++++++----------- > gdb/solib-svr4.c | 54 ++++++++++++++++++++++++++++++---------------- > gdb/solib-svr4.h | 5 +++++ > gdb/solib.c | 15 ------------- > gdb/solist.h | 11 ---------- > gdb/symtab.c | 6 +----- > 7 files changed, 56 insertions(+), 71 deletions(-) > > diff --git a/gdb/solib-darwin.c b/gdb/solib-darwin.c > index 443ebb64a4..b386cd35ed 100644 > --- a/gdb/solib-darwin.c > +++ b/gdb/solib-darwin.c > @@ -638,14 +638,6 @@ darwin_relocate_section_addresses (struct so_list *so, > so->addr_low = sec->addr; > } > > -static struct block_symbol > -darwin_lookup_lib_symbol (struct objfile *objfile, > - const char *name, > - const domain_enum domain) > -{ > - return {}; > -} > - > static gdb_bfd_ref_ptr > darwin_bfd_open (const char *pathname) > { > @@ -688,6 +680,5 @@ _initialize_darwin_solib (void) > darwin_so_ops.current_sos = darwin_current_sos; > darwin_so_ops.open_symbol_file_object = open_symbol_file_object; > darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code; > - darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol; > darwin_so_ops.bfd_open = darwin_bfd_open; > } > diff --git a/gdb/solib-spu.c b/gdb/solib-spu.c > index 5b97b9bcf6..ed33a0adf2 100644 > --- a/gdb/solib-spu.c > +++ b/gdb/solib-spu.c > @@ -385,19 +385,21 @@ spu_bfd_open (const char *pathname) > return abfd; > } > > -/* Lookup global symbol in a SPE executable. */ > -static struct block_symbol > -spu_lookup_lib_symbol (struct objfile *objfile, > - const char *name, > - const domain_enum domain) > +/* Search order prefers the current objfile for SPE executables. */ > +static void > +spu_iterate_over_objfiles_in_search_order > + (struct gdbarch *gdbarch, > + iterate_over_objfiles_in_search_order_cb_ftype *cb, > + void *cb_data, struct objfile *objfile) > { > - if (bfd_get_arch (objfile->obfd) == bfd_arch_spu) > - return lookup_global_symbol_from_objfile (objfile, GLOBAL_BLOCK, name, > - domain); > + if (objfile != nullptr && bfd_get_arch (objfile->obfd) == bfd_arch_spu) > + { > + if (cb (objfile, cb_data) != 0) > + return; > + } > > - if (svr4_so_ops.lookup_lib_global_symbol != NULL) > - return svr4_so_ops.lookup_lib_global_symbol (objfile, name, domain); > - return {}; > + return svr4_iterate_over_objfiles_in_search_order( > + gdbarch, cb, cb_data, objfile); > } > > /* Enable shared library breakpoint. */ > @@ -515,9 +517,10 @@ set_spu_solib_ops (struct gdbarch *gdbarch) > spu_so_ops.free_so = spu_free_so; > spu_so_ops.current_sos = spu_current_sos; > spu_so_ops.bfd_open = spu_bfd_open; > - spu_so_ops.lookup_lib_global_symbol = spu_lookup_lib_symbol; > } > > + set_gdbarch_iterate_over_objfiles_in_search_order > + (gdbarch, spu_iterate_over_objfiles_in_search_order); > set_solib_ops (gdbarch, &spu_so_ops); > } > > diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c > index c0c505acaa..c92d60874f 100644 > --- a/gdb/solib-svr4.c > +++ b/gdb/solib-svr4.c > @@ -3202,32 +3202,46 @@ svr4_lp64_fetch_link_map_offsets (void) > > struct target_so_ops svr4_so_ops; > > -/* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a > +/* Search order for ELF DSOs linked with -Bsymbolic. Those DSOs have a > different rule for symbol lookup. The lookup begins here in the DSO, not in > the main executable. */ > > -static struct block_symbol > -elf_lookup_lib_symbol (struct objfile *objfile, > - const char *name, > - const domain_enum domain) > +void > +svr4_iterate_over_objfiles_in_search_order > + (struct gdbarch *gdbarch, > + iterate_over_objfiles_in_search_order_cb_ftype *cb, > + void *cb_data, struct objfile *current_objfile) > { > - bfd *abfd; > - > - if (objfile == symfile_objfile) > - abfd = exec_bfd; > - else > + if (current_objfile != nullptr) > { > - /* OBJFILE should have been passed as the non-debug one. */ > - gdb_assert (objfile->separate_debug_objfile_backlink == NULL); > + bfd *abfd; > > - abfd = objfile->obfd; > - } > + if (current_objfile == symfile_objfile) > + abfd = exec_bfd; > + else > + { > + /* OBJFILE should have been passed as the non-debug one. */ > + gdb_assert (current_objfile->separate_debug_objfile_backlink == nullptr); > > - if (abfd == NULL || scan_dyntag (DT_SYMBOLIC, abfd, NULL, NULL) != 1) > - return {}; > + abfd = current_objfile->obfd; > + } > > - return lookup_global_symbol_from_objfile (objfile, GLOBAL_BLOCK, name, > - domain); > + if (abfd != nullptr && > + scan_dyntag (DT_SYMBOLIC, abfd, nullptr, nullptr) == 1) > + { > + if (cb (current_objfile, cb_data) != 0) > + return; > + } > + } > + > + for (objfile *objfile : current_program_space->objfiles ()) > + { > + if (objfile != current_objfile) > + { > + if (cb (objfile, cb_data) != 0) > + return; > + } > + } > } > > void > @@ -3244,11 +3258,13 @@ _initialize_svr4_solib (void) > svr4_so_ops.open_symbol_file_object = open_symbol_file_object; > svr4_so_ops.in_dynsym_resolve_code = svr4_in_dynsym_resolve_code; > svr4_so_ops.bfd_open = solib_bfd_open; > - svr4_so_ops.lookup_lib_global_symbol = elf_lookup_lib_symbol; > svr4_so_ops.same = svr4_same; > svr4_so_ops.keep_data_in_core = svr4_keep_data_in_core; > svr4_so_ops.update_breakpoints = svr4_update_solib_event_breakpoints; > svr4_so_ops.handle_event = svr4_handle_solib_event; > > gdb::observers::free_objfile.attach (svr4_free_objfile_observer); > + > + set_gdbarch_iterate_over_objfiles_in_search_order > + (gdbarch, svr4_iterate_over_objfiles_in_search_order); > } > diff --git a/gdb/solib-svr4.h b/gdb/solib-svr4.h > index a051e70b79..b99b8e2e3a 100644 > --- a/gdb/solib-svr4.h > +++ b/gdb/solib-svr4.h > @@ -21,6 +21,7 @@ > #define SOLIB_SVR4_H > > #include "solist.h" > +#include "gdbarch.h" > > struct objfile; > struct target_so_ops; > @@ -107,4 +108,8 @@ extern struct link_map_offsets *svr4_lp64_fetch_link_map_offsets (void); > SVR4 run time loader. */ > int svr4_in_dynsym_resolve_code (CORE_ADDR pc); > > +extern void svr4_iterate_over_objfiles_in_search_order ( > + struct gdbarch *gdbarch, iterate_over_objfiles_in_search_order_cb_ftype *cb, > + void *cb_data, struct objfile *objfile); > + > #endif /* solib-svr4.h */ > diff --git a/gdb/solib.c b/gdb/solib.c > index 29a17ad5d4..ec3bf06c50 100644 > --- a/gdb/solib.c > +++ b/gdb/solib.c > @@ -1441,21 +1441,6 @@ show_auto_solib_add (struct ui_file *file, int from_tty, > } > > > -/* Handler for library-specific lookup of global symbol NAME in OBJFILE. Call > - the library-specific handler if it is installed for the current target. */ > - > -struct block_symbol > -solib_global_lookup (struct objfile *objfile, > - const char *name, > - const domain_enum domain) > -{ > - const struct target_so_ops *ops = solib_ops (target_gdbarch ()); > - > - if (ops->lookup_lib_global_symbol != NULL) > - return ops->lookup_lib_global_symbol (objfile, name, domain); > - return {}; > -} > - > /* Lookup the value for a specific symbol from dynamic symbol table. Look > up symbol from ABFD. MATCH_SYM is a callback function to determine > whether to pick up a symbol. DATA is the input of this callback > diff --git a/gdb/solist.h b/gdb/solist.h > index e1410c2b79..ee99fc815b 100644 > --- a/gdb/solist.h > +++ b/gdb/solist.h > @@ -139,12 +139,6 @@ struct target_so_ops > unsigned o_flags, > gdb::unique_xmalloc_ptr *temp_pathname); > > - /* Hook for looking up global symbols in a library-specific way. */ > - struct block_symbol (*lookup_lib_global_symbol) > - (struct objfile *objfile, > - const char *name, > - const domain_enum domain); > - > /* Given two so_list objects, one from the GDB thread list > and another from the list returned by current_sos, return 1 > if they represent the same library. > @@ -209,9 +203,4 @@ extern gdb_bfd_ref_ptr solib_bfd_open (const char *in_pathname); > /* FIXME: gdbarch needs to control this variable. */ > extern struct target_so_ops *current_target_so_ops; > > -/* Handler for library-specific global symbol lookup in solib.c. */ > -struct block_symbol solib_global_lookup (struct objfile *objfile, > - const char *name, > - const domain_enum domain); > - > #endif > diff --git a/gdb/symtab.c b/gdb/symtab.c > index 87a0c8e4da..cd6a87581d 100644 > --- a/gdb/symtab.c > +++ b/gdb/symtab.c > @@ -2669,11 +2669,7 @@ lookup_global_symbol (const char *name, > return result; > } > > - /* Call library-specific lookup procedure. */ > - if (objfile != NULL) > - result = solib_global_lookup (objfile, name, domain); > - > - /* If that didn't work go a global search (of global blocks, heh). */ > + /* Do a global search (of global blocks, heh). */ > if (result.symbol == NULL) > { > memset (&lookup_data, 0, sizeof (lookup_data)); > -- > 2.22.0.770.g0f2c4a37fd-goog >