/* GDB routines for manipulating the minimal symbol tables.
- Copyright 1992 Free Software Foundation, Inc.
+ Copyright (C) 1992-2020 Free Software Foundation, Inc.
Contributed by Cygnus Support, using pieces from other GDB modules.
-This file is part of GDB.
+ This file is part of GDB.
-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 2 of the License, or
-(at your option) any later version.
+ 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.
+ 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, write to the Free Software
-Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* This file contains support routines for creating, manipulating, and
In many cases, even if a file was compiled with no special options for
debugging at all, as long as was not stripped it will contain sufficient
information to build useful minimal symbol tables using this structure.
-
+
Even when a file contains enough debugging information to build a full
symbol table, these minimal symbols are still useful for quickly mapping
between names and addresses, and vice versa. They are also sometimes used
- to figure out what full symbol table entries need to be read in. */
+ to figure out what full symbol table entries need to be read in. */
#include "defs.h"
+#include <ctype.h>
#include "symtab.h"
#include "bfd.h"
+#include "filenames.h"
#include "symfile.h"
#include "objfiles.h"
#include "demangle.h"
+#include "value.h"
+#include "cp-abi.h"
+#include "target.h"
+#include "cp-support.h"
+#include "language.h"
+#include "cli/cli-utils.h"
+#include "gdbsupport/symbol.h"
+#include <algorithm>
+#include "safe-ctype.h"
+#include "gdbsupport/parallel-for.h"
+
+#if CXX_STD_THREAD
+#include <mutex>
+#endif
+
+/* See minsyms.h. */
+
+bool
+msymbol_is_function (struct objfile *objfile, minimal_symbol *minsym,
+ CORE_ADDR *func_address_p)
+{
+ CORE_ADDR msym_addr = MSYMBOL_VALUE_ADDRESS (objfile, minsym);
+
+ switch (minsym->type)
+ {
+ case mst_slot_got_plt:
+ case mst_data:
+ case mst_bss:
+ case mst_abs:
+ case mst_file_data:
+ case mst_file_bss:
+ case mst_data_gnu_ifunc:
+ {
+ struct gdbarch *gdbarch = get_objfile_arch (objfile);
+ CORE_ADDR pc
+ = gdbarch_convert_from_func_ptr_addr (gdbarch, msym_addr,
+ current_top_target ());
+ if (pc != msym_addr)
+ {
+ if (func_address_p != NULL)
+ *func_address_p = pc;
+ return true;
+ }
+ return false;
+ }
+ default:
+ if (func_address_p != NULL)
+ *func_address_p = msym_addr;
+ return true;
+ }
+}
/* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
- At the end, copy them all into one newly allocated location on an objfile's
- symbol obstack. */
+ At the end, copy them all into one newly allocated array. */
#define BUNCH_SIZE 127
struct msym_bunch
+ {
+ struct msym_bunch *next;
+ struct minimal_symbol contents[BUNCH_SIZE];
+ };
+
+/* See minsyms.h. */
+
+unsigned int
+msymbol_hash_iw (const char *string)
{
- struct msym_bunch *next;
- struct minimal_symbol contents[BUNCH_SIZE];
+ unsigned int hash = 0;
+
+ while (*string && *string != '(')
+ {
+ string = skip_spaces (string);
+ if (*string && *string != '(')
+ {
+ hash = SYMBOL_HASH_NEXT (hash, *string);
+ ++string;
+ }
+ }
+ return hash;
+}
+
+/* See minsyms.h. */
+
+unsigned int
+msymbol_hash (const char *string)
+{
+ unsigned int hash = 0;
+
+ for (; *string; ++string)
+ hash = SYMBOL_HASH_NEXT (hash, *string);
+ return hash;
+}
+
+/* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
+static void
+add_minsym_to_hash_table (struct minimal_symbol *sym,
+ struct minimal_symbol **table,
+ unsigned int hash_value)
+{
+ if (sym->hash_next == NULL)
+ {
+ unsigned int hash = hash_value % MINIMAL_SYMBOL_HASH_SIZE;
+
+ sym->hash_next = table[hash];
+ table[hash] = sym;
+ }
+}
+
+/* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
+ TABLE. */
+static void
+add_minsym_to_demangled_hash_table (struct minimal_symbol *sym,
+ struct objfile *objfile,
+ unsigned int hash_value)
+{
+ if (sym->demangled_hash_next == NULL)
+ {
+ objfile->per_bfd->demangled_hash_languages.set (sym->language ());
+
+ struct minimal_symbol **table
+ = objfile->per_bfd->msymbol_demangled_hash;
+ unsigned int hash_index = hash_value % MINIMAL_SYMBOL_HASH_SIZE;
+ sym->demangled_hash_next = table[hash_index];
+ table[hash_index] = sym;
+ }
+}
+
+/* Worker object for lookup_minimal_symbol. Stores temporary results
+ while walking the symbol tables. */
+
+struct found_minimal_symbols
+{
+ /* External symbols are best. */
+ bound_minimal_symbol external_symbol {};
+
+ /* File-local symbols are next best. */
+ bound_minimal_symbol file_symbol {};
+
+ /* Symbols for shared library trampolines are next best. */
+ bound_minimal_symbol trampoline_symbol {};
+
+ /* Called when a symbol name matches. Check if the minsym is a
+ better type than what we had already found, and record it in one
+ of the members fields if so. Returns true if we collected the
+ real symbol, in which case we can stop searching. */
+ bool maybe_collect (const char *sfile, objfile *objf,
+ minimal_symbol *msymbol);
};
-/* Bunch currently being filled up.
- The next field points to chain of filled bunches. */
+/* See declaration above. */
-static struct msym_bunch *msym_bunch;
+bool
+found_minimal_symbols::maybe_collect (const char *sfile,
+ struct objfile *objfile,
+ minimal_symbol *msymbol)
+{
+ switch (MSYMBOL_TYPE (msymbol))
+ {
+ case mst_file_text:
+ case mst_file_data:
+ case mst_file_bss:
+ if (sfile == NULL
+ || filename_cmp (msymbol->filename, sfile) == 0)
+ {
+ file_symbol.minsym = msymbol;
+ file_symbol.objfile = objfile;
+ }
+ break;
-/* Number of slots filled in current bunch. */
+ case mst_solib_trampoline:
-static int msym_bunch_index;
+ /* If a trampoline symbol is found, we prefer to keep
+ looking for the *real* symbol. If the actual symbol
+ is not found, then we'll use the trampoline
+ entry. */
+ if (trampoline_symbol.minsym == NULL)
+ {
+ trampoline_symbol.minsym = msymbol;
+ trampoline_symbol.objfile = objfile;
+ }
+ break;
+
+ case mst_unknown:
+ default:
+ external_symbol.minsym = msymbol;
+ external_symbol.objfile = objfile;
+ /* We have the real symbol. No use looking further. */
+ return true;
+ }
-/* Total number of minimal symbols recorded so far for the objfile. */
+ /* Keep looking. */
+ return false;
+}
-static int msym_count;
+/* Walk the mangled name hash table, and pass each symbol whose name
+ matches LOOKUP_NAME according to NAMECMP to FOUND. */
+
+static void
+lookup_minimal_symbol_mangled (const char *lookup_name,
+ const char *sfile,
+ struct objfile *objfile,
+ struct minimal_symbol **table,
+ unsigned int hash,
+ int (*namecmp) (const char *, const char *),
+ found_minimal_symbols &found)
+{
+ for (minimal_symbol *msymbol = table[hash];
+ msymbol != NULL;
+ msymbol = msymbol->hash_next)
+ {
+ const char *symbol_name = msymbol->linkage_name ();
-/* Prototypes for local functions. */
+ if (namecmp (symbol_name, lookup_name) == 0
+ && found.maybe_collect (sfile, objfile, msymbol))
+ return;
+ }
+}
-static int
-compare_minimal_symbols PARAMS ((const void *, const void *));
+/* Walk the demangled name hash table, and pass each symbol whose name
+ matches LOOKUP_NAME according to MATCHER to FOUND. */
+
+static void
+lookup_minimal_symbol_demangled (const lookup_name_info &lookup_name,
+ const char *sfile,
+ struct objfile *objfile,
+ struct minimal_symbol **table,
+ unsigned int hash,
+ symbol_name_matcher_ftype *matcher,
+ found_minimal_symbols &found)
+{
+ for (minimal_symbol *msymbol = table[hash];
+ msymbol != NULL;
+ msymbol = msymbol->demangled_hash_next)
+ {
+ const char *symbol_name = msymbol->search_name ();
-static int
-compact_minimal_symbols PARAMS ((struct minimal_symbol *, int));
+ if (matcher (symbol_name, lookup_name, NULL)
+ && found.maybe_collect (sfile, objfile, msymbol))
+ return;
+ }
+}
-/* Look through all the current minimal symbol tables and find the first
- minimal symbol that matches NAME. If OBJF is non-NULL, it specifies a
- particular objfile and the search is limited to that objfile. Returns
- a pointer to the minimal symbol that matches, or NULL if no match is found.
+/* Look through all the current minimal symbol tables and find the
+ first minimal symbol that matches NAME. If OBJF is non-NULL, limit
+ the search to that objfile. If SFILE is non-NULL, the only file-scope
+ symbols considered will be from that source file (global symbols are
+ still preferred). Returns a pointer to the minimal symbol that
+ matches, or NULL if no match is found.
Note: One instance where there may be duplicate minimal symbols with
the same name is when the symbol tables for a shared library and the
symbol tables for an executable contain global symbols with the same
- names (the dynamic linker deals with the duplication). */
+ names (the dynamic linker deals with the duplication).
+
+ It's also possible to have minimal symbols with different mangled
+ names, but identical demangled names. For example, the GNU C++ v3
+ ABI requires the generation of two (or perhaps three) copies of
+ constructor functions --- "in-charge", "not-in-charge", and
+ "allocate" copies; destructors may be duplicated as well.
+ Obviously, there must be distinct mangled names for each of these,
+ but the demangled names are all the same: S::S or S::~S. */
+
+struct bound_minimal_symbol
+lookup_minimal_symbol (const char *name, const char *sfile,
+ struct objfile *objf)
+{
+ found_minimal_symbols found;
-struct minimal_symbol *
-lookup_minimal_symbol (name, objf)
- register const char *name;
- struct objfile *objf;
+ unsigned int mangled_hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
+
+ auto *mangled_cmp
+ = (case_sensitivity == case_sensitive_on
+ ? strcmp
+ : strcasecmp);
+
+ if (sfile != NULL)
+ sfile = lbasename (sfile);
+
+ lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
+
+ for (objfile *objfile : current_program_space->objfiles ())
+ {
+ if (found.external_symbol.minsym != NULL)
+ break;
+
+ if (objf == NULL || objf == objfile
+ || objf == objfile->separate_debug_objfile_backlink)
+ {
+ if (symbol_lookup_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "lookup_minimal_symbol (%s, %s, %s)\n",
+ name, sfile != NULL ? sfile : "NULL",
+ objfile_debug_name (objfile));
+ }
+
+ /* Do two passes: the first over the ordinary hash table,
+ and the second over the demangled hash table. */
+ lookup_minimal_symbol_mangled (name, sfile, objfile,
+ objfile->per_bfd->msymbol_hash,
+ mangled_hash, mangled_cmp, found);
+
+ /* If not found, try the demangled hash table. */
+ if (found.external_symbol.minsym == NULL)
+ {
+ /* Once for each language in the demangled hash names
+ table (usually just zero or one languages). */
+ for (unsigned iter = 0; iter < nr_languages; ++iter)
+ {
+ if (!objfile->per_bfd->demangled_hash_languages.test (iter))
+ continue;
+ enum language lang = (enum language) iter;
+
+ unsigned int hash
+ = (lookup_name.search_name_hash (lang)
+ % MINIMAL_SYMBOL_HASH_SIZE);
+
+ symbol_name_matcher_ftype *match
+ = get_symbol_name_matcher (language_def (lang),
+ lookup_name);
+ struct minimal_symbol **msymbol_demangled_hash
+ = objfile->per_bfd->msymbol_demangled_hash;
+
+ lookup_minimal_symbol_demangled (lookup_name, sfile, objfile,
+ msymbol_demangled_hash,
+ hash, match, found);
+
+ if (found.external_symbol.minsym != NULL)
+ break;
+ }
+ }
+ }
+ }
+
+ /* External symbols are best. */
+ if (found.external_symbol.minsym != NULL)
+ {
+ if (symbol_lookup_debug)
+ {
+ minimal_symbol *minsym = found.external_symbol.minsym;
+
+ fprintf_unfiltered (gdb_stdlog,
+ "lookup_minimal_symbol (...) = %s (external)\n",
+ host_address_to_string (minsym));
+ }
+ return found.external_symbol;
+ }
+
+ /* File-local symbols are next best. */
+ if (found.file_symbol.minsym != NULL)
+ {
+ if (symbol_lookup_debug)
+ {
+ minimal_symbol *minsym = found.file_symbol.minsym;
+
+ fprintf_unfiltered (gdb_stdlog,
+ "lookup_minimal_symbol (...) = %s (file-local)\n",
+ host_address_to_string (minsym));
+ }
+ return found.file_symbol;
+ }
+
+ /* Symbols for shared library trampolines are next best. */
+ if (found.trampoline_symbol.minsym != NULL)
+ {
+ if (symbol_lookup_debug)
+ {
+ minimal_symbol *minsym = found.trampoline_symbol.minsym;
+
+ fprintf_unfiltered (gdb_stdlog,
+ "lookup_minimal_symbol (...) = %s (trampoline)\n",
+ host_address_to_string (minsym));
+ }
+
+ return found.trampoline_symbol;
+ }
+
+ /* Not found. */
+ if (symbol_lookup_debug)
+ fprintf_unfiltered (gdb_stdlog, "lookup_minimal_symbol (...) = NULL\n");
+ return {};
+}
+
+/* See minsyms.h. */
+
+struct bound_minimal_symbol
+lookup_bound_minimal_symbol (const char *name)
+{
+ return lookup_minimal_symbol (name, NULL, NULL);
+}
+
+/* See gdbsupport/symbol.h. */
+
+int
+find_minimal_symbol_address (const char *name, CORE_ADDR *addr,
+ struct objfile *objfile)
+{
+ struct bound_minimal_symbol sym
+ = lookup_minimal_symbol (name, NULL, objfile);
+
+ if (sym.minsym != NULL)
+ *addr = BMSYMBOL_VALUE_ADDRESS (sym);
+
+ return sym.minsym == NULL;
+}
+
+/* Get the lookup name form best suitable for linkage name
+ matching. */
+
+static const char *
+linkage_name_str (const lookup_name_info &lookup_name)
+{
+ /* Unlike most languages (including C++), Ada uses the
+ encoded/linkage name as the search name recorded in symbols. So
+ if debugging in Ada mode, prefer the Ada-encoded name. This also
+ makes Ada's verbatim match syntax ("<...>") work, because
+ "lookup_name.name()" includes the "<>"s, while
+ "lookup_name.ada().lookup_name()" is the encoded name with "<>"s
+ stripped. */
+ if (current_language->la_language == language_ada)
+ return lookup_name.ada ().lookup_name ().c_str ();
+
+ return lookup_name.name ().c_str ();
+}
+
+/* See minsyms.h. */
+
+void
+iterate_over_minimal_symbols
+ (struct objfile *objf, const lookup_name_info &lookup_name,
+ gdb::function_view<bool (struct minimal_symbol *)> callback)
+{
+ /* The first pass is over the ordinary hash table. */
+ {
+ const char *name = linkage_name_str (lookup_name);
+ unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
+ auto *mangled_cmp
+ = (case_sensitivity == case_sensitive_on
+ ? strcmp
+ : strcasecmp);
+
+ for (minimal_symbol *iter = objf->per_bfd->msymbol_hash[hash];
+ iter != NULL;
+ iter = iter->hash_next)
+ {
+ if (mangled_cmp (iter->linkage_name (), name) == 0)
+ if (callback (iter))
+ return;
+ }
+ }
+
+ /* The second pass is over the demangled table. Once for each
+ language in the demangled hash names table (usually just zero or
+ one). */
+ for (unsigned liter = 0; liter < nr_languages; ++liter)
+ {
+ if (!objf->per_bfd->demangled_hash_languages.test (liter))
+ continue;
+
+ enum language lang = (enum language) liter;
+ const language_defn *lang_def = language_def (lang);
+ symbol_name_matcher_ftype *name_match
+ = get_symbol_name_matcher (lang_def, lookup_name);
+
+ unsigned int hash
+ = lookup_name.search_name_hash (lang) % MINIMAL_SYMBOL_HASH_SIZE;
+ for (minimal_symbol *iter = objf->per_bfd->msymbol_demangled_hash[hash];
+ iter != NULL;
+ iter = iter->demangled_hash_next)
+ if (name_match (iter->search_name (), lookup_name, NULL))
+ if (callback (iter))
+ return;
+ }
+}
+
+/* See minsyms.h. */
+
+bound_minimal_symbol
+lookup_minimal_symbol_linkage (const char *name, struct objfile *objf)
+{
+ unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
+
+ for (objfile *objfile : objf->separate_debug_objfiles ())
+ {
+ for (minimal_symbol *msymbol = objfile->per_bfd->msymbol_hash[hash];
+ msymbol != NULL;
+ msymbol = msymbol->hash_next)
+ {
+ if (strcmp (msymbol->linkage_name (), name) == 0
+ && (MSYMBOL_TYPE (msymbol) == mst_data
+ || MSYMBOL_TYPE (msymbol) == mst_bss))
+ return {msymbol, objfile};
+ }
+ }
+
+ return {};
+}
+
+/* See minsyms.h. */
+
+struct bound_minimal_symbol
+lookup_minimal_symbol_text (const char *name, struct objfile *objf)
{
- struct objfile *objfile;
struct minimal_symbol *msymbol;
- struct minimal_symbol *found_symbol = NULL;
- struct minimal_symbol *found_file_symbol = NULL;
-#ifdef IBM6000_TARGET
- struct minimal_symbol *trampoline_symbol = NULL;
-#endif
+ struct bound_minimal_symbol found_symbol = { NULL, NULL };
+ struct bound_minimal_symbol found_file_symbol = { NULL, NULL };
+
+ unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
- for (objfile = object_files;
- objfile != NULL && found_symbol == NULL;
- objfile = objfile -> next)
+ for (objfile *objfile : current_program_space->objfiles ())
{
- if (objf == NULL || objf == objfile)
+ if (found_symbol.minsym != NULL)
+ break;
+
+ if (objf == NULL || objf == objfile
+ || objf == objfile->separate_debug_objfile_backlink)
{
- for (msymbol = objfile -> msymbols;
- msymbol != NULL && SYMBOL_NAME (msymbol) != NULL &&
- found_symbol == NULL;
- msymbol++)
+ for (msymbol = objfile->per_bfd->msymbol_hash[hash];
+ msymbol != NULL && found_symbol.minsym == NULL;
+ msymbol = msymbol->hash_next)
{
- if (SYMBOL_MATCHES_NAME (msymbol, name))
+ if (strcmp (msymbol->linkage_name (), name) == 0 &&
+ (MSYMBOL_TYPE (msymbol) == mst_text
+ || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
+ || MSYMBOL_TYPE (msymbol) == mst_file_text))
{
switch (MSYMBOL_TYPE (msymbol))
{
case mst_file_text:
- case mst_file_data:
- case mst_file_bss:
- /* It is file-local. If we find more than one, just
- return the latest one (the user can't expect
- useful behavior in that case). */
- found_file_symbol = msymbol;
+ found_file_symbol.minsym = msymbol;
+ found_file_symbol.objfile = objfile;
break;
-
- case mst_unknown:
-#ifdef IBM6000_TARGET
- /* I *think* all platforms using shared
- libraries (and trampoline code) will suffer
- this problem. Consider a case where there are
- 5 shared libraries, each referencing `foo'
- with a trampoline entry. When someone wants
- to put a breakpoint on `foo' and the only
- info we have is minimal symbol vector, we
- want to use the real `foo', rather than one
- of those trampoline entries. MGO */
-
- /* If a trampoline symbol is found, we prefer to
- keep looking for the *real* symbol. If the
- actual symbol not found, then we'll use the
- trampoline entry. Sorry for the machine
- dependent code here, but I hope this will
- benefit other platforms as well. For
- trampoline entries, we used mst_unknown
- earlier. Perhaps we should define a
- `mst_trampoline' type?? */
-
- if (trampoline_symbol == NULL)
- trampoline_symbol = msymbol;
- break;
-#else
- /* FALLTHROUGH */
-#endif
default:
- found_symbol = msymbol;
+ found_symbol.minsym = msymbol;
+ found_symbol.objfile = objfile;
break;
}
}
}
}
/* External symbols are best. */
- if (found_symbol)
+ if (found_symbol.minsym)
return found_symbol;
/* File-local symbols are next best. */
- if (found_file_symbol)
- return found_file_symbol;
+ return found_file_symbol;
+}
- /* Symbols for IBM shared library trampolines are next best. */
-#ifdef IBM6000_TARGET
- if (trampoline_symbol)
- return trampoline_symbol;
-#endif
+/* See minsyms.h. */
+
+struct minimal_symbol *
+lookup_minimal_symbol_by_pc_name (CORE_ADDR pc, const char *name,
+ struct objfile *objf)
+{
+ struct minimal_symbol *msymbol;
+
+ unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
+
+ for (objfile *objfile : current_program_space->objfiles ())
+ {
+ if (objf == NULL || objf == objfile
+ || objf == objfile->separate_debug_objfile_backlink)
+ {
+ for (msymbol = objfile->per_bfd->msymbol_hash[hash];
+ msymbol != NULL;
+ msymbol = msymbol->hash_next)
+ {
+ if (MSYMBOL_VALUE_ADDRESS (objfile, msymbol) == pc
+ && strcmp (msymbol->linkage_name (), name) == 0)
+ return msymbol;
+ }
+ }
+ }
return NULL;
}
+/* A helper function that makes *PC section-relative. This searches
+ the sections of OBJFILE and if *PC is in a section, it subtracts
+ the section offset and returns true. Otherwise it returns
+ false. */
-/* Search through the minimal symbol table for each objfile and find the
- symbol whose address is the largest address that is still less than or
- equal to PC. Returns a pointer to the minimal symbol if such a symbol
- is found, or NULL if PC is not in a suitable range. Note that we need
- to look through ALL the minimal symbol tables before deciding on the
- symbol that comes closest to the specified PC. This is because objfiles
- can overlap, for example objfile A has .text at 0x100 and .data at 0x40000
- and objfile B has .text at 0x234 and .data at 0x40048. */
+static int
+frob_address (struct objfile *objfile, CORE_ADDR *pc)
+{
+ struct obj_section *iter;
-struct minimal_symbol *
-lookup_minimal_symbol_by_pc (pc)
- register CORE_ADDR pc;
-{
- register int lo;
- register int hi;
- register int new;
- register struct objfile *objfile;
- register struct minimal_symbol *msymbol;
- register struct minimal_symbol *best_symbol = NULL;
-
- for (objfile = object_files;
- objfile != NULL;
- objfile = objfile -> next)
- {
- /* If this objfile has a minimal symbol table, go search it using
- a binary search. Note that a minimal symbol table always consists
- of at least two symbols, a "real" symbol and the terminating
- "null symbol". If there are no real symbols, then there is no
- minimal symbol table at all. */
-
- if ((msymbol = objfile -> msymbols) != NULL)
+ ALL_OBJFILE_OSECTIONS (objfile, iter)
+ {
+ if (*pc >= obj_section_addr (iter) && *pc < obj_section_endaddr (iter))
+ {
+ *pc -= obj_section_offset (iter);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/* Helper for lookup_minimal_symbol_by_pc_section. Convert a
+ lookup_msym_prefer to a minimal_symbol_type. */
+
+static minimal_symbol_type
+msym_prefer_to_msym_type (lookup_msym_prefer prefer)
+{
+ switch (prefer)
+ {
+ case lookup_msym_prefer::TEXT:
+ return mst_text;
+ case lookup_msym_prefer::TRAMPOLINE:
+ return mst_solib_trampoline;
+ case lookup_msym_prefer::GNU_IFUNC:
+ return mst_text_gnu_ifunc;
+ }
+
+ /* Assert here instead of in a default switch case above so that
+ -Wswitch warns if a new enumerator is added. */
+ gdb_assert_not_reached ("unhandled lookup_msym_prefer");
+}
+
+/* Search through the minimal symbol table for each objfile and find
+ the symbol whose address is the largest address that is still less
+ than or equal to PC, and matches SECTION (which is not NULL).
+ Returns a pointer to the minimal symbol if such a symbol is found,
+ or NULL if PC is not in a suitable range.
+ Note that we need to look through ALL the minimal symbol tables
+ before deciding on the symbol that comes closest to the specified PC.
+ This is because objfiles can overlap, for example objfile A has .text
+ at 0x100 and .data at 0x40000 and objfile B has .text at 0x234 and
+ .data at 0x40048.
+
+ If WANT_TRAMPOLINE is set, prefer mst_solib_trampoline symbols when
+ there are text and trampoline symbols at the same address.
+ Otherwise prefer mst_text symbols. */
+
+bound_minimal_symbol
+lookup_minimal_symbol_by_pc_section (CORE_ADDR pc_in, struct obj_section *section,
+ lookup_msym_prefer prefer)
+{
+ int lo;
+ int hi;
+ int newobj;
+ struct minimal_symbol *msymbol;
+ struct minimal_symbol *best_symbol = NULL;
+ struct objfile *best_objfile = NULL;
+ struct bound_minimal_symbol result;
+
+ if (section == NULL)
+ {
+ section = find_pc_section (pc_in);
+ if (section == NULL)
+ return {};
+ }
+
+ minimal_symbol_type want_type = msym_prefer_to_msym_type (prefer);
+
+ /* We can not require the symbol found to be in section, because
+ e.g. IRIX 6.5 mdebug relies on this code returning an absolute
+ symbol - but find_pc_section won't return an absolute section and
+ hence the code below would skip over absolute symbols. We can
+ still take advantage of the call to find_pc_section, though - the
+ object file still must match. In case we have separate debug
+ files, search both the file and its separate debug file. There's
+ no telling which one will have the minimal symbols. */
+
+ gdb_assert (section != NULL);
+
+ for (objfile *objfile : section->objfile->separate_debug_objfiles ())
+ {
+ CORE_ADDR pc = pc_in;
+
+ /* If this objfile has a minimal symbol table, go search it
+ using a binary search. */
+
+ if (objfile->per_bfd->minimal_symbol_count > 0)
{
+ int best_zero_sized = -1;
+
+ msymbol = objfile->per_bfd->msymbols.get ();
lo = 0;
- hi = objfile -> minimal_symbol_count - 1;
+ hi = objfile->per_bfd->minimal_symbol_count - 1;
/* This code assumes that the minimal symbols are sorted by
ascending address values. If the pc value is greater than or
or equal to the desired pc value, we accomplish two things:
(1) the case where the pc value is larger than any minimal
symbol address is trivially solved, (2) the address associated
- with the hi index is always the one we want when the interation
+ with the hi index is always the one we want when the iteration
terminates. In essence, we are iterating the test interval
down until the pc value is pushed out of it from the high end.
- Warning: this code is trickier than it would appear at first. */
+ Warning: this code is trickier than it would appear at first. */
- /* Should also requires that pc is <= end of objfile. FIXME! */
- if (pc >= SYMBOL_VALUE_ADDRESS (&msymbol[lo]))
+ if (frob_address (objfile, &pc)
+ && pc >= MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[lo]))
{
- while (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) > pc)
+ while (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) > pc)
{
- /* pc is still strictly less than highest address */
- /* Note "new" will always be >= lo */
- new = (lo + hi) / 2;
- if ((SYMBOL_VALUE_ADDRESS (&msymbol[new]) >= pc) ||
- (lo == new))
+ /* pc is still strictly less than highest address. */
+ /* Note "new" will always be >= lo. */
+ newobj = (lo + hi) / 2;
+ if ((MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[newobj]) >= pc)
+ || (lo == newobj))
{
- hi = new;
+ hi = newobj;
}
else
{
- lo = new;
+ lo = newobj;
}
}
- /* The minimal symbol indexed by hi now is the best one in this
- objfile's minimal symbol table. See if it is the best one
- overall. */
- if ((best_symbol == NULL) ||
- (SYMBOL_VALUE_ADDRESS (best_symbol) <
- SYMBOL_VALUE_ADDRESS (&msymbol[hi])))
+ /* If we have multiple symbols at the same address, we want
+ hi to point to the last one. That way we can find the
+ right symbol if it has an index greater than hi. */
+ while (hi < objfile->per_bfd->minimal_symbol_count - 1
+ && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
+ == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi + 1])))
+ hi++;
+
+ /* Skip various undesirable symbols. */
+ while (hi >= 0)
{
- best_symbol = &msymbol[hi];
- }
- }
- }
- }
- return (best_symbol);
-}
+ /* Skip any absolute symbols. This is apparently
+ what adb and dbx do, and is needed for the CM-5.
+ There are two known possible problems: (1) on
+ ELF, apparently end, edata, etc. are absolute.
+ Not sure ignoring them here is a big deal, but if
+ we want to use them, the fix would go in
+ elfread.c. (2) I think shared library entry
+ points on the NeXT are absolute. If we want
+ special handling for this it probably should be
+ triggered by a special mst_abs_or_lib or some
+ such. */
+
+ if (MSYMBOL_TYPE (&msymbol[hi]) == mst_abs)
+ {
+ hi--;
+ continue;
+ }
-/* Just like lookup_minimal_symbol_by_pc, but look up the closest minimal
- symbol > PC, not the one <= PC. */
+ /* If SECTION was specified, skip any symbol from
+ wrong section. */
+ if (section
+ /* Some types of debug info, such as COFF,
+ don't fill the bfd_section member, so don't
+ throw away symbols on those platforms. */
+ && MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]) != NULL
+ && (!matching_obj_sections
+ (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi]),
+ section)))
+ {
+ hi--;
+ continue;
+ }
-struct minimal_symbol *
-lookup_next_minimal_symbol (pc)
- CORE_ADDR pc;
-{
- register int lo;
- register int hi;
- register int new;
- register struct objfile *objfile;
- register struct minimal_symbol *msymbol;
- register struct minimal_symbol *best_symbol = NULL;
-
- for (objfile = object_files;
- objfile != NULL;
- objfile = objfile -> next)
- {
- /* If this objfile has a minimal symbol table, go search it using
- a binary search. Note that a minimal symbol table always consists
- of at least two symbols, a "real" symbol and the terminating
- "null symbol". If there are no real symbols, then there is no
- minimal symbol table at all. */
-
- if ((msymbol = objfile -> msymbols) != NULL)
- {
- lo = 0;
- hi = objfile -> minimal_symbol_count - 1;
+ /* If we are looking for a trampoline and this is a
+ text symbol, or the other way around, check the
+ preceding symbol too. If they are otherwise
+ identical prefer that one. */
+ if (hi > 0
+ && MSYMBOL_TYPE (&msymbol[hi]) != want_type
+ && MSYMBOL_TYPE (&msymbol[hi - 1]) == want_type
+ && (MSYMBOL_SIZE (&msymbol[hi])
+ == MSYMBOL_SIZE (&msymbol[hi - 1]))
+ && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
+ == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1]))
+ && (MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi])
+ == MSYMBOL_OBJ_SECTION (objfile, &msymbol[hi - 1])))
+ {
+ hi--;
+ continue;
+ }
- /* This code assumes that the minimal symbols are sorted by
- ascending address values. If the pc value is greater than or
- equal to the first symbol's address, then some symbol in this
- minimal symbol table is a suitable candidate for being the
- "best" symbol. This includes the last real symbol, for cases
- where the pc value is larger than any address in this vector.
+ /* If the minimal symbol has a zero size, save it
+ but keep scanning backwards looking for one with
+ a non-zero size. A zero size may mean that the
+ symbol isn't an object or function (e.g. a
+ label), or it may just mean that the size was not
+ specified. */
+ if (MSYMBOL_SIZE (&msymbol[hi]) == 0)
+ {
+ if (best_zero_sized == -1)
+ best_zero_sized = hi;
+ hi--;
+ continue;
+ }
- By iterating until the address associated with the current
- hi index (the endpoint of the test interval) is less than
- or equal to the desired pc value, we accomplish two things:
- (1) the case where the pc value is larger than any minimal
- symbol address is trivially solved, (2) the address associated
- with the hi index is always the one we want when the interation
- terminates. In essence, we are iterating the test interval
- down until the pc value is pushed out of it from the high end.
+ /* If we are past the end of the current symbol, try
+ the previous symbol if it has a larger overlapping
+ size. This happens on i686-pc-linux-gnu with glibc;
+ the nocancel variants of system calls are inside
+ the cancellable variants, but both have sizes. */
+ if (hi > 0
+ && MSYMBOL_SIZE (&msymbol[hi]) != 0
+ && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
+ + MSYMBOL_SIZE (&msymbol[hi]))
+ && pc < (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1])
+ + MSYMBOL_SIZE (&msymbol[hi - 1])))
+ {
+ hi--;
+ continue;
+ }
- Warning: this code is trickier than it would appear at first. */
+ /* Otherwise, this symbol must be as good as we're going
+ to get. */
+ break;
+ }
- /* Intentionally does not check that pc <= start of objfile.
- dbxread.c:process_one_symbol wants to call this with zero and
- get the first minimal symbol. */
- if (pc < SYMBOL_VALUE_ADDRESS (&msymbol[hi]))
- {
- while (SYMBOL_VALUE_ADDRESS (&msymbol[lo]) <= pc)
+ /* If HI has a zero size, and best_zero_sized is set,
+ then we had two or more zero-sized symbols; prefer
+ the first one we found (which may have a higher
+ address). Also, if we ran off the end, be sure
+ to back up. */
+ if (best_zero_sized != -1
+ && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0))
+ hi = best_zero_sized;
+
+ /* If the minimal symbol has a non-zero size, and this
+ PC appears to be outside the symbol's contents, then
+ refuse to use this symbol. If we found a zero-sized
+ symbol with an address greater than this symbol's,
+ use that instead. We assume that if symbols have
+ specified sizes, they do not overlap. */
+
+ if (hi >= 0
+ && MSYMBOL_SIZE (&msymbol[hi]) != 0
+ && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])
+ + MSYMBOL_SIZE (&msymbol[hi])))
{
- /* pc is still strictly less than highest address */
- /* Note "new" will always be >= lo */
- new = (lo + hi) / 2;
- if ((SYMBOL_VALUE_ADDRESS (&msymbol[new]) < pc) ||
- (lo == new))
- {
- hi = new;
- }
+ if (best_zero_sized != -1)
+ hi = best_zero_sized;
else
- {
- lo = new;
- }
+ /* Go on to the next object file. */
+ continue;
}
+
/* The minimal symbol indexed by hi now is the best one in this
- objfile's minimal symbol table. See if it is the best one
- overall. */
+ objfile's minimal symbol table. See if it is the best one
+ overall. */
- if ((best_symbol == NULL) ||
- (SYMBOL_VALUE_ADDRESS (best_symbol) >
- SYMBOL_VALUE_ADDRESS (&msymbol[lo])))
+ if (hi >= 0
+ && ((best_symbol == NULL) ||
+ (MSYMBOL_VALUE_RAW_ADDRESS (best_symbol) <
+ MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]))))
{
- best_symbol = &msymbol[lo];
+ best_symbol = &msymbol[hi];
+ best_objfile = objfile;
}
}
}
}
- return (best_symbol);
+
+ result.minsym = best_symbol;
+ result.objfile = best_objfile;
+ return result;
}
-/* Prepare to start collecting minimal symbols. Note that presetting
- msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal
- symbol to allocate the memory for the first bunch. */
+/* See minsyms.h. */
-void
-init_minimal_symbol_collection ()
+struct bound_minimal_symbol
+lookup_minimal_symbol_by_pc (CORE_ADDR pc)
{
- msym_count = 0;
- msym_bunch = NULL;
- msym_bunch_index = BUNCH_SIZE;
+ return lookup_minimal_symbol_by_pc_section (pc, NULL);
}
-void
-prim_record_minimal_symbol (name, address, ms_type)
- const char *name;
- CORE_ADDR address;
- enum minimal_symbol_type ms_type;
-{
- register struct msym_bunch *new;
- register struct minimal_symbol *msymbol;
-
- if (msym_bunch_index == BUNCH_SIZE)
- {
- new = (struct msym_bunch *) xmalloc (sizeof (struct msym_bunch));
- msym_bunch_index = 0;
- new -> next = msym_bunch;
- msym_bunch = new;
- }
- msymbol = &msym_bunch -> contents[msym_bunch_index];
- SYMBOL_NAME (msymbol) = (char *) name;
- SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol, language_unknown);
- SYMBOL_VALUE_ADDRESS (msymbol) = address;
- SYMBOL_SECTION (msymbol) = -1;
- MSYMBOL_TYPE (msymbol) = ms_type;
- /* FIXME: This info, if it remains, needs its own field. */
- MSYMBOL_INFO (msymbol) = NULL; /* FIXME! */
- msym_bunch_index++;
- msym_count++;
+/* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */
+
+bool
+in_gnu_ifunc_stub (CORE_ADDR pc)
+{
+ bound_minimal_symbol msymbol
+ = lookup_minimal_symbol_by_pc_section (pc, NULL,
+ lookup_msym_prefer::GNU_IFUNC);
+ return msymbol.minsym && MSYMBOL_TYPE (msymbol.minsym) == mst_text_gnu_ifunc;
}
-/* FIXME: Why don't we just combine this function with the one above
- and pass it a NULL info pointer value if info is not needed? */
+/* See elf_gnu_ifunc_resolve_addr for its real implementation. */
-void
-prim_record_minimal_symbol_and_info (name, address, ms_type, info, section)
- const char *name;
- CORE_ADDR address;
- enum minimal_symbol_type ms_type;
- char *info;
- int section;
-{
- register struct msym_bunch *new;
- register struct minimal_symbol *msymbol;
-
- if (msym_bunch_index == BUNCH_SIZE)
- {
- new = (struct msym_bunch *) xmalloc (sizeof (struct msym_bunch));
- msym_bunch_index = 0;
- new -> next = msym_bunch;
- msym_bunch = new;
- }
- msymbol = &msym_bunch -> contents[msym_bunch_index];
- SYMBOL_NAME (msymbol) = (char *) name;
- SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol, language_unknown);
- SYMBOL_VALUE_ADDRESS (msymbol) = address;
- SYMBOL_SECTION (msymbol) = section;
- MSYMBOL_TYPE (msymbol) = ms_type;
- /* FIXME: This info, if it remains, needs its own field. */
- MSYMBOL_INFO (msymbol) = info; /* FIXME! */
- msym_bunch_index++;
- msym_count++;
+static CORE_ADDR
+stub_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ error (_("GDB cannot resolve STT_GNU_IFUNC symbol at address %s without "
+ "the ELF support compiled in."),
+ paddress (gdbarch, pc));
+}
+
+/* See elf_gnu_ifunc_resolve_name for its real implementation. */
+
+static bool
+stub_gnu_ifunc_resolve_name (const char *function_name,
+ CORE_ADDR *function_address_p)
+{
+ error (_("GDB cannot resolve STT_GNU_IFUNC symbol \"%s\" without "
+ "the ELF support compiled in."),
+ function_name);
+}
+
+/* See elf_gnu_ifunc_resolver_stop for its real implementation. */
+
+static void
+stub_gnu_ifunc_resolver_stop (struct breakpoint *b)
+{
+ internal_error (__FILE__, __LINE__,
+ _("elf_gnu_ifunc_resolver_stop cannot be reached."));
+}
+
+/* See elf_gnu_ifunc_resolver_return_stop for its real implementation. */
+
+static void
+stub_gnu_ifunc_resolver_return_stop (struct breakpoint *b)
+{
+ internal_error (__FILE__, __LINE__,
+ _("elf_gnu_ifunc_resolver_return_stop cannot be reached."));
}
-/* Compare two minimal symbols by address and return a signed result based
- on unsigned comparisons, so that we sort into unsigned numeric order. */
+/* See elf_gnu_ifunc_fns for its real implementation. */
+
+static const struct gnu_ifunc_fns stub_gnu_ifunc_fns =
+{
+ stub_gnu_ifunc_resolve_addr,
+ stub_gnu_ifunc_resolve_name,
+ stub_gnu_ifunc_resolver_stop,
+ stub_gnu_ifunc_resolver_return_stop,
+};
+
+/* A placeholder for &elf_gnu_ifunc_fns. */
+
+const struct gnu_ifunc_fns *gnu_ifunc_fns_p = &stub_gnu_ifunc_fns;
+
+\f
+
+/* Return leading symbol character for a BFD. If BFD is NULL,
+ return the leading symbol character from the main objfile. */
static int
-compare_minimal_symbols (fn1p, fn2p)
- const PTR fn1p;
- const PTR fn2p;
+get_symbol_leading_char (bfd *abfd)
{
- register const struct minimal_symbol *fn1;
- register const struct minimal_symbol *fn2;
+ if (abfd != NULL)
+ return bfd_get_symbol_leading_char (abfd);
+ if (symfile_objfile != NULL && symfile_objfile->obfd != NULL)
+ return bfd_get_symbol_leading_char (symfile_objfile->obfd);
+ return 0;
+}
- fn1 = (const struct minimal_symbol *) fn1p;
- fn2 = (const struct minimal_symbol *) fn2p;
+/* See minsyms.h. */
- if (SYMBOL_VALUE_ADDRESS (fn1) < SYMBOL_VALUE_ADDRESS (fn2))
+minimal_symbol_reader::minimal_symbol_reader (struct objfile *obj)
+: m_objfile (obj),
+ m_msym_bunch (NULL),
+ /* Note that presetting m_msym_bunch_index to BUNCH_SIZE causes the
+ first call to save a minimal symbol to allocate the memory for
+ the first bunch. */
+ m_msym_bunch_index (BUNCH_SIZE),
+ m_msym_count (0)
+{
+}
+
+/* Discard the currently collected minimal symbols, if any. If we wish
+ to save them for later use, we must have already copied them somewhere
+ else before calling this function. */
+
+minimal_symbol_reader::~minimal_symbol_reader ()
+{
+ struct msym_bunch *next;
+
+ while (m_msym_bunch != NULL)
{
- return (-1);
+ next = m_msym_bunch->next;
+ xfree (m_msym_bunch);
+ m_msym_bunch = next;
}
- else if (SYMBOL_VALUE_ADDRESS (fn1) > SYMBOL_VALUE_ADDRESS (fn2))
+}
+
+/* See minsyms.h. */
+
+void
+minimal_symbol_reader::record (const char *name, CORE_ADDR address,
+ enum minimal_symbol_type ms_type)
+{
+ int section;
+
+ switch (ms_type)
{
- return (1);
+ case mst_text:
+ case mst_text_gnu_ifunc:
+ case mst_file_text:
+ case mst_solib_trampoline:
+ section = SECT_OFF_TEXT (m_objfile);
+ break;
+ case mst_data:
+ case mst_data_gnu_ifunc:
+ case mst_file_data:
+ section = SECT_OFF_DATA (m_objfile);
+ break;
+ case mst_bss:
+ case mst_file_bss:
+ section = SECT_OFF_BSS (m_objfile);
+ break;
+ default:
+ section = -1;
}
+
+ record_with_info (name, address, ms_type, section);
+}
+
+/* Convert an enumerator of type minimal_symbol_type to its string
+ representation. */
+
+static const char *
+mst_str (minimal_symbol_type t)
+{
+#define MST_TO_STR(x) case x: return #x;
+ switch (t)
+ {
+ MST_TO_STR (mst_unknown);
+ MST_TO_STR (mst_text);
+ MST_TO_STR (mst_text_gnu_ifunc);
+ MST_TO_STR (mst_slot_got_plt);
+ MST_TO_STR (mst_data);
+ MST_TO_STR (mst_bss);
+ MST_TO_STR (mst_abs);
+ MST_TO_STR (mst_solib_trampoline);
+ MST_TO_STR (mst_file_text);
+ MST_TO_STR (mst_file_data);
+ MST_TO_STR (mst_file_bss);
+
+ default:
+ return "mst_???";
+ }
+#undef MST_TO_STR
+}
+
+/* See minsyms.h. */
+
+struct minimal_symbol *
+minimal_symbol_reader::record_full (gdb::string_view name,
+ bool copy_name, CORE_ADDR address,
+ enum minimal_symbol_type ms_type,
+ int section)
+{
+ struct msym_bunch *newobj;
+ struct minimal_symbol *msymbol;
+
+ /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
+ the minimal symbols, because if there is also another symbol
+ at the same address (e.g. the first function of the file),
+ lookup_minimal_symbol_by_pc would have no way of getting the
+ right one. */
+ if (ms_type == mst_file_text && name[0] == 'g'
+ && (name == GCC_COMPILED_FLAG_SYMBOL
+ || name == GCC2_COMPILED_FLAG_SYMBOL))
+ return (NULL);
+
+ /* It's safe to strip the leading char here once, since the name
+ is also stored stripped in the minimal symbol table. */
+ if (name[0] == get_symbol_leading_char (m_objfile->obfd))
+ name = name.substr (1);
+
+ if (ms_type == mst_file_text && startswith (name, "__gnu_compiled"))
+ return (NULL);
+
+ if (symtab_create_debug >= 2)
+ printf_unfiltered ("Recording minsym: %-21s %18s %4d %.*s\n",
+ mst_str (ms_type), hex_string (address), section,
+ (int) name.size (), name.data ());
+
+ if (m_msym_bunch_index == BUNCH_SIZE)
+ {
+ newobj = XCNEW (struct msym_bunch);
+ m_msym_bunch_index = 0;
+ newobj->next = m_msym_bunch;
+ m_msym_bunch = newobj;
+ }
+ msymbol = &m_msym_bunch->contents[m_msym_bunch_index];
+ msymbol->set_language (language_auto,
+ &m_objfile->per_bfd->storage_obstack);
+
+ if (copy_name)
+ msymbol->m_name = obstack_strndup (&m_objfile->per_bfd->storage_obstack,
+ name.data (), name.size ());
else
+ msymbol->m_name = name.data ();
+
+ SET_MSYMBOL_VALUE_ADDRESS (msymbol, address);
+ MSYMBOL_SECTION (msymbol) = section;
+
+ MSYMBOL_TYPE (msymbol) = ms_type;
+
+ /* If we already read minimal symbols for this objfile, then don't
+ ever allocate a new one. */
+ if (!m_objfile->per_bfd->minsyms_read)
{
- return (0);
+ m_msym_bunch_index++;
+ m_objfile->per_bfd->n_minsyms++;
}
+ m_msym_count++;
+ return msymbol;
}
-/* Discard the currently collected minimal symbols, if any. If we wish
- to save them for later use, we must have already copied them somewhere
- else before calling this function.
-
- FIXME: We could allocate the minimal symbol bunches on their own
- obstack and then simply blow the obstack away when we are done with
- it. Is it worth the extra trouble though? */
+/* Compare two minimal symbols by address and return true if FN1's address
+ is less than FN2's, so that we sort into unsigned numeric order.
+ Within groups with the same address, sort by name. */
-/* ARGSUSED */
-void
-discard_minimal_symbols (foo)
- int foo;
+static inline bool
+minimal_symbol_is_less_than (const minimal_symbol &fn1,
+ const minimal_symbol &fn2)
{
- register struct msym_bunch *next;
-
- while (msym_bunch != NULL)
+ if (MSYMBOL_VALUE_RAW_ADDRESS (&fn1) < MSYMBOL_VALUE_RAW_ADDRESS (&fn2))
+ {
+ return true; /* addr 1 is less than addr 2. */
+ }
+ else if (MSYMBOL_VALUE_RAW_ADDRESS (&fn1) > MSYMBOL_VALUE_RAW_ADDRESS (&fn2))
+ {
+ return false; /* addr 1 is greater than addr 2. */
+ }
+ else
+ /* addrs are equal: sort by name */
{
- next = msym_bunch -> next;
- free ((PTR)msym_bunch);
- msym_bunch = next;
+ const char *name1 = fn1.linkage_name ();
+ const char *name2 = fn2.linkage_name ();
+
+ if (name1 && name2) /* both have names */
+ return strcmp (name1, name2) < 0;
+ else if (name2)
+ return true; /* fn1 has no name, so it is "less". */
+ else if (name1) /* fn2 has no name, so it is "less". */
+ return false;
+ else
+ return false; /* Neither has a name, so they're equal. */
}
}
to linearly scan the table, which is done in a number of places. So we
just do one linear scan here and toss out the duplicates.
- Note that we are not concerned here about recovering the space that
- is potentially freed up, because the strings themselves are allocated
- on the symbol_obstack, and will get automatically freed when the symbol
- table is freed. The caller can free up the unused minimal symbols at
- the end of the compacted region if their allocation strategy allows it.
-
- Also note we only go up to the next to last entry within the loop
- and then copy the last entry explicitly after the loop terminates.
-
Since the different sources of information for each symbol may
have different levels of "completeness", we may have duplicates
that have one entry with type "mst_unknown" and the other with a
overwrite its type with the type from the one we are compacting out. */
static int
-compact_minimal_symbols (msymbol, mcount)
- struct minimal_symbol *msymbol;
- int mcount;
+compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount,
+ struct objfile *objfile)
{
struct minimal_symbol *copyfrom;
struct minimal_symbol *copyto;
copyfrom = copyto = msymbol;
while (copyfrom < msymbol + mcount - 1)
{
- if (SYMBOL_VALUE_ADDRESS (copyfrom) ==
- SYMBOL_VALUE_ADDRESS ((copyfrom + 1)) &&
- (STREQ (SYMBOL_NAME (copyfrom), SYMBOL_NAME ((copyfrom + 1)))))
+ if (MSYMBOL_VALUE_RAW_ADDRESS (copyfrom)
+ == MSYMBOL_VALUE_RAW_ADDRESS ((copyfrom + 1))
+ && MSYMBOL_SECTION (copyfrom) == MSYMBOL_SECTION (copyfrom + 1)
+ && strcmp (copyfrom->linkage_name (),
+ (copyfrom + 1)->linkage_name ()) == 0)
{
- if (MSYMBOL_TYPE((copyfrom + 1)) == mst_unknown)
+ if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown)
{
MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom);
}
copyfrom++;
}
else
- {
- *copyto++ = *copyfrom++;
- }
+ *copyto++ = *copyfrom++;
}
*copyto++ = *copyfrom++;
mcount = copyto - msymbol;
return (mcount);
}
+static void
+clear_minimal_symbol_hash_tables (struct objfile *objfile)
+{
+ for (size_t i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++)
+ {
+ objfile->per_bfd->msymbol_hash[i] = 0;
+ objfile->per_bfd->msymbol_demangled_hash[i] = 0;
+ }
+}
+
+/* This struct is used to store values we compute for msymbols on the
+ background threads but don't need to keep around long term. */
+struct computed_hash_values
+{
+ /* Length of the linkage_name of the symbol. */
+ size_t name_length;
+ /* Hash code (using fast_hash) of the linkage_name. */
+ hashval_t mangled_name_hash;
+ /* The msymbol_hash of the linkage_name. */
+ unsigned int minsym_hash;
+ /* The msymbol_hash of the search_name. */
+ unsigned int minsym_demangled_hash;
+};
+
+/* Build (or rebuild) the minimal symbol hash tables. This is necessary
+ after compacting or sorting the table since the entries move around
+ thus causing the internal minimal_symbol pointers to become jumbled. */
+
+static void
+build_minimal_symbol_hash_tables
+ (struct objfile *objfile,
+ const std::vector<computed_hash_values>& hash_values)
+{
+ int i;
+ struct minimal_symbol *msym;
+
+ /* (Re)insert the actual entries. */
+ int mcount = objfile->per_bfd->minimal_symbol_count;
+ for ((i = 0,
+ msym = objfile->per_bfd->msymbols.get ());
+ i < mcount;
+ i++, msym++)
+ {
+ msym->hash_next = 0;
+ add_minsym_to_hash_table (msym, objfile->per_bfd->msymbol_hash,
+ hash_values[i].minsym_hash);
+
+ msym->demangled_hash_next = 0;
+ if (msym->search_name () != msym->linkage_name ())
+ add_minsym_to_demangled_hash_table
+ (msym, objfile, hash_values[i].minsym_demangled_hash);
+ }
+}
+
/* Add the minimal symbols in the existing bunches to the objfile's official
minimal symbol table. In most cases there is no minimal symbol table yet
for this objfile, and the existing bunches are used to create one. Once
in a while (for shared libraries for example), we add symbols (e.g. common
- symbols) to an existing objfile.
-
- Because of the way minimal symbols are collected, we generally have no way
- of knowing what source language applies to any particular minimal symbol.
- Specifically, we have no way of knowing if the minimal symbol comes from a
- C++ compilation unit or not. So for the sake of supporting cached
- demangled C++ names, we have no choice but to try and demangle each new one
- that comes in. If the demangling succeeds, then we assume it is a C++
- symbol and set the symbol's language and demangled name fields
- appropriately. Note that in order to avoid unnecessary demanglings, and
- allocating obstack space that subsequently can't be freed for the demangled
- names, we mark all newly added symbols with language_auto. After
- compaction of the minimal symbols, we go back and scan the entire minimal
- symbol table looking for these new symbols. For each new symbol we attempt
- to demangle it, and if successful, record it as a language_cplus symbol
- and cache the demangled form on the symbol obstack. Symbols which don't
- demangle are marked as language_unknown symbols, which inhibits future
- attempts to demangle them if we later add more minimal symbols. */
+ symbols) to an existing objfile. */
void
-install_minimal_symbols (objfile)
- struct objfile *objfile;
+minimal_symbol_reader::install ()
{
- register int bindex;
- register int mcount;
- register struct msym_bunch *bunch;
- register struct minimal_symbol *msymbols;
+ int mcount;
+ struct msym_bunch *bunch;
+ struct minimal_symbol *msymbols;
int alloc_count;
- register char leading_char;
- if (msym_count > 0)
+ if (m_objfile->per_bfd->minsyms_read)
+ return;
+
+ if (m_msym_count > 0)
{
- /* Allocate enough space in the obstack, into which we will gather the
- bunches of new and existing minimal symbols, sort them, and then
- compact out the duplicate entries. Once we have a final table,
- we will give back the excess space. */
+ if (symtab_create_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "Installing %d minimal symbols of objfile %s.\n",
+ m_msym_count, objfile_name (m_objfile));
+ }
+
+ /* Allocate enough space, into which we will gather the bunches
+ of new and existing minimal symbols, sort them, and then
+ compact out the duplicate entries. Once we have a final
+ table, we will give back the excess space. */
- alloc_count = msym_count + objfile->minimal_symbol_count + 1;
- obstack_blank (&objfile->symbol_obstack,
- alloc_count * sizeof (struct minimal_symbol));
- msymbols = (struct minimal_symbol *)
- obstack_base (&objfile->symbol_obstack);
+ alloc_count = m_msym_count + m_objfile->per_bfd->minimal_symbol_count;
+ gdb::unique_xmalloc_ptr<minimal_symbol>
+ msym_holder (XNEWVEC (minimal_symbol, alloc_count));
+ msymbols = msym_holder.get ();
/* Copy in the existing minimal symbols, if there are any. */
- if (objfile->minimal_symbol_count)
- memcpy ((char *)msymbols, (char *)objfile->msymbols,
- objfile->minimal_symbol_count * sizeof (struct minimal_symbol));
+ if (m_objfile->per_bfd->minimal_symbol_count)
+ memcpy (msymbols, m_objfile->per_bfd->msymbols.get (),
+ m_objfile->per_bfd->minimal_symbol_count
+ * sizeof (struct minimal_symbol));
/* Walk through the list of minimal symbol bunches, adding each symbol
- to the new contiguous array of symbols. Note that we start with the
- current, possibly partially filled bunch (thus we use the current
- msym_bunch_index for the first bunch we copy over), and thereafter
- each bunch is full. */
-
- mcount = objfile->minimal_symbol_count;
- leading_char = bfd_get_symbol_leading_char (objfile->obfd);
-
- for (bunch = msym_bunch; bunch != NULL; bunch = bunch -> next)
+ to the new contiguous array of symbols. Note that we start with the
+ current, possibly partially filled bunch (thus we use the current
+ msym_bunch_index for the first bunch we copy over), and thereafter
+ each bunch is full. */
+
+ mcount = m_objfile->per_bfd->minimal_symbol_count;
+
+ for (bunch = m_msym_bunch; bunch != NULL; bunch = bunch->next)
{
- for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++)
- {
- msymbols[mcount] = bunch -> contents[bindex];
- SYMBOL_LANGUAGE (&msymbols[mcount]) = language_auto;
- if (SYMBOL_NAME (&msymbols[mcount])[0] == leading_char)
- {
- SYMBOL_NAME(&msymbols[mcount])++;
- }
- }
- msym_bunch_index = BUNCH_SIZE;
+ memcpy (&msymbols[mcount], &bunch->contents[0],
+ m_msym_bunch_index * sizeof (struct minimal_symbol));
+ mcount += m_msym_bunch_index;
+ m_msym_bunch_index = BUNCH_SIZE;
}
/* Sort the minimal symbols by address. */
-
- qsort (msymbols, mcount, sizeof (struct minimal_symbol),
- compare_minimal_symbols);
-
+
+ std::sort (msymbols, msymbols + mcount, minimal_symbol_is_less_than);
+
/* Compact out any duplicates, and free up whatever space we are
- no longer using. */
-
- mcount = compact_minimal_symbols (msymbols, mcount);
-
- obstack_blank (&objfile->symbol_obstack,
- (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol));
- msymbols = (struct minimal_symbol *)
- obstack_finish (&objfile->symbol_obstack);
-
- /* We also terminate the minimal symbol table with a "null symbol",
- which is *not* included in the size of the table. This makes it
- easier to find the end of the table when we are handed a pointer
- to some symbol in the middle of it. Zero out the fields in the
- "null symbol" allocated at the end of the array. Note that the
- symbol count does *not* include this null symbol, which is why it
- is indexed by mcount and not mcount-1. */
-
- SYMBOL_NAME (&msymbols[mcount]) = NULL;
- SYMBOL_VALUE_ADDRESS (&msymbols[mcount]) = 0;
- MSYMBOL_INFO (&msymbols[mcount]) = NULL;
- MSYMBOL_TYPE (&msymbols[mcount]) = mst_unknown;
- SYMBOL_INIT_LANGUAGE_SPECIFIC (&msymbols[mcount], language_unknown);
+ no longer using. */
+
+ mcount = compact_minimal_symbols (msymbols, mcount, m_objfile);
+ msym_holder.reset (XRESIZEVEC (struct minimal_symbol,
+ msym_holder.release (),
+ mcount));
/* Attach the minimal symbol table to the specified objfile.
- The strings themselves are also located in the symbol_obstack
- of this objfile. */
+ The strings themselves are also located in the storage_obstack
+ of this objfile. */
- objfile -> minimal_symbol_count = mcount;
- objfile -> msymbols = msymbols;
+ if (m_objfile->per_bfd->minimal_symbol_count != 0)
+ clear_minimal_symbol_hash_tables (m_objfile);
- /* Now walk through all the minimal symbols, selecting the newly added
- ones and attempting to cache their C++ demangled names. */
+ m_objfile->per_bfd->minimal_symbol_count = mcount;
+ m_objfile->per_bfd->msymbols = std::move (msym_holder);
- for ( ; mcount-- > 0 ; msymbols++)
+#if CXX_STD_THREAD
+ /* Mutex that is used when modifying or accessing the demangled
+ hash table. */
+ std::mutex demangled_mutex;
+#endif
+
+ std::vector<computed_hash_values> hash_values (mcount);
+
+ msymbols = m_objfile->per_bfd->msymbols.get ();
+ gdb::parallel_for_each
+ (&msymbols[0], &msymbols[mcount],
+ [&] (minimal_symbol *start, minimal_symbol *end)
+ {
+ for (minimal_symbol *msym = start; msym < end; ++msym)
+ {
+ size_t idx = msym - msymbols;
+ hash_values[idx].name_length = strlen (msym->linkage_name ());
+ if (!msym->name_set)
+ {
+ /* This will be freed later, by compute_and_set_names. */
+ char *demangled_name
+ = symbol_find_demangled_name (msym, msym->linkage_name ());
+ symbol_set_demangled_name
+ (msym, demangled_name,
+ &m_objfile->per_bfd->storage_obstack);
+ msym->name_set = 1;
+ }
+ /* This mangled_name_hash computation has to be outside of
+ the name_set check, or compute_and_set_names below will
+ be called with an invalid hash value. */
+ hash_values[idx].mangled_name_hash
+ = fast_hash (msym->linkage_name (),
+ hash_values[idx].name_length);
+ hash_values[idx].minsym_hash
+ = msymbol_hash (msym->linkage_name ());
+ /* We only use this hash code if the search name differs
+ from the linkage name. See the code in
+ build_minimal_symbol_hash_tables. */
+ if (msym->search_name () != msym->linkage_name ())
+ hash_values[idx].minsym_demangled_hash
+ = search_name_hash (msym->language (), msym->search_name ());
+ }
+ {
+ /* To limit how long we hold the lock, we only acquire it here
+ and not while we demangle the names above. */
+#if CXX_STD_THREAD
+ std::lock_guard<std::mutex> guard (demangled_mutex);
+#endif
+ for (minimal_symbol *msym = start; msym < end; ++msym)
+ {
+ size_t idx = msym - msymbols;
+ msym->compute_and_set_names
+ (gdb::string_view (msym->linkage_name (),
+ hash_values[idx].name_length),
+ false,
+ m_objfile->per_bfd,
+ hash_values[idx].mangled_name_hash);
+ }
+ }
+ });
+
+ build_minimal_symbol_hash_tables (m_objfile, hash_values);
+ }
+}
+
+/* Check if PC is in a shared library trampoline code stub.
+ Return minimal symbol for the trampoline entry or NULL if PC is not
+ in a trampoline code stub. */
+
+static struct minimal_symbol *
+lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc)
+{
+ bound_minimal_symbol msymbol
+ = lookup_minimal_symbol_by_pc_section (pc, NULL,
+ lookup_msym_prefer::TRAMPOLINE);
+
+ if (msymbol.minsym != NULL
+ && MSYMBOL_TYPE (msymbol.minsym) == mst_solib_trampoline)
+ return msymbol.minsym;
+ return NULL;
+}
+
+/* If PC is in a shared library trampoline code stub, return the
+ address of the `real' function belonging to the stub.
+ Return 0 if PC is not in a trampoline code stub or if the real
+ function is not found in the minimal symbol table.
+
+ We may fail to find the right function if a function with the
+ same name is defined in more than one shared library, but this
+ is considered bad programming style. We could return 0 if we find
+ a duplicate function in case this matters someday. */
+
+CORE_ADDR
+find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc)
+{
+ struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
+
+ if (tsymbol != NULL)
+ {
+ for (objfile *objfile : current_program_space->objfiles ())
{
- SYMBOL_INIT_DEMANGLED_NAME (msymbols, &objfile->symbol_obstack);
+ for (minimal_symbol *msymbol : objfile->msymbols ())
+ {
+ /* Also handle minimal symbols pointing to function
+ descriptors. */
+ if ((MSYMBOL_TYPE (msymbol) == mst_text
+ || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc
+ || MSYMBOL_TYPE (msymbol) == mst_data
+ || MSYMBOL_TYPE (msymbol) == mst_data_gnu_ifunc)
+ && strcmp (msymbol->linkage_name (),
+ tsymbol->linkage_name ()) == 0)
+ {
+ CORE_ADDR func;
+
+ /* Ignore data symbols that are not function
+ descriptors. */
+ if (msymbol_is_function (objfile, msymbol, &func))
+ return func;
+ }
+ }
}
}
+ return 0;
}
+/* See minsyms.h. */
+
+CORE_ADDR
+minimal_symbol_upper_bound (struct bound_minimal_symbol minsym)
+{
+ short section;
+ struct obj_section *obj_section;
+ CORE_ADDR result;
+ struct minimal_symbol *iter, *msymbol;
+
+ gdb_assert (minsym.minsym != NULL);
+
+ /* If the minimal symbol has a size, use it. Otherwise use the
+ lesser of the next minimal symbol in the same section, or the end
+ of the section, as the end of the function. */
+
+ if (MSYMBOL_SIZE (minsym.minsym) != 0)
+ return BMSYMBOL_VALUE_ADDRESS (minsym) + MSYMBOL_SIZE (minsym.minsym);
+
+ /* Step over other symbols at this same address, and symbols in
+ other sections, to find the next symbol in this section with a
+ different address. */
+
+ struct minimal_symbol *past_the_end
+ = (minsym.objfile->per_bfd->msymbols.get ()
+ + minsym.objfile->per_bfd->minimal_symbol_count);
+ msymbol = minsym.minsym;
+ section = MSYMBOL_SECTION (msymbol);
+ for (iter = msymbol + 1; iter != past_the_end; ++iter)
+ {
+ if ((MSYMBOL_VALUE_RAW_ADDRESS (iter)
+ != MSYMBOL_VALUE_RAW_ADDRESS (msymbol))
+ && MSYMBOL_SECTION (iter) == section)
+ break;
+ }
+
+ obj_section = MSYMBOL_OBJ_SECTION (minsym.objfile, minsym.minsym);
+ if (iter != past_the_end
+ && (MSYMBOL_VALUE_ADDRESS (minsym.objfile, iter)
+ < obj_section_endaddr (obj_section)))
+ result = MSYMBOL_VALUE_ADDRESS (minsym.objfile, iter);
+ else
+ /* We got the start address from the last msymbol in the objfile.
+ So the end address is the end of the section. */
+ result = obj_section_endaddr (obj_section);
+
+ return result;
+}
projects / deliverable / binutils-gdb.git / blobdiff