X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Ffindvar.c;h=fdce436baac214f2ed2fddd06cbe3c904e481472;hb=79bb5c2356e7651d0aad0a0c3818f1727bc3cb74;hp=79c4221f73624b37100743390cdbd1c8aab46ad3;hpb=0b30217134add051e159a192066a1e568ebd837f;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/findvar.c b/gdb/findvar.c index 79c4221f73..fdce436baa 100644 --- a/gdb/findvar.c +++ b/gdb/findvar.c @@ -1,7 +1,6 @@ /* Find a variable's value in memory, for GDB, the GNU debugger. - Copyright (C) 1986-2001, 2003-2005, 2007-2012 Free Software - Foundation, Inc. + Copyright (C) 1986-2013 Free Software Foundation, Inc. This file is part of GDB. @@ -34,6 +33,7 @@ #include "user-regs.h" #include "block.h" #include "objfiles.h" +#include "language.h" /* Basic byte-swapping routines. All 'extract' functions return a host-format integer from a target-format integer at ADDR which is @@ -367,17 +367,15 @@ address_to_signed_pointer (struct gdbarch *gdbarch, struct type *type, int symbol_read_needs_frame (struct symbol *sym) { + if (SYMBOL_COMPUTED_OPS (sym) != NULL) + return SYMBOL_COMPUTED_OPS (sym)->read_needs_frame (sym); + switch (SYMBOL_CLASS (sym)) { /* All cases listed explicitly so that gcc -Wall will detect it if we failed to consider one. */ case LOC_COMPUTED: - /* FIXME: cagney/2004-01-26: It should be possible to - unconditionally call the SYMBOL_COMPUTED_OPS method when available. - Unfortunately DWARF 2 stores the frame-base (instead of the - function) location in a function's symbol. Oops! For the - moment enable this when/where applicable. */ - return SYMBOL_COMPUTED_OPS (sym)->read_needs_frame (sym); + gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method")); case LOC_REGISTER: case LOC_ARG: @@ -405,18 +403,50 @@ symbol_read_needs_frame (struct symbol *sym) return 1; } -/* Given a struct symbol for a variable, - and a stack frame id, read the value of the variable - and return a (pointer to a) struct value containing the value. - If the variable cannot be found, throw error. */ +/* Private data to be used with minsym_lookup_iterator_cb. */ + +struct minsym_lookup_data +{ + /* The name of the minimal symbol we are searching for. */ + const char *name; + + /* The field where the callback should store the minimal symbol + if found. It should be initialized to NULL before the search + is started. */ + struct minimal_symbol *result; + + /* The objfile in which the symbol was found. */ + struct objfile *objfile; +}; + +/* A callback function for gdbarch_iterate_over_objfiles_in_search_order. + It searches by name for a minimal symbol within the given OBJFILE. + The arguments are passed via CB_DATA, which in reality is a pointer + to struct minsym_lookup_data. */ + +static int +minsym_lookup_iterator_cb (struct objfile *objfile, void *cb_data) +{ + struct minsym_lookup_data *data = (struct minsym_lookup_data *) cb_data; + + gdb_assert (data->result == NULL); + + data->result = lookup_minimal_symbol (data->name, NULL, objfile); + data->objfile = objfile; + + /* The iterator should stop iff a match was found. */ + return (data->result != NULL); +} + +/* A default implementation for the "la_read_var_value" hook in + the language vector which should work in most situations. */ struct value * -read_var_value (struct symbol *var, struct frame_info *frame) +default_read_var_value (struct symbol *var, struct frame_info *frame) { struct value *v; struct type *type = SYMBOL_TYPE (var); CORE_ADDR addr; - int len; /* Call check_typedef on our type to make sure that, if TYPE is a TYPE_CODE_TYPEDEF, its length is set to the length of the target type @@ -425,17 +455,18 @@ read_var_value (struct symbol *var, struct frame_info *frame) set the returned value type description correctly. */ check_typedef (type); - len = TYPE_LENGTH (type); - if (symbol_read_needs_frame (var)) gdb_assert (frame); + if (SYMBOL_COMPUTED_OPS (var) != NULL) + return SYMBOL_COMPUTED_OPS (var)->read_variable (var, frame); + switch (SYMBOL_CLASS (var)) { case LOC_CONST: /* Put the constant back in target format. */ v = allocate_value (type); - store_signed_integer (value_contents_raw (v), len, + store_signed_integer (value_contents_raw (v), TYPE_LENGTH (type), gdbarch_byte_order (get_type_arch (type)), (LONGEST) SYMBOL_VALUE (var)); VALUE_LVAL (v) = not_lval; @@ -448,7 +479,8 @@ read_var_value (struct symbol *var, struct frame_info *frame) { CORE_ADDR addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), - SYMBOL_OBJ_SECTION (var)); + SYMBOL_OBJ_SECTION (SYMBOL_OBJFILE (var), + var)); store_typed_address (value_contents_raw (v), type, addr); } @@ -460,7 +492,8 @@ read_var_value (struct symbol *var, struct frame_info *frame) case LOC_CONST_BYTES: v = allocate_value (type); - memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var), len); + memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var), + TYPE_LENGTH (type)); VALUE_LVAL (v) = not_lval; return v; @@ -468,7 +501,8 @@ read_var_value (struct symbol *var, struct frame_info *frame) v = allocate_value_lazy (type); if (overlay_debugging) addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), - SYMBOL_OBJ_SECTION (var)); + SYMBOL_OBJ_SECTION (SYMBOL_OBJFILE (var), + var)); else addr = SYMBOL_VALUE_ADDRESS (var); break; @@ -513,7 +547,8 @@ read_var_value (struct symbol *var, struct frame_info *frame) v = allocate_value_lazy (type); if (overlay_debugging) addr = symbol_overlayed_address - (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_OBJ_SECTION (var)); + (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_OBJ_SECTION (SYMBOL_OBJFILE (var), + var)); else addr = BLOCK_START (SYMBOL_BLOCK_VALUE (var)); break; @@ -551,28 +586,33 @@ read_var_value (struct symbol *var, struct frame_info *frame) break; case LOC_COMPUTED: - /* FIXME: cagney/2004-01-26: It should be possible to - unconditionally call the SYMBOL_COMPUTED_OPS method when available. - Unfortunately DWARF 2 stores the frame-base (instead of the - function) location in a function's symbol. Oops! For the - moment enable this when/where applicable. */ - return SYMBOL_COMPUTED_OPS (var)->read_variable (var, frame); + gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method")); case LOC_UNRESOLVED: { + struct minsym_lookup_data lookup_data; struct minimal_symbol *msym; struct obj_section *obj_section; - msym = lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (var), NULL, NULL); + memset (&lookup_data, 0, sizeof (lookup_data)); + lookup_data.name = SYMBOL_LINKAGE_NAME (var); + + gdbarch_iterate_over_objfiles_in_search_order + (get_objfile_arch (SYMBOL_SYMTAB (var)->objfile), + minsym_lookup_iterator_cb, &lookup_data, + SYMBOL_SYMTAB (var)->objfile); + msym = lookup_data.result; + if (msym == NULL) error (_("No global symbol \"%s\"."), SYMBOL_LINKAGE_NAME (var)); if (overlay_debugging) addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym), - SYMBOL_OBJ_SECTION (msym)); + SYMBOL_OBJ_SECTION (lookup_data.objfile, + msym)); else addr = SYMBOL_VALUE_ADDRESS (msym); - obj_section = SYMBOL_OBJ_SECTION (msym); + obj_section = SYMBOL_OBJ_SECTION (lookup_data.objfile, msym); if (obj_section && (obj_section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0) addr = target_translate_tls_address (obj_section->objfile, addr); @@ -594,6 +634,19 @@ read_var_value (struct symbol *var, struct frame_info *frame) return v; } +/* Calls VAR's language la_read_var_value hook with the given arguments. */ + +struct value * +read_var_value (struct symbol *var, struct frame_info *frame) +{ + const struct language_defn *lang = language_def (SYMBOL_LANGUAGE (var)); + + gdb_assert (lang != NULL); + gdb_assert (lang->la_read_var_value != NULL); + + return lang->la_read_var_value (var, frame); +} + /* Install default attributes for register values. */ struct value * @@ -625,7 +678,10 @@ default_value_from_register (struct type *type, int regnum, /* VALUE must be an lval_register value. If regnum is the value's associated register number, and len the length of the values type, read one or more registers in FRAME, starting with register REGNUM, - until we've read LEN bytes. */ + until we've read LEN bytes. + + If any of the registers we try to read are optimized out, then mark the + complete resulting value as optimized out. */ void read_frame_register_value (struct value *value, struct frame_info *frame) @@ -651,6 +707,12 @@ read_frame_register_value (struct value *value, struct frame_info *frame) struct value *regval = get_frame_register_value (frame, regnum); int reg_len = TYPE_LENGTH (value_type (regval)) - reg_offset; + if (value_optimized_out (regval)) + { + set_value_optimized_out (value, 1); + break; + } + /* If the register length is larger than the number of bytes remaining to copy, then only copy the appropriate bytes. */ if (reg_len > len)