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      1 
      2 /*--------------------------------------------------------------------*/
      3 /*--- Basic definitions and helper functions for DWARF3.           ---*/
      4 /*---                                                   d3basics.c ---*/
      5 /*--------------------------------------------------------------------*/
      6 
      7 /*
      8    This file is part of Valgrind, a dynamic binary instrumentation
      9    framework.
     10 
     11    Copyright (C) 2008-2010 OpenWorks LLP
     12       info (at) open-works.co.uk
     13 
     14    This program is free software; you can redistribute it and/or
     15    modify it under the terms of the GNU General Public License as
     16    published by the Free Software Foundation; either version 2 of the
     17    License, or (at your option) any later version.
     18 
     19    This program is distributed in the hope that it will be useful, but
     20    WITHOUT ANY WARRANTY; without even the implied warranty of
     21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     22    General Public License for more details.
     23 
     24    You should have received a copy of the GNU General Public License
     25    along with this program; if not, write to the Free Software
     26    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
     27    02111-1307, USA.
     28 
     29    The GNU General Public License is contained in the file COPYING.
     30 
     31    Neither the names of the U.S. Department of Energy nor the
     32    University of California nor the names of its contributors may be
     33    used to endorse or promote products derived from this software
     34    without prior written permission.
     35 */
     36 
     37 #include "pub_core_basics.h"
     38 #include "pub_core_debuginfo.h"
     39 #include "pub_core_libcassert.h"
     40 #include "pub_core_libcprint.h"
     41 #include "pub_core_options.h"
     42 #include "pub_core_xarray.h"
     43 
     44 #include "pub_core_vki.h"       /* VKI_PROT_READ */
     45 #include "pub_core_aspacemgr.h" /* VG_(is_valid_for_client) */
     46 
     47 #include "priv_misc.h"
     48 #include "priv_d3basics.h"      /* self */
     49 #include "priv_storage.h"
     50 
     51 HChar* ML_(pp_DW_children) ( DW_children hashch )
     52 {
     53    switch (hashch) {
     54       case DW_children_no:  return "no children";
     55       case DW_children_yes: return "has children";
     56       default:              return "DW_children_???";
     57    }
     58 }
     59 
     60 HChar* ML_(pp_DW_TAG) ( DW_TAG tag )
     61 {
     62    switch (tag) {
     63       case DW_TAG_padding:            return "DW_TAG_padding";
     64       case DW_TAG_array_type:         return "DW_TAG_array_type";
     65       case DW_TAG_class_type:         return "DW_TAG_class_type";
     66       case DW_TAG_entry_point:        return "DW_TAG_entry_point";
     67       case DW_TAG_enumeration_type:   return "DW_TAG_enumeration_type";
     68       case DW_TAG_formal_parameter:   return "DW_TAG_formal_parameter";
     69       case DW_TAG_imported_declaration:
     70          return "DW_TAG_imported_declaration";
     71       case DW_TAG_label:              return "DW_TAG_label";
     72       case DW_TAG_lexical_block:      return "DW_TAG_lexical_block";
     73       case DW_TAG_member:             return "DW_TAG_member";
     74       case DW_TAG_pointer_type:       return "DW_TAG_pointer_type";
     75       case DW_TAG_reference_type:     return "DW_TAG_reference_type";
     76       case DW_TAG_compile_unit:       return "DW_TAG_compile_unit";
     77       case DW_TAG_string_type:        return "DW_TAG_string_type";
     78       case DW_TAG_structure_type:     return "DW_TAG_structure_type";
     79       case DW_TAG_subroutine_type:    return "DW_TAG_subroutine_type";
     80       case DW_TAG_typedef:            return "DW_TAG_typedef";
     81       case DW_TAG_union_type:         return "DW_TAG_union_type";
     82       case DW_TAG_unspecified_parameters:
     83          return "DW_TAG_unspecified_parameters";
     84       case DW_TAG_variant:            return "DW_TAG_variant";
     85       case DW_TAG_common_block:       return "DW_TAG_common_block";
     86       case DW_TAG_common_inclusion:   return "DW_TAG_common_inclusion";
     87       case DW_TAG_inheritance:        return "DW_TAG_inheritance";
     88       case DW_TAG_inlined_subroutine:
     89          return "DW_TAG_inlined_subroutine";
     90       case DW_TAG_module:             return "DW_TAG_module";
     91       case DW_TAG_ptr_to_member_type: return "DW_TAG_ptr_to_member_type";
     92       case DW_TAG_set_type:           return "DW_TAG_set_type";
     93       case DW_TAG_subrange_type:      return "DW_TAG_subrange_type";
     94       case DW_TAG_with_stmt:          return "DW_TAG_with_stmt";
     95       case DW_TAG_access_declaration: return "DW_TAG_access_declaration";
     96       case DW_TAG_base_type:          return "DW_TAG_base_type";
     97       case DW_TAG_catch_block:        return "DW_TAG_catch_block";
     98       case DW_TAG_const_type:         return "DW_TAG_const_type";
     99       case DW_TAG_constant:           return "DW_TAG_constant";
    100       case DW_TAG_enumerator:         return "DW_TAG_enumerator";
    101       case DW_TAG_file_type:          return "DW_TAG_file_type";
    102       case DW_TAG_friend:             return "DW_TAG_friend";
    103       case DW_TAG_namelist:           return "DW_TAG_namelist";
    104       case DW_TAG_namelist_item:      return "DW_TAG_namelist_item";
    105       case DW_TAG_packed_type:        return "DW_TAG_packed_type";
    106       case DW_TAG_subprogram:         return "DW_TAG_subprogram";
    107       case DW_TAG_template_type_param:
    108          return "DW_TAG_template_type_param";
    109       case DW_TAG_template_value_param:
    110          return "DW_TAG_template_value_param";
    111       case DW_TAG_thrown_type:        return "DW_TAG_thrown_type";
    112       case DW_TAG_try_block:          return "DW_TAG_try_block";
    113       case DW_TAG_variant_part:       return "DW_TAG_variant_part";
    114       case DW_TAG_variable:           return "DW_TAG_variable";
    115       case DW_TAG_volatile_type:      return "DW_TAG_volatile_type";
    116       /* DWARF 3.  */
    117       case DW_TAG_dwarf_procedure:    return "DW_TAG_dwarf_procedure";
    118       case DW_TAG_restrict_type:      return "DW_TAG_restrict_type";
    119       case DW_TAG_interface_type:     return "DW_TAG_interface_type";
    120       case DW_TAG_namespace:          return "DW_TAG_namespace";
    121       case DW_TAG_imported_module:    return "DW_TAG_imported_module";
    122       case DW_TAG_unspecified_type:   return "DW_TAG_unspecified_type";
    123       case DW_TAG_partial_unit:       return "DW_TAG_partial_unit";
    124       case DW_TAG_imported_unit:      return "DW_TAG_imported_unit";
    125       case DW_TAG_condition:          return "DW_TAG_condition";
    126       case DW_TAG_shared_type:        return "DW_TAG_shared_type";
    127       /* DWARF 4.  */
    128       case DW_TAG_type_unit:          return "DW_TAG_type_unit";
    129       case DW_TAG_rvalue_reference_type: return "DW_TAG_rvalue_reference_type";
    130       case DW_TAG_template_alias:     return "DW_TAG_template_alias";
    131       /* SGI/MIPS Extensions.  */
    132       case DW_TAG_MIPS_loop:          return "DW_TAG_MIPS_loop";
    133       /* HP extensions.  See:
    134          ftp://ftp.hp.com/pub/lang/tools/WDB/wdb-4.0.tar.gz .  */
    135       case DW_TAG_HP_array_descriptor:
    136          return "DW_TAG_HP_array_descriptor";
    137       /* GNU extensions.  */
    138       case DW_TAG_format_label:       return "DW_TAG_format_label";
    139       case DW_TAG_function_template:  return "DW_TAG_function_template";
    140       case DW_TAG_class_template:     return "DW_TAG_class_template";
    141       case DW_TAG_GNU_BINCL:          return "DW_TAG_GNU_BINCL";
    142       case DW_TAG_GNU_EINCL:          return "DW_TAG_GNU_EINCL";
    143       /* Extensions for UPC.  See: http://upc.gwu.edu/~upc.  */
    144       case DW_TAG_upc_shared_type:    return "DW_TAG_upc_shared_type";
    145       case DW_TAG_upc_strict_type:    return "DW_TAG_upc_strict_type";
    146       case DW_TAG_upc_relaxed_type:   return "DW_TAG_upc_relaxed_type";
    147       /* PGI (STMicroelectronics) extensions.  No documentation available.  */
    148       case DW_TAG_PGI_kanji_type:     return "DW_TAG_PGI_kanji_type";
    149       case DW_TAG_PGI_interface_block:
    150          return "DW_TAG_PGI_interface_block";
    151       default:                        return "DW_TAG_???";
    152    }
    153 }
    154 
    155 HChar* ML_(pp_DW_FORM) ( DW_FORM form )
    156 {
    157    switch (form) {
    158       case DW_FORM_addr:      return "DW_FORM_addr";
    159       case DW_FORM_block2:    return "DW_FORM_block2";
    160       case DW_FORM_block4:    return "DW_FORM_block4";
    161       case DW_FORM_data2:     return "DW_FORM_data2";
    162       case DW_FORM_data4:     return "DW_FORM_data4";
    163       case DW_FORM_data8:     return "DW_FORM_data8";
    164       case DW_FORM_string:    return "DW_FORM_string";
    165       case DW_FORM_block:     return "DW_FORM_block";
    166       case DW_FORM_block1:    return "DW_FORM_block1";
    167       case DW_FORM_data1:     return "DW_FORM_data1";
    168       case DW_FORM_flag:      return "DW_FORM_flag";
    169       case DW_FORM_sdata:     return "DW_FORM_sdata";
    170       case DW_FORM_strp:      return "DW_FORM_strp";
    171       case DW_FORM_udata:     return "DW_FORM_udata";
    172       case DW_FORM_ref_addr:  return "DW_FORM_ref_addr";
    173       case DW_FORM_ref1:      return "DW_FORM_ref1";
    174       case DW_FORM_ref2:      return "DW_FORM_ref2";
    175       case DW_FORM_ref4:      return "DW_FORM_ref4";
    176       case DW_FORM_ref8:      return "DW_FORM_ref8";
    177       case DW_FORM_ref_udata: return "DW_FORM_ref_udata";
    178       case DW_FORM_indirect:  return "DW_FORM_indirect";
    179       case DW_FORM_sec_offset:return "DW_FORM_sec_offset";
    180       case DW_FORM_exprloc:   return "DW_FORM_exprloc";
    181       case DW_FORM_flag_present:return "DW_FORM_flag_present";
    182       case DW_FORM_ref_sig8:  return "DW_FORM_ref_sig8";
    183       default:                return "DW_FORM_???";
    184    }
    185 }
    186 
    187 HChar* ML_(pp_DW_AT) ( DW_AT attr )
    188 {
    189    switch (attr) {
    190       case DW_AT_sibling:             return "DW_AT_sibling";
    191       case DW_AT_location:            return "DW_AT_location";
    192       case DW_AT_name: return "DW_AT_name";
    193       case DW_AT_ordering: return "DW_AT_ordering";
    194       case DW_AT_subscr_data: return "DW_AT_subscr_data";
    195       case DW_AT_byte_size: return "DW_AT_byte_size";
    196       case DW_AT_bit_offset: return "DW_AT_bit_offset";
    197       case DW_AT_bit_size: return "DW_AT_bit_size";
    198       case DW_AT_element_list: return "DW_AT_element_list";
    199       case DW_AT_stmt_list: return "DW_AT_stmt_list";
    200       case DW_AT_low_pc: return "DW_AT_low_pc";
    201       case DW_AT_high_pc: return "DW_AT_high_pc";
    202       case DW_AT_language: return "DW_AT_language";
    203       case DW_AT_member: return "DW_AT_member";
    204       case DW_AT_discr: return "DW_AT_discr";
    205       case DW_AT_discr_value: return "DW_AT_discr_value";
    206       case DW_AT_visibility: return "DW_AT_visibility";
    207       case DW_AT_import: return "DW_AT_import";
    208       case DW_AT_string_length: return "DW_AT_string_length";
    209       case DW_AT_common_reference: return "DW_AT_common_reference";
    210       case DW_AT_comp_dir: return "DW_AT_comp_dir";
    211       case DW_AT_const_value: return "DW_AT_const_value";
    212       case DW_AT_containing_type: return "DW_AT_containing_type";
    213       case DW_AT_default_value: return "DW_AT_default_value";
    214       case DW_AT_inline: return "DW_AT_inline";
    215       case DW_AT_is_optional: return "DW_AT_is_optional";
    216       case DW_AT_lower_bound: return "DW_AT_lower_bound";
    217       case DW_AT_producer: return "DW_AT_producer";
    218       case DW_AT_prototyped: return "DW_AT_prototyped";
    219       case DW_AT_return_addr: return "DW_AT_return_addr";
    220       case DW_AT_start_scope: return "DW_AT_start_scope";
    221       case DW_AT_stride_size: return "DW_AT_stride_size";
    222       case DW_AT_upper_bound: return "DW_AT_upper_bound";
    223       case DW_AT_abstract_origin: return "DW_AT_abstract_origin";
    224       case DW_AT_accessibility: return "DW_AT_accessibility";
    225       case DW_AT_address_class: return "DW_AT_address_class";
    226       case DW_AT_artificial: return "DW_AT_artificial";
    227       case DW_AT_base_types: return "DW_AT_base_types";
    228       case DW_AT_calling_convention: return "DW_AT_calling_convention";
    229       case DW_AT_count: return "DW_AT_count";
    230       case DW_AT_data_member_location: return "DW_AT_data_member_location";
    231       case DW_AT_decl_column: return "DW_AT_decl_column";
    232       case DW_AT_decl_file: return "DW_AT_decl_file";
    233       case DW_AT_decl_line: return "DW_AT_decl_line";
    234       case DW_AT_declaration: return "DW_AT_declaration";
    235       case DW_AT_discr_list: return "DW_AT_discr_list";
    236       case DW_AT_encoding: return "DW_AT_encoding";
    237       case DW_AT_external: return "DW_AT_external";
    238       case DW_AT_frame_base: return "DW_AT_frame_base";
    239       case DW_AT_friend: return "DW_AT_friend";
    240       case DW_AT_identifier_case: return "DW_AT_identifier_case";
    241       case DW_AT_macro_info: return "DW_AT_macro_info";
    242       case DW_AT_namelist_items: return "DW_AT_namelist_items";
    243       case DW_AT_priority: return "DW_AT_priority";
    244       case DW_AT_segment: return "DW_AT_segment";
    245       case DW_AT_specification: return "DW_AT_specification";
    246       case DW_AT_static_link: return "DW_AT_static_link";
    247       case DW_AT_type: return "DW_AT_type";
    248       case DW_AT_use_location: return "DW_AT_use_location";
    249       case DW_AT_variable_parameter: return "DW_AT_variable_parameter";
    250       case DW_AT_virtuality: return "DW_AT_virtuality";
    251       case DW_AT_vtable_elem_location: return "DW_AT_vtable_elem_location";
    252       /* DWARF 3 values.  */
    253       case DW_AT_allocated: return "DW_AT_allocated";
    254       case DW_AT_associated: return "DW_AT_associated";
    255       case DW_AT_data_location: return "DW_AT_data_location";
    256       case DW_AT_stride: return "DW_AT_stride";
    257       case DW_AT_entry_pc: return "DW_AT_entry_pc";
    258       case DW_AT_use_UTF8: return "DW_AT_use_UTF8";
    259       case DW_AT_extension: return "DW_AT_extension";
    260       case DW_AT_ranges: return "DW_AT_ranges";
    261       case DW_AT_trampoline: return "DW_AT_trampoline";
    262       case DW_AT_call_column: return "DW_AT_call_column";
    263       case DW_AT_call_file: return "DW_AT_call_file";
    264       case DW_AT_call_line: return "DW_AT_call_line";
    265       case DW_AT_description: return "DW_AT_description";
    266       case DW_AT_binary_scale: return "DW_AT_binary_scale";
    267       case DW_AT_decimal_scale: return "DW_AT_decimal_scale";
    268       case DW_AT_small: return "DW_AT_small";
    269       case DW_AT_decimal_sign: return "DW_AT_decimal_sign";
    270       case DW_AT_digit_count: return "DW_AT_digit_count";
    271       case DW_AT_picture_string: return "DW_AT_picture_string";
    272       case DW_AT_mutable: return "DW_AT_mutable";
    273       case DW_AT_threads_scaled: return "DW_AT_threads_scaled";
    274       case DW_AT_explicit: return "DW_AT_explicit";
    275       case DW_AT_object_pointer: return "DW_AT_object_pointer";
    276       case DW_AT_endianity: return "DW_AT_endianity";
    277       case DW_AT_elemental: return "DW_AT_elemental";
    278       case DW_AT_pure: return "DW_AT_pure";
    279       case DW_AT_recursive: return "DW_AT_recursive";
    280       /* DWARF 4 values.  */
    281       case DW_AT_signature: return "DW_AT_signature";
    282       case DW_AT_main_subprogram: return "DW_AT_main_subprogram";
    283       case DW_AT_data_bit_offset: return "DW_AT_data_bit_offset";
    284       case DW_AT_const_expr: return "DW_AT_const_expr";
    285       case DW_AT_enum_class: return "DW_AT_enum_class";
    286       case DW_AT_linkage_name: return "DW_AT_linkage_name";
    287       /* SGI/MIPS extensions.  */
    288       /* case DW_AT_MIPS_fde: return "DW_AT_MIPS_fde"; */
    289       /* DW_AT_MIPS_fde == DW_AT_HP_unmodifiable */
    290       case DW_AT_MIPS_loop_begin: return "DW_AT_MIPS_loop_begin";
    291       case DW_AT_MIPS_tail_loop_begin: return "DW_AT_MIPS_tail_loop_begin";
    292       case DW_AT_MIPS_epilog_begin: return "DW_AT_MIPS_epilog_begin";
    293       case DW_AT_MIPS_loop_unroll_factor: return "DW_AT_MIPS_loop_unroll_factor";
    294       case DW_AT_MIPS_software_pipeline_depth: return "DW_AT_MIPS_software_pipeline_depth";
    295       case DW_AT_MIPS_linkage_name: return "DW_AT_MIPS_linkage_name";
    296       case DW_AT_MIPS_stride: return "DW_AT_MIPS_stride";
    297       case DW_AT_MIPS_abstract_name: return "DW_AT_MIPS_abstract_name";
    298       case DW_AT_MIPS_clone_origin: return "DW_AT_MIPS_clone_origin";
    299       case DW_AT_MIPS_has_inlines: return "DW_AT_MIPS_has_inlines";
    300       /* HP extensions.  */
    301       case DW_AT_HP_block_index: return "DW_AT_HP_block_index";
    302       case DW_AT_HP_unmodifiable: return "DW_AT_HP_unmodifiable";
    303       case DW_AT_HP_actuals_stmt_list: return "DW_AT_HP_actuals_stmt_list";
    304       case DW_AT_HP_proc_per_section: return "DW_AT_HP_proc_per_section";
    305       case DW_AT_HP_raw_data_ptr: return "DW_AT_HP_raw_data_ptr";
    306       case DW_AT_HP_pass_by_reference: return "DW_AT_HP_pass_by_reference";
    307       case DW_AT_HP_opt_level: return "DW_AT_HP_opt_level";
    308       case DW_AT_HP_prof_version_id: return "DW_AT_HP_prof_version_id";
    309       case DW_AT_HP_opt_flags: return "DW_AT_HP_opt_flags";
    310       case DW_AT_HP_cold_region_low_pc: return "DW_AT_HP_cold_region_low_pc";
    311       case DW_AT_HP_cold_region_high_pc: return "DW_AT_HP_cold_region_high_pc";
    312       case DW_AT_HP_all_variables_modifiable: return "DW_AT_HP_all_variables_modifiable";
    313       case DW_AT_HP_linkage_name: return "DW_AT_HP_linkage_name";
    314       case DW_AT_HP_prof_flags: return "DW_AT_HP_prof_flags";
    315       /* GNU extensions.  */
    316       case DW_AT_sf_names: return "DW_AT_sf_names";
    317       case DW_AT_src_info: return "DW_AT_src_info";
    318       case DW_AT_mac_info: return "DW_AT_mac_info";
    319       case DW_AT_src_coords: return "DW_AT_src_coords";
    320       case DW_AT_body_begin: return "DW_AT_body_begin";
    321       case DW_AT_body_end: return "DW_AT_body_end";
    322       case DW_AT_GNU_vector: return "DW_AT_GNU_vector";
    323       /* VMS extensions.  */
    324       case DW_AT_VMS_rtnbeg_pd_address: return "DW_AT_VMS_rtnbeg_pd_address";
    325       /* UPC extension.  */
    326       case DW_AT_upc_threads_scaled: return "DW_AT_upc_threads_scaled";
    327       /* PGI (STMicroelectronics) extensions.  */
    328       case DW_AT_PGI_lbase: return "DW_AT_PGI_lbase";
    329       case DW_AT_PGI_soffset: return "DW_AT_PGI_soffset";
    330       case DW_AT_PGI_lstride: return "DW_AT_PGI_lstride";
    331       default: return "DW_AT_???";
    332    }
    333 }
    334 
    335 
    336 /* ------ To do with evaluation of Dwarf expressions ------ */
    337 
    338 /* FIXME: duplicated in readdwarf.c */
    339 static
    340 ULong read_leb128 ( UChar* data, Int* length_return, Int sign )
    341 {
    342   ULong  result = 0;
    343   UInt   num_read = 0;
    344   Int    shift = 0;
    345   UChar  byte;
    346 
    347   vg_assert(sign == 0 || sign == 1);
    348 
    349   do
    350     {
    351       byte = * data ++;
    352       num_read ++;
    353 
    354       result |= ((ULong)(byte & 0x7f)) << shift;
    355 
    356       shift += 7;
    357 
    358     }
    359   while (byte & 0x80);
    360 
    361   if (length_return != NULL)
    362     * length_return = num_read;
    363 
    364   if (sign && (shift < 64) && (byte & 0x40))
    365     result |= -(1ULL << shift);
    366 
    367   return result;
    368 }
    369 
    370 /* Small helper functions easier to use
    371  * value is returned and the given pointer is
    372  * moved past end of leb128 data */
    373 /* FIXME: duplicated in readdwarf.c */
    374 static ULong read_leb128U( UChar **data )
    375 {
    376   Int len;
    377   ULong val = read_leb128( *data, &len, 0 );
    378   *data += len;
    379   return val;
    380 }
    381 
    382 /* Same for signed data */
    383 /* FIXME: duplicated in readdwarf.c */
    384 static Long read_leb128S( UChar **data )
    385 {
    386    Int len;
    387    ULong val = read_leb128( *data, &len, 1 );
    388    *data += len;
    389    return (Long)val;
    390 }
    391 
    392 /* FIXME: duplicates logic in readdwarf.c: copy_convert_CfiExpr_tree
    393    and {FP,SP}_REG decls */
    394 static Bool get_Dwarf_Reg( /*OUT*/Addr* a, Word regno, RegSummary* regs )
    395 {
    396    vg_assert(regs);
    397 #  if defined(VGP_x86_linux) || defined(VGP_x86_darwin)
    398    if (regno == 5/*EBP*/) { *a = regs->fp; return True; }
    399    if (regno == 4/*ESP*/) { *a = regs->sp; return True; }
    400 #  elif defined(VGP_amd64_linux) || defined(VGP_amd64_darwin)
    401    if (regno == 6/*RBP*/) { *a = regs->fp; return True; }
    402    if (regno == 7/*RSP*/) { *a = regs->sp; return True; }
    403 #  elif defined(VGP_ppc32_linux)
    404    if (regno == 1/*SP*/) { *a = regs->sp; return True; }
    405 #  elif defined(VGP_ppc64_linux)
    406    if (regno == 1/*SP*/) { *a = regs->sp; return True; }
    407 #  elif defined(VGP_arm_linux)
    408    if (regno == 13) { *a = regs->sp; return True; }
    409    if (regno == 11) { *a = regs->fp; return True; }
    410 #  elif defined(VGP_ppc32_aix5) || defined(VGP_ppc64_aix5)
    411    vg_assert(0); /* this function should never be called */
    412 #  else
    413 #    error "Unknown platform"
    414 #  endif
    415    return False;
    416 }
    417 
    418 /* Convert a stated address to an actual address */
    419 static Bool bias_address( Addr* a, const DebugInfo* di )
    420 {
    421    if (di->text_present
    422        && di->text_size > 0
    423        && *a >= di->text_debug_svma && *a < di->text_debug_svma + di->text_size) {
    424       *a += di->text_debug_bias;
    425    }
    426    else if (di->data_present
    427             && di->data_size > 0
    428             && *a >= di->data_debug_svma && *a < di->data_debug_svma + di->data_size) {
    429       *a += di->data_debug_bias;
    430    }
    431    else if (di->sdata_present
    432             && di->sdata_size > 0
    433             && *a >= di->sdata_debug_svma && *a < di->sdata_debug_svma + di->sdata_size) {
    434       *a += di->sdata_debug_bias;
    435    }
    436    else if (di->rodata_present
    437             && di->rodata_size > 0
    438             && *a >= di->rodata_debug_svma && *a < di->rodata_debug_svma + di->rodata_size) {
    439       *a += di->rodata_debug_bias;
    440    }
    441    else if (di->bss_present
    442             && di->bss_size > 0
    443             && *a >= di->bss_debug_svma && *a < di->bss_debug_svma + di->bss_size) {
    444       *a += di->bss_debug_bias;
    445    }
    446    else if (di->sbss_present
    447             && di->sbss_size > 0
    448             && *a >= di->sbss_debug_svma && *a < di->sbss_debug_svma + di->sbss_size) {
    449       *a += di->sbss_debug_bias;
    450    }
    451    else {
    452       return False;
    453    }
    454 
    455    return True;
    456 }
    457 
    458 
    459 /* Evaluate a standard DWARF3 expression.  See detailed description in
    460    priv_d3basics.h.  Doesn't handle DW_OP_piece/DW_OP_bit_piece yet.  */
    461 GXResult ML_(evaluate_Dwarf3_Expr) ( UChar* expr, UWord exprszB,
    462                                      GExpr* fbGX, RegSummary* regs,
    463                                      const DebugInfo* di,
    464                                      Bool push_initial_zero )
    465 {
    466 #  define N_EXPR_STACK 20
    467 
    468 #  define FAIL(_str)                                          \
    469       do {                                                    \
    470          res.kind = GXR_Failure;                              \
    471          res.word = (UWord)(_str);                            \
    472          return res;                                          \
    473       } while (0)
    474 
    475 #  define PUSH(_arg)                                          \
    476       do {                                                    \
    477          vg_assert(sp >= -1 && sp < N_EXPR_STACK);            \
    478          if (sp == N_EXPR_STACK-1)                            \
    479             FAIL("evaluate_Dwarf3_Expr: stack overflow(1)");  \
    480          sp++;                                                \
    481          stack[sp] = (_arg);                                  \
    482       } while (0)
    483 
    484 #  define POP(_lval)                                          \
    485       do {                                                    \
    486          vg_assert(sp >= -1 && sp < N_EXPR_STACK);            \
    487          if (sp == -1)                                        \
    488             FAIL("evaluate_Dwarf3_Expr: stack underflow(1)"); \
    489          _lval = stack[sp];                                   \
    490          sp--;                                                \
    491       } while (0)
    492 
    493    UChar    opcode;
    494    UChar*   limit;
    495    Int      sp; /* # of top element: valid is -1 .. N_EXPR_STACK-1 */
    496    Addr     stack[N_EXPR_STACK]; /* stack of addresses, as per D3 spec */
    497    GXResult fbval, res;
    498    Addr     a1;
    499    Word     sw1, sw2;
    500    UWord    uw1, uw2;
    501    Bool     ok;
    502 
    503    sp = -1;
    504    vg_assert(expr);
    505    vg_assert(exprszB >= 0);
    506    limit = expr + exprszB;
    507 
    508    /* Deal with the case where the entire expression is a single
    509       Register Name Operation (D3 spec sec 2.6.1).  Then the
    510       denotation of the expression as a whole is a register name. */
    511    if (exprszB == 1
    512        && expr[0] >= DW_OP_reg0 && expr[0] <= DW_OP_reg31) {
    513       res.kind = GXR_RegNo;
    514       res.word = (UWord)(expr[0] - DW_OP_reg0);
    515       return res;
    516    }
    517    if (exprszB > 1
    518        && expr[0] == DW_OP_regx) {
    519       /* JRS: 2008Feb20: I believe the following is correct, but would
    520          like to see a test case show up before enabling it. */
    521       expr++;
    522       res.kind = GXR_RegNo;
    523       res.word = (UWord)read_leb128U( &expr );
    524       if (expr != limit)
    525          FAIL("evaluate_Dwarf3_Expr: DW_OP_regx*: invalid expr size");
    526       else
    527          return res;
    528       /*NOTREACHED*/
    529    }
    530 
    531    /* Evidently this expression denotes a value, not a register name.
    532       So evaluate it accordingly. */
    533 
    534    if (push_initial_zero)
    535       PUSH(0);
    536 
    537    while (True) {
    538 
    539       vg_assert(sp >= -1 && sp < N_EXPR_STACK);
    540 
    541       if (expr > limit)
    542          /* overrun - something's wrong */
    543          FAIL("evaluate_Dwarf3_Expr: ran off end of expr");
    544 
    545       if (expr == limit) {
    546          /* end of expr - return expr on the top of stack. */
    547          if (sp == -1)
    548             /* stack empty.  Bad. */
    549             FAIL("evaluate_Dwarf3_Expr: stack empty at end of expr");
    550          else
    551             break;
    552       }
    553 
    554       opcode = *expr++;
    555       switch (opcode) {
    556          case DW_OP_addr:
    557             /* Presumably what is given in the Dwarf3 is a SVMA (how
    558                could it be otherwise?)  So we add the appropriate bias
    559                on before pushing the result. */
    560             a1 = *(Addr*)expr;
    561             if (bias_address(&a1, di)) {
    562                PUSH( a1 );
    563                expr += sizeof(Addr);
    564             }
    565             else {
    566                FAIL("evaluate_Dwarf3_Expr: DW_OP_addr with address "
    567                     "in unknown section");
    568             }
    569             break;
    570          case DW_OP_fbreg:
    571             if (!fbGX)
    572                FAIL("evaluate_Dwarf3_Expr: DW_OP_fbreg with "
    573                     "no expr for fbreg present");
    574             fbval = ML_(evaluate_GX)(fbGX, NULL, regs, di);
    575             /* Convert fbval into something we can use.  If we got a
    576                Value, no problem.  However, as per D3 spec sec 3.3.5
    577                (Low Level Information) sec 2, we could also get a
    578                RegNo, and that is taken to mean the value in the
    579                indicated register.  So we have to manually
    580                "dereference" it. */
    581             a1 = 0;
    582             switch (fbval.kind) {
    583                case GXR_Failure:
    584                   return fbval; /* propagate failure */
    585                case GXR_Addr:
    586                   a1 = fbval.word; break; /* use as-is */
    587                case GXR_RegNo:
    588                   ok = get_Dwarf_Reg( &a1, fbval.word, regs );
    589                   if (!ok) return fbval; /* propagate failure */
    590                   break;
    591                case GXR_Value:
    592                   FAIL("evaluate_Dwarf3_Expr: DW_OP_{implicit,stack}_value "
    593                        "in DW_AT_frame_base");
    594                default:
    595                   vg_assert(0);
    596             }
    597             sw1 = (Word)read_leb128S( &expr );
    598             PUSH( a1 + sw1 );
    599             break;
    600          /* DW_OP_breg* denotes 'contents of specified register, plus
    601             constant offset'.  So provided we know what the register's
    602             value is, we can evaluate this.  Contrast DW_OP_reg*,
    603             which indicates that denoted location is in a register
    604             itself.  If DW_OP_reg* shows up here the expression is
    605             malformed, since we are evaluating for value now, and
    606             DW_OP_reg* denotes a register location, not a value.  See
    607             D3 Spec sec 2.6.1 ("Register Name Operations") for
    608             details. */
    609          case DW_OP_breg0 ... DW_OP_breg31:
    610             if (!regs)
    611                FAIL("evaluate_Dwarf3_Expr: DW_OP_breg* but no reg info");
    612             a1 = 0;
    613             if (!get_Dwarf_Reg( &a1, opcode - DW_OP_breg0, regs ))
    614                FAIL("evaluate_Dwarf3_Expr: unhandled DW_OP_breg*");
    615             sw1 = (Word)read_leb128S( &expr );
    616             a1 += sw1;
    617             PUSH( a1 );
    618             break;
    619          case DW_OP_bregx:
    620             if (!regs)
    621                FAIL("evaluate_Dwarf3_Expr: DW_OP_bregx but no reg info");
    622             a1 = 0;
    623             uw1 = (UWord)read_leb128U( &expr );
    624             if (!get_Dwarf_Reg( &a1, uw1, regs ))
    625                FAIL("evaluate_Dwarf3_Expr: unhandled DW_OP_bregx reg value");
    626             sw1 = (Word)read_leb128S( &expr );
    627             a1 += sw1;
    628             PUSH( a1 );
    629             break;
    630          /* As per comment on DW_OP_breg*, the following denote that
    631             the value in question is in a register, not in memory.  So
    632             we simply return failure. (iow, the expression is
    633             malformed). */
    634          case DW_OP_reg0 ... DW_OP_reg31:
    635          case DW_OP_regx:
    636             FAIL("evaluate_Dwarf3_Expr: DW_OP_reg* "
    637                  "whilst evaluating for a value");
    638             break;
    639          case DW_OP_plus_uconst:
    640             POP(uw1);
    641             uw1 += (UWord)read_leb128U( &expr );
    642             PUSH(uw1);
    643             break;
    644          case DW_OP_GNU_push_tls_address:
    645             /* GDB contains the following cryptic comment: */
    646             /* Variable is at a constant offset in the thread-local
    647             storage block into the objfile for the current thread and
    648             the dynamic linker module containing this expression. Here
    649             we return returns the offset from that base.  The top of the
    650             stack has the offset from the beginning of the thread
    651             control block at which the variable is located.  Nothing
    652             should follow this operator, so the top of stack would be
    653             returned.  */
    654             /* But no spec resulting from Googling.  Punt for now. */
    655             FAIL("warning: evaluate_Dwarf3_Expr: unhandled "
    656                  "DW_OP_GNU_push_tls_address");
    657             /*NOTREACHED*/
    658          case DW_OP_deref:
    659             POP(uw1);
    660             if (VG_(am_is_valid_for_client)( (Addr)uw1, sizeof(Addr),
    661                                              VKI_PROT_READ )) {
    662                uw1 = *(UWord*)uw1;
    663                PUSH(uw1);
    664             } else {
    665                FAIL("warning: evaluate_Dwarf3_Expr: DW_OP_deref: "
    666                     "address not valid for client");
    667             }
    668             break;
    669          case DW_OP_deref_size:
    670             POP(uw1);
    671             uw2 = *expr++;
    672             if (VG_(am_is_valid_for_client)( (Addr)uw1, uw2,
    673                                              VKI_PROT_READ )) {
    674                switch (uw2) {
    675                  case 1: uw1 = *(UChar*)uw1; break;
    676                  case 2: uw1 = *(UShort*)uw1; break;
    677                  case 4: uw1 = *(UInt*)uw1; break;
    678                  case 8: uw1 = *(ULong*)uw1; break;
    679                  default:
    680                     FAIL("warning: evaluate_Dwarf3_Expr: unhandled "
    681                          "DW_OP_deref_size size");
    682                }
    683                PUSH(uw1);
    684             } else {
    685                FAIL("warning: evaluate_Dwarf3_Expr: DW_OP_deref_size: "
    686                     "address not valid for client");
    687             }
    688             break;
    689          case DW_OP_lit0 ... DW_OP_lit31:
    690             PUSH(opcode - DW_OP_lit0);
    691             break;
    692          case DW_OP_const1u:
    693 	    uw1 = *expr++;
    694 	    PUSH(uw1);
    695             break;
    696          case DW_OP_const2u:
    697 	    uw1 = *(UShort *)expr;
    698 	    expr += 2;
    699 	    PUSH(uw1);
    700 	    break;
    701          case DW_OP_const4u:
    702 	    uw1 = *(UInt *)expr;
    703 	    expr += 4;
    704 	    PUSH(uw1);
    705 	    break;
    706          case DW_OP_const8u:
    707 	    uw1 = *(ULong *)expr;
    708 	    expr += 8;
    709 	    PUSH(uw1);
    710 	    break;
    711          case DW_OP_constu:
    712             uw1 = read_leb128U( &expr );
    713             PUSH(uw1);
    714             break;
    715          case DW_OP_const1s:
    716 	    uw1 = *(Char *)expr;
    717 	    expr++;
    718 	    PUSH(uw1);
    719             break;
    720          case DW_OP_const2s:
    721 	    uw1 = *(Short *)expr;
    722 	    expr += 2;
    723 	    PUSH(uw1);
    724 	    break;
    725          case DW_OP_const4s:
    726 	    uw1 = *(Int *)expr;
    727 	    expr += 4;
    728 	    PUSH(uw1);
    729 	    break;
    730          case DW_OP_const8s:
    731 	    uw1 = *(Long *)expr;
    732 	    expr += 8;
    733 	    PUSH(uw1);
    734 	    break;
    735          case DW_OP_consts:
    736             uw1 = read_leb128S( &expr );
    737             PUSH(uw1);
    738             break;
    739          case DW_OP_dup:
    740 	    POP(uw1);
    741 	    PUSH(uw1);
    742 	    PUSH(uw1);
    743 	    break;
    744 	 case DW_OP_drop:
    745 	    POP(uw1);
    746 	    break;
    747          case DW_OP_over:
    748             uw1 = 1;
    749             goto do_pick;
    750 	 case DW_OP_pick:
    751 	    uw1 = *expr++;
    752          do_pick:
    753             if (sp < (Int)uw1)
    754                FAIL("evaluate_Dwarf3_Expr: stack underflow");
    755             uw1 = stack[sp - uw1];
    756             PUSH(uw1);
    757             break;
    758          case DW_OP_swap:
    759             if (sp < 1)
    760                FAIL("evaluate_Dwarf3_Expr: stack underflow");
    761             uw1 = stack[sp];
    762             stack[sp] = stack[sp - 1];
    763             stack[sp - 1] = uw1;
    764             break;
    765          case DW_OP_rot:
    766             if (sp < 2)
    767                FAIL("evaluate_Dwarf3_Expr: stack underflow");
    768             uw1 = stack[sp];
    769             stack[sp] = stack[sp - 1];
    770             stack[sp - 1] = stack[sp - 2];
    771             stack[sp - 2] = uw1;
    772             break;
    773          case DW_OP_abs:
    774             POP(sw1);
    775             if (sw1 < 0)
    776                sw1 = -sw1;
    777             PUSH(sw1);
    778             break;
    779          case DW_OP_div:
    780             POP(sw2);
    781             if (sw2 == 0)
    782                FAIL("evaluate_Dwarf3_Expr: division by zero");
    783             POP(sw1);
    784             sw1 /= sw2;
    785             PUSH(sw1);
    786             break;
    787          case DW_OP_mod:
    788             POP(uw2);
    789             if (uw2 == 0)
    790                FAIL("evaluate_Dwarf3_Expr: division by zero");
    791             POP(uw1);
    792             uw1 %= uw2;
    793             PUSH(uw1);
    794             break;
    795 #define BINARY(name, op, s) \
    796          case DW_OP_##name:		\
    797             POP(s##w2);			\
    798             POP(s##w1);			\
    799             s##w1 = s##w1 op s##w2;	\
    800             PUSH(s##w1);		\
    801             break
    802 #define UNARY(name, op, s) \
    803          case DW_OP_##name:		\
    804             POP(s##w1);			\
    805             s##w1 = op s##w1;		\
    806             PUSH(s##w1);		\
    807             break
    808          BINARY (and, &, u);
    809          BINARY (minus, -, u);
    810          BINARY (mul, *, u);
    811          UNARY (neg, -, u);
    812          UNARY (not, ~, u);
    813          BINARY (or, |, u);
    814          BINARY (plus, +, u);
    815          BINARY (shl, <<, u);
    816          BINARY (shr, >>, u);
    817          BINARY (shra, >>, s);
    818          BINARY (xor, ^, u);
    819          BINARY (le, <=, s);
    820          BINARY (lt, <, s);
    821          BINARY (ge, >=, s);
    822          BINARY (gt, >, s);
    823          BINARY (ne, !=, u);
    824          BINARY (eq, ==, u);
    825 #undef UNARY
    826 #undef BINARY
    827          case DW_OP_skip:
    828             sw1 = *(Short *)expr;
    829             expr += 2;
    830             if (expr + sw1 < limit - exprszB)
    831                FAIL("evaluate_Dwarf3_Expr: DW_OP_skip before start of expr");
    832             if (expr + sw1 >= limit)
    833                FAIL("evaluate_Dwarf3_Expr: DW_OP_skip after end of expr");
    834             expr += sw1;
    835             break;
    836          case DW_OP_bra:
    837             sw1 = *(Short *)expr;
    838             expr += 2;
    839             if (expr + sw1 < limit - exprszB)
    840                FAIL("evaluate_Dwarf3_Expr: DW_OP_bra before start of expr");
    841             if (expr + sw1 >= limit)
    842                FAIL("evaluate_Dwarf3_Expr: DW_OP_bra after end of expr");
    843             POP(uw1);
    844             if (uw1)
    845                expr += sw1;
    846             break;
    847          case DW_OP_nop:
    848             break;
    849          case DW_OP_call_frame_cfa:
    850             if (!regs)
    851                FAIL("evaluate_Dwarf3_Expr: "
    852                     "DW_OP_call_frame_cfa but no reg info");
    853 #if defined(VGP_ppc32_linux) || defined(VGP_ppc64_linux)
    854             /* Valgrind on ppc32/ppc64 currently doesn't use unwind info. */
    855             uw1 = *(Addr *)(regs->sp);
    856 #else
    857             uw1 = ML_(get_CFA)(regs->ip, regs->sp, regs->fp, 0, ~(UWord) 0);
    858 #endif
    859             /* we expect this to fail on arm-linux, since ML_(get_CFA)
    860                always returns zero at present. */
    861             if (!uw1)
    862                FAIL("evaluate_Dwarf3_Expr: Could not resolve "
    863                     "DW_OP_call_frame_cfa");
    864             PUSH(uw1);
    865             break;
    866          case DW_OP_implicit_value:
    867             sw1 = (Word)read_leb128S( &expr );
    868             uw1 = 0;
    869             switch (sw1) {
    870                case 1:
    871                   uw1 = *(UChar *)expr;
    872                   expr += 1;
    873                   break;
    874                case 2:
    875                   uw1 = *(UShort *)expr;
    876                   expr += 2;
    877                   break;
    878                case 4:
    879                   uw1 = *(UInt *)expr;
    880                   expr += 4;
    881                   break;
    882                case 8:
    883                   uw1 = *(ULong *)expr;
    884                   expr += 8;
    885                   break;
    886                default:
    887                   FAIL("evaluate_Dwarf3_Expr: Unhandled "
    888                        "DW_OP_implicit_value size");
    889             }
    890             if (expr != limit)
    891                FAIL("evaluate_Dwarf3_Expr: DW_OP_implicit_value "
    892                     "does not terminate expression");
    893             res.word = uw1;
    894             res.kind = GXR_Value;
    895             return res;
    896          case DW_OP_stack_value:
    897             POP (uw1);
    898             res.word = uw1;
    899             res.kind = GXR_Value;
    900             if (expr != limit)
    901                FAIL("evaluate_Dwarf3_Expr: DW_OP_stack_value "
    902                     "does not terminate expression");
    903             break;
    904          default:
    905             if (!VG_(clo_xml))
    906                VG_(message)(Vg_DebugMsg,
    907                             "warning: evaluate_Dwarf3_Expr: unhandled "
    908                             "DW_OP_ 0x%x\n", (Int)opcode);
    909             FAIL("evaluate_Dwarf3_Expr: unhandled DW_OP_");
    910             /*NOTREACHED*/
    911       }
    912 
    913    }
    914 
    915    vg_assert(sp >= 0 && sp < N_EXPR_STACK);
    916    res.word = stack[sp];
    917    res.kind = GXR_Addr;
    918    return res;
    919 
    920 #  undef POP
    921 #  undef PUSH
    922 #  undef FAIL
    923 #  undef N_EXPR_STACK
    924 }
    925 
    926 
    927 /* Evaluate a so-called Guarded (DWARF3) expression.  See detailed
    928    description in priv_d3basics.h. */
    929 GXResult ML_(evaluate_GX)( GExpr* gx, GExpr* fbGX,
    930                            RegSummary* regs, const DebugInfo* di )
    931 {
    932    GXResult res;
    933    Addr     aMin, aMax;
    934    UChar    uc;
    935    UShort   nbytes;
    936    UWord    nGuards = 0;
    937    UChar* p = &gx->payload[0];
    938    uc = *p++; /*biasMe*/
    939    vg_assert(uc == 0 || uc == 1);
    940    /* in fact it's senseless to evaluate if the guards need biasing.
    941       So don't. */
    942    vg_assert(uc == 0);
    943    while (True) {
    944       uc = *p++;
    945       if (uc == 1) { /*isEnd*/
    946          /* didn't find any matching range. */
    947          res.kind = GXR_Failure;
    948          res.word = (UWord)"no matching range";
    949          return res;
    950       }
    951       vg_assert(uc == 0);
    952       aMin   = * (Addr*)p;   p += sizeof(Addr);
    953       aMax   = * (Addr*)p;   p += sizeof(Addr);
    954       nbytes = * (UShort*)p; p += sizeof(UShort);
    955       nGuards++;
    956       if (0) VG_(printf)("           guard %d: %#lx %#lx\n",
    957                          (Int)nGuards, aMin,aMax);
    958       if (regs == NULL) {
    959          vg_assert(aMin == (Addr)0);
    960          vg_assert(aMax == ~(Addr)0);
    961          /* Assert this is the first guard. */
    962          vg_assert(nGuards == 1);
    963          res = ML_(evaluate_Dwarf3_Expr)(
    964                   p, (UWord)nbytes, fbGX, regs, di,
    965                   False/*push_initial_zero*/ );
    966          /* Now check there are no more guards. */
    967          p += (UWord)nbytes;
    968          vg_assert(*p == 1); /*isEnd*/
    969          return res;
    970       } else {
    971          if (aMin <= regs->ip && regs->ip <= aMax) {
    972             /* found a matching range.  Evaluate the expression. */
    973             return ML_(evaluate_Dwarf3_Expr)(
    974                       p, (UWord)nbytes, fbGX, regs, di,
    975                       False/*push_initial_zero*/ );
    976          }
    977       }
    978       /* else keep searching */
    979       p += (UWord)nbytes;
    980    }
    981 }
    982 
    983 
    984 /* Evaluate a very simple Guarded (DWARF3) expression.  The expression
    985    is expected to denote a constant, with no reference to any
    986    registers nor to any frame base expression.  The expression is
    987    expected to have at least one guard.  If there is more than one
    988    guard, all the sub-expressions are evaluated and compared.  The
    989    address ranges on the guards are ignored.  GXR_Failure is returned
    990    in the following circumstances:
    991    * no guards
    992    * any of the subexpressions require a frame base expression
    993    * any of the subexpressions denote a register location
    994    * any of the subexpressions do not produce a manifest constant
    995    * there's more than one subexpression, all of which successfully
    996      evaluate to a constant, but they don't all produce the same constant.
    997    JRS 23Jan09: the special-casing in this function is a nasty kludge.
    998    Really it ought to be pulled out and turned into a general
    999    constant- expression evaluator.
   1000 */
   1001 GXResult ML_(evaluate_trivial_GX)( GExpr* gx, const DebugInfo* di )
   1002 {
   1003    GXResult   res;
   1004    Addr       aMin, aMax;
   1005    UChar      uc;
   1006    UShort     nbytes;
   1007    Word       i, nGuards;
   1008    MaybeULong *mul, *mul2;
   1009 
   1010    HChar*  badness = NULL;
   1011    UChar*  p       = &gx->payload[0]; /* must remain unsigned */
   1012    XArray* results = VG_(newXA)( ML_(dinfo_zalloc), "di.d3basics.etG.1",
   1013                                  ML_(dinfo_free),
   1014                                  sizeof(MaybeULong) );
   1015 
   1016    uc = *p++; /*biasMe*/
   1017    vg_assert(uc == 0 || uc == 1);
   1018    /* in fact it's senseless to evaluate if the guards need biasing.
   1019       So don't. */
   1020    vg_assert(uc == 0);
   1021 
   1022    nGuards = 0;
   1023    while (True) {
   1024       MaybeULong thisResult;
   1025       uc = *p++;
   1026       if (uc == 1) /*isEnd*/
   1027          break;
   1028       vg_assert(uc == 0);
   1029       aMin   = * (Addr*)p;   p += sizeof(Addr);
   1030       aMax   = * (Addr*)p;   p += sizeof(Addr);
   1031       nbytes = * (UShort*)p; p += sizeof(UShort);
   1032       nGuards++;
   1033       if (0) VG_(printf)("           guard %ld: %#lx %#lx\n",
   1034                          nGuards, aMin,aMax);
   1035 
   1036       thisResult.b  = False;
   1037       thisResult.ul = 0;
   1038 
   1039       /* Peer at this particular subexpression, to see if it's
   1040          obviously a constant. */
   1041       if (nbytes == 1 + sizeof(Addr) && *p == DW_OP_addr) {
   1042          /* DW_OP_addr a */
   1043          Addr a = *(Addr*)(p+1);
   1044          if (bias_address(&a, di)) {
   1045             thisResult.b = True;
   1046             thisResult.ul = (ULong)a;
   1047          } else {
   1048             if (!badness)
   1049                badness = "trivial GExpr denotes constant address "
   1050                          "in unknown section (1)";
   1051          }
   1052       }
   1053       else
   1054       if (nbytes == 1 + sizeof(Addr) + 1 + 1
   1055           /* 11 byte block: 3 c0 b6 2b 0 0 0 0 0 23 4
   1056              (DW_OP_addr: 2bb6c0; DW_OP_plus_uconst: 4)
   1057              This is really a nasty kludge - only matches if the
   1058              trailing ULEB denotes a number in the range 0 .. 127
   1059              inclusive. */
   1060           && p[0] == DW_OP_addr
   1061           && p[1 + sizeof(Addr)] == DW_OP_plus_uconst
   1062           && p[1 + sizeof(Addr) + 1] < 0x80 /*1-byte ULEB*/) {
   1063          Addr a = *(Addr*)&p[1];
   1064          if (bias_address(&a, di)) {
   1065             thisResult.b = True;
   1066             thisResult.ul = (ULong)a + (ULong)p[1 + sizeof(Addr) + 1];
   1067          } else {
   1068             if (!badness)
   1069                badness = "trivial GExpr denotes constant address "
   1070                          "in unknown section (2)";
   1071          }
   1072       }
   1073       else
   1074       if (nbytes == 2 + sizeof(Addr)
   1075           && *p == DW_OP_addr
   1076           && *(p + 1 + sizeof(Addr)) == DW_OP_GNU_push_tls_address) {
   1077          if (!badness)
   1078             badness = "trivial GExpr is DW_OP_addr plus trailing junk";
   1079       }
   1080       else if (nbytes >= 1 && *p >= DW_OP_reg0 && *p <= DW_OP_reg31) {
   1081          if (!badness)
   1082             badness = "trivial GExpr denotes register (1)";
   1083       }
   1084       else if (nbytes >= 1 && *p == DW_OP_fbreg) {
   1085          if (!badness)
   1086             badness = "trivial GExpr requires fbGX";
   1087       }
   1088       else if (nbytes >= 1 && *p >= DW_OP_breg0 && *p <= DW_OP_breg31) {
   1089          if (!badness)
   1090             badness = "trivial GExpr requires register value";
   1091       }
   1092       else if (nbytes >= 1 && *p == DW_OP_regx) {
   1093          if (!badness)
   1094             badness = "trivial GExpr denotes register (2)";
   1095       }
   1096       else if (0) {
   1097          VG_(printf)(" ML_(evaluate_trivial_GX): unhandled:\n   ");
   1098          ML_(pp_GX)( gx );
   1099          VG_(printf)("\n");
   1100          tl_assert(0);
   1101       }
   1102       else
   1103          if (!badness)
   1104             badness = "non-trivial GExpr";
   1105 
   1106       VG_(addToXA)( results, &thisResult );
   1107 
   1108       p += (UWord)nbytes;
   1109    }
   1110 
   1111    res.kind = GXR_Failure;
   1112 
   1113    tl_assert(nGuards == VG_(sizeXA)( results ));
   1114    tl_assert(nGuards >= 0);
   1115    if (nGuards == 0) {
   1116       tl_assert(!badness);
   1117       res.word = (UWord)"trivial GExpr has no guards (!)";
   1118       VG_(deleteXA)( results );
   1119       return res;
   1120    }
   1121 
   1122    for (i = 0; i < nGuards; i++) {
   1123       mul = VG_(indexXA)( results, i );
   1124       if (mul->b == False)
   1125          break;
   1126    }
   1127 
   1128    vg_assert(i >= 0 && i <= nGuards);
   1129    if (i < nGuards) {
   1130       /* at least one subexpression failed to produce a manifest constant. */
   1131       vg_assert(badness);
   1132       res.word = (UWord)badness;
   1133       VG_(deleteXA)( results );
   1134       return res;
   1135    }
   1136 
   1137    /* All the subexpressions produced a constant, but did they all produce
   1138       the same one? */
   1139    mul = VG_(indexXA)( results, 0 );
   1140    tl_assert(mul->b == True); /* we just established that all exprs are ok */
   1141 
   1142    for (i = 1; i < nGuards; i++) {
   1143       mul2 = VG_(indexXA)( results, i );
   1144       tl_assert(mul2->b == True);
   1145       if (mul2->ul != mul->ul) {
   1146          res.word = (UWord)"trivial GExpr: subexpressions disagree";
   1147          VG_(deleteXA)( results );
   1148          return res;
   1149       }
   1150    }
   1151 
   1152    /* Well, we have success.  All subexpressions evaluated, and
   1153       they all agree.  Hurrah. */
   1154    res.kind = GXR_Addr;
   1155    res.word = (UWord)mul->ul; /* NB: narrowing from ULong */
   1156    VG_(deleteXA)( results );
   1157    return res;
   1158 }
   1159 
   1160 
   1161 void ML_(pp_GXResult) ( GXResult res )
   1162 {
   1163    switch (res.kind) {
   1164       case GXR_Failure:
   1165          VG_(printf)("GXR_Failure(%s)", (HChar*)res.word); break;
   1166       case GXR_Addr:
   1167          VG_(printf)("GXR_Addr(0x%lx)", res.word); break;
   1168       case GXR_Value:
   1169          VG_(printf)("GXR_Value(0x%lx)", res.word); break;
   1170       case GXR_RegNo:
   1171          VG_(printf)("GXR_RegNo(%lu)", res.word); break;
   1172       default:
   1173          VG_(printf)("GXR_???"); break;
   1174    }
   1175 }
   1176 
   1177 
   1178 void ML_(pp_GX) ( GExpr* gx ) {
   1179    Addr   aMin, aMax;
   1180    UChar  uc;
   1181    UShort nbytes;
   1182    UChar* p = &gx->payload[0];
   1183    uc = *p++;
   1184    VG_(printf)("GX(%s){", uc == 0 ? "final" : "Breqd" );
   1185    vg_assert(uc == 0 || uc == 1);
   1186    while (True) {
   1187       uc = *p++;
   1188       if (uc == 1)
   1189          break; /*isEnd*/
   1190       vg_assert(uc == 0);
   1191       aMin   = * (Addr*)p;  p += sizeof(Addr);
   1192       aMax   = * (Addr*)p;  p += sizeof(Addr);
   1193       nbytes = * (UShort*)p; p += sizeof(UShort);
   1194       VG_(printf)("[%#lx,%#lx]=", aMin, aMax);
   1195       while (nbytes > 0) {
   1196          VG_(printf)("%02x", (UInt)*p++);
   1197          nbytes--;
   1198       }
   1199       if (*p == 0)
   1200          VG_(printf)(",");
   1201    }
   1202    VG_(printf)("}");
   1203 }
   1204 
   1205 
   1206 /*--------------------------------------------------------------------*/
   1207 /*--- end                                               d3basics.c ---*/
   1208 /*--------------------------------------------------------------------*/
   1209