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) 2008-2013 OpenWorks LLP
12       info@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_libcbase.h"
42 #include "pub_core_options.h"
43 #include "pub_core_xarray.h"
44 
45 #include "pub_core_vki.h"       /* VKI_PROT_READ */
46 #include "pub_core_aspacemgr.h" /* VG_(is_valid_for_client) */
47 
48 #include "priv_misc.h"
49 #include "priv_image.h"
50 #include "priv_d3basics.h"      /* self */
51 #include "priv_storage.h"
52 
ML_(pp_DW_children)53 const HChar* ML_(pp_DW_children) ( DW_children hashch )
54 {
55    switch (hashch) {
56       case DW_children_no:  return "no children";
57       case DW_children_yes: return "has children";
58    }
59    return "DW_children_???";
60 }
61 
ML_(pp_DW_TAG)62 const HChar* ML_(pp_DW_TAG) ( DW_TAG tag )
63 {
64    switch (tag) {
65       case DW_TAG_padding:            return "DW_TAG_padding";
66       case DW_TAG_array_type:         return "DW_TAG_array_type";
67       case DW_TAG_class_type:         return "DW_TAG_class_type";
68       case DW_TAG_entry_point:        return "DW_TAG_entry_point";
69       case DW_TAG_enumeration_type:   return "DW_TAG_enumeration_type";
70       case DW_TAG_formal_parameter:   return "DW_TAG_formal_parameter";
71       case DW_TAG_imported_declaration:
72          return "DW_TAG_imported_declaration";
73       case DW_TAG_label:              return "DW_TAG_label";
74       case DW_TAG_lexical_block:      return "DW_TAG_lexical_block";
75       case DW_TAG_member:             return "DW_TAG_member";
76       case DW_TAG_pointer_type:       return "DW_TAG_pointer_type";
77       case DW_TAG_reference_type:     return "DW_TAG_reference_type";
78       case DW_TAG_compile_unit:       return "DW_TAG_compile_unit";
79       case DW_TAG_string_type:        return "DW_TAG_string_type";
80       case DW_TAG_structure_type:     return "DW_TAG_structure_type";
81       case DW_TAG_subroutine_type:    return "DW_TAG_subroutine_type";
82       case DW_TAG_typedef:            return "DW_TAG_typedef";
83       case DW_TAG_union_type:         return "DW_TAG_union_type";
84       case DW_TAG_unspecified_parameters:
85          return "DW_TAG_unspecified_parameters";
86       case DW_TAG_variant:            return "DW_TAG_variant";
87       case DW_TAG_common_block:       return "DW_TAG_common_block";
88       case DW_TAG_common_inclusion:   return "DW_TAG_common_inclusion";
89       case DW_TAG_inheritance:        return "DW_TAG_inheritance";
90       case DW_TAG_inlined_subroutine:
91          return "DW_TAG_inlined_subroutine";
92       case DW_TAG_module:             return "DW_TAG_module";
93       case DW_TAG_ptr_to_member_type: return "DW_TAG_ptr_to_member_type";
94       case DW_TAG_set_type:           return "DW_TAG_set_type";
95       case DW_TAG_subrange_type:      return "DW_TAG_subrange_type";
96       case DW_TAG_with_stmt:          return "DW_TAG_with_stmt";
97       case DW_TAG_access_declaration: return "DW_TAG_access_declaration";
98       case DW_TAG_base_type:          return "DW_TAG_base_type";
99       case DW_TAG_catch_block:        return "DW_TAG_catch_block";
100       case DW_TAG_const_type:         return "DW_TAG_const_type";
101       case DW_TAG_constant:           return "DW_TAG_constant";
102       case DW_TAG_enumerator:         return "DW_TAG_enumerator";
103       case DW_TAG_file_type:          return "DW_TAG_file_type";
104       case DW_TAG_friend:             return "DW_TAG_friend";
105       case DW_TAG_namelist:           return "DW_TAG_namelist";
106       case DW_TAG_namelist_item:      return "DW_TAG_namelist_item";
107       case DW_TAG_packed_type:        return "DW_TAG_packed_type";
108       case DW_TAG_subprogram:         return "DW_TAG_subprogram";
109       case DW_TAG_template_type_param:
110          return "DW_TAG_template_type_param";
111       case DW_TAG_template_value_param:
112          return "DW_TAG_template_value_param";
113       case DW_TAG_thrown_type:        return "DW_TAG_thrown_type";
114       case DW_TAG_try_block:          return "DW_TAG_try_block";
115       case DW_TAG_variant_part:       return "DW_TAG_variant_part";
116       case DW_TAG_variable:           return "DW_TAG_variable";
117       case DW_TAG_volatile_type:      return "DW_TAG_volatile_type";
118       /* DWARF 3.  */
119       case DW_TAG_dwarf_procedure:    return "DW_TAG_dwarf_procedure";
120       case DW_TAG_restrict_type:      return "DW_TAG_restrict_type";
121       case DW_TAG_interface_type:     return "DW_TAG_interface_type";
122       case DW_TAG_namespace:          return "DW_TAG_namespace";
123       case DW_TAG_imported_module:    return "DW_TAG_imported_module";
124       case DW_TAG_unspecified_type:   return "DW_TAG_unspecified_type";
125       case DW_TAG_partial_unit:       return "DW_TAG_partial_unit";
126       case DW_TAG_imported_unit:      return "DW_TAG_imported_unit";
127       case DW_TAG_condition:          return "DW_TAG_condition";
128       case DW_TAG_shared_type:        return "DW_TAG_shared_type";
129       /* DWARF 4.  */
130       case DW_TAG_type_unit:          return "DW_TAG_type_unit";
131       case DW_TAG_rvalue_reference_type: return "DW_TAG_rvalue_reference_type";
132       case DW_TAG_template_alias:     return "DW_TAG_template_alias";
133       /* SGI/MIPS Extensions.  */
134       case DW_TAG_MIPS_loop:          return "DW_TAG_MIPS_loop";
135       /* HP extensions.  See:
136          ftp://ftp.hp.com/pub/lang/tools/WDB/wdb-4.0.tar.gz .  */
137       case DW_TAG_HP_array_descriptor:
138          return "DW_TAG_HP_array_descriptor";
139       /* GNU extensions.  */
140       case DW_TAG_format_label:       return "DW_TAG_format_label";
141       case DW_TAG_function_template:  return "DW_TAG_function_template";
142       case DW_TAG_class_template:     return "DW_TAG_class_template";
143       case DW_TAG_GNU_BINCL:          return "DW_TAG_GNU_BINCL";
144       case DW_TAG_GNU_EINCL:          return "DW_TAG_GNU_EINCL";
145       /* Extensions for UPC.  See: http://upc.gwu.edu/~upc.  */
146       case DW_TAG_upc_shared_type:    return "DW_TAG_upc_shared_type";
147       case DW_TAG_upc_strict_type:    return "DW_TAG_upc_strict_type";
148       case DW_TAG_upc_relaxed_type:   return "DW_TAG_upc_relaxed_type";
149       /* PGI (STMicroelectronics) extensions.  No documentation available.  */
150       case DW_TAG_PGI_kanji_type:     return "DW_TAG_PGI_kanji_type";
151       case DW_TAG_PGI_interface_block:
152          return "DW_TAG_PGI_interface_block";
153    }
154    return "DW_TAG_???";
155 }
156 
ML_(pp_DW_FORM)157 const HChar* ML_(pp_DW_FORM) ( DW_FORM form )
158 {
159    switch (form) {
160       case DW_FORM_addr:      return "DW_FORM_addr";
161       case DW_FORM_block2:    return "DW_FORM_block2";
162       case DW_FORM_block4:    return "DW_FORM_block4";
163       case DW_FORM_data2:     return "DW_FORM_data2";
164       case DW_FORM_data4:     return "DW_FORM_data4";
165       case DW_FORM_data8:     return "DW_FORM_data8";
166       case DW_FORM_string:    return "DW_FORM_string";
167       case DW_FORM_block:     return "DW_FORM_block";
168       case DW_FORM_block1:    return "DW_FORM_block1";
169       case DW_FORM_data1:     return "DW_FORM_data1";
170       case DW_FORM_flag:      return "DW_FORM_flag";
171       case DW_FORM_sdata:     return "DW_FORM_sdata";
172       case DW_FORM_strp:      return "DW_FORM_strp";
173       case DW_FORM_udata:     return "DW_FORM_udata";
174       case DW_FORM_ref_addr:  return "DW_FORM_ref_addr";
175       case DW_FORM_ref1:      return "DW_FORM_ref1";
176       case DW_FORM_ref2:      return "DW_FORM_ref2";
177       case DW_FORM_ref4:      return "DW_FORM_ref4";
178       case DW_FORM_ref8:      return "DW_FORM_ref8";
179       case DW_FORM_ref_udata: return "DW_FORM_ref_udata";
180       case DW_FORM_indirect:  return "DW_FORM_indirect";
181       case DW_FORM_sec_offset:return "DW_FORM_sec_offset";
182       case DW_FORM_exprloc:   return "DW_FORM_exprloc";
183       case DW_FORM_flag_present:return "DW_FORM_flag_present";
184       case DW_FORM_ref_sig8:  return "DW_FORM_ref_sig8";
185       case DW_FORM_GNU_ref_alt:return "DW_FORM_GNU_ref_alt";
186       case DW_FORM_GNU_strp_alt:return "DW_FORM_GNU_strp_alt";
187    }
188    return "DW_FORM_???";
189 }
190 
ML_(pp_DW_AT)191 const HChar* ML_(pp_DW_AT) ( DW_AT attr )
192 {
193    switch (attr) {
194       case DW_AT_sibling:             return "DW_AT_sibling";
195       case DW_AT_location:            return "DW_AT_location";
196       case DW_AT_name: return "DW_AT_name";
197       case DW_AT_ordering: return "DW_AT_ordering";
198       case DW_AT_subscr_data: return "DW_AT_subscr_data";
199       case DW_AT_byte_size: return "DW_AT_byte_size";
200       case DW_AT_bit_offset: return "DW_AT_bit_offset";
201       case DW_AT_bit_size: return "DW_AT_bit_size";
202       case DW_AT_element_list: return "DW_AT_element_list";
203       case DW_AT_stmt_list: return "DW_AT_stmt_list";
204       case DW_AT_low_pc: return "DW_AT_low_pc";
205       case DW_AT_high_pc: return "DW_AT_high_pc";
206       case DW_AT_language: return "DW_AT_language";
207       case DW_AT_member: return "DW_AT_member";
208       case DW_AT_discr: return "DW_AT_discr";
209       case DW_AT_discr_value: return "DW_AT_discr_value";
210       case DW_AT_visibility: return "DW_AT_visibility";
211       case DW_AT_import: return "DW_AT_import";
212       case DW_AT_string_length: return "DW_AT_string_length";
213       case DW_AT_common_reference: return "DW_AT_common_reference";
214       case DW_AT_comp_dir: return "DW_AT_comp_dir";
215       case DW_AT_const_value: return "DW_AT_const_value";
216       case DW_AT_containing_type: return "DW_AT_containing_type";
217       case DW_AT_default_value: return "DW_AT_default_value";
218       case DW_AT_inline: return "DW_AT_inline";
219       case DW_AT_is_optional: return "DW_AT_is_optional";
220       case DW_AT_lower_bound: return "DW_AT_lower_bound";
221       case DW_AT_producer: return "DW_AT_producer";
222       case DW_AT_prototyped: return "DW_AT_prototyped";
223       case DW_AT_return_addr: return "DW_AT_return_addr";
224       case DW_AT_start_scope: return "DW_AT_start_scope";
225       case DW_AT_stride_size: return "DW_AT_stride_size";
226       case DW_AT_upper_bound: return "DW_AT_upper_bound";
227       case DW_AT_abstract_origin: return "DW_AT_abstract_origin";
228       case DW_AT_accessibility: return "DW_AT_accessibility";
229       case DW_AT_address_class: return "DW_AT_address_class";
230       case DW_AT_artificial: return "DW_AT_artificial";
231       case DW_AT_base_types: return "DW_AT_base_types";
232       case DW_AT_calling_convention: return "DW_AT_calling_convention";
233       case DW_AT_count: return "DW_AT_count";
234       case DW_AT_data_member_location: return "DW_AT_data_member_location";
235       case DW_AT_decl_column: return "DW_AT_decl_column";
236       case DW_AT_decl_file: return "DW_AT_decl_file";
237       case DW_AT_decl_line: return "DW_AT_decl_line";
238       case DW_AT_declaration: return "DW_AT_declaration";
239       case DW_AT_discr_list: return "DW_AT_discr_list";
240       case DW_AT_encoding: return "DW_AT_encoding";
241       case DW_AT_external: return "DW_AT_external";
242       case DW_AT_frame_base: return "DW_AT_frame_base";
243       case DW_AT_friend: return "DW_AT_friend";
244       case DW_AT_identifier_case: return "DW_AT_identifier_case";
245       case DW_AT_macro_info: return "DW_AT_macro_info";
246       case DW_AT_namelist_items: return "DW_AT_namelist_items";
247       case DW_AT_priority: return "DW_AT_priority";
248       case DW_AT_segment: return "DW_AT_segment";
249       case DW_AT_specification: return "DW_AT_specification";
250       case DW_AT_static_link: return "DW_AT_static_link";
251       case DW_AT_type: return "DW_AT_type";
252       case DW_AT_use_location: return "DW_AT_use_location";
253       case DW_AT_variable_parameter: return "DW_AT_variable_parameter";
254       case DW_AT_virtuality: return "DW_AT_virtuality";
255       case DW_AT_vtable_elem_location: return "DW_AT_vtable_elem_location";
256       /* DWARF 3 values.  */
257       case DW_AT_allocated: return "DW_AT_allocated";
258       case DW_AT_associated: return "DW_AT_associated";
259       case DW_AT_data_location: return "DW_AT_data_location";
260       case DW_AT_stride: return "DW_AT_stride";
261       case DW_AT_entry_pc: return "DW_AT_entry_pc";
262       case DW_AT_use_UTF8: return "DW_AT_use_UTF8";
263       case DW_AT_extension: return "DW_AT_extension";
264       case DW_AT_ranges: return "DW_AT_ranges";
265       case DW_AT_trampoline: return "DW_AT_trampoline";
266       case DW_AT_call_column: return "DW_AT_call_column";
267       case DW_AT_call_file: return "DW_AT_call_file";
268       case DW_AT_call_line: return "DW_AT_call_line";
269       case DW_AT_description: return "DW_AT_description";
270       case DW_AT_binary_scale: return "DW_AT_binary_scale";
271       case DW_AT_decimal_scale: return "DW_AT_decimal_scale";
272       case DW_AT_small: return "DW_AT_small";
273       case DW_AT_decimal_sign: return "DW_AT_decimal_sign";
274       case DW_AT_digit_count: return "DW_AT_digit_count";
275       case DW_AT_picture_string: return "DW_AT_picture_string";
276       case DW_AT_mutable: return "DW_AT_mutable";
277       case DW_AT_threads_scaled: return "DW_AT_threads_scaled";
278       case DW_AT_explicit: return "DW_AT_explicit";
279       case DW_AT_object_pointer: return "DW_AT_object_pointer";
280       case DW_AT_endianity: return "DW_AT_endianity";
281       case DW_AT_elemental: return "DW_AT_elemental";
282       case DW_AT_pure: return "DW_AT_pure";
283       case DW_AT_recursive: return "DW_AT_recursive";
284       /* DWARF 4 values.  */
285       case DW_AT_signature: return "DW_AT_signature";
286       case DW_AT_main_subprogram: return "DW_AT_main_subprogram";
287       case DW_AT_data_bit_offset: return "DW_AT_data_bit_offset";
288       case DW_AT_const_expr: return "DW_AT_const_expr";
289       case DW_AT_enum_class: return "DW_AT_enum_class";
290       case DW_AT_linkage_name: return "DW_AT_linkage_name";
291       /* SGI/MIPS extensions.  */
292       /* case DW_AT_MIPS_fde: return "DW_AT_MIPS_fde"; */
293       /* DW_AT_MIPS_fde == DW_AT_HP_unmodifiable */
294       case DW_AT_MIPS_loop_begin: return "DW_AT_MIPS_loop_begin";
295       case DW_AT_MIPS_tail_loop_begin: return "DW_AT_MIPS_tail_loop_begin";
296       case DW_AT_MIPS_epilog_begin: return "DW_AT_MIPS_epilog_begin";
297       case DW_AT_MIPS_loop_unroll_factor: return "DW_AT_MIPS_loop_unroll_factor";
298       case DW_AT_MIPS_software_pipeline_depth: return "DW_AT_MIPS_software_pipeline_depth";
299       case DW_AT_MIPS_linkage_name: return "DW_AT_MIPS_linkage_name";
300       case DW_AT_MIPS_stride: return "DW_AT_MIPS_stride";
301       case DW_AT_MIPS_abstract_name: return "DW_AT_MIPS_abstract_name";
302       case DW_AT_MIPS_clone_origin: return "DW_AT_MIPS_clone_origin";
303       case DW_AT_MIPS_has_inlines: return "DW_AT_MIPS_has_inlines";
304       /* HP extensions.  */
305       case DW_AT_HP_block_index: return "DW_AT_HP_block_index";
306       case DW_AT_HP_unmodifiable: return "DW_AT_HP_unmodifiable";
307       case DW_AT_HP_actuals_stmt_list: return "DW_AT_HP_actuals_stmt_list";
308       case DW_AT_HP_proc_per_section: return "DW_AT_HP_proc_per_section";
309       case DW_AT_HP_raw_data_ptr: return "DW_AT_HP_raw_data_ptr";
310       case DW_AT_HP_pass_by_reference: return "DW_AT_HP_pass_by_reference";
311       case DW_AT_HP_opt_level: return "DW_AT_HP_opt_level";
312       case DW_AT_HP_prof_version_id: return "DW_AT_HP_prof_version_id";
313       case DW_AT_HP_opt_flags: return "DW_AT_HP_opt_flags";
314       case DW_AT_HP_cold_region_low_pc: return "DW_AT_HP_cold_region_low_pc";
315       case DW_AT_HP_cold_region_high_pc: return "DW_AT_HP_cold_region_high_pc";
316       case DW_AT_HP_all_variables_modifiable: return "DW_AT_HP_all_variables_modifiable";
317       case DW_AT_HP_linkage_name: return "DW_AT_HP_linkage_name";
318       case DW_AT_HP_prof_flags: return "DW_AT_HP_prof_flags";
319       /* GNU extensions.  */
320       case DW_AT_sf_names: return "DW_AT_sf_names";
321       case DW_AT_src_info: return "DW_AT_src_info";
322       case DW_AT_mac_info: return "DW_AT_mac_info";
323       case DW_AT_src_coords: return "DW_AT_src_coords";
324       case DW_AT_body_begin: return "DW_AT_body_begin";
325       case DW_AT_body_end: return "DW_AT_body_end";
326       case DW_AT_GNU_vector: return "DW_AT_GNU_vector";
327       case DW_AT_GNU_all_tail_call_sites: return "DW_AT_GNU_all_tail_call_sites";
328       case DW_AT_GNU_all_call_sites: return "DW_AT_GNU_all_call_sites";
329       /* VMS extensions.  */
330       case DW_AT_VMS_rtnbeg_pd_address: return "DW_AT_VMS_rtnbeg_pd_address";
331       /* UPC extension.  */
332       case DW_AT_upc_threads_scaled: return "DW_AT_upc_threads_scaled";
333       /* PGI (STMicroelectronics) extensions.  */
334       case DW_AT_PGI_lbase: return "DW_AT_PGI_lbase";
335       case DW_AT_PGI_soffset: return "DW_AT_PGI_soffset";
336       case DW_AT_PGI_lstride: return "DW_AT_PGI_lstride";
337    }
338    return "DW_AT_???";
339 }
340 
341 
342 /* ------ To do with evaluation of Dwarf expressions ------ */
343 
344 /* FIXME: duplicated in readdwarf.c */
345 static
read_leb128(const UChar * data,Int * length_return,Int sign)346 ULong read_leb128 ( const UChar* data, Int* length_return, Int sign )
347 {
348   ULong  result = 0;
349   UInt   num_read = 0;
350   Int    shift = 0;
351   UChar  byte;
352 
353   vg_assert(sign == 0 || sign == 1);
354 
355   do
356     {
357       byte = * data ++;
358       num_read ++;
359 
360       result |= ((ULong)(byte & 0x7f)) << shift;
361 
362       shift += 7;
363 
364     }
365   while (byte & 0x80);
366 
367   if (length_return != NULL)
368     * length_return = num_read;
369 
370   if (sign && (shift < 64) && (byte & 0x40))
371     result |= -(1ULL << shift);
372 
373   return result;
374 }
375 
376 /* Small helper functions easier to use
377  * value is returned and the given pointer is
378  * moved past end of leb128 data */
379 /* FIXME: duplicated in readdwarf.c */
read_leb128U(const UChar ** data)380 static ULong read_leb128U( const UChar **data )
381 {
382   Int len;
383   ULong val = read_leb128( *data, &len, 0 );
384   *data += len;
385   return val;
386 }
387 
388 /* Same for signed data */
389 /* FIXME: duplicated in readdwarf.c */
read_leb128S(const UChar ** data)390 static Long read_leb128S( const UChar **data )
391 {
392    Int len;
393    ULong val = read_leb128( *data, &len, 1 );
394    *data += len;
395    return (Long)val;
396 }
397 
398 /* FIXME: duplicates logic in readdwarf.c: copy_convert_CfiExpr_tree
399    and {FP,SP}_REG decls */
get_Dwarf_Reg(Addr * a,Word regno,const RegSummary * regs)400 static Bool get_Dwarf_Reg( /*OUT*/Addr* a, Word regno, const RegSummary* regs )
401 {
402    vg_assert(regs);
403 #  if defined(VGP_x86_linux) || defined(VGP_x86_darwin)
404    if (regno == 5/*EBP*/) { *a = regs->fp; return True; }
405    if (regno == 4/*ESP*/) { *a = regs->sp; return True; }
406 #  elif defined(VGP_amd64_linux) || defined(VGP_amd64_darwin)
407    if (regno == 6/*RBP*/) { *a = regs->fp; return True; }
408    if (regno == 7/*RSP*/) { *a = regs->sp; return True; }
409 #  elif defined(VGP_ppc32_linux)
410    if (regno == 1/*SP*/) { *a = regs->sp; return True; }
411 #  elif defined(VGP_ppc64be_linux) || defined(VGP_ppc64le_linux)
412    if (regno == 1/*SP*/) { *a = regs->sp; return True; }
413 #  elif defined(VGP_arm_linux)
414    if (regno == 13) { *a = regs->sp; return True; }
415    if (regno == 11) { *a = regs->fp; return True; }
416 #  elif defined(VGP_s390x_linux)
417    if (regno == 15) { *a = regs->sp; return True; }
418    if (regno == 11) { *a = regs->fp; return True; }
419 #  elif defined(VGP_mips32_linux)
420    if (regno == 29) { *a = regs->sp; return True; }
421    if (regno == 30) { *a = regs->fp; return True; }
422 #  elif defined(VGP_mips64_linux)
423    if (regno == 29) { *a = regs->sp; return True; }
424    if (regno == 30) { *a = regs->fp; return True; }
425 #  elif defined(VGP_arm64_linux)
426    if (regno == 31) { *a = regs->sp; return True; }
427 #  elif defined(VGP_tilegx_linux)
428    if (regno == 52) { *a = regs->fp; return True; }
429    if (regno == 54) { *a = regs->sp; return True; }
430 #  else
431 #    error "Unknown platform"
432 #  endif
433    return False;
434 }
435 
436 /* Convert a stated address to an actual address */
bias_address(Addr * a,const DebugInfo * di)437 static Bool bias_address( Addr* a, const DebugInfo* di )
438 {
439    if (di->text_present
440        && di->text_size > 0
441        && *a >= di->text_debug_svma && *a < di->text_debug_svma + di->text_size) {
442       *a += di->text_debug_bias;
443    }
444    else if (di->data_present
445             && di->data_size > 0
446             && *a >= di->data_debug_svma && *a < di->data_debug_svma + di->data_size) {
447       *a += di->data_debug_bias;
448    }
449    else if (di->sdata_present
450             && di->sdata_size > 0
451             && *a >= di->sdata_debug_svma && *a < di->sdata_debug_svma + di->sdata_size) {
452       *a += di->sdata_debug_bias;
453    }
454    else if (di->rodata_present
455             && di->rodata_size > 0
456             && *a >= di->rodata_debug_svma && *a < di->rodata_debug_svma + di->rodata_size) {
457       *a += di->rodata_debug_bias;
458    }
459    else if (di->bss_present
460             && di->bss_size > 0
461             && *a >= di->bss_debug_svma && *a < di->bss_debug_svma + di->bss_size) {
462       *a += di->bss_debug_bias;
463    }
464    else if (di->sbss_present
465             && di->sbss_size > 0
466             && *a >= di->sbss_debug_svma && *a < di->sbss_debug_svma + di->sbss_size) {
467       *a += di->sbss_debug_bias;
468    }
469    else {
470       return False;
471    }
472 
473    return True;
474 }
475 
476 
477 /* Evaluate a standard DWARF3 expression.  See detailed description in
478    priv_d3basics.h.  Doesn't handle DW_OP_piece/DW_OP_bit_piece yet.  */
ML_(evaluate_Dwarf3_Expr)479 GXResult ML_(evaluate_Dwarf3_Expr) ( const UChar* expr, UWord exprszB,
480                                      const GExpr* fbGX, const RegSummary* regs,
481                                      const DebugInfo* di,
482                                      Bool push_initial_zero )
483 {
484 #  define N_EXPR_STACK 20
485 
486 #  define FAIL(_str)                                          \
487       do {                                                    \
488          res.kind = GXR_Failure;                              \
489          res.word = (UWord)(_str);                            \
490          return res;                                          \
491       } while (0)
492 
493 #  define PUSH(_arg)                                          \
494       do {                                                    \
495          vg_assert(sp >= -1 && sp < N_EXPR_STACK);            \
496          if (sp == N_EXPR_STACK-1)                            \
497             FAIL("evaluate_Dwarf3_Expr: stack overflow(1)");  \
498          sp++;                                                \
499          stack[sp] = (_arg);                                  \
500       } while (0)
501 
502 #  define POP(_lval)                                          \
503       do {                                                    \
504          vg_assert(sp >= -1 && sp < N_EXPR_STACK);            \
505          if (sp == -1)                                        \
506             FAIL("evaluate_Dwarf3_Expr: stack underflow(1)"); \
507          _lval = stack[sp];                                   \
508          sp--;                                                \
509       } while (0)
510 
511    UChar    opcode;
512    const UChar* limit;
513    Int      sp; /* # of top element: valid is -1 .. N_EXPR_STACK-1 */
514    Addr     stack[N_EXPR_STACK]; /* stack of addresses, as per D3 spec */
515    GXResult fbval, res;
516    Addr     a1;
517    Word     sw1, sw2;
518    UWord    uw1, uw2;
519    Bool     ok;
520 
521    sp = -1;
522    vg_assert(expr);
523    vg_assert(exprszB >= 0);
524    limit = expr + exprszB;
525 
526    /* Deal with the case where the entire expression is a single
527       Register Name Operation (D3 spec sec 2.6.1).  Then the
528       denotation of the expression as a whole is a register name. */
529    if (exprszB == 1
530        && expr[0] >= DW_OP_reg0 && expr[0] <= DW_OP_reg31) {
531       res.kind = GXR_RegNo;
532       res.word = (UWord)(expr[0] - DW_OP_reg0);
533       return res;
534    }
535    if (exprszB > 1
536        && expr[0] == DW_OP_regx) {
537       /* JRS: 2008Feb20: I believe the following is correct, but would
538          like to see a test case show up before enabling it. */
539       expr++;
540       res.kind = GXR_RegNo;
541       res.word = (UWord)read_leb128U( &expr );
542       if (expr != limit)
543          FAIL("evaluate_Dwarf3_Expr: DW_OP_regx*: invalid expr size");
544       else
545          return res;
546       /*NOTREACHED*/
547    }
548 
549    /* Evidently this expression denotes a value, not a register name.
550       So evaluate it accordingly. */
551 
552    if (push_initial_zero)
553       PUSH(0);
554 
555    while (True) {
556 
557       vg_assert(sp >= -1 && sp < N_EXPR_STACK);
558 
559       if (expr > limit)
560          /* overrun - something's wrong */
561          FAIL("evaluate_Dwarf3_Expr: ran off end of expr");
562 
563       if (expr == limit) {
564          /* end of expr - return expr on the top of stack. */
565          if (sp == -1)
566             /* stack empty.  Bad. */
567             FAIL("evaluate_Dwarf3_Expr: stack empty at end of expr");
568          else
569             break;
570       }
571 
572       opcode = *expr++;
573       switch (opcode) {
574          case DW_OP_addr:
575             /* Presumably what is given in the Dwarf3 is a SVMA (how
576                could it be otherwise?)  So we add the appropriate bias
577                on before pushing the result. */
578             a1 = ML_(read_Addr)(expr);
579             if (bias_address(&a1, di)) {
580                PUSH( a1 );
581                expr += sizeof(Addr);
582             }
583             else {
584                FAIL("evaluate_Dwarf3_Expr: DW_OP_addr with address "
585                     "in unknown section");
586             }
587             break;
588          case DW_OP_fbreg:
589             if (!fbGX)
590                FAIL("evaluate_Dwarf3_Expr: DW_OP_fbreg with "
591                     "no expr for fbreg present");
592             fbval = ML_(evaluate_GX)(fbGX, NULL, regs, di);
593             /* Convert fbval into something we can use.  If we got a
594                Value, no problem.  However, as per D3 spec sec 3.3.5
595                (Low Level Information) sec 2, we could also get a
596                RegNo, and that is taken to mean the value in the
597                indicated register.  So we have to manually
598                "dereference" it. */
599             a1 = 0;
600             switch (fbval.kind) {
601                case GXR_Failure:
602                   return fbval; /* propagate failure */
603                case GXR_Addr:
604                   a1 = fbval.word; break; /* use as-is */
605                case GXR_RegNo:
606                   ok = get_Dwarf_Reg( &a1, fbval.word, regs );
607                   if (!ok) return fbval; /* propagate failure */
608                   break;
609                case GXR_Value:
610                   FAIL("evaluate_Dwarf3_Expr: DW_OP_{implicit,stack}_value "
611                        "in DW_AT_frame_base");
612                default:
613                   vg_assert(0);
614             }
615             sw1 = (Word)read_leb128S( &expr );
616             PUSH( a1 + sw1 );
617             break;
618          /* DW_OP_breg* denotes 'contents of specified register, plus
619             constant offset'.  So provided we know what the register's
620             value is, we can evaluate this.  Contrast DW_OP_reg*,
621             which indicates that denoted location is in a register
622             itself.  If DW_OP_reg* shows up here the expression is
623             malformed, since we are evaluating for value now, and
624             DW_OP_reg* denotes a register location, not a value.  See
625             D3 Spec sec 2.6.1 ("Register Name Operations") for
626             details. */
627          case DW_OP_breg0 ... DW_OP_breg31:
628             if (!regs)
629                FAIL("evaluate_Dwarf3_Expr: DW_OP_breg* but no reg info");
630             a1 = 0;
631             if (!get_Dwarf_Reg( &a1, opcode - DW_OP_breg0, regs ))
632                FAIL("evaluate_Dwarf3_Expr: unhandled DW_OP_breg*");
633             sw1 = (Word)read_leb128S( &expr );
634             a1 += sw1;
635             PUSH( a1 );
636             break;
637          case DW_OP_bregx:
638             if (!regs)
639                FAIL("evaluate_Dwarf3_Expr: DW_OP_bregx but no reg info");
640             a1 = 0;
641             uw1 = (UWord)read_leb128U( &expr );
642             if (!get_Dwarf_Reg( &a1, uw1, regs ))
643                FAIL("evaluate_Dwarf3_Expr: unhandled DW_OP_bregx reg value");
644             sw1 = (Word)read_leb128S( &expr );
645             a1 += sw1;
646             PUSH( a1 );
647             break;
648          /* As per comment on DW_OP_breg*, the following denote that
649             the value in question is in a register, not in memory.  So
650             we simply return failure. (iow, the expression is
651             malformed). */
652          case DW_OP_reg0 ... DW_OP_reg31:
653          case DW_OP_regx:
654             FAIL("evaluate_Dwarf3_Expr: DW_OP_reg* "
655                  "whilst evaluating for a value");
656             break;
657          case DW_OP_plus_uconst:
658             POP(uw1);
659             uw1 += (UWord)read_leb128U( &expr );
660             PUSH(uw1);
661             break;
662          case DW_OP_GNU_push_tls_address:
663             /* GDB contains the following cryptic comment: */
664             /* Variable is at a constant offset in the thread-local
665             storage block into the objfile for the current thread and
666             the dynamic linker module containing this expression. Here
667             we return returns the offset from that base.  The top of the
668             stack has the offset from the beginning of the thread
669             control block at which the variable is located.  Nothing
670             should follow this operator, so the top of stack would be
671             returned.  */
672             /* But no spec resulting from Googling.  Punt for now. */
673             FAIL("warning: evaluate_Dwarf3_Expr: unhandled "
674                  "DW_OP_GNU_push_tls_address");
675             /*NOTREACHED*/
676          case DW_OP_deref:
677             POP(uw1);
678             if (VG_(am_is_valid_for_client)( (Addr)uw1, sizeof(Addr),
679                                              VKI_PROT_READ )) {
680                uw1 = ML_(read_UWord)((void *)uw1);
681                PUSH(uw1);
682             } else {
683                FAIL("warning: evaluate_Dwarf3_Expr: DW_OP_deref: "
684                     "address not valid for client");
685             }
686             break;
687          case DW_OP_deref_size:
688             POP(uw1);
689             uw2 = *expr++;
690             if (VG_(am_is_valid_for_client)( (Addr)uw1, uw2,
691                                              VKI_PROT_READ )) {
692                switch (uw2) {
693                  case 1: uw1 = ML_(read_UChar)((void*)uw1); break;
694                  case 2: uw1 = ML_(read_UShort)((void*)uw1); break;
695                  case 4: uw1 = ML_(read_UInt)((void*)uw1); break;
696                  case 8: uw1 = ML_(read_ULong)((void*)uw1); break;
697                  default:
698                     FAIL("warning: evaluate_Dwarf3_Expr: unhandled "
699                          "DW_OP_deref_size size");
700                }
701                PUSH(uw1);
702             } else {
703                FAIL("warning: evaluate_Dwarf3_Expr: DW_OP_deref_size: "
704                     "address not valid for client");
705             }
706             break;
707          case DW_OP_lit0 ... DW_OP_lit31:
708             PUSH(opcode - DW_OP_lit0);
709             break;
710          case DW_OP_const1u:
711 	    uw1 = *expr++;
712 	    PUSH(uw1);
713             break;
714          case DW_OP_const2u:
715 	    uw1 = ML_(read_UShort)(expr);
716 	    expr += 2;
717 	    PUSH(uw1);
718 	    break;
719          case DW_OP_const4u:
720 	    uw1 = ML_(read_UInt)(expr);
721 	    expr += 4;
722 	    PUSH(uw1);
723 	    break;
724          case DW_OP_const8u:
725 	    uw1 = ML_(read_ULong)(expr);
726 	    expr += 8;
727 	    PUSH(uw1);
728 	    break;
729          case DW_OP_constu:
730             uw1 = read_leb128U( &expr );
731             PUSH(uw1);
732             break;
733          case DW_OP_const1s:
734 	    uw1 = *(const Char *)expr;
735 	    expr++;
736 	    PUSH(uw1);
737             break;
738          case DW_OP_const2s:
739 	    uw1 = ML_(read_Short)(expr);
740 	    expr += 2;
741 	    PUSH(uw1);
742 	    break;
743          case DW_OP_const4s:
744 	    uw1 = ML_(read_Int)(expr);
745 	    expr += 4;
746 	    PUSH(uw1);
747 	    break;
748          case DW_OP_const8s:
749 	    uw1 = ML_(read_Long)(expr);
750 	    expr += 8;
751 	    PUSH(uw1);
752 	    break;
753          case DW_OP_consts:
754             uw1 = read_leb128S( &expr );
755             PUSH(uw1);
756             break;
757          case DW_OP_dup:
758 	    POP(uw1);
759 	    PUSH(uw1);
760 	    PUSH(uw1);
761 	    break;
762 	 case DW_OP_drop:
763 	    POP(uw1);
764 	    break;
765          case DW_OP_over:
766             uw1 = 1;
767             goto do_pick;
768 	 case DW_OP_pick:
769 	    uw1 = *expr++;
770          do_pick:
771             if (sp < (Int)uw1)
772                FAIL("evaluate_Dwarf3_Expr: stack underflow");
773             uw1 = stack[sp - uw1];
774             PUSH(uw1);
775             break;
776          case DW_OP_swap:
777             if (sp < 1)
778                FAIL("evaluate_Dwarf3_Expr: stack underflow");
779             uw1 = stack[sp];
780             stack[sp] = stack[sp - 1];
781             stack[sp - 1] = uw1;
782             break;
783          case DW_OP_rot:
784             if (sp < 2)
785                FAIL("evaluate_Dwarf3_Expr: stack underflow");
786             uw1 = stack[sp];
787             stack[sp] = stack[sp - 1];
788             stack[sp - 1] = stack[sp - 2];
789             stack[sp - 2] = uw1;
790             break;
791          case DW_OP_abs:
792             POP(sw1);
793             if (sw1 < 0)
794                sw1 = -sw1;
795             PUSH(sw1);
796             break;
797          case DW_OP_div:
798             POP(sw2);
799             if (sw2 == 0)
800                FAIL("evaluate_Dwarf3_Expr: division by zero");
801             POP(sw1);
802             sw1 /= sw2;
803             PUSH(sw1);
804             break;
805          case DW_OP_mod:
806             POP(uw2);
807             if (uw2 == 0)
808                FAIL("evaluate_Dwarf3_Expr: division by zero");
809             POP(uw1);
810             uw1 %= uw2;
811             PUSH(uw1);
812             break;
813 #define BINARY(name, op, s) \
814          case DW_OP_##name:		\
815             POP(s##w2);			\
816             POP(s##w1);			\
817             s##w1 = s##w1 op s##w2;	\
818             PUSH(s##w1);		\
819             break
820 #define UNARY(name, op, s) \
821          case DW_OP_##name:		\
822             POP(s##w1);			\
823             s##w1 = op s##w1;		\
824             PUSH(s##w1);		\
825             break
826          BINARY (and, &, u);
827          BINARY (minus, -, u);
828          BINARY (mul, *, u);
829          UNARY (neg, -, u);
830          UNARY (not, ~, u);
831          BINARY (or, |, u);
832          BINARY (plus, +, u);
833          BINARY (shl, <<, u);
834          BINARY (shr, >>, u);
835          BINARY (shra, >>, s);
836          BINARY (xor, ^, u);
837          BINARY (le, <=, s);
838          BINARY (lt, <, s);
839          BINARY (ge, >=, s);
840          BINARY (gt, >, s);
841          BINARY (ne, !=, u);
842          BINARY (eq, ==, u);
843 #undef UNARY
844 #undef BINARY
845          case DW_OP_skip:
846             sw1 = ML_(read_Short)(expr);
847             expr += 2;
848             if (expr + sw1 < limit - exprszB)
849                FAIL("evaluate_Dwarf3_Expr: DW_OP_skip before start of expr");
850             if (expr + sw1 >= limit)
851                FAIL("evaluate_Dwarf3_Expr: DW_OP_skip after end of expr");
852             expr += sw1;
853             break;
854          case DW_OP_bra:
855             sw1 = ML_(read_Short)(expr);
856             expr += 2;
857             if (expr + sw1 < limit - exprszB)
858                FAIL("evaluate_Dwarf3_Expr: DW_OP_bra before start of expr");
859             if (expr + sw1 >= limit)
860                FAIL("evaluate_Dwarf3_Expr: DW_OP_bra after end of expr");
861             POP(uw1);
862             if (uw1)
863                expr += sw1;
864             break;
865          case DW_OP_nop:
866             break;
867          case DW_OP_call_frame_cfa:
868             if (!regs)
869                FAIL("evaluate_Dwarf3_Expr: "
870                     "DW_OP_call_frame_cfa but no reg info");
871 #if defined(VGP_ppc32_linux) || defined(VGP_ppc64be_linux) \
872     || defined(VGP_ppc64le_linux)
873             /* Valgrind on ppc32/ppc64 currently doesn't use unwind info. */
874             uw1 = ML_(read_Addr)((UChar*)regs->sp);
875 #else
876             uw1 = ML_(get_CFA)(regs->ip, regs->sp, regs->fp, 0, ~(UWord) 0);
877 #endif
878             /* we expect this to fail on arm-linux, since ML_(get_CFA)
879                always returns zero at present. */
880             if (!uw1)
881                FAIL("evaluate_Dwarf3_Expr: Could not resolve "
882                     "DW_OP_call_frame_cfa");
883             PUSH(uw1);
884             break;
885          case DW_OP_implicit_value:
886             sw1 = (Word)read_leb128S( &expr );
887             uw1 = 0;
888             switch (sw1) {
889                case 1:
890                   uw1 = ML_(read_UChar)(expr);
891                   expr += 1;
892                   break;
893                case 2:
894                   uw1 = ML_(read_UShort)(expr);
895                   expr += 2;
896                   break;
897                case 4:
898                   uw1 = ML_(read_UInt)(expr);
899                   expr += 4;
900                   break;
901                case 8:
902                   uw1 = ML_(read_ULong)(expr);
903                   expr += 8;
904                   break;
905                default:
906                   FAIL("evaluate_Dwarf3_Expr: Unhandled "
907                        "DW_OP_implicit_value size");
908             }
909             if (expr != limit)
910                FAIL("evaluate_Dwarf3_Expr: DW_OP_implicit_value "
911                     "does not terminate expression");
912             res.word = uw1;
913             res.kind = GXR_Value;
914             return res;
915          case DW_OP_stack_value:
916             POP (uw1);
917             res.word = uw1;
918             res.kind = GXR_Value;
919             if (expr != limit)
920                FAIL("evaluate_Dwarf3_Expr: DW_OP_stack_value "
921                     "does not terminate expression");
922             break;
923          default:
924             if (!VG_(clo_xml))
925                VG_(message)(Vg_DebugMsg,
926                             "warning: evaluate_Dwarf3_Expr: unhandled "
927                             "DW_OP_ 0x%x\n", (Int)opcode);
928             FAIL("evaluate_Dwarf3_Expr: unhandled DW_OP_");
929             /*NOTREACHED*/
930       }
931 
932    }
933 
934    vg_assert(sp >= 0 && sp < N_EXPR_STACK);
935    res.word = stack[sp];
936    res.kind = GXR_Addr;
937    return res;
938 
939 #  undef POP
940 #  undef PUSH
941 #  undef FAIL
942 #  undef N_EXPR_STACK
943 }
944 
945 
946 /* Evaluate a so-called Guarded (DWARF3) expression.  See detailed
947    description in priv_d3basics.h. */
ML_(evaluate_GX)948 GXResult ML_(evaluate_GX)( const GExpr* gx, const GExpr* fbGX,
949                            const RegSummary* regs, const DebugInfo* di )
950 {
951    GXResult res;
952    Addr     aMin, aMax;
953    UChar    uc;
954    UShort   nbytes;
955    UWord    nGuards = 0;
956    const UChar* p = &gx->payload[0];
957    uc = *p++; /*biasMe*/
958    vg_assert(uc == 0 || uc == 1);
959    /* in fact it's senseless to evaluate if the guards need biasing.
960       So don't. */
961    vg_assert(uc == 0);
962    while (True) {
963       uc = *p++;
964       if (uc == 1) { /*isEnd*/
965          /* didn't find any matching range. */
966          res.kind = GXR_Failure;
967          res.word = (UWord)"no matching range";
968          return res;
969       }
970       vg_assert(uc == 0);
971       aMin   = ML_(read_Addr)(p);   p += sizeof(Addr);
972       aMax   = ML_(read_Addr)(p);   p += sizeof(Addr);
973       nbytes = ML_(read_UShort)(p); p += sizeof(UShort);
974       nGuards++;
975       if (0) VG_(printf)("           guard %d: %#lx %#lx\n",
976                          (Int)nGuards, aMin,aMax);
977       if (regs == NULL) {
978          vg_assert(aMin == (Addr)0);
979          vg_assert(aMax == ~(Addr)0);
980          /* Assert this is the first guard. */
981          vg_assert(nGuards == 1);
982          res = ML_(evaluate_Dwarf3_Expr)(
983                   p, (UWord)nbytes, fbGX, regs, di,
984                   False/*push_initial_zero*/ );
985          /* Now check there are no more guards. */
986          p += (UWord)nbytes;
987          vg_assert(*p == 1); /*isEnd*/
988          return res;
989       } else {
990          if (aMin <= regs->ip && regs->ip <= aMax) {
991             /* found a matching range.  Evaluate the expression. */
992             return ML_(evaluate_Dwarf3_Expr)(
993                       p, (UWord)nbytes, fbGX, regs, di,
994                       False/*push_initial_zero*/ );
995          }
996       }
997       /* else keep searching */
998       p += (UWord)nbytes;
999    }
1000 }
1001 
1002 
1003 /* Evaluate a very simple Guarded (DWARF3) expression.  The expression
1004    is expected to denote a constant, with no reference to any
1005    registers nor to any frame base expression.  The expression is
1006    expected to have at least one guard.  If there is more than one
1007    guard, all the sub-expressions are evaluated and compared.  The
1008    address ranges on the guards are ignored.  GXR_Failure is returned
1009    in the following circumstances:
1010    * no guards
1011    * any of the subexpressions require a frame base expression
1012    * any of the subexpressions denote a register location
1013    * any of the subexpressions do not produce a manifest constant
1014    * there's more than one subexpression, all of which successfully
1015      evaluate to a constant, but they don't all produce the same constant.
1016    JRS 23Jan09: the special-casing in this function is a nasty kludge.
1017    Really it ought to be pulled out and turned into a general
1018    constant- expression evaluator.
1019 */
ML_(evaluate_trivial_GX)1020 GXResult ML_(evaluate_trivial_GX)( const GExpr* gx, const DebugInfo* di )
1021 {
1022    GXResult   res;
1023    Addr       aMin, aMax;
1024    UChar      uc;
1025    UShort     nbytes;
1026    Word       i, nGuards;
1027    MaybeULong *mul, *mul2;
1028 
1029    const HChar*  badness = NULL;
1030    const UChar*  p       = &gx->payload[0]; /* must remain unsigned */
1031    XArray* results = VG_(newXA)( ML_(dinfo_zalloc), "di.d3basics.etG.1",
1032                                  ML_(dinfo_free),
1033                                  sizeof(MaybeULong) );
1034 
1035    uc = *p++; /*biasMe*/
1036    vg_assert(uc == 0 || uc == 1);
1037    /* in fact it's senseless to evaluate if the guards need biasing.
1038       So don't. */
1039    vg_assert(uc == 0);
1040 
1041    nGuards = 0;
1042    while (True) {
1043       MaybeULong thisResult;
1044       uc = *p++;
1045       if (uc == 1) /*isEnd*/
1046          break;
1047       vg_assert(uc == 0);
1048       aMin   = ML_(read_Addr)(p);   p += sizeof(Addr);
1049       aMax   = ML_(read_Addr)(p);   p += sizeof(Addr);
1050       nbytes = ML_(read_UShort)(p); p += sizeof(UShort);
1051       nGuards++;
1052       if (0) VG_(printf)("           guard %ld: %#lx %#lx\n",
1053                          nGuards, aMin,aMax);
1054 
1055       thisResult.b  = False;
1056       thisResult.ul = 0;
1057 
1058       /* Peer at this particular subexpression, to see if it's
1059          obviously a constant. */
1060       if (nbytes == 1 + sizeof(Addr) && *p == DW_OP_addr) {
1061          /* DW_OP_addr a */
1062          Addr a = ML_(read_Addr)((p+1));
1063          if (bias_address(&a, di)) {
1064             thisResult.b = True;
1065             thisResult.ul = (ULong)a;
1066          } else {
1067             if (!badness)
1068                badness = "trivial GExpr denotes constant address "
1069                          "in unknown section (1)";
1070          }
1071       }
1072       else
1073       if (nbytes == 1 + sizeof(Addr) + 1 + 1
1074           /* 11 byte block: 3 c0 b6 2b 0 0 0 0 0 23 4
1075              (DW_OP_addr: 2bb6c0; DW_OP_plus_uconst: 4)
1076              This is really a nasty kludge - only matches if the
1077              trailing ULEB denotes a number in the range 0 .. 127
1078              inclusive. */
1079           && p[0] == DW_OP_addr
1080           && p[1 + sizeof(Addr)] == DW_OP_plus_uconst
1081           && p[1 + sizeof(Addr) + 1] < 0x80 /*1-byte ULEB*/) {
1082          Addr a = ML_(read_Addr)(&p[1]);
1083          if (bias_address(&a, di)) {
1084             thisResult.b = True;
1085             thisResult.ul = (ULong)a + (ULong)p[1 + sizeof(Addr) + 1];
1086          } else {
1087             if (!badness)
1088                badness = "trivial GExpr denotes constant address "
1089                          "in unknown section (2)";
1090          }
1091       }
1092       else
1093       if (nbytes == 2 + sizeof(Addr)
1094           && *p == DW_OP_addr
1095           && *(p + 1 + sizeof(Addr)) == DW_OP_GNU_push_tls_address) {
1096          if (!badness)
1097             badness = "trivial GExpr is DW_OP_addr plus trailing junk";
1098       }
1099       else if (nbytes >= 1 && *p >= DW_OP_reg0 && *p <= DW_OP_reg31) {
1100          if (!badness)
1101             badness = "trivial GExpr denotes register (1)";
1102       }
1103       else if (nbytes >= 1 && *p == DW_OP_fbreg) {
1104          if (!badness)
1105             badness = "trivial GExpr requires fbGX";
1106       }
1107       else if (nbytes >= 1 && *p >= DW_OP_breg0 && *p <= DW_OP_breg31) {
1108          if (!badness)
1109             badness = "trivial GExpr requires register value";
1110       }
1111       else if (nbytes >= 1 && *p == DW_OP_regx) {
1112          if (!badness)
1113             badness = "trivial GExpr denotes register (2)";
1114       }
1115       else if (0) {
1116          VG_(printf)(" ML_(evaluate_trivial_GX): unhandled:\n   ");
1117          ML_(pp_GX)( gx );
1118          VG_(printf)("\n");
1119          vg_assert(0);
1120       }
1121       else
1122          if (!badness)
1123             badness = "non-trivial GExpr";
1124 
1125       VG_(addToXA)( results, &thisResult );
1126 
1127       p += (UWord)nbytes;
1128    }
1129 
1130    res.kind = GXR_Failure;
1131 
1132    vg_assert(nGuards == VG_(sizeXA)( results ));
1133    vg_assert(nGuards >= 0);
1134    if (nGuards == 0) {
1135       vg_assert(!badness);
1136       res.word = (UWord)"trivial GExpr has no guards (!)";
1137       VG_(deleteXA)( results );
1138       return res;
1139    }
1140 
1141    for (i = 0; i < nGuards; i++) {
1142       mul = VG_(indexXA)( results, i );
1143       if (mul->b == False)
1144          break;
1145    }
1146 
1147    vg_assert(i >= 0 && i <= nGuards);
1148    if (i < nGuards) {
1149       /* at least one subexpression failed to produce a manifest constant. */
1150       vg_assert(badness);
1151       res.word = (UWord)badness;
1152       VG_(deleteXA)( results );
1153       return res;
1154    }
1155 
1156    /* All the subexpressions produced a constant, but did they all produce
1157       the same one? */
1158    mul = VG_(indexXA)( results, 0 );
1159    vg_assert(mul->b == True); /* we just established that all exprs are ok */
1160 
1161    for (i = 1; i < nGuards; i++) {
1162       mul2 = VG_(indexXA)( results, i );
1163       vg_assert(mul2->b == True);
1164       if (mul2->ul != mul->ul) {
1165          res.word = (UWord)"trivial GExpr: subexpressions disagree";
1166          VG_(deleteXA)( results );
1167          return res;
1168       }
1169    }
1170 
1171    /* Well, we have success.  All subexpressions evaluated, and
1172       they all agree.  Hurrah. */
1173    res.kind = GXR_Addr;
1174    res.word = (UWord)mul->ul; /* NB: narrowing from ULong */
1175    VG_(deleteXA)( results );
1176    return res;
1177 }
1178 
1179 
ML_(pp_GXResult)1180 void ML_(pp_GXResult) ( GXResult res )
1181 {
1182    switch (res.kind) {
1183       case GXR_Failure:
1184          VG_(printf)("GXR_Failure(%s)", (HChar*)res.word); break;
1185       case GXR_Addr:
1186          VG_(printf)("GXR_Addr(0x%lx)", res.word); break;
1187       case GXR_Value:
1188          VG_(printf)("GXR_Value(0x%lx)", res.word); break;
1189       case GXR_RegNo:
1190          VG_(printf)("GXR_RegNo(%lu)", res.word); break;
1191       default:
1192          VG_(printf)("GXR_???"); break;
1193    }
1194 }
1195 
1196 
ML_(pp_GX)1197 void ML_(pp_GX) ( const GExpr* gx )
1198 {
1199    Addr   aMin, aMax;
1200    UChar  uc;
1201    UShort nbytes;
1202    const UChar* p = &gx->payload[0];
1203    uc = *p++;
1204    VG_(printf)("GX(%s){", uc == 0 ? "final" : "Breqd" );
1205    vg_assert(uc == 0 || uc == 1);
1206    while (True) {
1207       uc = *p++;
1208       if (uc == 1)
1209          break; /*isEnd*/
1210       vg_assert(uc == 0);
1211       aMin   = ML_(read_Addr)(p);  p += sizeof(Addr);
1212       aMax   = ML_(read_Addr)(p);  p += sizeof(Addr);
1213       nbytes = ML_(read_UShort)(p); p += sizeof(UShort);
1214       VG_(printf)("[%#lx,%#lx]=", aMin, aMax);
1215       while (nbytes > 0) {
1216          VG_(printf)("%02x", (UInt)*p++);
1217          nbytes--;
1218       }
1219       if (*p == 0)
1220          VG_(printf)(",");
1221    }
1222    VG_(printf)("}");
1223 }
1224 
1225 
1226 /*--------------------------------------------------------------------*/
1227 /*--- end                                               d3basics.c ---*/
1228 /*--------------------------------------------------------------------*/
1229