Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1 | /* Return scope DIEs containing PC address. |
| 2 | Copyright (C) 2005, 2007 Red Hat, Inc. |
| 3 | This file is part of Red Hat elfutils. |
| 4 | |
| 5 | Red Hat elfutils is free software; you can redistribute it and/or modify |
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| 40 | this file solely under the GPL without exception. |
| 41 | |
| 42 | Red Hat elfutils is an included package of the Open Invention Network. |
| 43 | An included package of the Open Invention Network is a package for which |
| 44 | Open Invention Network licensees cross-license their patents. No patent |
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| 48 | <http://www.openinventionnetwork.com>. */ |
| 49 | |
| 50 | #ifdef HAVE_CONFIG_H |
| 51 | # include <config.h> |
| 52 | #endif |
| 53 | |
| 54 | #include <assert.h> |
| 55 | #include <stdlib.h> |
| 56 | #include "libdwP.h" |
| 57 | #include <dwarf.h> |
| 58 | |
| 59 | |
| 60 | struct args |
| 61 | { |
| 62 | Dwarf_Addr pc; |
| 63 | Dwarf_Die *scopes; |
| 64 | unsigned int inlined, nscopes; |
| 65 | Dwarf_Die inlined_origin; |
| 66 | }; |
| 67 | |
| 68 | /* Preorder visitor: prune the traversal if this DIE does not contain PC. */ |
| 69 | static int |
| 70 | pc_match (unsigned int depth, struct Dwarf_Die_Chain *die, void *arg) |
| 71 | { |
| 72 | struct args *a = arg; |
| 73 | |
| 74 | if (a->scopes != NULL) |
| 75 | die->prune = true; |
| 76 | else |
| 77 | { |
| 78 | /* dwarf_haspc returns an error if there are no appropriate attributes. |
| 79 | But we use it indiscriminantly instead of presuming which tags can |
| 80 | have PC attributes. So when it fails for that reason, treat it just |
| 81 | as a nonmatching return. */ |
| 82 | int result = INTUSE(dwarf_haspc) (&die->die, a->pc); |
| 83 | if (result < 0) |
| 84 | { |
| 85 | int error = INTUSE(dwarf_errno) (); |
| 86 | if (error != DWARF_E_NOERROR && error != DWARF_E_NO_DEBUG_RANGES) |
| 87 | { |
| 88 | __libdw_seterrno (error); |
| 89 | return -1; |
| 90 | } |
| 91 | result = 0; |
| 92 | } |
| 93 | if (result == 0) |
| 94 | die->prune = true; |
| 95 | |
| 96 | if (!die->prune |
| 97 | && INTUSE (dwarf_tag) (&die->die) == DW_TAG_inlined_subroutine) |
| 98 | a->inlined = depth; |
| 99 | } |
| 100 | |
| 101 | return 0; |
| 102 | } |
| 103 | |
| 104 | /* Preorder visitor for second partial traversal after finding a |
| 105 | concrete inlined instance. */ |
| 106 | static int |
| 107 | origin_match (unsigned int depth, struct Dwarf_Die_Chain *die, void *arg) |
| 108 | { |
| 109 | struct args *a = arg; |
| 110 | |
| 111 | if (die->die.addr != a->inlined_origin.addr) |
| 112 | return 0; |
| 113 | |
| 114 | /* We have a winner! This is the abstract definition of the inline |
| 115 | function of which A->scopes[A->nscopes - 1] is a concrete instance. |
| 116 | */ |
| 117 | |
| 118 | unsigned int nscopes = a->nscopes + depth; |
| 119 | Dwarf_Die *scopes = realloc (a->scopes, nscopes * sizeof scopes[0]); |
| 120 | if (scopes == NULL) |
| 121 | { |
| 122 | free (a->scopes); |
| 123 | __libdw_seterrno (DWARF_E_NOMEM); |
| 124 | return -1; |
| 125 | } |
| 126 | |
| 127 | a->scopes = scopes; |
| 128 | do |
| 129 | { |
| 130 | die = die->parent; |
| 131 | scopes[a->nscopes++] = die->die; |
| 132 | } |
| 133 | while (a->nscopes < nscopes); |
| 134 | assert (die->parent == NULL); |
| 135 | return a->nscopes; |
| 136 | } |
| 137 | |
| 138 | /* Postorder visitor: first (innermost) call wins. */ |
| 139 | static int |
| 140 | pc_record (unsigned int depth, struct Dwarf_Die_Chain *die, void *arg) |
| 141 | { |
| 142 | struct args *a = arg; |
| 143 | |
| 144 | if (die->prune) |
| 145 | return 0; |
| 146 | |
| 147 | if (a->scopes == NULL) |
| 148 | { |
| 149 | /* We have hit the innermost DIE that contains the target PC. */ |
| 150 | |
| 151 | a->nscopes = depth + 1 - a->inlined; |
| 152 | a->scopes = malloc (a->nscopes * sizeof a->scopes[0]); |
| 153 | if (a->scopes == NULL) |
| 154 | { |
| 155 | __libdw_seterrno (DWARF_E_NOMEM); |
| 156 | return -1; |
| 157 | } |
| 158 | |
| 159 | for (unsigned int i = 0; i < a->nscopes; ++i) |
| 160 | { |
| 161 | a->scopes[i] = die->die; |
| 162 | die = die->parent; |
| 163 | } |
| 164 | |
| 165 | if (a->inlined == 0) |
| 166 | { |
| 167 | assert (die == NULL); |
| 168 | return a->nscopes; |
| 169 | } |
| 170 | |
| 171 | /* This is the concrete inlined instance itself. |
| 172 | Record its abstract_origin pointer. */ |
| 173 | Dwarf_Die *const inlinedie = &a->scopes[depth - a->inlined]; |
| 174 | |
| 175 | assert (INTUSE (dwarf_tag) (inlinedie) == DW_TAG_inlined_subroutine); |
| 176 | Dwarf_Attribute attr_mem; |
| 177 | Dwarf_Attribute *attr = INTUSE (dwarf_attr) (inlinedie, |
| 178 | DW_AT_abstract_origin, |
| 179 | &attr_mem); |
| 180 | if (INTUSE (dwarf_formref_die) (attr, &a->inlined_origin) == NULL) |
| 181 | return -1; |
| 182 | return 0; |
| 183 | } |
| 184 | |
| 185 | |
| 186 | /* We've recorded the scopes back to one that is a concrete inlined |
| 187 | instance. Now return out of the traversal back to the scope |
| 188 | containing that instance. */ |
| 189 | |
| 190 | assert (a->inlined); |
| 191 | if (depth >= a->inlined) |
| 192 | /* Not there yet. */ |
| 193 | return 0; |
| 194 | |
| 195 | /* Now we are in a scope that contains the concrete inlined instance. |
| 196 | Search it for the inline function's abstract definition. |
| 197 | If we don't find it, return to search the containing scope. |
| 198 | If we do find it, the nonzero return value will bail us out |
| 199 | of the postorder traversal. */ |
| 200 | return __libdw_visit_scopes (depth, die, &origin_match, NULL, a); |
| 201 | } |
| 202 | |
| 203 | |
| 204 | int |
| 205 | dwarf_getscopes (Dwarf_Die *cudie, Dwarf_Addr pc, Dwarf_Die **scopes) |
| 206 | { |
| 207 | if (cudie == NULL) |
| 208 | return -1; |
| 209 | |
| 210 | struct Dwarf_Die_Chain cu = { .parent = NULL, .die = *cudie }; |
| 211 | struct args a = { .pc = pc }; |
| 212 | |
| 213 | int result = __libdw_visit_scopes (0, &cu, &pc_match, &pc_record, &a); |
| 214 | |
| 215 | if (result == 0 && a.scopes != NULL) |
| 216 | result = __libdw_visit_scopes (0, &cu, &origin_match, NULL, &a); |
| 217 | |
| 218 | if (result > 0) |
| 219 | *scopes = a.scopes; |
| 220 | |
| 221 | return result; |
| 222 | } |