/* Return location expression list.
- Copyright (C) 2000-2010 Red Hat, Inc.
+ Copyright (C) 2000-2010, 2013 Red Hat, Inc.
This file is part of elfutils.
Written by Ulrich Drepper <drepper@redhat.com>, 2000.
case DW_AT_frame_base:
case DW_AT_return_addr:
case DW_AT_static_link:
+ case DW_AT_segment:
break;
default:
return getlocation (attr->cu, &block, llbuf, listlen, cu_sec_idx (attr->cu));
}
+static int
+attr_base_address (attr, basep)
+ Dwarf_Attribute *attr;
+ Dwarf_Addr *basep;
+{
+ /* Fetch the CU's base address. */
+ Dwarf_Die cudie = CUDIE (attr->cu);
+
+ /* Find the base address of the compilation unit. It will
+ normally be specified by DW_AT_low_pc. In DWARF-3 draft 4,
+ the base address could be overridden by DW_AT_entry_pc. It's
+ been removed, but GCC emits DW_AT_entry_pc and not DW_AT_lowpc
+ for compilation units with discontinuous ranges. */
+ Dwarf_Attribute attr_mem;
+ if (unlikely (INTUSE(dwarf_lowpc) (&cudie, basep) != 0)
+ && INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (&cudie,
+ DW_AT_entry_pc,
+ &attr_mem),
+ basep) != 0)
+ {
+ if (INTUSE(dwarf_errno) () != 0)
+ return -1;
+
+ /* The compiler provided no base address when it should
+ have. Buggy GCC does this when it used absolute
+ addresses in the location list and no DW_AT_ranges. */
+ *basep = 0;
+ }
+ return 0;
+}
+
+static int
+initial_offset_base (attr, offset, basep)
+ Dwarf_Attribute *attr;
+ ptrdiff_t *offset;
+ Dwarf_Addr *basep;
+{
+ if (attr_base_address (attr, basep) != 0)
+ return -1;
+
+ Dwarf_Word start_offset;
+ if (__libdw_formptr (attr, IDX_debug_loc,
+ DWARF_E_NO_LOCLIST,
+ NULL, &start_offset) == NULL)
+ return -1;
+
+ *offset = start_offset;
+ return 0;
+}
+
+static ptrdiff_t
+getlocations_addr (attr, offset, basep, startp, endp, address,
+ locs, expr, exprlen)
+ Dwarf_Attribute *attr;
+ ptrdiff_t offset;
+ Dwarf_Addr *basep;
+ Dwarf_Addr *startp;
+ Dwarf_Addr *endp;
+ Dwarf_Addr address;
+ Elf_Data *locs;
+ Dwarf_Op **expr;
+ size_t *exprlen;
+{
+ unsigned char *readp = locs->d_buf + offset;
+ unsigned char *readendp = locs->d_buf + locs->d_size;
+
+ next:
+ if (readendp - readp < attr->cu->address_size * 2)
+ {
+ invalid:
+ __libdw_seterrno (DWARF_E_INVALID_DWARF);
+ return -1;
+ }
+
+ Dwarf_Addr begin;
+ Dwarf_Addr end;
+
+ switch (__libdw_read_begin_end_pair_inc (attr->cu->dbg, IDX_debug_loc,
+ &readp, attr->cu->address_size,
+ &begin, &end, basep))
+ {
+ case 0: /* got location range. */
+ break;
+ case 1: /* base address setup. */
+ goto next;
+ case 2: /* end of loclist */
+ return 0;
+ default: /* error */
+ return -1;
+ }
+
+ if (readendp - readp < 2)
+ goto invalid;
+
+ /* We have a location expression. */
+ Dwarf_Block block;
+ block.length = read_2ubyte_unaligned_inc (attr->cu->dbg, readp);
+ block.data = readp;
+ if (readendp - readp < (ptrdiff_t) block.length)
+ goto invalid;
+ readp += block.length;
+
+ *startp = *basep + begin;
+ *endp = *basep + end;
+
+ /* If address is minus one we want them all, otherwise only matching. */
+ if (address != (Dwarf_Word) -1 && (address < *startp || address >= *endp))
+ goto next;
+
+ if (getlocation (attr->cu, &block, expr, exprlen, IDX_debug_loc) != 0)
+ return -1;
+
+ return readp - (unsigned char *) locs->d_buf;
+}
+
int
dwarf_getlocation_addr (attr, address, llbufs, listlens, maxlocs)
Dwarf_Attribute *attr;
if (result != 1)
return result ?: 1;
- unsigned char *endp;
- unsigned char *readp = __libdw_formptr (attr, IDX_debug_loc,
- DWARF_E_NO_LOCLIST, &endp, NULL);
- if (readp == NULL)
+ Dwarf_Addr base, start, end;
+ Dwarf_Op *expr;
+ size_t expr_len;
+ ptrdiff_t off = 0;
+ size_t got = 0;
+
+ /* This is a true loclistptr, fetch the initial base address and offset. */
+ if (initial_offset_base (attr, &off, &base) != 0)
return -1;
- Dwarf_Addr base = (Dwarf_Addr) -1;
- size_t got = 0;
- while (got < maxlocs)
+ const Elf_Data *d = attr->cu->dbg->sectiondata[IDX_debug_loc];
+ if (d == NULL)
{
- if (endp - readp < attr->cu->address_size * 2)
+ __libdw_seterrno (DWARF_E_NO_LOCLIST);
+ return -1;
+ }
+
+ while (got < maxlocs
+ && (off = getlocations_addr (attr, off, &base, &start, &end,
+ address, d, &expr, &expr_len)) > 0)
+ {
+ /* This one matches the address. */
+ if (llbufs != NULL)
{
- invalid:
- __libdw_seterrno (DWARF_E_INVALID_DWARF);
- return -1;
+ llbufs[got] = expr;
+ listlens[got] = expr_len;
}
+ ++got;
+ }
- Dwarf_Addr begin;
- Dwarf_Addr end;
+ /* We might stop early, so off can be zero or positive on success. */
+ if (off < 0)
+ return -1;
- int status
- = __libdw_read_begin_end_pair_inc (attr->cu->dbg, IDX_debug_loc,
- &readp, attr->cu->address_size,
- &begin, &end, &base);
- if (status == 2) /* End of list entry. */
- break;
- else if (status == 1) /* Base address selected. */
- continue;
- else if (status < 0)
- return status;
-
- if (endp - readp < 2)
- goto invalid;
-
- /* We have a location expression. */
- block.length = read_2ubyte_unaligned_inc (attr->cu->dbg, readp);
- block.data = readp;
- if (endp - readp < (ptrdiff_t) block.length)
- goto invalid;
- readp += block.length;
-
- if (base == (Dwarf_Addr) -1)
+ return got;
+}
+
+ptrdiff_t
+dwarf_getlocations (attr, offset, basep, startp, endp, expr, exprlen)
+ Dwarf_Attribute *attr;
+ ptrdiff_t offset;
+ Dwarf_Addr *basep;
+ Dwarf_Addr *startp;
+ Dwarf_Addr *endp;
+ Dwarf_Op **expr;
+ size_t *exprlen;
+{
+ if (! attr_ok (attr))
+ return -1;
+
+ /* 1 is an invalid offset, meaning no more locations. */
+ if (offset == 1)
+ return 0;
+
+ if (offset == 0)
+ {
+ /* If it has a block form, it's a single location expression. */
+ Dwarf_Block block;
+ if (INTUSE(dwarf_formblock) (attr, &block) == 0)
{
- /* Fetch the CU's base address. */
- Dwarf_Die cudie = CUDIE (attr->cu);
-
- /* Find the base address of the compilation unit. It will
- normally be specified by DW_AT_low_pc. In DWARF-3 draft 4,
- the base address could be overridden by DW_AT_entry_pc. It's
- been removed, but GCC emits DW_AT_entry_pc and not DW_AT_lowpc
- for compilation units with discontinuous ranges. */
- Dwarf_Attribute attr_mem;
- if (unlikely (INTUSE(dwarf_lowpc) (&cudie, &base) != 0)
- && INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (&cudie,
- DW_AT_entry_pc,
- &attr_mem),
- &base) != 0)
- {
- if (INTUSE(dwarf_errno) () != 0)
- return -1;
+ if (getlocation (attr->cu, &block, expr, exprlen,
+ cu_sec_idx (attr->cu)) != 0)
+ return -1;
- /* The compiler provided no base address when it should
- have. Buggy GCC does this when it used absolute
- addresses in the location list and no DW_AT_ranges. */
- base = 0;
- }
+ /* This is the one and only location covering everything. */
+ *startp = 0;
+ *endp = -1;
+ return 1;
}
- if (address >= base + begin && address < base + end)
+ int error = INTUSE(dwarf_errno) ();
+ if (unlikely (error != DWARF_E_NO_BLOCK))
{
- /* This one matches the address. */
- if (llbufs != NULL
- && unlikely (getlocation (attr->cu, &block,
- &llbufs[got], &listlens[got],
- IDX_debug_loc) != 0))
- return -1;
- ++got;
+ __libdw_seterrno (error);
+ return -1;
}
+
+ int result = check_constant_offset (attr, expr, exprlen);
+ if (result != 1)
+ {
+ if (result == 0)
+ {
+ /* This is the one and only location covering everything. */
+ *startp = 0;
+ *endp = -1;
+ return 1;
+ }
+ return result;
+ }
+
+ /* We must be looking at a true loclistptr, fetch the initial
+ base address and offset. */
+ if (initial_offset_base (attr, &offset, basep) != 0)
+ return -1;
}
- return got;
+ const Elf_Data *d = attr->cu->dbg->sectiondata[IDX_debug_loc];
+ if (d == NULL)
+ {
+ __libdw_seterrno (DWARF_E_NO_LOCLIST);
+ return -1;
+ }
+
+ return getlocations_addr (attr, offset, basep, startp, endp,
+ (Dwarf_Word) -1, d, expr, exprlen);
}
/* Interfaces for libdw.
- Copyright (C) 2002-2010 Red Hat, Inc.
+ Copyright (C) 2002-2010, 2013 Red Hat, Inc.
This file is part of elfutils.
This file is free software; you can redistribute it and/or modify
Dwarf_Op **exprs, size_t *exprlens,
size_t nlocs);
+/* Enumerate the locations ranges and descriptions covered by the
+ given attribute. In the first call OFFSET should be zero and
+ *BASEP need not be initialized. Returns -1 for errors, zero when
+ there are no more locations to report, or a nonzero OFFSET
+ value to pass to the next call. Each subsequent call must preserve
+ *BASEP from the prior call. Successful calls fill in *STARTP and
+ *ENDP with a contiguous address range and *EXPR with a pointer to
+ an array of operations with length *EXPRLEN. If the attribute
+ describes a single location description and not a location list the
+ first call (with OFFSET zero) will return the location description
+ in *EXPR with *STARTP set to zero and *ENDP set to minus one. */
+extern ptrdiff_t dwarf_getlocations (Dwarf_Attribute *attr,
+ ptrdiff_t offset, Dwarf_Addr *basep,
+ Dwarf_Addr *startp, Dwarf_Addr *endp,
+ Dwarf_Op **expr, size_t *exprlen);
+
/* Return the block associated with a DW_OP_implicit_value operation.
The OP pointer must point into an expression that dwarf_getlocation
or dwarf_getlocation_addr has returned given the same ATTR. */
projects / thirdparty / elfutils.git / commitdiff
