From cfdd86ed929c137eaca5dd49cd266bb739c6cdbd Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 8 Jul 2009 13:15:07 -0700 Subject: [PATCH] Handle DW_AT_data_member_location of class constant magically in dwarf_getlocation{,_addr}. --- libdw/ChangeLog | 6 +++++ libdw/dwarf_getlocation.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 66 insertions(+) diff --git a/libdw/ChangeLog b/libdw/ChangeLog index 6ae3154..600f6dc 100644 --- a/libdw/ChangeLog +++ b/libdw/ChangeLog @@ -1,3 +1,9 @@ +2009-07-08 Roland McGrath + + * dwarf_getlocation.c (check_constant_offset): New function. + (dwarf_getlocation, dwarf_getlocation_addr): Call it to + handle DW_AT_data_member_location of data[48] as constant offset. + 2009-06-18 Roland McGrath * libdwP.h (__libdw_read_address_inc): Constify. diff --git a/libdw/dwarf_getlocation.c b/libdw/dwarf_getlocation.c index 504db37..62106ce 100644 --- a/libdw/dwarf_getlocation.c +++ b/libdw/dwarf_getlocation.c @@ -55,6 +55,7 @@ #include #include #include +#include #include @@ -111,6 +112,57 @@ loc_compare (const void *p1, const void *p2) return 0; } +/* DW_AT_data_member_location can be a constant as well as a loclistptr. + Only data[48] indicate a loclistptr. */ +static int +check_constant_offset (Dwarf_Attribute *attr, + Dwarf_Op **llbuf, size_t *listlen) +{ + if (attr->code != DW_AT_data_member_location + || attr->form == DW_FORM_data4 + || attr->form == DW_FORM_data8) + return 1; + + /* Check whether we already cached this location. */ + struct loc_s fake = { .addr = attr->valp }; + struct loc_s **found = tfind (&fake, &attr->cu->locs, loc_compare); + + if (found == NULL) + { + Dwarf_Word offset; + if (INTUSE(dwarf_formudata) (attr, &offset) != 0) + return -1; + + Dwarf_Op *result = libdw_alloc (attr->cu->dbg, + Dwarf_Op, sizeof (Dwarf_Op), 1); + + result->atom = DW_OP_plus_uconst; + result->number = offset; + result->number2 = 0; + result->offset = 0; + + /* Insert a record in the search tree so we can find it again later. */ + struct loc_s *newp = libdw_alloc (attr->cu->dbg, + struct loc_s, sizeof (struct loc_s), + 1); + newp->addr = attr->valp; + newp->loc = result; + newp->nloc = 1; + + found = tsearch (newp, &attr->cu->locs, loc_compare); + } + + assert ((*found)->nloc == 1); + + if (llbuf != NULL) + { + *llbuf = (*found)->loc; + *listlen = 1; + } + + return 0; +} + static int getlocation (struct Dwarf_CU *cu, const Dwarf_Block *block, Dwarf_Op **llbuf, size_t *listlen, int sec_index) @@ -333,6 +385,10 @@ dwarf_getlocation (attr, llbuf, listlen) Dwarf_Op **llbuf; size_t *listlen; { + int result = check_constant_offset (attr, llbuf, listlen); + if (result != 1) + return result; + if (! attr_ok (attr)) return -1; @@ -378,6 +434,10 @@ dwarf_getlocation_addr (attr, address, llbufs, listlens, maxlocs) return -1; } + int result = check_constant_offset (attr, &llbufs[0], &listlens[0]); + if (result != 1) + return result ?: 1; + unsigned char *endp; unsigned char *readp = __libdw_formptr (attr, IDX_debug_loc, DWARF_E_NO_LOCLIST, &endp, NULL); -- 2.7.4