#include "dwarf2loc.h"
#include "cp-support.h"
#include "hashtab.h"
+#include "command.h"
+#include "gdbcmd.h"
#include <fcntl.h>
#include "gdb_string.h"
char *macinfo_buffer;
char *ranges_buffer;
char *loc_buffer;
+
+ /* A list of all the compilation units. This will be set if and
+ only if we have encountered a compilation unit with inter-CU
+ references. */
+ struct dwarf2_per_cu_data **all_comp_units;
+
+ /* The number of compilation units in ALL_COMP_UNITS. */
+ int n_comp_units;
+
+ /* A chain of compilation units that are currently read in, so that
+ they can be freed later. */
+ struct dwarf2_per_cu_data *read_in_chain;
};
static struct dwarf2_per_objfile *dwarf2_per_objfile;
unit, including partial DIEs. */
struct obstack comp_unit_obstack;
+ /* When multiple dwarf2_cu structures are living in memory, this field
+ chains them all together, so that they can be released efficiently.
+ We will probably also want a generation counter so that most-recently-used
+ compilation units are cached... */
+ struct dwarf2_per_cu_data *read_in_chain;
+
+ /* Backchain to our per_cu entry if the tree has been built. */
+ struct dwarf2_per_cu_data *per_cu;
+
+ /* How many compilation units ago was this CU last referenced? */
+ int last_used;
+
+ /* Mark used when releasing cached dies. */
+ unsigned int mark : 1;
+
+ /* This flag will be set if this compilation unit might include
+ inter-compilation-unit references. */
+ unsigned int has_form_ref_addr : 1;
+
/* This flag will be set if this compilation unit includes any
DW_TAG_namespace DIEs. If we know that there are explicit
DIEs for namespaces, we don't need to try to infer them
unsigned int has_namespace_info : 1;
};
+struct dwarf2_per_cu_data
+{
+ /* The start offset and length of this compilation unit. 2**31-1
+ bytes should suffice to store the length of any compilation unit
+ - if it doesn't, GDB will fall over anyway. */
+ unsigned long offset;
+ unsigned long length : 31;
+
+ /* Flag indicating this compilation unit will be read in before
+ any of the current compilation units are processed. */
+ unsigned long queued : 1;
+
+ /* Set iff currently read in. */
+ struct dwarf2_cu *cu;
+};
+
/* The line number information for a compilation unit (found in the
.debug_line section) begins with a "statement program header",
which contains the following information. */
int nfnfields;
};
+/* Loaded secondary compilation units are kept in memory until they
+ have not been referenced for the processing of this many
+ compilation units. Set this to zero to disable caching. Cache
+ sizes of up to at least twenty will improve startup time for
+ typical inter-CU-reference binaries, at an obvious memory cost. */
+static int dwarf2_max_cache_age = 5;
+
/* Various complaints about symbol reading that don't abort the process */
static void
static int partial_die_eq (const void *item_lhs, const void *item_rhs);
+static struct dwarf2_per_cu_data *dwarf2_find_containing_comp_unit
+ (unsigned long offset, struct objfile *objfile);
+
+static struct dwarf2_per_cu_data *dwarf2_find_comp_unit
+ (unsigned long offset, struct objfile *objfile);
+
+static void free_one_comp_unit (void *);
+
+static void free_cached_comp_units (void *);
+
+static void age_cached_comp_units (void);
+
+static void free_one_cached_comp_unit (void *);
+
+static void create_all_comp_units (struct objfile *);
+
+static void dwarf2_mark (struct dwarf2_cu *);
+
+static void dwarf2_clear_marks (struct dwarf2_per_cu_data *);
+
/* Try to locate the sections we need for DWARF 2 debugging
information and return true if we have enough to do something. */
char *beg_of_comp_unit;
struct partial_die_info comp_unit_die;
struct partial_symtab *pst;
+ struct cleanup *back_to;
CORE_ADDR lowpc, highpc, baseaddr;
info_ptr = dwarf2_per_objfile->info_buffer;
+ /* Any cached compilation units will be linked by the per-objfile
+ read_in_chain. Make sure to free them when we're done. */
+ back_to = make_cleanup (free_cached_comp_units, NULL);
+
/* Since the objects we're extracting from .debug_info vary in
length, only the individual functions to extract them (like
read_comp_unit_head and load_partial_die) can really know whether
cu.list_in_scope = &file_symbols;
- cu.partial_dies = NULL;
-
/* Read the abbrevs for this compilation unit into a table */
dwarf2_read_abbrevs (abfd, &cu);
make_cleanup (dwarf2_free_abbrev_table, &cu);
+ if (cu.has_form_ref_addr && dwarf2_per_objfile->all_comp_units == NULL)
+ create_all_comp_units (objfile);
+
/* Read the compilation unit die */
abbrev = peek_die_abbrev (info_ptr, &bytes_read, &cu);
info_ptr = read_partial_die (&comp_unit_die, abbrev, bytes_read,
objfile->global_psymbols.next,
objfile->static_psymbols.next);
- if (comp_unit_die.dirname)
- pst->dirname = xstrdup (comp_unit_die.dirname);
+ if (comp_unit_die.dirname)
+ pst->dirname = xstrdup (comp_unit_die.dirname);
pst->read_symtab_private = (char *)
obstack_alloc (&objfile->objfile_obstack, sizeof (struct dwarf2_pinfo));
/* Store the function that reads in the rest of the symbol table */
pst->read_symtab = dwarf2_psymtab_to_symtab;
+ if (dwarf2_per_objfile->all_comp_units != NULL)
+ {
+ struct dwarf2_per_cu_data *per_cu;
+
+ per_cu = dwarf2_find_comp_unit (cu.header.offset, objfile);
+
+ /* If this compilation unit was already read in, free the
+ cached copy in order to read it in again. This is
+ necessary because we skipped some symbols when we first
+ read in the compilation unit (see load_partial_dies).
+ This problem could be avoided, but the benefit is
+ unclear. */
+ if (per_cu->cu != NULL)
+ free_one_cached_comp_unit (per_cu->cu);
+
+ cu.per_cu = per_cu;
+
+ /* Note that this is a pointer to our stack frame, being
+ added to a global data structure. It will be cleaned up
+ in free_stack_comp_unit when we finish with this
+ compilation unit. */
+ per_cu->cu = &cu;
+ }
+ else
+ cu.per_cu = NULL;
+
/* Check if comp unit has_children.
If so, read the rest of the partial symbols from this comp unit.
If not, there's no more debug_info for this comp unit. */
do_cleanups (back_to_inner);
}
+ do_cleanups (back_to);
+}
+
+/* Load the DIEs for a secondary CU into memory. */
+
+static void
+load_comp_unit (struct dwarf2_per_cu_data *this_cu, struct objfile *objfile)
+{
+ bfd *abfd = objfile->obfd;
+ char *info_ptr, *beg_of_comp_unit;
+ struct partial_die_info comp_unit_die;
+ struct dwarf2_cu *cu;
+ struct abbrev_info *abbrev;
+ unsigned int bytes_read;
+ struct cleanup *back_to;
+
+ info_ptr = dwarf2_per_objfile->info_buffer + this_cu->offset;
+ beg_of_comp_unit = info_ptr;
+
+ cu = xmalloc (sizeof (struct dwarf2_cu));
+ memset (cu, 0, sizeof (struct dwarf2_cu));
+
+ obstack_init (&cu->comp_unit_obstack);
+
+ cu->objfile = objfile;
+ info_ptr = partial_read_comp_unit_head (&cu->header, info_ptr, abfd);
+
+ /* Complete the cu_header. */
+ cu->header.offset = beg_of_comp_unit - dwarf2_per_objfile->info_buffer;
+ cu->header.first_die_ptr = info_ptr;
+ cu->header.cu_head_ptr = beg_of_comp_unit;
+
+ /* Read the abbrevs for this compilation unit into a table. */
+ dwarf2_read_abbrevs (abfd, cu);
+ back_to = make_cleanup (dwarf2_free_abbrev_table, cu);
+
+ /* Read the compilation unit die. */
+ abbrev = peek_die_abbrev (info_ptr, &bytes_read, cu);
+ info_ptr = read_partial_die (&comp_unit_die, abbrev, bytes_read,
+ abfd, info_ptr, cu);
+
+ /* Set the language we're debugging. */
+ set_cu_language (comp_unit_die.language, cu);
+
+ /* Link this compilation unit into the compilation unit tree. */
+ this_cu->cu = cu;
+ cu->per_cu = this_cu;
+
+ /* Check if comp unit has_children.
+ If so, read the rest of the partial symbols from this comp unit.
+ If not, there's no more debug_info for this comp unit. */
+ if (comp_unit_die.has_children)
+ load_partial_dies (abfd, info_ptr, 0, cu);
+
+ do_cleanups (back_to);
+}
+
+/* Create a list of all compilation units in OBJFILE. We do this only
+ if an inter-comp-unit reference is found; presumably if there is one,
+ there will be many, and one will occur early in the .debug_info section.
+ So there's no point in building this list incrementally. */
+
+static void
+create_all_comp_units (struct objfile *objfile)
+{
+ int n_allocated;
+ int n_comp_units;
+ struct dwarf2_per_cu_data **all_comp_units;
+ char *info_ptr = dwarf2_per_objfile->info_buffer;
+
+ n_comp_units = 0;
+ n_allocated = 10;
+ all_comp_units = xmalloc (n_allocated
+ * sizeof (struct dwarf2_per_cu_data *));
+
+ while (info_ptr < dwarf2_per_objfile->info_buffer + dwarf2_per_objfile->info_size)
+ {
+ struct comp_unit_head cu_header;
+ char *beg_of_comp_unit;
+ struct dwarf2_per_cu_data *this_cu;
+ unsigned long offset;
+ int bytes_read;
+
+ offset = info_ptr - dwarf2_per_objfile->info_buffer;
+
+ /* Read just enough information to find out where the next
+ compilation unit is. */
+ cu_header.length = read_initial_length (objfile->obfd, info_ptr,
+ &cu_header, &bytes_read);
+
+ /* Save the compilation unit for later lookup. */
+ this_cu = obstack_alloc (&objfile->objfile_obstack,
+ sizeof (struct dwarf2_per_cu_data));
+ memset (this_cu, 0, sizeof (*this_cu));
+ this_cu->offset = offset;
+ this_cu->length = cu_header.length + cu_header.initial_length_size;
+
+ if (n_comp_units == n_allocated)
+ {
+ n_allocated *= 2;
+ all_comp_units = xrealloc (all_comp_units,
+ n_allocated
+ * sizeof (struct dwarf2_per_cu_data *));
+ }
+ all_comp_units[n_comp_units++] = this_cu;
+
+ info_ptr = info_ptr + this_cu->length;
+ }
+
+ dwarf2_per_objfile->all_comp_units
+ = obstack_alloc (&objfile->objfile_obstack,
+ n_comp_units * sizeof (struct dwarf2_per_cu_data *));
+ memcpy (dwarf2_per_objfile->all_comp_units, all_comp_units,
+ n_comp_units * sizeof (struct dwarf2_per_cu_data *));
+ xfree (all_comp_units);
+ dwarf2_per_objfile->n_comp_units = n_comp_units;
}
/* Process all loaded DIEs for compilation unit CU, starting at FIRST_DIE.
/* We're in the global namespace. */
processing_current_prefix = "";
+ memset (&cu, 0, sizeof (struct dwarf2_cu));
obstack_init (&cu.comp_unit_obstack);
back_to = make_cleanup (free_stack_comp_unit, &cu);
= xrealloc (cur_attrs, (allocated_attrs
* sizeof (struct attr_abbrev)));
}
+
+ /* Record whether this compilation unit might have
+ inter-compilation-unit references. If we don't know what form
+ this attribute will have, then it might potentially be a
+ DW_FORM_ref_addr, so we conservatively expect inter-CU
+ references. */
+
+ if (abbrev_form == DW_FORM_ref_addr
+ || abbrev_form == DW_FORM_indirect)
+ cu->has_form_ref_addr = 1;
+
cur_attrs[cur_abbrev->num_attrs].name = abbrev_name;
cur_attrs[cur_abbrev->num_attrs++].form = abbrev_form;
abbrev_name = read_unsigned_leb128 (abfd, abbrev_ptr, &bytes_read);
return find_partial_die_in_comp_unit (offset, cu);
}
- internal_error (__FILE__, __LINE__,
- "unsupported inter-compilation-unit reference");
+ per_cu = dwarf2_find_containing_comp_unit (offset, cu->objfile);
+
+ /* If this offset isn't pointing into a known compilation unit,
+ the debug information is probably corrupted. */
+ if (per_cu == NULL)
+ error ("Dwarf Error: could not find partial DIE containing "
+ "offset 0x%lx [in module %s]",
+ (long) offset, bfd_get_filename (cu->objfile->obfd));
+
+ if (per_cu->cu == NULL)
+ {
+ load_comp_unit (per_cu, cu->objfile);
+ per_cu->cu->read_in_chain = dwarf2_per_objfile->read_in_chain;
+ dwarf2_per_objfile->read_in_chain = per_cu;
+ }
+
+ per_cu->cu->last_used = 0;
+ *target_cu = per_cu->cu;
+ return find_partial_die_in_comp_unit (offset, per_cu->cu);
}
/* Adjust PART_DIE before generating a symbol for it. This function
}
}
+/* Locate the compilation unit from CU's objfile which contains the
+ DIE at OFFSET. Returns NULL on failure. */
+
+static struct dwarf2_per_cu_data *
+dwarf2_find_containing_comp_unit (unsigned long offset,
+ struct objfile *objfile)
+{
+ struct dwarf2_per_cu_data *this_cu;
+ int low, high;
+
+ if (dwarf2_per_objfile->all_comp_units == NULL)
+ error ("Dwarf Error: offset 0x%lx points outside this "
+ "compilation unit [in module %s]",
+ offset, bfd_get_filename (objfile->obfd));
+
+ low = 0;
+ high = dwarf2_per_objfile->n_comp_units - 1;
+ while (high > low)
+ {
+ int mid = low + (high - low) / 2;
+ if (dwarf2_per_objfile->all_comp_units[mid]->offset >= offset)
+ high = mid;
+ else
+ low = mid + 1;
+ }
+ gdb_assert (low == high);
+ if (dwarf2_per_objfile->all_comp_units[low]->offset > offset)
+ {
+ gdb_assert (low > 0);
+ gdb_assert (dwarf2_per_objfile->all_comp_units[low-1]->offset <= offset);
+ return dwarf2_per_objfile->all_comp_units[low-1];
+ }
+ else
+ {
+ this_cu = dwarf2_per_objfile->all_comp_units[low];
+ if (low == dwarf2_per_objfile->n_comp_units - 1
+ && offset >= this_cu->offset + this_cu->length)
+ error ("invalid dwarf2 offset %ld", offset);
+ gdb_assert (offset < this_cu->offset + this_cu->length);
+ return this_cu;
+ }
+}
+
+static struct dwarf2_per_cu_data *
+dwarf2_find_comp_unit (unsigned long offset, struct objfile *objfile)
+{
+ struct dwarf2_per_cu_data *this_cu;
+ this_cu = dwarf2_find_containing_comp_unit (offset, objfile);
+ if (this_cu->offset != offset)
+ error ("no compilation unit with offset %ld\n", offset);
+ return this_cu;
+}
+
+/* Release one cached compilation unit, CU. We unlink it from the tree
+ of compilation units, but we don't remove it from the read_in_chain;
+ the caller is responsible for that. */
+
+static void
+free_one_comp_unit (void *data)
+{
+ struct dwarf2_cu *cu = data;
+
+ if (cu->per_cu != NULL)
+ cu->per_cu->cu = NULL;
+ cu->per_cu = NULL;
+
+ obstack_free (&cu->comp_unit_obstack, NULL);
+
+ xfree (cu);
+}
+
/* This cleanup function is passed the address of a dwarf2_cu on the stack
- when we're finished with it. We can't free the pointer itself, but
- release any associated storage.
+ when we're finished with it. We can't free the pointer itself, but be
+ sure to unlink it from the cache. Also release any associated storage
+ and perform cache maintenance.
Only used during partial symbol parsing. */
obstack_free (&cu->comp_unit_obstack, NULL);
cu->partial_dies = NULL;
+
+ if (cu->per_cu != NULL)
+ {
+ /* This compilation unit is on the stack in our caller, so we
+ should not xfree it. Just unlink it. */
+ cu->per_cu->cu = NULL;
+ cu->per_cu = NULL;
+
+ /* If we had a per-cu pointer, then we may have other compilation
+ units loaded, so age them now. */
+ age_cached_comp_units ();
+ }
+}
+
+/* Free all cached compilation units. */
+
+static void
+free_cached_comp_units (void *data)
+{
+ struct dwarf2_per_cu_data *per_cu, **last_chain;
+
+ per_cu = dwarf2_per_objfile->read_in_chain;
+ last_chain = &dwarf2_per_objfile->read_in_chain;
+ while (per_cu != NULL)
+ {
+ struct dwarf2_per_cu_data *next_cu;
+
+ next_cu = per_cu->cu->read_in_chain;
+
+ free_one_comp_unit (per_cu->cu);
+ *last_chain = next_cu;
+
+ per_cu = next_cu;
+ }
+}
+
+/* Increase the age counter on each cached compilation unit, and free
+ any that are too old. */
+
+static void
+age_cached_comp_units (void)
+{
+ struct dwarf2_per_cu_data *per_cu, **last_chain;
+
+ dwarf2_clear_marks (dwarf2_per_objfile->read_in_chain);
+ per_cu = dwarf2_per_objfile->read_in_chain;
+ while (per_cu != NULL)
+ {
+ per_cu->cu->last_used ++;
+ if (per_cu->cu->last_used <= dwarf2_max_cache_age)
+ dwarf2_mark (per_cu->cu);
+ per_cu = per_cu->cu->read_in_chain;
+ }
+
+ per_cu = dwarf2_per_objfile->read_in_chain;
+ last_chain = &dwarf2_per_objfile->read_in_chain;
+ while (per_cu != NULL)
+ {
+ struct dwarf2_per_cu_data *next_cu;
+
+ next_cu = per_cu->cu->read_in_chain;
+
+ if (!per_cu->cu->mark)
+ {
+ free_one_comp_unit (per_cu->cu);
+ *last_chain = next_cu;
+ }
+ else
+ last_chain = &per_cu->cu->read_in_chain;
+
+ per_cu = next_cu;
+ }
+}
+
+/* Remove a single compilation unit from the cache. */
+
+static void
+free_one_cached_comp_unit (void *target_cu)
+{
+ struct dwarf2_per_cu_data *per_cu, **last_chain;
+
+ per_cu = dwarf2_per_objfile->read_in_chain;
+ last_chain = &dwarf2_per_objfile->read_in_chain;
+ while (per_cu != NULL)
+ {
+ struct dwarf2_per_cu_data *next_cu;
+
+ next_cu = per_cu->cu->read_in_chain;
+
+ if (per_cu->cu == target_cu)
+ {
+ free_one_comp_unit (per_cu->cu);
+ *last_chain = next_cu;
+ break;
+ }
+ else
+ last_chain = &per_cu->cu->read_in_chain;
+
+ per_cu = next_cu;
+ }
+}
+
+/* Set the mark field in CU and in every other compilation unit in the
+ cache that we must keep because we are keeping CU. */
+
+static void
+dwarf2_mark (struct dwarf2_cu *cu)
+{
+ if (cu->mark)
+ return;
+ cu->mark = 1;
+}
+
+static void
+dwarf2_clear_marks (struct dwarf2_per_cu_data *per_cu)
+{
+ while (per_cu)
+ {
+ per_cu->cu->mark = 0;
+ per_cu = per_cu->cu->read_in_chain;
+ }
}
/* Allocation function for the libiberty hash table which uses an
return part_die_lhs->offset == part_die_rhs->offset;
}
+static struct cmd_list_element *set_dwarf2_cmdlist;
+static struct cmd_list_element *show_dwarf2_cmdlist;
+
+static void
+set_dwarf2_cmd (char *args, int from_tty)
+{
+ help_list (set_dwarf2_cmdlist, "maintenance set dwarf2 ", -1, gdb_stdout);
+}
+
+static void
+show_dwarf2_cmd (char *args, int from_tty)
+{
+ cmd_show_list (show_dwarf2_cmdlist, from_tty, "");
+}
+
void _initialize_dwarf2_read (void);
void
_initialize_dwarf2_read (void)
{
dwarf2_objfile_data_key = register_objfile_data ();
+
+ add_prefix_cmd ("dwarf2", class_maintenance, set_dwarf2_cmd,
+ "Set DWARF 2 specific variables.\n"
+ "Configure DWARF 2 variables such as the cache size",
+ &set_dwarf2_cmdlist, "maintenance set dwarf2 ",
+ 0/*allow-unknown*/, &maintenance_set_cmdlist);
+
+ add_prefix_cmd ("dwarf2", class_maintenance, show_dwarf2_cmd,
+ "Show DWARF 2 specific variables\n"
+ "Show DWARF 2 variables such as the cache size",
+ &show_dwarf2_cmdlist, "maintenance show dwarf2 ",
+ 0/*allow-unknown*/, &maintenance_show_cmdlist);
+
+ add_setshow_zinteger_cmd ("max-cache-age", class_obscure,
+ &dwarf2_max_cache_age,
+ "Set the upper bound on the age of cached "
+ "dwarf2 compilation units.",
+ "Show the upper bound on the age of cached "
+ "dwarf2 compilation units.",
+ "A higher limit means that cached "
+ "compilation units will be stored\n"
+ "in memory longer, and more total memory will "
+ "be used. Zero disables\n"
+ "caching, which can slow down startup.",
+ "The upper bound on the age of cached "
+ "dwarf2 compilation units is %d.",
+ NULL, NULL, &set_dwarf2_cmdlist,
+ &show_dwarf2_cmdlist);
}
projects / binutils-gdb.git / commitdiff