diff options
Diffstat (limited to 'gdb/dwarf2read.c')
| -rw-r--r-- | gdb/dwarf2read.c | 89 |
1 files changed, 75 insertions, 14 deletions
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c index 7b36f678a30..dafee420268 100644 --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -52,6 +52,10 @@ #include "gdb_assert.h" #include <sys/types.h> +/* Loaded secondary compilation units are kept in memory until they have not + been referenced for the processing of this many compilation units. */ +#define MAX_CACHE_AGE 20 + #ifndef DWARF2_REG_TO_REGNUM #define DWARF2_REG_TO_REGNUM(REG) (REG) #endif @@ -274,6 +278,9 @@ struct dwarf2_cu /* 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; }; static const struct objfile_data *dwarf2_cu_tree; @@ -970,7 +977,11 @@ dwarf2_symbol_mark_computed (struct attribute *attr, struct symbol *sym, static struct dwarf2_per_cu_data *dwarf2_find_containing_comp_unit (unsigned long offset, struct dwarf2_cu *cu); -static void clear_per_cu_pointer (void *data); +static void clear_per_cu_pointer (void *); + +static void free_cached_comp_units (void *); + +static void free_one_cached_comp_unit (struct dwarf2_cu *, struct dwarf2_cu *); /* Allocation function for the libiberty splay tree which uses an obstack. */ static void * @@ -1270,6 +1281,7 @@ dwarf2_build_psymtabs_hard (struct objfile *objfile, int mainline) struct cleanup *back_to; CORE_ADDR lowpc, highpc, baseaddr; splay_tree cu_tree = NULL; + struct dwarf2_cu cu; info_ptr = dwarf_info_buffer; @@ -1304,6 +1316,13 @@ dwarf2_build_psymtabs_hard (struct objfile *objfile, int mainline) obstack_init (&dwarf2_tmp_obstack); back_to = make_cleanup (dwarf2_free_tmp_obstack, NULL); + /* read_in_chain, unlike every other field in the dwarf2_cu object, + is live across the loop. The function clear_per_cu_pointer will + free any allocated compilation units that have not been used in + several psymtabs. Others will remain on the list. */ + cu.read_in_chain = NULL; + make_cleanup (free_cached_comp_units, &cu); + /* Since the objects we're extracting from dwarf_info_buffer vary in length, only the individual functions to extract them (like read_comp_unit_head and load_partial_die) can really know whether @@ -1320,7 +1339,6 @@ dwarf2_build_psymtabs_hard (struct objfile *objfile, int mainline) while (info_ptr < dwarf_info_buffer + dwarf_info_size) { struct cleanup *back_to_inner; - struct dwarf2_cu cu; struct abbrev_info *abbrev; unsigned int bytes_read; struct dwarf2_per_cu_data *this_cu; @@ -1390,6 +1408,14 @@ dwarf2_build_psymtabs_hard (struct objfile *objfile, int mainline) node = splay_tree_lookup (cu_tree, cu.header.offset); gdb_assert (node != NULL); per_cu = (struct dwarf2_per_cu_data *) node->value; + + /* If we were already read in, free ourselves to read in again. + Yes, this is pointless duplication. Fixing this will provide + a nice speed boost but require a lot of editing in this + function. */ + if (per_cu->cu != NULL) + free_one_cached_comp_unit (&cu, per_cu->cu); + cu.per_cu = per_cu; /* Note that this is a pointer to our stack frame. It will @@ -1401,7 +1427,6 @@ dwarf2_build_psymtabs_hard (struct objfile *objfile, int mainline) cu.per_cu = NULL; make_cleanup (clear_per_cu_pointer, &cu); - cu.read_in_chain = NULL; /* Check if comp unit has_children. If so, read the rest of the partial symbols from this comp unit. @@ -5064,6 +5089,7 @@ find_partial_die (unsigned long offset, struct dwarf2_cu *cu, cu->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); } @@ -8765,31 +8791,66 @@ dwarf2_find_containing_comp_unit (unsigned long offset, } static void -clear_per_cu_pointer (void *data) +free_comp_units_worker (struct dwarf2_cu *cu, int aging, + struct dwarf2_cu *target_cu) { - struct dwarf2_per_cu_data *this_cu, *per_cu; - struct dwarf2_cu *cu = data; + struct dwarf2_per_cu_data *this_cu, *per_cu, **last_chain; this_cu = cu->per_cu; - if (this_cu == NULL) + if (this_cu == NULL && target_cu == NULL) return; - per_cu = this_cu->cu->read_in_chain; + per_cu = cu->read_in_chain; + last_chain = &cu->read_in_chain; while (per_cu != NULL) { struct dwarf2_per_cu_data *next_cu; - obstack_free (&per_cu->cu->partial_die_obstack, NULL); - next_cu = per_cu->cu->read_in_chain; - xfree (per_cu->cu); - per_cu->cu = NULL; + + if ((aging && per_cu->cu->last_used < MAX_CACHE_AGE) + || (target_cu && per_cu->cu == target_cu) + || (!aging && target_cu == NULL)) + { + obstack_free (&per_cu->cu->partial_die_obstack, NULL); + xfree (per_cu->cu); + per_cu->cu = NULL; + *last_chain = next_cu; + } + else + { + per_cu->cu->last_used++; + last_chain = &per_cu->cu->read_in_chain; + } + per_cu = next_cu; } /* This compilation unit is on the stack in dwarf2_build_psymtabs_hard, - so we should not xfree it. */ - this_cu->cu = NULL; + so we should not xfree it. Just unlink it. */ + if (target_cu == NULL) + { + cu->per_cu = NULL; + this_cu->cu = NULL; + } +} + +static void +clear_per_cu_pointer (void *data) +{ + free_comp_units_worker (data, 1, NULL); +} + +static void +free_cached_comp_units (void *data) +{ + free_comp_units_worker (data, 0, NULL); +} + +static void +free_one_cached_comp_unit (struct dwarf2_cu *cu, struct dwarf2_cu *target_cu) +{ + free_comp_units_worker (cu, 0, target_cu); } void _initialize_dwarf2_read (void); |