diff options
Diffstat (limited to 'gdb/buildsym.c')
| -rw-r--r-- | gdb/buildsym.c | 220 |
1 files changed, 149 insertions, 71 deletions
diff --git a/gdb/buildsym.c b/gdb/buildsym.c index 4aeb6ac..35b3f17 100644 --- a/gdb/buildsym.c +++ b/gdb/buildsym.c @@ -21,7 +21,53 @@ file-reading routines. Routines to support specific debugging information formats (stabs, - DWARF, etc) belong somewhere else. */ + DWARF, etc) belong somewhere else. + + The basic way this module is used is as follows: + + buildsym_init (); + cleanups = make_cleanup (really_free_pendings, NULL); + cust = start_symtab (...); + ... read debug info ... + cust = end_symtab (...); + do_cleanups (cleanups); + + The compunit symtab pointer ("cust") is returned from both start_symtab + and end_symtab to simplify the debug info readers. + + There are minor variations on this, e.g., dwarf2read.c splits end_symtab + into two calls: end_symtab_get_static_block, end_symtab_from_static_block, + but all debug info readers follow this basic flow. + + Reading DWARF Type Units is another variation: + + buildsym_init (); + cleanups = make_cleanup (really_free_pendings, NULL); + cust = start_symtab (...); + ... read debug info ... + cust = end_expandable_symtab (...); + do_cleanups (cleanups); + + And then reading subsequent Type Units within the containing "Comp Unit" + will use a second flow: + + buildsym_init (); + cleanups = make_cleanup (really_free_pendings, NULL); + cust = restart_symtab (...); + ... read debug info ... + cust = augment_type_symtab (...); + do_cleanups (cleanups); + + dbxread.c and xcoffread.c use another variation: + + buildsym_init (); + cleanups = make_cleanup (really_free_pendings, NULL); + cust = start_symtab (...); + ... read debug info ... + cust = end_symtab (...); + ... start_symtab + read + end_symtab repeated ... + do_cleanups (cleanups); +*/ #include "defs.h" #include "bfd.h" @@ -146,6 +192,8 @@ static struct subfile_stack *subfile_stack; currently reading. */ static struct macro_table *pending_macros; +static void free_buildsym_compunit (void); + static int compare_line_numbers (const void *ln1p, const void *ln2p); static void record_pending_block (struct objfile *objfile, @@ -220,8 +268,12 @@ find_symbol_in_list (struct pending *list, char *name, int length) return (NULL); } -/* At end of reading syms, or in case of quit, really free as many - `struct pending's as we can easily find. */ +/* At end of reading syms, or in case of quit, ensure everything associated + with building symtabs is freed. This is intended to be registered as a + cleanup before doing psymtab->symtab expansion. + + N.B. This is *not* intended to be used when building psymtabs. Some debug + info readers call this anyway, which is harmless if confusing. */ void really_free_pendings (void *dummy) @@ -253,12 +305,13 @@ really_free_pendings (void *dummy) if (pending_macros) free_macro_table (pending_macros); + pending_macros = NULL; if (pending_addrmap) - { - obstack_free (&pending_addrmap_obstack, NULL); - pending_addrmap = NULL; - } + obstack_free (&pending_addrmap_obstack, NULL); + pending_addrmap = NULL; + + free_buildsym_compunit (); } /* This function is called to discard any pending blocks. */ @@ -744,6 +797,7 @@ free_buildsym_compunit (void) xfree (buildsym_compunit->comp_dir); xfree (buildsym_compunit); buildsym_compunit = NULL; + current_subfile = NULL; } /* For stabs readers, the first N_SO symbol is assumed to be the @@ -943,6 +997,32 @@ get_macro_table (void) return pending_macros; } +/* Init state to prepare for building a symtab. + Note: This can't be done in buildsym_init because dbxread.c and xcoffread.c + can call start_symtab+end_symtab multiple times after one call to + buildsym_init. */ + +static void +prepare_for_building (const char *name, CORE_ADDR start_addr) +{ + set_last_source_file (name); + last_source_start_addr = start_addr; + + local_symbols = NULL; + within_function = 0; + have_line_numbers = 0; + + context_stack_depth = 0; + + /* These should have been reset either by successful completion of building + a symtab, or by the really_free_pendings cleanup. */ + gdb_assert (file_symbols == NULL); + gdb_assert (global_symbols == NULL); + gdb_assert (pending_macros == NULL); + gdb_assert (pending_addrmap == NULL); + gdb_assert (current_subfile == NULL); +} + /* Start a new symtab for a new source file in OBJFILE. Called, for example, when a stabs symbol of type N_SO is seen, or when a DWARF TAG_compile_unit DIE is seen. It indicates the start of data for @@ -956,11 +1036,11 @@ struct compunit_symtab * start_symtab (struct objfile *objfile, const char *name, const char *comp_dir, CORE_ADDR start_addr) { - restart_symtab (start_addr); + prepare_for_building (name, start_addr); buildsym_compunit = start_buildsym_compunit (objfile, comp_dir); - /* Allocate the primary symtab now. The caller needs it to allocate + /* Allocate the compunit symtab now. The caller needs it to allocate non-primary symtabs. It is also needed by get_macro_table. */ buildsym_compunit->compunit_symtab = allocate_compunit_symtab (objfile, name); @@ -976,43 +1056,27 @@ start_symtab (struct objfile *objfile, const char *name, const char *comp_dir, of the subfiles list. */ buildsym_compunit->main_subfile = current_subfile; - set_last_source_file (name); - return buildsym_compunit->compunit_symtab; } /* Restart compilation for a symtab. + CUST is the result of end_expandable_symtab. + NAME, START_ADDR are the source file we are resuming with. + This is used when a symtab is built from multiple sources. - The symtab is first built with start_symtab and then for each additional - piece call restart_symtab. */ + The symtab is first built with start_symtab/end_expandable_symtab + and then for each additional piece call restart_symtab/augment_*_symtab. + Note: At the moment there is only augment_type_symtab. */ void -restart_symtab (CORE_ADDR start_addr) +restart_symtab (struct compunit_symtab *cust, + const char *name, CORE_ADDR start_addr) { - set_last_source_file (NULL); - last_source_start_addr = start_addr; - file_symbols = NULL; - global_symbols = NULL; - within_function = 0; - have_line_numbers = 0; + prepare_for_building (name, start_addr); - /* Context stack is initially empty. Allocate first one with room - for 10 levels; reuse it forever afterward. */ - if (context_stack == NULL) - { - context_stack_size = INITIAL_CONTEXT_STACK_SIZE; - context_stack = (struct context_stack *) - xmalloc (context_stack_size * sizeof (struct context_stack)); - } - context_stack_depth = 0; - - /* We shouldn't have any address map at this point. */ - gdb_assert (! pending_addrmap); - - /* Reset the sub source files list. The list should already be empty, - but free it anyway in case some code didn't finish cleaning up after - an error. */ - free_buildsym_compunit (); + buildsym_compunit = start_buildsym_compunit (COMPUNIT_OBJFILE (cust), + COMPUNIT_DIRNAME (cust)); + buildsym_compunit->compunit_symtab = cust; } /* Subroutine of end_symtab to simplify it. Look for a subfile that @@ -1101,19 +1165,30 @@ block_compar (const void *ap, const void *bp) - (BLOCK_START (b) < BLOCK_START (a))); } -/* Reset globals used to build symtabs. */ +/* Reset state after a successful building of a symtab. + This exists because dbxread.c and xcoffread.c can call + start_symtab+end_symtab multiple times after one call to buildsym_init, + and before the really_free_pendings cleanup is called. + We keep the free_pendings list around for dbx/xcoff sake. */ static void reset_symtab_globals (void) { set_last_source_file (NULL); - free_buildsym_compunit (); + + local_symbols = NULL; + file_symbols = NULL; + global_symbols = NULL; + + /* We don't free pending_macros here because if the symtab was successfully + built then ownership was transferred to the symtab. */ pending_macros = NULL; + if (pending_addrmap) - { - obstack_free (&pending_addrmap_obstack, NULL); - pending_addrmap = NULL; - } + obstack_free (&pending_addrmap_obstack, NULL); + pending_addrmap = NULL; + + free_buildsym_compunit (); } /* Implementation of the first part of end_symtab. It allows modifying @@ -1221,23 +1296,6 @@ end_symtab_get_static_block (CORE_ADDR end_addr, int expandable, int required) } /* Subroutine of end_symtab_from_static_block to simplify it. - Handle the "no blockvector" case. - When this happens there is nothing to record, so just free up - any memory we allocated while reading debug info. */ - -static void -end_symtab_without_blockvector (void) -{ - /* Free up all the subfiles. - We won't be adding a compunit to the objfile's list of compunits, - so there's nothing to unchain. However, since each symtab - is added to the objfile's obstack we can't free that space. - We could do better, but this is believed to be a sufficiently rare - event. */ - free_buildsym_compunit (); -} - -/* Subroutine of end_symtab_from_static_block to simplify it. Handle the "have blockvector" case. See end_symtab_from_static_block for a description of the arguments. */ @@ -1349,7 +1407,7 @@ end_symtab_with_blockvector (struct block *static_block, gdb_assert (main_symtab == COMPUNIT_FILETABS (cu)); } - /* Fill out the primary symtab. */ + /* Fill out the compunit symtab. */ if (buildsym_compunit->comp_dir != NULL) { @@ -1406,7 +1464,6 @@ end_symtab_with_blockvector (struct block *static_block, } add_compunit_symtab_to_objfile (cu); - free_buildsym_compunit (); return cu; } @@ -1428,7 +1485,15 @@ end_symtab_from_static_block (struct block *static_block, if (static_block == NULL) { - end_symtab_without_blockvector (); + /* Handle the "no blockvector" case. + When this happens there is nothing to record, so there's nothing + to do: memory will be freed up later. + + Note: We won't be adding a compunit to the objfile's list of + compunits, so there's nothing to unchain. However, since each symtab + is added to the objfile's obstack we can't free that space. + We could do better, but this is believed to be a sufficiently rare + event. */ cu = NULL; } else @@ -1506,8 +1571,9 @@ set_missing_symtab (struct pending *pending_list, This is the case for DWARF4 Type Units. */ void -augment_type_symtab (struct compunit_symtab *cust) +augment_type_symtab (void) { + struct compunit_symtab *cust = buildsym_compunit->compunit_symtab; const struct blockvector *blockvector = COMPUNIT_BLOCKVECTOR (cust); if (context_stack_depth > 0) @@ -1674,17 +1740,29 @@ get_last_source_file (void) void buildsym_init (void) { - free_pendings = NULL; - file_symbols = NULL; - global_symbols = NULL; - pending_blocks = NULL; - pending_macros = NULL; using_directives = NULL; subfile_stack = NULL; - /* We shouldn't have any address map at this point. */ - gdb_assert (! pending_addrmap); pending_addrmap_interesting = 0; + + /* Context stack is initially empty. Allocate first one with room + for a few levels; reuse it forever afterward. */ + if (context_stack == NULL) + { + context_stack_size = INITIAL_CONTEXT_STACK_SIZE; + context_stack = (struct context_stack *) + xmalloc (context_stack_size * sizeof (struct context_stack)); + } + + /* Ensure the really_free_pendings cleanup was called after + the last time. */ + gdb_assert (free_pendings == NULL); + gdb_assert (pending_blocks == NULL); + gdb_assert (file_symbols == NULL); + gdb_assert (global_symbols == NULL); + gdb_assert (pending_macros == NULL); + gdb_assert (pending_addrmap == NULL); + gdb_assert (buildsym_compunit == NULL); } /* Initialize anything that needs initializing when a completely new |