diff options
| -rw-r--r-- | gdb/ChangeLog | 4 | ||||
| -rw-r--r-- | gdb/symtab.c | 56 |
2 files changed, 60 insertions, 0 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 496ea3b8043..97806a147a0 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,9 @@ 2009-05-23 Eli Zaretskii <eliz@gnu.org> + * symtab.c (skip_prologue_using_lineinfo): New function. + (find_function_start_sal): Use it to get to the first line of + function's body that has an entry in the lineinfo table. + * symmisc.c (dump_symtab): Switch the current language to the language of the symtab we are dumping only if the symtab's language is neither language_auto nor language_unknown. diff --git a/gdb/symtab.c b/gdb/symtab.c index b8a6c31b1b0..5d375abaa94 100644 --- a/gdb/symtab.c +++ b/gdb/symtab.c @@ -2599,6 +2599,47 @@ find_function_start_pc (struct gdbarch *gdbarch, return pc; } +/* Given a function start address FUNC_ADDR and SYMTAB, find the first + address for that function that has an entry in SYMTAB's line info + table. If such an entry cannot be found, return FUNC_ADDR + unaltered. */ +CORE_ADDR +skip_prologue_using_lineinfo (CORE_ADDR func_addr, struct symtab *symtab) +{ + CORE_ADDR func_start, func_end; + struct linetable *l; + int ind, i, len; + int best_lineno = 0; + CORE_ADDR best_pc = func_addr; + + /* Give up if this symbol has no lineinfo table. */ + l = LINETABLE (symtab); + if (l == NULL) + return func_addr; + + /* Get the range for the function's PC values, or give up if we + cannot, for some reason. */ + if (!find_pc_partial_function (func_addr, NULL, &func_start, &func_end)) + return func_addr; + + /* Linetable entries are ordered by PC values, see the commentary in + symtab.h where `struct linetable' is defined. Thus, the first + entry whose PC is in the range [FUNC_START..FUNC_END[ is the + address we are looking for. */ + for (i = 0; i < l->nitems; i++) + { + struct linetable_entry *item = &(l->item[i]); + + /* Don't use line numbers of zero, they mark special entries in + the table. See the commentary on symtab.h before the + definition of struct linetable. */ + if (item->line > 0 && func_start <= item->pc && item->pc < func_end) + return item->pc; + } + + return func_addr; +} + /* Given a function symbol SYM, find the symtab and line for the start of the function. If the argument FUNFIRSTLINE is nonzero, we want the first line @@ -2649,6 +2690,21 @@ find_function_start_sal (struct symbol *sym, int funfirstline) sal = find_pc_sect_line (pc, SYMBOL_OBJ_SECTION (sym), 0); } + /* If we still don't have a valid source line, try to find the first + PC in the lineinfo table that belongs to the same function. This + happens with COFF debug info, which does not seem to have an + entry in lineinfo table for the code after the prologue which has + no direct relation to source. For example, this was found to be + the case with the DJGPP target using "gcc -gcoff" when the + compiler inserted code after the prologue to make sure the stack + is aligned. */ + if (funfirstline && sal.symtab == NULL) + { + pc = skip_prologue_using_lineinfo (pc, SYMBOL_SYMTAB (sym)); + /* Recalculate the line number. */ + sal = find_pc_sect_line (pc, SYMBOL_OBJ_SECTION (sym), 0); + } + sal.pc = pc; return sal; |