From 52948f01e4a11f5fcebdca112036f907ac69e7ad Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Thu, 3 May 2018 16:36:20 -0600 Subject: [PATCH] Add validity bits for psymtab high and low fields Right now some psymtab code checks whether a psymtab's textlow or texthigh fields are valid by comparing against 0. I imagine this is mildly wrong in the current environment, but once psymtabs are relocated dynamically, it will no longer be correct, because it will be much more normal to see a psymtab with a textlow of zero -- this will just mean it appears at the start of the text section. This patch introduces validity bits to handle this situation more nicely, and changes users of the code to follow. gdb/ChangeLog 2018-07-26 Tom Tromey * dbxread.c (end_psymtab): Use text_high_valid and text_low_valid. * mdebugread.c (parse_partial_symbols): Use text_low_valid. (psymtab_to_symtab_1): Use text_high_valid and text_low_valid. * psympriv.h (struct partial_symtab) : Update comment. : New fields. : Update. * xcoffread.c (scan_xcoff_symtab): Use text_low_valid. --- gdb/ChangeLog | 12 ++++++++++++ gdb/dbxread.c | 8 +++----- gdb/mdebugread.c | 8 ++++---- gdb/psympriv.h | 11 ++++++++++- gdb/xcoffread.c | 2 +- 5 files changed, 30 insertions(+), 11 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index e6972c29505..b4ab4ff6360 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2018-07-26 Tom Tromey + + * dbxread.c (end_psymtab): Use text_high_valid and + text_low_valid. + * mdebugread.c (parse_partial_symbols): Use text_low_valid. + (psymtab_to_symtab_1): Use text_high_valid and text_low_valid. + * psympriv.h (struct partial_symtab) : + Update comment. + : New fields. + : Update. + * xcoffread.c (scan_xcoff_symtab): Use text_low_valid. + 2018-07-26 Tom Tromey * dbxread.c (read_dbx_symtab, end_psymtab, read_ofile_symtab): diff --git a/gdb/dbxread.c b/gdb/dbxread.c index d5d4e083c5a..5409a727467 100644 --- a/gdb/dbxread.c +++ b/gdb/dbxread.c @@ -2002,7 +2002,7 @@ dbx_end_psymtab (struct objfile *objfile, struct partial_symtab *pst, a reliable texthigh by taking the address plus size of the last function in the file. */ - if (pst->text_high () == 0 && last_function_name + if (!pst->text_high_valid && last_function_name && gdbarch_sofun_address_maybe_missing (gdbarch)) { int n; @@ -2047,13 +2047,11 @@ dbx_end_psymtab (struct objfile *objfile, struct partial_symtab *pst, /* If we know our own starting text address, then walk through all other psymtabs for this objfile, and if any didn't know their ending text address, set it to our starting address. Take care to not set our - own ending address to our starting address, nor to set addresses on - `dependency' files that have both textlow and texthigh zero. */ + own ending address to our starting address. */ ALL_OBJFILE_PSYMTABS (objfile, p1) { - if (p1->text_high () == 0 && p1->text_low () != 0 - && p1 != pst) + if (!p1->text_high_valid && p1->text_low_valid && p1 != pst) p1->set_text_high (pst->text_low ()); } } diff --git a/gdb/mdebugread.c b/gdb/mdebugread.c index 262c619d401..436ef95dd32 100644 --- a/gdb/mdebugread.c +++ b/gdb/mdebugread.c @@ -2736,7 +2736,7 @@ parse_partial_symbols (minimal_symbol_reader &reader, /* Kludge for Irix 5.2 zero fh->adr. */ if (!relocatable - && (pst->text_low () == 0 + && (!pst->text_low_valid || procaddr < pst->text_low ())) pst->set_text_low (procaddr); if (high > pst->text_high ()) @@ -3512,7 +3512,7 @@ parse_partial_symbols (minimal_symbol_reader &reader, /* Kludge for Irix 5.2 zero fh->adr. */ if (!relocatable - && (pst->text_low () == 0 + && (!pst->text_low_valid || procaddr < pst->text_low ())) pst->set_text_low (procaddr); @@ -3711,7 +3711,7 @@ parse_partial_symbols (minimal_symbol_reader &reader, other cases. */ save_pst = fdr_to_pst[f_idx].pst; if (save_pst != NULL - && save_pst->text_low () != 0 + && save_pst->text_low_valid && !(objfile->flags & OBJF_REORDERED)) { ALL_OBJFILE_PSYMTABS (objfile, pst) @@ -3922,7 +3922,7 @@ psymtab_to_symtab_1 (struct objfile *objfile, /* Do nothing if this is a dummy psymtab. */ if (pst->n_global_syms == 0 && pst->n_static_syms == 0 - && pst->text_low () == 0 && pst->text_high () == 0) + && !pst->text_low_valid && !pst->text_high_valid) return; /* Now read the symbols for this symtab. */ diff --git a/gdb/psympriv.h b/gdb/psympriv.h index 7116a1a5957..b3bda82b7b3 100644 --- a/gdb/psympriv.h +++ b/gdb/psympriv.h @@ -114,12 +114,14 @@ struct partial_symtab void set_text_low (CORE_ADDR addr) { m_text_low = addr; + text_low_valid = 1; } /* Set the hight text address of this partial_symtab. */ void set_text_high (CORE_ADDR addr) { m_text_high = addr; + text_high_valid = 1; } @@ -144,7 +146,9 @@ struct partial_symtab /* Range of text addresses covered by this file; texthigh is the beginning of the next section. Do not use if PSYMTABS_ADDRMAP_SUPPORTED is set. Do not refer directly to these fields. Instead, use the - accessors. */ + accessors. The validity of these fields is determined by the + text_low_valid and text_high_valid fields; these are located later + in this structure for better packing. */ CORE_ADDR m_text_low; CORE_ADDR m_text_high; @@ -230,6 +234,11 @@ struct partial_symtab ENUM_BITFIELD (psymtab_search_status) searched_flag : 2; + /* Validity of the m_text_low and m_text_high fields. */ + + unsigned int text_low_valid : 1; + unsigned int text_high_valid : 1; + /* Pointer to compunit eventually allocated for this source file, 0 if !readin or if we haven't looked for the symtab after it was readin. */ diff --git a/gdb/xcoffread.c b/gdb/xcoffread.c index 1aa2e523db2..7ca4b3ef3b2 100644 --- a/gdb/xcoffread.c +++ b/gdb/xcoffread.c @@ -2344,7 +2344,7 @@ scan_xcoff_symtab (minimal_symbol_reader &reader, if (highval > pst->text_high ()) pst->set_text_high (highval); - if (pst->text_low () == 0 + if (!pst->text_low_valid || symbol.n_value < pst->text_low ()) pst->set_text_low (symbol.n_value); } -- 2.30.2