cv8: Fix line number issues with multiple files.
Patch by: Knut St. Osmundsen
[#263 state:resolved]
diff --git a/modules/dbgfmts/codeview/cv-symline.c b/modules/dbgfmts/codeview/cv-symline.c
index 2b71302..8d70302 100644
--- a/modules/dbgfmts/codeview/cv-symline.c
+++ b/modules/dbgfmts/codeview/cv-symline.c
@@ -127,12 +127,15 @@
size_t num_pairs;
} cv8_lineset;
+/* Note: Due to line number sorting requirements (by section offset it seems)
+ * one file may need more than one record per section. */
typedef struct cv8_lineinfo {
STAILQ_ENTRY(cv8_lineinfo) link;
const cv_filename *fn; /* filename associated with line numbers */
yasm_section *sect; /* section line numbers are for */
yasm_symrec *sectsym; /* symbol for beginning of sect */
unsigned long num_linenums;
+ int first_in_sect; /* First lineinfo for this section. */
STAILQ_HEAD(cv8_lineset_head, cv8_lineset) linesets;
} cv8_lineinfo;
@@ -443,23 +446,9 @@
|| strcmp(filename, info->cv8_cur_li->fn->filename) != 0) {
yasm_bytecode *sectbc;
char symname[8];
+ int first_in_sect = !info->cv8_cur_li;
- /* first see if we already have a lineinfo that is for this section and
- * filename
- */
- STAILQ_FOREACH(info->cv8_cur_li, &info->cv8_lineinfos, link) {
- if (sect == info->cv8_cur_li->sect
- && strcmp(filename, info->cv8_cur_li->fn->filename) == 0)
- break;
- }
-
- if (info->cv8_cur_li) {
- info->cv8_cur_ls = STAILQ_LAST(&info->cv8_cur_li->linesets,
- cv8_lineset, link);
- goto done; /* found one */
- }
-
- /* Nope; find file */
+ /* Find file */
for (i=0; i<dbgfmt_cv->filenames_size; i++) {
if (strcmp(filename, dbgfmt_cv->filenames[i].filename) == 0)
break;
@@ -471,6 +460,7 @@
info->cv8_cur_li = yasm_xmalloc(sizeof(cv8_lineinfo));
info->cv8_cur_li->fn = &dbgfmt_cv->filenames[i];
info->cv8_cur_li->sect = sect;
+ info->cv8_cur_li->first_in_sect = first_in_sect;
sectbc = yasm_section_bcs_first(sect);
if (sectbc->symrecs && sectbc->symrecs[0])
info->cv8_cur_li->sectsym = sectbc->symrecs[0];
@@ -485,7 +475,6 @@
STAILQ_INSERT_TAIL(&info->cv8_lineinfos, info->cv8_cur_li, link);
info->cv8_cur_ls = NULL;
}
-done:
/* build new lineset if necessary */
if (!info->cv8_cur_ls || info->cv8_cur_ls->num_pairs >= 126) {
@@ -622,13 +611,19 @@
cv_generate_line_section);
/* Output line numbers for sections */
+ head = NULL;
STAILQ_FOREACH(li, &info.cv8_lineinfos, link) {
- head = cv8_add_symhead(info.debug_symline, CV8_LINE_NUMS, 0);
+ if (li->first_in_sect) {
+ if (head)
+ cv8_set_symhead_end(head, yasm_section_bcs_last(info.debug_symline));
+ head = cv8_add_symhead(info.debug_symline, CV8_LINE_NUMS, 0);
+ }
bc = yasm_bc_create_common(&cv8_lineinfo_bc_callback, li, 0);
- bc->len = 24+li->num_linenums*8;
+ bc->len = (li->first_in_sect ? 24 : 12) + li->num_linenums*8;
yasm_cv__append_bc(info.debug_symline, bc);
- cv8_set_symhead_end(head, yasm_section_bcs_last(info.debug_symline));
}
+ if (head)
+ cv8_set_symhead_end(head, yasm_section_bcs_last(info.debug_symline));
/* Already aligned 4 */
@@ -880,22 +875,25 @@
unsigned long i;
cv8_lineset *ls;
- /* start offset and section */
- cv_out_sym(li->sectsym, (unsigned long)(buf - bufstart), bc, &buf,
- d, output_value);
+ if (li->first_in_sect) {
+ /* start offset and section */
+ cv_out_sym(li->sectsym, (unsigned long)(buf - bufstart), bc, &buf,
+ d, output_value);
- /* Two bytes of pad/alignment */
- YASM_WRITE_8(buf, 0);
- YASM_WRITE_8(buf, 0);
+ /* Two bytes of pad/alignment */
+ YASM_WRITE_8(buf, 0);
+ YASM_WRITE_8(buf, 0);
- /* Section length covered by line number info */
- cval = yasm_calc_bc_dist(yasm_section_bcs_first(li->sect),
- yasm_section_bcs_last(li->sect));
- yasm_arch_intnum_tobytes(object->arch, cval, buf, 4, 32, 0, bc, 0);
- buf += 4;
+ /* Section length covered by line number info */
+ cval = yasm_calc_bc_dist(yasm_section_bcs_first(li->sect),
+ yasm_section_bcs_last(li->sect));
+ yasm_arch_intnum_tobytes(object->arch, cval, buf, 4, 32, 0, bc, 0);
+ yasm_intnum_destroy(cval);
+ buf += 4;
+ }
/* Offset of source file in info table */
- yasm_intnum_set_uint(cval, li->fn->info_off);
+ cval = yasm_intnum_create_uint(li->fn->info_off);
yasm_arch_intnum_tobytes(object->arch, cval, buf, 4, 32, 0, bc, 0);
buf += 4;
diff --git a/modules/dbgfmts/codeview/cv8.txt b/modules/dbgfmts/codeview/cv8.txt
index 04f152b..a4bbdd8 100644
--- a/modules/dbgfmts/codeview/cv8.txt
+++ b/modules/dbgfmts/codeview/cv8.txt
@@ -25,15 +25,17 @@
2 bytes - section index (SECTION to section start)
2 bytes - pad/align (0)
4 bytes - section length covered by line number info
- 4 bytes - offset of source file in source file info table
- 4 bytes - number of line number pairs
- 4 bytes - number of bytes of line number pairs + 12
- followed by pairs of:
- 4 bytes - offset in section
- 4 bytes - line number; if high bit is set,
- end of statement/breakpointable (?) - e.g. lines containing
- just labels should have line numbers
+ followed by one or more source mappings:
+ 4 bytes - offset of source file in source file info table
+ 4 bytes - number of line number pairs
+ 4 bytes - number of bytes this mapping takes, i.e. 12 + pair-count * 8.
+
+ followed by pairs of:
+ 4 bytes - offset in section
+ 4 bytes - line number; if high bit is set,
+ end of statement/breakpointable (?) - e.g. lines containing
+ just labels should have line numbers
0x000000F1: symbol information
enclosed data per below
diff --git a/modules/dbgfmts/codeview/tests/cv8-multi.asm b/modules/dbgfmts/codeview/tests/cv8-multi.asm
new file mode 100644
index 0000000..ddb9adc
--- /dev/null
+++ b/modules/dbgfmts/codeview/tests/cv8-multi.asm
@@ -0,0 +1,23 @@
+;
+; Test for windbg's ability to single step thru two (or more) source files
+; contributing instructions to the same sections.
+;
+; YASM 1.2.0 and earlier used to generate one CV8_LINE_NUMS per file per
+; section, thus potentially having several CV8_LINE_NUMS records for each
+; section. It is seems that this confuses either the linker or/and windbg
+; and prevents single stepping in and out of include files.
+;
+; MASM generates one line number debug subsection for each code section,
+; repeating the 12 bytes before the offset/lineno pairs for each new file.
+;
+; It also appears that line numbers must be ordered by section offset, and
+; therefore cannot be grouped per file as done by YASM 1.2.0 and earlier.
+;
+_start:
+global _start
+%include "cv8-multi.mac"
+ mov eax, 42
+%include "cv8-multi.mac"
+ xor eax, eax
+ ret
+
diff --git a/modules/dbgfmts/codeview/tests/cv8-multi.mac b/modules/dbgfmts/codeview/tests/cv8-multi.mac
new file mode 100644
index 0000000..5a559f4
--- /dev/null
+++ b/modules/dbgfmts/codeview/tests/cv8-multi.mac
@@ -0,0 +1,4 @@
+ int3
+ nop
+ ; Must be able to step back into the main file.
+
