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Fixing use of dwarf_nextcu.
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Sasha Nicolas committed Aug 18, 2017
1 parent 3ffe451 commit a8e9a65
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Showing 2 changed files with 75 additions and 90 deletions.
163 changes: 74 additions & 89 deletions symtabAPI/src/dwarfWalker.C
View file
Expand Up @@ -110,62 +110,55 @@ bool DwarfWalker::parse() {
/* Prepopulate type signatures for DW_FORM_ref_sig8 */
findAllSig8Types();

/* First .debug_types (0), then .debug_info (1) */
for (int i = 0; i < 2; ++i) {
bool is_info = i;

/* NB: parseModule used to compute compile_offset as 11 bytes before the
* first die offset, to account for the header. This would need 23 bytes
* instead for 64-bit format DWARF, and even more for type units.
* (See DWARF4 sections 7.4 & 7.5.1.)
* But more directly, we know the first CU is just at 0x0, and each
* following CU is already reported in next_cu_header.
*/
compile_offset = next_cu_header = 0;

/* Iterate over the compilation-unit headers. */
/* Old code previous to libdw
while (dwarf_next_cu_header_c(dbg(), is_info,
&cu_header_length,
&version,
&abbrev_offset,
&addr_size,
&offset_size,
&extension_size,
&signature,
&typeoffset,
&next_cu_header, &err) == DW_DLV_OK ) {
push();
bool ret = parseModule(is_info, fixUnknownMod);
pop();
if (!ret) return false;
compile_offset = next_cu_header;
}
*/
size_t cu_header_size = 0;
for(Dwarf_Off cu_off = 0, next_cu_off;
dwarf_nextcu(dbg(), cu_off, &next_cu_off, &cu_header_size,
NULL, NULL, NULL) == 0;
cu_off = next_cu_off)
{
Dwarf_Off cu_die_off = cu_off + cu_header_size;
Dwarf_Die cu_die, *cu_die_p;
if(i==0){ //.debug_types
cu_die_p = dwarf_offdie_types(dbg(), cu_die_off, &cu_die);
}else{
cu_die_p = dwarf_offdie(dbg(), cu_die_off, &cu_die);
}
assert(cu_die_p == NULL);
/* First .debug_types (0), then .debug_info (1).
* In DWARF4, only .debug_types contains DW_TAG_type_unit,
* but DWARF5 is considering them for .debug_info too.*/

push();
bool ret = parseModule(is_info, fixUnknownMod);
pop();
if (!ret) return false;
compile_offset = next_cu_header;
}
/* NB: parseModule used to compute compile_offset as 11 bytes before the
* first die offset, to account for the header. This would need 23 bytes
* instead for 64-bit format DWARF, and even more for type units.
* (See DWARF4 sections 7.4 & 7.5.1.)
* But more directly, we know the first CU is just at 0x0, and each
* following CU is already reported in next_cu_header.
*/
compile_offset = next_cu_header = 0;

/* Iterate over the compilation-unit headers for .debug_types. */
uint64_t type_signaturep;
for(Dwarf_Off cu_off = 0;
dwarf_next_unit(dbg(), cu_off, &next_cu_header, &cu_header_length,
NULL, &abbrev_offset, &addr_size, &offset_size,
&type_signaturep, NULL) == 0;
cu_off = next_cu_header)
{
Dwarf_Die cu_die;
if(!dwarf_offdie_types(dbg(), cu_off + cu_header_length, &cu_die))
continue;

push();
bool ret = parseModule(false, fixUnknownMod);
pop();
if (!ret) return false;
compile_offset = next_cu_header;
}

/* Iterate over the compilation-unit headers for .debug_info. */
for(Dwarf_Off cu_off = 0;
dwarf_nextcu(dbg(), cu_off, &next_cu_header, &cu_header_length,
&abbrev_offset, &addr_size, &offset_size) == 0;
cu_off = next_cu_header)
{
Dwarf_Die cu_die;
if(!dwarf_offdie(dbg(), cu_off + cu_header_length, &cu_die))
continue;

push();
bool ret = parseModule(true, fixUnknownMod);
pop();
if (!ret) return false;
compile_offset = next_cu_header;
}

if (!fixUnknownMod)
return true;

Expand Down Expand Up @@ -2653,45 +2646,37 @@ void DwarfWalker::findAllSig8Types()
/* First .debug_types (0), then .debug_info (1).
* In DWARF4, only .debug_types contains DW_TAG_type_unit,
* but DWARF5 is considering them for .debug_info too.*/
for (int i = 0; i < 2; ++i) {
//bool is_info = i;
//Dwarf_Error err;
compile_offset = next_cu_header = 0;

/* Iterate over the compilation-unit headers. */
/*while (dwarf_next_cu_header_c(dbg(), is_info,
&cu_header_length,
&version,
&abbrev_offset,
&addr_size,
&offset_size,
&extension_size,
&signature,
&typeoffset,
&next_cu_header, &err) == 0 ) {
parseModuleSig8(is_info);
compile_offset = next_cu_header;
}*/

size_t cu_header_size = 0;
for(Dwarf_Off cu_off = 0;
dwarf_nextcu(dbg(), cu_off, &next_cu_header, &cu_header_length,
&abbrev_offset, &addr_size, &offset_size) == 0;
cu_off = next_cu_header)
{
Dwarf_Off cu_die_off = cu_off + cu_header_size;
Dwarf_Die cu_die, *cu_die_p;
if(i==0){ //.debug_types
cu_die_p = dwarf_offdie_types(dbg(), cu_die_off, &cu_die);
}else{
cu_die_p = dwarf_offdie(dbg(), cu_die_off, &cu_die);
}
assert(cu_die_p == NULL);
compile_offset = next_cu_header = 0;

/* Iterate over the compilation-unit headers for .debug_types. */
uint64_t type_signaturep;
for(Dwarf_Off cu_off = 0;
dwarf_next_unit(dbg(), cu_off, &next_cu_header, &cu_header_length,
NULL, &abbrev_offset, &addr_size, &offset_size,
&type_signaturep, NULL) == 0;
cu_off = next_cu_header)
{
Dwarf_Die cu_die;
if(!dwarf_offdie_types(dbg(), cu_off + cu_header_length, &cu_die))
continue;

parseModuleSig8(i);
compile_offset = next_cu_header;
}
parseModuleSig8(false);
compile_offset = next_cu_header;
}

/* Iterate over the compilation-unit headers for .debug_info. */
for(Dwarf_Off cu_off = 0;
dwarf_nextcu(dbg(), cu_off, &next_cu_header, &cu_header_length,
&abbrev_offset, &addr_size, &offset_size) == 0;
cu_off = next_cu_header)
{
Dwarf_Die cu_die;
if(!dwarf_offdie(dbg(), cu_off + cu_header_length, &cu_die))
continue;

parseModuleSig8(true);
compile_offset = next_cu_header;
}
}

bool DwarfWalker::parseModuleSig8(bool is_info)
Expand Down
2 changes: 1 addition & 1 deletion symtabAPI/src/dwarfWalker.h
View file
Expand Up @@ -324,7 +324,7 @@ class DwarfWalker : public DwarfParseActions {
// Per-module info
Address modLow;
Address modHigh;
Dwarf_Word cu_header_length;
size_t cu_header_length;
Dwarf_Half version;
Dwarf_Word abbrev_offset;
uint8_t /*Dwarf_Half*/ addr_size;
Expand Down

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