Hi,
In order to improve our build workflow, I’m trying to link against very old .lib (1998).
LLD seams to be the best chance we have to migrate to clang compiler while being able to link with a very old proprietary library.
LLD is having trouble with those symbols:
003 C0000040 UNDEF notype Section | .idata$4
004 C0000040 UNDEF notype Section | .idata$5
SectionNumber = UNDEF = 0 →
The COFF spec says about this:
If the symbol referred to (by the SymbolTableIndex field) has storage class IMAGE_SYM_CLASS_SECTION, the symbolís address is the beginning of the section. The section is usually in the same file, except when the object file is part of an archive (library). In that case, the section may be found in any other object file in the archive that has the same archivemember name as the current object file. (The relationship with the archive-member name is used in the linking of import tables, i.e. the .idata section.)
IMAGE_SYM_CLASS_SECTION = 104 Definition of a section (Microsoft tools use STATIC storage class instead).
I’m still trying to understand the meaning of such symbol in order to allow LLD to resolve them correctly.
Does this mean .idata$4 and .idata$5 refer to the same address which is the beginning of section .idata$6 ?
But in that case what does the associated C0000040 value means ?
Any hint ?
Thanks you,
Vincent Rouillé
Here is the dumpbin data related to my issue:
FILE HEADER VALUES
14C machine (i386)
2 number of sections
31C231B8 time date stamp Sat Jun 15 05:44:56 1996
182 file pointer to symbol table
7 number of symbols
E0 size of optional header
100 characteristics
32 bit word machine
SECTION HEADER #1
.idata$2 name
0 virtual size
0 virtual address
14 size of raw data
144 file pointer to raw data
158 file pointer to relocation table
0 file pointer to line numbers
3 number of relocations
0 number of line numbers
C0100040 flags
Initialized Data
1 byte align
Read Write
RAW DATA #1
00000000 00 00 00 00 00 00 00 00 | 00 00 00 00 00 00 00 00 …|…
00000010 00 00 00 00 …
RELOCATIONS #1
Symbol Symbol
Offset Type Applied To Index Name
0000000C DIR32NB 00000000 2 .idata$6
00000000 DIR32NB 00000000 3 .idata$4
00000010 DIR32NB 00000000 4 .idata$5
SECTION HEADER #2
.idata$6 name
0 virtual size
0 virtual address
C size of raw data
176 file pointer to raw data
158 file pointer to relocation table
0 file pointer to line numbers
0 number of relocations
0 number of line numbers
C0200040 flags
Initialized Data
2 byte align
Read Write
RAW DATA #2
00000000 4D 53 56 43 52 54 2E 64 | 6C 6C 00 00 MSVCRT.d|ll…
COFF SYMBOL TABLE
000 00000000 SECT1 notype External | __IMPORT_DESCRIPTOR_MSVCRT
001 C0000040 SECT1 notype Section | .idata$2
002 00000000 SECT2 notype Static | .idata$6
003 C0000040 UNDEF notype Section | .idata$4
004 C0000040 UNDEF notype Section | .idata$5
005 00000000 UNDEF notype External | __NULL_IMPORT_DESCRIPTOR
006 00000000 UNDEF notype External | MSVCRT_NULL_THUNK_DATA
String Table Size = 0x50 bytes