OrdinalBase is an addend to the ordinals. We used to always set 1 to the field.
Although it produced a valid a DLL export table, it'd be a waste if the first
ordinal does not start with 1 -- we had to have NULL fields at the beginning of
the export address table. By setting the ordinal base, we can eliminate the
NULL fields.

llvm-svn: 197367

You can specify exported function's ordinal by /export:func,@<number> command
line option, but LLD ignored the option until now. This patch implements the
feature.

Ordinal is basically the index into the exported function address table. So,
for example, if /export:foo,@42 is specified, the linker writes foo's address
to 42th entry in the address table. Windows supports import-by-ordinal; you
can not only import a function by name, but by its ordinal. If you want to
allow your DLL users to import your functions by their ordinals, you need to
make sure that your functions are always exported with the same ordinals.
This is the feature for that situation.

llvm-svn: 197364

Symbol names exported from a DLL should be undecorated, not prefixed by
an underscore ones.

llvm-svn: 197307

llvm-svn: 197306

/EXPORT command line option can take an ordinal, NONAME flag, and DATA flag.
This patch is to parse these optional arguments.

llvm-svn: 197217

I should have run it before submitting but forgot to do that. Doing it now...

llvm-svn: 197214

The only data in .edata whose length varies is the string. This patch moves
all the strings to the end of the section, so that 16-bit or 32-bit integers
are aligned on correct boundaries.

llvm-svn: 197213

This is the first patch to emit data for the DLL export table. The DLL export
table is the data used by the Windows loader to find the address of exported
function from DLL. With this patch, LLD is able to emit a valid DLL export
table which the Windows loader can interpret and load.

The data structure of the DLL export table is described in the Microsoft
PE/COFF Specification, section 5.3.

DLL support is not complete yet; the linker needs to emit an import library
for a DLL, otherwise the linker cannot link against the DLL. We also do not
support export-only-by-ordinal yet.

llvm-svn: 197212