vector that represents the .o file at once, build up a vector for each
section of the .o file.  This is needed because the .o file writer needs
to be able to switch between sections as it emits them (e.g. switch
between the .text section and the .rel section when emitting code).

This patch has no functionality change.

llvm-svn: 22453

llvm-svn: 22400

llvm-svn: 22393

llvm-svn: 22382

allows objdump to know which function we are emitting to:

00000000 <foo>:     <----
   0:   b8 01 00 00 00          mov    $0x1,%eax
   5:   03 44 24 04             add    0x4(%esp,1),%eax
   9:   c3                      ret

... and allows .o files to be useful for linking :)

llvm-svn: 22378

Add a *VERY INITIAL* machine code emitter class.  This is enough to take
this C function:
int foo(int X) { return X +1; }

and make objdump produce the following:

$ objdump -d t-llvm.o

t-llvm.o:     file format elf32-i386

Disassembly of section .text:

00000000 <.text>:
   0:   b8 01 00 00 00          mov    $0x1,%eax
   5:   03 44 24 04             add    0x4(%esp,1),%eax
   9:   c3                      ret


Anything using branches or refering to the constant pool or requiring
relocations will not work yet.

llvm-svn: 22375

characters from them.

llvm-svn: 22371

Add support for emitting external and .bss symbols.

llvm-svn: 22358

module to the ELF file.  Test it by adding support for emitting common
symbols.  This allows us to compile this:

%X = weak global int 0
%Y = weak global int 0
%Z = weak global int 0

to an elf file that 'readelf's this:

Symbol table '.symtab' contains 4 entries:
   Num:    Value  Size Type    Bind   Vis      Ndx Name
     0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 00000004     4 OBJECT  GLOBAL DEFAULT  COM X
     2: 00000004     4 OBJECT  GLOBAL DEFAULT  COM Y
     3: 00000004     4 OBJECT  GLOBAL DEFAULT  COM Z

llvm-svn: 22343

For now, the elf writer is only capable of emitting an empty elf file, with
a section table and a section table string table.  This will be enhanced
in the future :)

llvm-svn: 22291