Commit Graph

8 Commits

Author SHA1 Message Date
Fangrui Song e29e30b139 [llvm-readobj] Change -long-option to --long-option in tests. NFC
We use both -long-option and --long-option in tests. Switch to --long-option for consistency.

In the "llvm-readelf" mode, -long-option is discouraged as it conflicts with grouped short options and it is not accepted by GNU readelf.

While updating the tests, change llvm-readobj -s to llvm-readobj -S to reduce confusion ("s" is --section-headers in llvm-readobj but --symbols in llvm-readelf).

llvm-svn: 359649
2019-05-01 05:27:20 +00:00
Reid Kleckner 98bbd07cc3 [MC] Enable .file support on COFF and diagnose it on unsupported targets
Summary:
The "single parameter" .file directive appears to be an ELF-only feature
that is intended to insert the main source filename into the string
table table.

I noticed that if you assemble an ELF .s file for COFF, typically it
will assert right away on a .file directive near the top of the file. My
first change was to make this emit a proper error in the asm parser so
that we don't assert so easily.

However, COFF actually does have some support for this directive, and if
you emit an object file, llvm-mc does not assert. When emitting a COFF
object, MC will take those file names and create "debug" symbol table
entries for them. I'm not familiar with these kinds of symbol table
entries, and I'm not aware of any users of them, but @compnerd added
them a while ago. They don't introduce absolute paths, and most main
source file paths are short enough that this extra entry shouldn't cause
any problems, so I enabled the flag in MCAsmInfoCOFF that indicates that
it's supported.

This has the side effect of adding an extra debug symbol to every object
produced by clang, which is a pretty big functional change. My question
is, should we keep the functionality or remove it in the name of symbol
table minimalism?

Reviewers: mstorsjo, compnerd

Subscribers: hiraditya, compnerd, llvm-commits

Differential Revision: https://reviews.llvm.org/D55900

llvm-svn: 349976
2018-12-21 23:35:48 +00:00
David Majnemer f4dc456eef llvm-readobj: pretty-print special COFF section names
Print IMAGE_SYM_DEBUG and the like instead of (-2).

llvm-svn: 218172
2014-09-20 00:25:06 +00:00
David Majnemer 44f51e5113 Object: Add support for bigobj
This adds support for reading the "bigobj" variant of COFF produced by
cl's /bigobj and mingw's -mbig-obj.

The most significant difference that bigobj brings is more than 2**16
sections to COFF.

bigobj brings a few interesting differences with it:
- It doesn't have a Characteristics field in the file header.
- It doesn't have a SizeOfOptionalHeader field in the file header (it's
  only used in executable files).
- Auxiliary symbol records have the same width as a symbol table entry.
  Since symbol table entries are bigger, so are auxiliary symbol
  records.

Write support will come soon.

Differential Revision: http://reviews.llvm.org/D5259

llvm-svn: 217496
2014-09-10 12:51:52 +00:00
Saleem Abdulrasool 734bca04ff MC: place .file records into the correct section
.file records are supposed to have a section identifier of 65534
(IMAGE_SCN_DEBUG) rather than 0.  This is spelt out clearly within the PE/COFF
specification.  Fix this minor oversight with the implementation for support for
.file records.

llvm-svn: 207851
2014-05-02 17:45:24 +00:00
Saleem Abdulrasool 7c34b6dd65 MC: duplicate .file test for WoA (SVN r207341)
Since the COFF tests are dependent on X86, duplicate the test for ARM.  Use the
default check prefix.

llvm-svn: 207365
2014-04-27 16:10:57 +00:00
Saleem Abdulrasool 057094c6f6 COFF: fix an off by one error
Adjust the tests to validate the number of auxiliary entries used to store the
filename.

Thanks to majnemer's sharp eye for catching the missing - 1 in the round up
calculation.

llvm-svn: 206359
2014-04-16 06:22:53 +00:00
Saleem Abdulrasool a2bf05aa2f COFF: add support for .file symbols
Add support for emitting .file records.  This is mostly a quality of
implementation change (more complete support for COFF file emission) that was
noticed while working on COFF file emission for Windows on ARM.

A .file record is emitted as a symbol with storage class FILE (103) and the name
".file".  A series of auxiliary format 4 records follow which contain the file
name.  The filename is stored as an ANSI string and is padded with NULL if the
length is not a multiple of COFF::SymbolSize (18).

llvm-svn: 206355
2014-04-16 04:15:32 +00:00