Currently we do not de-duplicate library files specified by /defaultlib option.
As a result, the same files are added multiple times to the input graph. In
particular, some popular files, such as kernel32.lib or oldnames.lib, are added
more than 10 times during linking of LLD. That makes the linker slower, as it
needs to parse the same file again and again.

This patch solves the issue by de-duplicating. The same file will be added only
once to the input graph. This patch improved the LLD linking time from 10.5
seconds to 7.7 seconds on my 4-core Core i7 Macbook Pro.

llvm-svn: 196504

If /functionpadmin is specified, the linker is supposed to make room at the
beginning of each function, so that self-modifying program would easily
hotpatch existing functions. Since I'm not sure if this feature is really used,
I'll make LLD to ignore the option for now.

llvm-svn: 196363

llvm-svn: 196200

llvm-svn: 196196

llvm-svn: 196185

llvm-svn: 196092

llvm-svn: 196056

/DEBUG option is to make the linker to emit debug information to the resulting
executable. It's not for enable debugging of the linker itself.

llvm-svn: 196040

/MERGE option is a bit complicated for many reasons. Firstly, it takes both
positive and negative arguments. That means we have to have one of three
distinctive values (set, clear or unchange) for each permission bit. In this
patch we represent the three values using two bitmasks.

Secondly, the permissions specified by the parameter is bitwise or-ed with the
default permissions of a section. There is an exception for that rule; if one
of READ, WRITE or EXECUTE bit is specified, unspecified bits need to be
cleared. (So if you specify only WRITE for example, the resulting section will
not have WRITE nor EXECUTE bits.)

Lastly, multiple /merge options are allowed.

llvm-svn: 195882

The current mapping for /section one character options is really bogus.
Map to the correct flags.

llvm-svn: 195774

Comment from Rui Ueyema.

llvm-svn: 195598

llvm-svn: 195597

This is needed before any of the search paths are searched for.

llvm-svn: 195596

Looks like -L paths are not positional. They need to be added to a list of
search paths and those needs to be searched when lld looks for a library.

llvm-svn: 195594

This adds LinkerScript support by creating a type Script which is of type
FileNode in the InputGraph. Once the LinkerScript Parser converts the
LinkerScript into a sequence of command, the commands are handled by the
equivalent LinkerScript node for the current Flavor/Target. For ELF, a
ELFGNULdScript gets created which converts the commands to ELF nodes and ELF
control nodes(ELFGroup for handling Group nodes).

Since the Inputfile type has to be determined in the Driver, the Driver needs
to determine the complete path of the file that needs to be processed by the
Linker. Due to this, few tests have been removed since the Driver uses paths
that doesnot exist.

llvm-svn: 195583

No change in functionality.

llvm-svn: 195582

Hidden nodes could be a result of expansion, where a flavor might decide to keep
the node that we want to expand but discard it from being processed by the
resolver.

Verifies with unittests.

llvm-svn: 195516

This is the first step towards DLL creation support. Resource-only DLLs
don't have entry point address.

llvm-svn: 195510

llvm-svn: 195393

It's allowed to specify library files *before* object files in the command
line. Object files seems to be processed first, and then their undefined
symbols are resolved from the libraries. This patch implements the compatible
behavior.

llvm-svn: 195295

llvm-svn: 195289

llvm-svn: 195284

llvm-svn: 195282

llvm-svn: 195281

So that the LLD won't print error message saying that it couldn't find
/implib or /safeseh files.

llvm-svn: 195276

llvm-svn: 195105

Also slightly reduces PECOFFLinkingContext's memory footprint (~128B).

llvm-svn: 194787

llvm-svn: 194757

llvm-svn: 194641

llvm-svn: 194556

This reverts commit r194551 because it broke the buildbot.

llvm-svn: 194552

llvm-svn: 194551

llvm-svn: 194545

no functionality change.

llvm-svn: 194360

These fields are for /align option. Section alignment can be set per-section
basis with /section option too. In order to avoid name conflicts, rename the
existing identifiers to become more specific. No functionality change.

llvm-svn: 194160

/section command line option is to set/reset attributes of the Characteristics
field in the section header. You can set non-default values with this option.
You can make .data section executable with this, for example.

This patch implements the parser of the command line option. The code to use
the parsed values will be committed in a separate patch.

llvm-svn: 194133

I'm not sure if it is really an alias for /nodefaultlib, but I can say that
they are at least similar. Making it an alias would be better than ignoring it.

llvm-svn: 194131

llvm-svn: 194130

/defaultlib options can be specified implicitly via the .drectve section, and
it's pretty common that multiple object files add the same library, such as
user32.lib, to the input. We shouldn't add the same library multiple times.

llvm-svn: 194129

msvcrt.lib contains "/disallowlib" command line option in its .drectve section.
I couldn't spot any documentation for the option. Ignore it for now so that we
can link the library without error.

llvm-svn: 194114