Summary:
On Windows, Posix integer file descriptors are a compatibility layer
over native file handles provided by the C runtime. There is a hard
limit on the maximum number of file descriptors that a process can open,
and the limit is 8192. LLD typically doesn't run into this limit because
it opens input files, maps them into memory, and then immediately closes
the file descriptor. This prevents it from running out of FDs.
For various reasons, I'd like to open handles to every input file and
keep them open during linking. That requires migrating MemoryBuffer over
to taking open native file handles instead of integer FDs.
Reviewers: aganea, Bigcheese
Reviewed By: aganea
Subscribers: smeenai, silvas, mehdi_amini, hiraditya, steven_wu, dexonsmith, dang, llvm-commits, zturner
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63453
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365588 91177308-0d34-0410-b5e6-96231b3b80d8
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change cuts across LLVM and compiler-rt to add support for
rendering custom events in the XRayRecord type, to allow for including
user-provided annotations in the output YAML (as raw bytes).
This work enables us to add custom event and typed event records into
the `llvm::xray::Trace` type for user-provided events. This can then be
programmatically handled through the C++ API and can be included in some
of the tooling as well. For now we support printing the raw data we
encounter in the custom events in the converted output.
Future work will allow us to start interpreting these custom and typed
events through a yet-to-be-defined API for extending the trace analysis
library.
Reviewers: mboerger
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D54139
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346214 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change implements the profile loading functionality in LLVM to
support XRay's profiling mode in compiler-rt.
We introduce a type named `llvm::xray::Profile` which allows building a
profile representation. We can load an XRay profile from a file to build
Profile instances, or do it manually through the Profile type's API.
The intent is to get the `llvm-xray` tool to generate `Profile`
instances and use that as the common abstraction through which all
conversion and analysis can be done. In the future we can generate
`Profile` instances from `Trace` instances as well, through conversion
functions.
Some of the key operations supported by the `Profile` API are:
- Path interning (`Profile::internPath(...)`) which returns a unique path
identifier.
- Block appending (`Profile::addBlock(...)`) to add thread-associated
profile information.
- Path ID to Path lookup (`Profile::expandPath(...)`) to look up a
PathID and return the original interned path.
- Block iteration.
A 'Path' in this context represents the function call stack in
leaf-to-root order. This is represented as a path in an internally
managed prefix tree in the `Profile` instance. Having a handle (PathID)
to identify the unique Paths we encounter for a particular Profile
allows us to reduce the amount of memory required to associate profile
data to a particular Path.
This is the first of a series of patches to migrate the `llvm-stacks`
tool towards using a single profile representation.
Depends on D48653.
Reviewers: kpw, eizan
Reviewed By: kpw
Subscribers: kpw, thakis, mgorny, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D48370
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341012 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change implements the profile loading functionality in LLVM to
support XRay's profiling mode in compiler-rt.
We introduce a type named `llvm::xray::Profile` which allows building a
profile representation. We can load an XRay profile from a file to build
Profile instances, or do it manually through the Profile type's API.
The intent is to get the `llvm-xray` tool to generate `Profile`
instances and use that as the common abstraction through which all
conversion and analysis can be done. In the future we can generate
`Profile` instances from `Trace` instances as well, through conversion
functions.
Some of the key operations supported by the `Profile` API are:
- Path interning (`Profile::internPath(...)`) which returns a unique path
identifier.
- Block appending (`Profile::addBlock(...)`) to add thread-associated
profile information.
- Path ID to Path lookup (`Profile::expandPath(...)`) to look up a
PathID and return the original interned path.
- Block iteration.
A 'Path' in this context represents the function call stack in
leaf-to-root order. This is represented as a path in an internally
managed prefix tree in the `Profile` instance. Having a handle (PathID)
to identify the unique Paths we encounter for a particular Profile
allows us to reduce the amount of memory required to associate profile
data to a particular Path.
This is the first of a series of patches to migrate the `llvm-stacks`
tool towards using a single profile representation.
Depends on D48653.
Reviewers: kpw, eizan
Reviewed By: kpw
Subscribers: mgorny, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D48370
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338825 91177308-0d34-0410-b5e6-96231b3b80d8
