Seen several beginner questions popping up in discourse about how to
implement and run custom passes. And then it turns out that they are
following the old "Writing an LLVM Pass" guide that describe legacy
passes, and then things are mixed up when they try to run that pass
using opt that nowadays default to the new pass manager.
This is an attempt to make it slightly clearer in the User Guides that
there are two different "Writing an LLVM Pass" pages depending on which
pass manager that should be used. This is done by renaming the legacy
version of "Writing an LLVM Pass" as "Writing an LLVM Pass (legacy PM
version)".
Also reordered the links to put the link to the new pass manager
documentation first.
This patch also moves the warning text that cross references the
description on how to write a pass for legacy/new PM to make sure it
ends up already in the beginning of the descriptions.
Also adding a new warning in the "Running a pass with opt" section of
the legacy PM version of the guide, to inform that those examples are
outdated.
And clarify in the "writing a pass" docs that both the legacy and new
PMs are being used for the codegen/optimization pipelines.
Reviewed By: ychen, asbirlea
Differential Revision: https://reviews.llvm.org/D97515
No longer rely on an external tool to build the llvm component layout.
Instead, leverage the existing `add_llvm_componentlibrary` cmake function and
introduce `add_llvm_component_group` to accurately describe component behavior.
These function store extra properties in the created targets. These properties
are processed once all components are defined to resolve library dependencies
and produce the header expected by llvm-config.
Differential Revision: https://reviews.llvm.org/D90848
As to not conflict with the legacy PM example passes under
llvm/lib/Transforms/Hello, this is under HelloNew. This makes the
CMakeLists.txt and general directory structure less confusing for people
following the example.
Much of the doc structure was taken from WritinAnLLVMPass.rst.
This adds a HelloWorld pass which simply prints out each function name.
More will follow after this, e.g. passes over different units of IR, analyses.
https://llvm.org/docs/WritingAnLLVMPass.html contains a lot more.
Relanded with missing "Support" dependency in LLVMBuild.txt.
Reviewed By: ychen, asbirlea
Differential Revision: https://reviews.llvm.org/D86979
As to not conflict with the legacy PM example passes under
llvm/lib/Transforms/Hello, this is under HelloNew. This makes the
CMakeLists.txt and general directory structure less confusing for people
following the example.
Much of the doc structure was taken from WritinAnLLVMPass.rst.
This adds a HelloWorld pass which simply prints out each function name.
More will follow after this, e.g. passes over different units of IR, analyses.
https://llvm.org/docs/WritingAnLLVMPass.html contains a lot more.
Reviewed By: ychen, asbirlea
Differential Revision: https://reviews.llvm.org/D86979
