llvm-project/llvm/bindings/go
David Green 9dd1d451d9 [AArch64] Add Tiny Code Model for AArch64
This adds the plumbing for the Tiny code model for the AArch64 backend. This,
instead of loading addresses through the normal ADRP;ADD pair used in the Small
model, uses a single ADR. The 21 bit range of an ADR means that the code and
its statically defined symbols need to be within 1MB of each other.

This makes it mostly interesting for embedded applications where we want to fit
as much as we can in as small a space as possible.

Differential Revision: https://reviews.llvm.org/D49673

llvm-svn: 340397
2018-08-22 11:31:39 +00:00
..
llvm [AArch64] Add Tiny Code Model for AArch64 2018-08-22 11:31:39 +00:00
README.txt Because of CVE-2018-6574, some compiler options and linker options are restricted to prevent arbitrary code execution. 2018-02-23 20:12:24 +00:00
build.sh
conftest.go

README.txt

This directory contains LLVM bindings for the Go programming language
(http://golang.org).

Prerequisites
-------------

* Go 1.2+.
* CMake (to build LLVM).

Using the bindings
------------------

The package path "llvm.org/llvm/bindings/go/llvm" can be used to
import the latest development version of LLVM from SVN. Paths such as
"llvm.org/llvm.v36/bindings/go/llvm" refer to released versions of LLVM.

It is recommended to use the "-d" flag with "go get" to download the
package or a dependency, as an additional step is required to build LLVM
(see "Building LLVM" below).

Building LLVM
-------------

The script "build.sh" in this directory can be used to build LLVM and prepare
it to be used by the bindings. If you receive an error message from "go build"
like this:

    ./analysis.go:4:84: fatal error: llvm-c/Analysis.h: No such file or directory
     #include <llvm-c/Analysis.h> // If you are getting an error here read bindings/go/README.txt

or like this:

    ./llvm_dep.go:5: undefined: run_build_sh

it means that LLVM needs to be built or updated by running the script.

    $ $GOPATH/src/llvm.org/llvm/bindings/go/build.sh

Any command line arguments supplied to the script are passed to LLVM's CMake
build system. A good set of arguments to use during development are:

    $ $GOPATH/src/llvm.org/llvm/bindings/go/build.sh -DCMAKE_BUILD_TYPE=Debug -DLLVM_TARGETS_TO_BUILD=host -DBUILD_SHARED_LIBS=ON

Note that CMake keeps a cache of build settings so once you have built
LLVM there is no need to pass these arguments again after updating.

Alternatively, you can build LLVM yourself, but you must then set the
CGO_CPPFLAGS, CGO_CXXFLAGS and CGO_LDFLAGS environment variables:

    $ export CGO_CPPFLAGS="`/path/to/llvm-build/bin/llvm-config --cppflags`"
    $ export CGO_CXXFLAGS=-std=c++11
    $ export CGO_LDFLAGS="`/path/to/llvm-build/bin/llvm-config --ldflags --libs --system-libs all`"
    $ go build -tags byollvm

If you see a compilation error while compiling your code with Go 1.9.4 or later as follows,

    go build llvm.org/llvm/bindings/go/llvm: invalid flag in #cgo LDFLAGS: -Wl,-headerpad_max_install_names

you need to setup $CGO_LDFLAGS_ALLOW to allow a compiler to specify some linker options:

    $ export CGO_LDFLAGS_ALLOW='-Wl,(-search_paths_first|-headerpad_max_install_names)'