README.txt
1This directory contains LLVM bindings for the Go programming language
2(http://golang.org).
3
4Prerequisites
5-------------
6
7* Go 1.2+.
8* CMake (to build LLVM).
9
10Using the bindings
11------------------
12
13The package path "llvm.org/llvm/bindings/go/llvm" can be used to
14import the latest development version of LLVM from SVN. Paths such as
15"llvm.org/llvm.v36/bindings/go/llvm" refer to released versions of LLVM.
16
17It is recommended to use the "-d" flag with "go get" to download the
18package or a dependency, as an additional step is required to build LLVM
19(see "Building LLVM" below).
20
21Building LLVM
22-------------
23
24The script "build.sh" in this directory can be used to build LLVM and prepare
25it to be used by the bindings. If you receive an error message from "go build"
26like this:
27
28 ./analysis.go:4:84: fatal error: llvm-c/Analysis.h: No such file or directory
29 #include <llvm-c/Analysis.h> // If you are getting an error here read bindings/go/README.txt
30
31or like this:
32
33 ./llvm_dep.go:5: undefined: run_build_sh
34
35it means that LLVM needs to be built or updated by running the script.
36
37 $ $GOPATH/src/llvm.org/llvm/bindings/go/build.sh
38
39Any command line arguments supplied to the script are passed to LLVM's CMake
40build system. A good set of arguments to use during development are:
41
42 $ $GOPATH/src/llvm.org/llvm/bindings/go/build.sh -DCMAKE_BUILD_TYPE=Debug -DLLVM_TARGETS_TO_BUILD=host -DBUILD_SHARED_LIBS=ON
43
44Note that CMake keeps a cache of build settings so once you have built
45LLVM there is no need to pass these arguments again after updating.
46
47Alternatively, you can build LLVM yourself, but you must then set the
48CGO_CPPFLAGS, CGO_CXXFLAGS and CGO_LDFLAGS environment variables:
49
50 $ export CGO_CPPFLAGS="`/path/to/llvm-build/bin/llvm-config --cppflags`"
51 $ export CGO_CXXFLAGS=-std=c++14
52 $ export CGO_LDFLAGS="`/path/to/llvm-build/bin/llvm-config --ldflags --libs --system-libs all`"
53 $ go build -tags byollvm
54
55If you see a compilation error while compiling your code with Go 1.9.4 or later as follows,
56
57 go build llvm.org/llvm/bindings/go/llvm: invalid flag in #cgo LDFLAGS: -Wl,-headerpad_max_install_names
58
59you need to setup $CGO_LDFLAGS_ALLOW to allow a compiler to specify some linker options:
60
61 $ export CGO_LDFLAGS_ALLOW='-Wl,(-search_paths_first|-headerpad_max_install_names)'
62