forked from OSchip/llvm-project
0779dffbd4
DIFlagBlockByRefStruct is an unused DIFlag that originally was used by clang to express (Objective-)C block captures in debug info. For the last year Clang has been emitting complex DIExpressions to describe block captures instead, which makes all the code supporting this flag redundant. This patch removes the flag and all supporting "dead" code, so we can reuse the bit for something else in the future. Since this only affects debug info generated by Clang with the block extension this mostly affects Apple platforms and I don't have any bitcode compatibility concerns for removing this. The Verifier will reject debug info that uses the bit and thus degrade gracefully when LTO'ing older bitcode with a newer compiler. rdar://problem/44304813 Differential Revision: https://reviews.llvm.org/D67453 llvm-svn: 372272 |
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| .. | ||
| llvm | ||
| README.txt | ||
| 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++14
$ 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)'