Support LLVM14

Signed-off-by: Nikita Baksalyar <nikita.baksalyar@gmail.com>

README.md

@@ -63,8 +63,9 @@ programs using Rust. It includes:
 
 `LLVM` is required in your build system to compile BPF bytecode using RedBPF.
 
-- **LLVM 13**  
-  It is needed to compile BPF bytecode.
+- **LLVM 14 or 13**
+  It is needed to compile BPF bytecode. If you're using Rust 1.60 or later, LLVM 14 is required.
+  If you need to use LLVM 13, use the feature `llvm13-0`.
 
 - One of the followings:
   1. The Linux kernel headers
@@ -74,7 +75,7 @@ programs using Rust. It includes:
 
 ### On Ubuntu 20.04 LTS
 
-Install LLVM 13 and the Linux kernel headers
+Install LLVM 14 and the Linux kernel headers
 ```console
 # apt-get update \
   && apt-get -y install \
@@ -85,12 +86,15 @@ Install LLVM 13 and the Linux kernel headers
        libelf-dev \
        linux-headers-generic \
        pkg-config \
-  && wget https://apt.llvm.org/llvm.sh && chmod +x llvm.sh && ./llvm.sh 13 && rm -f ./llvm.sh
-# llvm-config-13 --version | grep 13
+  && wget https://apt.llvm.org/llvm.sh && chmod +x llvm.sh && ./llvm.sh 14 && rm -f ./llvm.sh
+# llvm-config-14 --version | grep 14
 ```
 
 ### On Fedora 35
 
+Currently, only LLVM 13 is available in the official Fedora repositories.
+Consider building LLVM from source until Fedora 36 is released.
+
 Install LLVM 13 and the Linux kernel headers
 ```console
 # dnf install -y \
@@ -126,25 +130,28 @@ Install LLVM 13 and the Linux kernel headers
 # llvm-config --version | grep -q '^13'
 ```
 
+At the time of writing, LLVM 14 is not available in the official package repository.
+If you need to use Rust 1.60 or later, please build LLVM from source.
+
 ### Building LLVM from source
 
 If your Linux distro does not support the latest LLVM as pre-built packages
 yet, you may build LLVM from the LLVM source code.
 
 ```console
-$ tar -xaf llvm-13.0.0.src.tar.xz
-$ mkdir -p llvm-13.0.0.src/build
-$ cd llvm-13.0.0.src/build
-$ cmake .. -DCMAKE_INSTALL_PREFIX=$HOME/llvm-13-release -DCMAKE_BUILD_TYPE=Release -DLLVM_BUILD_LLVM_DYLIB=1
+$ tar -xaf llvm-14.0.0.src.tar.xz
+$ mkdir -p llvm-14.0.0.src/build
+$ cd llvm-14.0.0.src/build
+$ cmake .. -DCMAKE_INSTALL_PREFIX=$HOME/llvm-14-release -DCMAKE_BUILD_TYPE=Release -DLLVM_BUILD_LLVM_DYLIB=1
 $ cmake --build . --target install
 ```
 
 Then you can use your LLVM by specifying the custom installation path when
 installing `cargo-bpf` or building RedBPF like this:
 
 ```console
-$ LLVM_SYS_130_PREFIX=$HOME/llvm-13-release/ cargo install cargo-bpf
-$ LLVM_SYS_130_PREFIX=$HOME/llvm-13-release/ cargo build
+$ LLVM_SYS_140_PREFIX=$HOME/llvm-14-release/ cargo install cargo-bpf
+$ LLVM_SYS_140_PREFIX=$HOME/llvm-14-release/ cargo build
 ```
 
 Make sure correct `-DCMAKE_BUILD_TYPE` is specified. Typically `Debug` type is
@@ -235,7 +242,8 @@ There are two LLVM versions involved in compiling BPF programs:
 
 | Rust version | LLVM version of the rustc | Valid LLVM version of system |
 |:-------------|:-------------------------:|:-----------------------------|
-| 1.56 ~       | LLVM 13                   | LLVM 13 and newer            |
+| 1.56 ~ 1.60  | LLVM 13                   | LLVM 13 and newer            |
+| 1.60 ~       | LLVM 14                   | LLVM 14 and newer            |
 
 ## Docker images for RedBPF build test
 

TUTORIAL.md

@@ -45,14 +45,14 @@ For some reasons, you may want to build LLVM from source code.
 
 When you build LLVM, consider building LLVM with `Release` build mode.
 
-For example, when you build LLVM13 from source code, you can pass
+For example, when you build LLVM14 from source code, you can pass
 `-DCMAKE_BUILD_TYPE=Release` to the `cmake` command as below:
 
 ```console
-$ tar -xaf llvm-13.0.0.src.tar.xz
-$ mkdir -p llvm-13.0.0.src/build
-$ cd llvm-13.0.0.src/build
-$ cmake .. -DCMAKE_INSTALL_PREFIX=$HOME/llvm-13-release -DCMAKE_BUILD_TYPE=Release
+$ tar -xaf llvm-14.0.0.src.tar.xz
+$ mkdir -p llvm-14.0.0.src/build
+$ cd llvm-14.0.0.src/build
+$ cmake .. -DCMAKE_INSTALL_PREFIX=$HOME/llvm-14-release -DCMAKE_BUILD_TYPE=Release
 $ cmake --build . --target install
 ```
 

cargo-bpf/Cargo.toml

@@ -39,6 +39,7 @@ anyhow = "1.0"
 # if `strict-versioning` feature is off, llvm-sys-130 can be linked to
 # libLLVM13 and newer libraries.
 llvm-sys-130 = { version = "130", optional = true, package = "llvm-sys" }
+llvm-sys-140 = { version = "140", optional = true, package = "llvm-sys" }
 cfg-if = "1.0"
 rustversion = "1.0"
 rustc_version = "0.4.0"
@@ -53,11 +54,12 @@ cfg-if = "1.0.0"
 default = ["command-line", "llvm-sys"]
 bindings = ["libbpf-sys", "bpf-sys", "bindgen", "syn", "quote", "proc-macro2", "tempfile"]
 build = ["bindings", "libc", "toml_edit", "redbpf"]
-docsrs-llvm = ["llvm-sys-130/no-llvm-linking", "llvm-sys-130/disable-alltargets-init"]
+docsrs-llvm = ["llvm-sys-140/no-llvm-linking", "llvm-sys-140/disable-alltargets-init"]
 build-c = []
 command-line = ["build", "clap", "redbpf/load", "futures", "tokio", "hexdump"]
-llvm-sys = ["llvm-sys-130"]  # Use current default LLVM version or higher
+llvm-sys = ["llvm-sys-140"]  # Use current default LLVM version or higher
 llvm13 = ["llvm-sys-130"]
+llvm14 = ["llvm-sys-140"]
 
 [package.metadata.docs.rs]
 all-features = false

cargo-bpf/build.rs

@@ -56,7 +56,7 @@ fn print_cargo_bpf_llvm_version() {
 
 fn main() {
     cfg_if::cfg_if! {
-        if #[cfg(all(feature = "llvm-sys-130", not(feature = "docsrs-llvm")))] {
+        if #[cfg(all(any(feature = "llvm-sys-130", feature = "llvm-sys-140"), not(feature = "docsrs-llvm")))] {
             print_cargo_bpf_llvm_version();
         } else {
             println!("cargo:rustc-env=CARGO_BPF_LLVM_VERSION=0.0.0");

cargo-bpf/src/llvm.rs

@@ -22,6 +22,8 @@ second.
 cfg_if::cfg_if! {
     if #[cfg(feature = "llvm-sys-130")] {
         use llvm_sys_130 as llvm_sys;
+    } else if #[cfg(feature = "llvm-sys-140")] {
+        use llvm_sys_140 as llvm_sys;
     } else {
         compile_error!("Specify --features llvm13");
     }