Merge pull request #4 from termoshtt/init

* Skip creating proxy for initialization macros

* LLVM_InitializeAllTargets

* get_native_backend

* Fill all init

Author: denzp

build.rs

@@ -57,6 +57,19 @@ mod llvm {
         "execution_engine.rs",
     ];
 
+    const INIT_MACROS: &[&str] = &[
+        "LLVM_InitializeAllTargetInfos",
+        "LLVM_InitializeAllTargets",
+        "LLVM_InitializeAllTargetMCs",
+        "LLVM_InitializeAllAsmPrinters",
+        "LLVM_InitializeAllAsmParsers",
+        "LLVM_InitializeAllDisassemblers",
+        "LLVM_InitializeNativeTarget",
+        "LLVM_InitializeNativeAsmParser",
+        "LLVM_InitializeNativeAsmPrinter",
+        "LLVM_InitializeNativeDisassembler",
+    ];
+
     #[derive(Default)]
     pub struct Generator {
         declarations: Vec<Declaration>,
@@ -80,6 +93,11 @@ mod llvm {
             let mut file = File::create(path)?;
 
             for decl in self.declarations {
+                if INIT_MACROS.contains(&decl.name.as_str()) {
+                    // Skip target initialization wrappers
+                    // (see llvm-sys/wrappers/target.c)
+                    continue;
+                }
                 writeln!(
                     file,
                     "create_proxy!({}; {}; {});",

src/init.rs

@@ -0,0 +1,99 @@
+use super::SHARED_LIB;
+use llvm_sys::prelude::LLVMBool;
+
+use std::io::{BufRead, BufReader, Result};
+use std::process::Command;
+
+const POSSIBLE_BACKENDS: &[&str] = &[
+    "AArch64", "AMDGPU", "ARM", "BPF", "Hexagon", "Lanai", "Mips", "MSP430", "NVPTX", "PowerPC",
+    "Sparc", "SystemZ", "X86", "XCore",
+];
+
+fn get_native_arch() -> Result<String> {
+    let output = Command::new("rustc").args(&["--print", "cfg"]).output()?;
+    let buf = BufReader::new(output.stdout.as_slice());
+    for line in buf.lines() {
+        let line = line?;
+        if !line.starts_with("target_arch") {
+            continue;
+        }
+        // line should be like: target_arch="x86_64"
+        return Ok(line.split('"').nth(1).unwrap().into());
+    }
+    unreachable!("`rustc --print cfg` result is wrong");
+}
+
+fn arch2backend(arch: &str) -> String {
+    match arch {
+        "aarch64" => "AArch64".into(),
+        "arm" => "ARM".into(),
+        "mips" | "mips64" => "Mips".into(),
+        "powerpc" | "powerpc64" => "PowerPC".into(),
+        "sparc" | "sparc64" => "Sparc".into(),
+        "x86" | "x86_64" => "X86".into(),
+        _ => panic!("Unknown backend: {}", arch),
+    }
+}
+
+fn get_native_backend() -> String {
+    let arch = get_native_arch().expect("Fail to get native arch");
+    arch2backend(&arch)
+}
+
+unsafe fn init_all(postfix: &str) {
+    for backend in POSSIBLE_BACKENDS {
+        let name = format!("LLVMInitialize{}{}", backend, postfix);
+        if let Ok(entrypoint) = SHARED_LIB.get::<unsafe extern "C" fn()>(name.as_bytes()) {
+            entrypoint();
+        }
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn LLVM_InitializeAllTargetInfos() {
+    init_all("TargetInfo");
+}
+#[no_mangle]
+pub unsafe extern "C" fn LLVM_InitializeAllTargets() {
+    init_all("Target");
+}
+#[no_mangle]
+pub unsafe extern "C" fn LLVM_InitializeAllTargetMCs() {
+    init_all("TargetMC");
+}
+#[no_mangle]
+pub unsafe extern "C" fn LLVM_InitializeAllAsmParsers() {
+    init_all("AsmParser");
+}
+#[no_mangle]
+pub unsafe extern "C" fn LLVM_InitializeAllAsmPrinters() {
+    init_all("AsmPrinter");
+}
+
+unsafe fn init_native(postfix: &str) -> LLVMBool {
+    let backend = get_native_backend();
+    let name = format!("LLVMInitialize{}{}", backend, postfix);
+    if let Ok(entrypoint) = SHARED_LIB.get::<unsafe extern "C" fn()>(name.as_bytes()) {
+        entrypoint();
+        0
+    } else {
+        1
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn LLVM_InitializeNativeTarget() -> LLVMBool {
+    init_native("Target")
+}
+#[no_mangle]
+pub unsafe extern "C" fn LLVM_InitializeNativeAsmParser() -> LLVMBool {
+    init_native("AsmParser")
+}
+#[no_mangle]
+pub unsafe extern "C" fn LLVM_InitializeNativeAsmPrinter() -> LLVMBool {
+    init_native("AsmPrinter")
+}
+#[no_mangle]
+pub unsafe extern "C" fn LLVM_InitializeNativeDisassembler() -> LLVMBool {
+    init_native("Disassembler")
+}

src/lib.rs

@@ -45,6 +45,8 @@ use lib::Library;
 mod path;
 use path::find_lib_path;
 
+pub mod init;
+
 lazy_static! {
     static ref SHARED_LIB: Library = {
         let lib_path = match find_lib_path() {