First working version of LLVM in Windows

lib/llvm-backend/Cargo.toml

@@ -1,13 +1,12 @@
 [package]
 name = "wasmer-llvm-backend"
 version = "0.5.7"
-authors = ["Lachlan Sneff <lachlan.sneff@gmail.com>"]
+authors = ["The Wasmer Engineering Team <engineering@wasmer.io>"]
 edition = "2018"
 readme = "README.md"
 
 [dependencies]
 wasmer-runtime-core = { path = "../runtime-core", version = "0.5.7" }
-inkwell = { git = "https://github.com/wasmerio/inkwell", branch = "llvm8-0", features = ["llvm8-0"] }
 wasmparser = "0.34.0"
 hashbrown = "0.1.8"
 smallvec = "0.6.8"
@@ -16,6 +15,15 @@ libc = "0.2.49"
 nix = "0.14.0"
 capstone = { version = "0.5.0", optional = true }
 
+[dependencies.inkwell]
+git = "https://github.com/wasmerio/inkwell"
+branch = "llvm8-0"
+default-features = false
+features = ["llvm8-0", "target-x86"]
+
+[target.'cfg(windows)'.dependencies]
+winapi = { version = "0.3", features = ["memoryapi"] }
+
 [build-dependencies]
 cc = "1.0"
 lazy_static = "1.2.0"

lib/llvm-backend/cpp/object_loader.cpp

@@ -75,16 +75,16 @@ public:
     }
 
     virtual void registerEHFrames(uint8_t* addr, uint64_t LoadAddr, size_t size) override {
-        eh_frame_ptr = addr;
+        /* eh_frame_ptr = addr;
         eh_frame_size = size;
         eh_frames_registered = true;
-        callbacks.visit_fde(addr, size, __register_frame);
+        callbacks.visit_fde(addr, size, __register_frame);*/
     }
 
     virtual void deregisterEHFrames() override {
-        if (eh_frames_registered) {
+        /* if (eh_frames_registered) {
             callbacks.visit_fde(eh_frame_ptr, eh_frame_size, __deregister_frame);
-        }
+        }*/
     }
 
     virtual bool finalizeMemory(std::string *ErrMsg = nullptr) override {

lib/llvm-backend/src/backend.rs

@@ -1,14 +1,12 @@
 use crate::intrinsics::Intrinsics;
+use crate::structs::{Callbacks, LLVMModule, LLVMResult, MemProtect};
 use inkwell::{
     memory_buffer::MemoryBuffer,
     module::Module,
     targets::{CodeModel, FileType, InitializationConfig, RelocMode, Target, TargetMachine},
     OptimizationLevel,
 };
-use libc::{
-    c_char, mmap, mprotect, munmap, MAP_ANON, MAP_PRIVATE, PROT_EXEC, PROT_NONE, PROT_READ,
-    PROT_WRITE,
-};
+use libc::c_char;
 use std::{
     any::Any,
     ffi::{c_void, CString},
@@ -31,42 +29,6 @@ use wasmer_runtime_core::{
     vm, vmcalls,
 };
 
-#[repr(C)]
-struct LLVMModule {
-    _private: [u8; 0],
-}
-
-#[allow(non_camel_case_types, dead_code)]
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
-#[repr(C)]
-enum MemProtect {
-    NONE,
-    READ,
-    READ_WRITE,
-    READ_EXECUTE,
-}
-
-#[allow(non_camel_case_types, dead_code)]
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
-#[repr(C)]
-enum LLVMResult {
-    OK,
-    ALLOCATE_FAILURE,
-    PROTECT_FAILURE,
-    DEALLOC_FAILURE,
-    OBJECT_LOAD_FAILURE,
-}
-
-#[repr(C)]
-struct Callbacks {
-    alloc_memory: extern "C" fn(usize, MemProtect, &mut *mut u8, &mut usize) -> LLVMResult,
-    protect_memory: extern "C" fn(*mut u8, usize, MemProtect) -> LLVMResult,
-    dealloc_memory: extern "C" fn(*mut u8, usize) -> LLVMResult,
-
-    lookup_vm_symbol: extern "C" fn(*const c_char, usize) -> *const vm::Func,
-    visit_fde: extern "C" fn(*mut u8, usize, extern "C" fn(*mut u8)),
-}
-
 extern "C" {
     fn module_load(
         mem_ptr: *const u8,
@@ -99,69 +61,21 @@ extern "C" {
 }
 
 fn get_callbacks() -> Callbacks {
-    fn round_up_to_page_size(size: usize) -> usize {
-        (size + (4096 - 1)) & !(4096 - 1)
-    }
-
     extern "C" fn alloc_memory(
         size: usize,
         protect: MemProtect,
         ptr_out: &mut *mut u8,
         size_out: &mut usize,
     ) -> LLVMResult {
-        let size = round_up_to_page_size(size);
-        let ptr = unsafe {
-            mmap(
-                ptr::null_mut(),
-                size,
-                match protect {
-                    MemProtect::NONE => PROT_NONE,
-                    MemProtect::READ => PROT_READ,
-                    MemProtect::READ_WRITE => PROT_READ | PROT_WRITE,
-                    MemProtect::READ_EXECUTE => PROT_READ | PROT_EXEC,
-                },
-                MAP_PRIVATE | MAP_ANON,
-                -1,
-                0,
-            )
-        };
-        if ptr as isize == -1 {
-            return LLVMResult::ALLOCATE_FAILURE;
-        }
-        *ptr_out = ptr as _;
-        *size_out = size;
-        LLVMResult::OK
+        unsafe { crate::platform::alloc_memory(size, protect, ptr_out, size_out) }
     }
 
     extern "C" fn protect_memory(ptr: *mut u8, size: usize, protect: MemProtect) -> LLVMResult {
-        let res = unsafe {
-            mprotect(
-                ptr as _,
-                round_up_to_page_size(size),
-                match protect {
-                    MemProtect::NONE => PROT_NONE,
-                    MemProtect::READ => PROT_READ,
-                    MemProtect::READ_WRITE => PROT_READ | PROT_WRITE,
-                    MemProtect::READ_EXECUTE => PROT_READ | PROT_EXEC,
-                },
-            )
-        };
-
-        if res == 0 {
-            LLVMResult::OK
-        } else {
-            LLVMResult::PROTECT_FAILURE
-        }
+        unsafe { crate::platform::protect_memory(ptr, size, protect) }
     }
 
     extern "C" fn dealloc_memory(ptr: *mut u8, size: usize) -> LLVMResult {
-        let res = unsafe { munmap(ptr as _, round_up_to_page_size(size)) };
-
-        if res == 0 {
-            LLVMResult::OK
-        } else {
-            LLVMResult::DEALLOC_FAILURE
-        }
+        unsafe { crate::platform::dealloc_memory(ptr, size) }
     }
 
     extern "C" fn lookup_vm_symbol(name_ptr: *const c_char, length: usize) -> *const vm::Func {

lib/llvm-backend/src/lib.rs

@@ -7,6 +7,7 @@ mod intrinsics;
 mod platform;
 mod read_info;
 mod state;
+mod structs;
 mod trampolines;
 
 pub use code::LLVMFunctionCodeGenerator as FunctionCodeGenerator;

lib/llvm-backend/src/platform/common.rs

@@ -0,0 +1,3 @@
+pub fn round_up_to_page_size(size: usize) -> usize {
+    (size + (4096 - 1)) & !(4096 - 1)
+}

lib/llvm-backend/src/platform/mod.rs

@@ -1,7 +1,14 @@
+mod common;
+
 #[cfg(unix)]
 mod unix;
 #[cfg(unix)]
 pub use self::unix::*;
 
 #[cfg(target_family = "windows")]
-compile_error!("windows not yet supported for the llvm-based compiler backend");
+mod win;
+#[cfg(target_family = "windows")]
+pub use self::win::*;
+
+#[cfg(not(any(unix, target_family = "windows")))]
+compile_error!("Your system is not yet supported for the llvm-based compiler backend");

lib/llvm-backend/src/platform/unix.rs

@@ -1,3 +1,9 @@
+use super::common::round_up_to_page_size;
+use crate::structs::{LLVMResult, MemProtect};
+use libc::{
+    c_char, mmap, mprotect, munmap, MAP_ANON, MAP_PRIVATE, PROT_EXEC, PROT_NONE, PROT_READ,
+    PROT_WRITE,
+};
 use libc::{c_void, siginfo_t};
 use nix::sys::signal::{sigaction, SaFlags, SigAction, SigHandler, SigSet, SIGBUS, SIGSEGV};
 
@@ -68,3 +74,60 @@ extern "C" fn signal_trap_handler(
         throw_trap(2);
     }
 }
+
+pub unsafe fn alloc_memory(
+    size: usize,
+    protect: MemProtect,
+    ptr_out: &mut *mut u8,
+    size_out: &mut usize,
+) -> LLVMResult {
+    let size = round_up_to_page_size(size);
+    let ptr = mmap(
+        ptr::null_mut(),
+        size,
+        match protect {
+            MemProtect::NONE => PROT_NONE,
+            MemProtect::READ => PROT_READ,
+            MemProtect::READ_WRITE => PROT_READ | PROT_WRITE,
+            MemProtect::READ_EXECUTE => PROT_READ | PROT_EXEC,
+        },
+        MAP_PRIVATE | MAP_ANON,
+        -1,
+        0,
+    );
+    if ptr as isize == -1 {
+        return LLVMResult::ALLOCATE_FAILURE;
+    }
+    *ptr_out = ptr as _;
+    *size_out = size;
+    LLVMResult::OK
+}
+
+pub unsafe fn protect_memory(ptr: *mut u8, size: usize, protect: MemProtect) -> LLVMResult {
+    let res = mprotect(
+        ptr as _,
+        round_up_to_page_size(size),
+        match protect {
+            MemProtect::NONE => PROT_NONE,
+            MemProtect::READ => PROT_READ,
+            MemProtect::READ_WRITE => PROT_READ | PROT_WRITE,
+            MemProtect::READ_EXECUTE => PROT_READ | PROT_EXEC,
+        },
+    );
+
+    if res == 0 {
+        LLVMResult::OK
+    } else {
+        LLVMResult::PROTECT_FAILURE
+    }
+}
+
+pub unsafe fn dealloc_memory(ptr: *mut u8, size: usize) -> LLVMResult {
+    let res = munmap(ptr as _, round_up_to_page_size(size));
+
+    if res == 0 {
+        LLVMResult::OK
+    } else {
+        LLVMResult::DEALLOC_FAILURE
+    }
+}

lib/llvm-backend/src/platform/win.rs

@@ -0,0 +1,80 @@
+use super::common::round_up_to_page_size;
+use crate::structs::{LLVMResult, MemProtect};
+use std::ptr;
+
+use winapi::um::memoryapi::{VirtualAlloc, VirtualFree};
+use winapi::um::winnt::{
+    MEM_COMMIT, MEM_DECOMMIT, MEM_RESERVE, PAGE_EXECUTE_READ, PAGE_NOACCESS, PAGE_READONLY,
+    PAGE_READWRITE,
+};
+
+pub unsafe fn visit_fde(_addr: *mut u8, _size: usize, _visitor: extern "C" fn(*mut u8)) {
+    // Do nothing on Windows
+}
+
+pub unsafe fn install_signal_handler() {
+    // Do nothing on Windows
+}
+
+pub unsafe fn alloc_memory(
+    size: usize,
+    protect: MemProtect,
+    ptr_out: &mut *mut u8,
+    size_out: &mut usize,
+) -> LLVMResult {
+    let size = round_up_to_page_size(size);
+    let flags = if protect == MemProtect::NONE {
+        MEM_RESERVE
+    } else {
+        MEM_RESERVE | MEM_COMMIT
+    };
+    let ptr = VirtualAlloc(
+        ptr::null_mut(),
+        size,
+        flags,
+        memprotect_to_protect_const(protect),
+    );
+
+    if ptr.is_null() {
+        return LLVMResult::ALLOCATE_FAILURE;
+    }
+
+    *ptr_out = ptr as _;
+    *size_out = size;
+    LLVMResult::OK
+}
+
+pub unsafe fn protect_memory(ptr: *mut u8, size: usize, protect: MemProtect) -> LLVMResult {
+    let size = round_up_to_page_size(size);
+    let ptr = VirtualAlloc(
+        ptr as _,
+        size,
+        MEM_COMMIT,
+        memprotect_to_protect_const(protect),
+    );
+
+    if ptr.is_null() {
+        LLVMResult::PROTECT_FAILURE
+    } else {
+        LLVMResult::OK
+    }
+}
+
+pub unsafe fn dealloc_memory(ptr: *mut u8, size: usize) -> LLVMResult {
+    let success = VirtualFree(ptr as _, size, MEM_DECOMMIT);
+    // If the function succeeds, the return value is nonzero.
+    if success == 1 {
+        LLVMResult::OK
+    } else {
+        LLVMResult::DEALLOC_FAILURE
+    }
+}
+
+fn memprotect_to_protect_const(protect: MemProtect) -> u32 {
+    match protect {
+        MemProtect::NONE => PAGE_NOACCESS,
+        MemProtect::READ => PAGE_READONLY,
+        MemProtect::READ_WRITE => PAGE_READWRITE,
+        MemProtect::READ_EXECUTE => PAGE_EXECUTE_READ,
+    }
+}

lib/llvm-backend/src/structs.rs

@@ -0,0 +1,39 @@
+use libc::c_char;
+
+use wasmer_runtime_core::vm;
+
+#[repr(C)]
+pub struct LLVMModule {
+    _private: [u8; 0],
+}
+
+#[allow(non_camel_case_types, dead_code)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[repr(C)]
+pub enum MemProtect {
+    NONE,
+    READ,
+    READ_WRITE,
+    READ_EXECUTE,
+}
+
+#[allow(non_camel_case_types, dead_code)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[repr(C)]
+pub enum LLVMResult {
+    OK,
+    ALLOCATE_FAILURE,
+    PROTECT_FAILURE,
+    DEALLOC_FAILURE,
+    OBJECT_LOAD_FAILURE,
+}
+
+#[repr(C)]
+pub struct Callbacks {
+    pub alloc_memory: extern "C" fn(usize, MemProtect, &mut *mut u8, &mut usize) -> LLVMResult,
+    pub protect_memory: extern "C" fn(*mut u8, usize, MemProtect) -> LLVMResult,
+    pub dealloc_memory: extern "C" fn(*mut u8, usize) -> LLVMResult,
+
+    pub lookup_vm_symbol: extern "C" fn(*const c_char, usize) -> *const vm::Func,
+    pub visit_fde: extern "C" fn(*mut u8, usize, extern "C" fn(*mut u8)),
+}