Merge branch 'master' into feature/clif-cgapi

.appveyor.yml

@@ -64,6 +64,7 @@ build_script:
   - rename target wapm-cli-target
   - cd ..
   - move wapm-cli\wapm-cli-target wapm-cli-target
+  - cargo build --release --manifest-path lib/runtime-c-api/Cargo.toml
 
 test_script:
   - cargo test --manifest-path lib/spectests/Cargo.toml --features clif

.circleci/config.yml

@@ -191,6 +191,11 @@ jobs:
             echo "${CIRCLE_TAG}" >> artifacts/git_version
             make build-install
             cp ./wasmer.tar.gz ./artifacts/$(./binary-name.sh)
+      - run:
+          name: Dynamic library
+          command: |
+            cargo build --release --manifest-path lib/runtime-c-api/Cargo.toml
+            cp target/release/libwasmer_runtime_c_api.so ./artifacts
       - persist_to_workspace:
           root: .
           paths:
@@ -278,6 +283,13 @@ jobs:
             cp ./wasmer.tar.gz ./artifacts/$(./binary-name.sh)
             # VERSION=$(cargo pkgid | cut -d# -f2 | cut -d: -f2)
             # echo "${VERSION}" >> artifacts/version
+      - run:
+          name: Generate dynamic library for the runtime C API
+          command: |
+            export PATH="$HOME/.cargo/bin:$PATH"
+            cargo build --release --manifest-path lib/runtime-c-api/Cargo.toml
+            install_name_tool -id "@rpath/libwasmer_runtime_c_api.dylib" target/release/libwasmer_runtime_c_api.dylib
+            cp target/release/libwasmer_runtime_c_api.dylib ./artifacts
       - persist_to_workspace:
           root: .
           paths:
@@ -351,7 +363,7 @@ jobs:
             # VERSION_TAG=$(git describe --exact-match --tags)
             #if [ "$VERSION" == "$VERSION_TAG" ]; then
             # echo "Versions match, publishing to Github"
-            ghr -t ${GITHUB_TOKEN} -u ${CIRCLE_PROJECT_USERNAME} -r ${CIRCLE_PROJECT_REPONAME} -c ${CIRCLE_SHA1} -soft ${VERSION} ./artifacts/
+            ghr -t ${GITHUB_TOKEN} -u ${CIRCLE_PROJECT_USERNAME} -r ${CIRCLE_PROJECT_REPONAME} -c ${CIRCLE_SHA1} ${VERSION} ./artifacts/  || true
             #else
             #    echo "Versions don't match. Wasmer output version (wasmer --version) is ${VERSION} while Git tag is ${VERSION_TAG}"
             #    exit 1

ARCHITECTURE.md

@@ -2,7 +2,7 @@
 
 Wasmer uses the following components:
 
-- [Cranelift](https://github.com/cranestation/cranelift): for compiling Wasm binaries to machine code
+- Compiler backends: for compiling Wasm binaries to machine code ([more info here](https://github.com/wasmerio/wasmer/tree/master/lib#backends))
 - [wabt](https://github.com/pepyakin/wabt-rs): for transforming `.wast` files to `.wasm` and running WebAssembly spec tests
 - [wasmparser](https://github.com/yurydelendik/wasmparser.rs): for parsing the `.wasm` files and translating them into WebAssembly modules
 
@@ -67,3 +67,8 @@ Once that's finished, we will have a `Instance` function that will be ready to e
 
 Wasmer's Emscripten integration tries to wrap (and emulate) all the different syscalls that Emscripten needs.
 We provide this integration by filling the `import_object` with the Emscripten functions, while instantiating the WebAssembly Instance.
+
+## WASI
+
+Wasmer's WASI integration implements all the different syscalls that WASI needs.
+We provide this integration by filling the `import_object` with the WASI functions, while instantiating the WebAssembly Instance.

CHANGELOG.md

@@ -6,6 +6,7 @@ Blocks of changes will separated by version increments.
 
 ## **[Unreleased]**
 
+- [#470](https://github.com/wasmerio/wasmer/pull/470) Add mapdir support to Emscripten, implement getdents for Unix
 - [#467](https://github.com/wasmerio/wasmer/pull/467) `wasmer_instantiate` returns better error messages in the runtime C API
 - [#463](https://github.com/wasmerio/wasmer/pull/463) Fix bug in WASI path_open allowing one level above preopened dir to be accessed
 - [#461](https://github.com/wasmerio/wasmer/pull/461) Prevent passing negative lengths in various places in the runtime C API

Cargo.lock

@@ -1412,6 +1412,7 @@ version = "0.4.2"
 dependencies = [
  "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hashbrown 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",

README.md

@@ -28,11 +28,12 @@ curl https://get.wasmer.io -sSfL | sh
 
 Wasmer runtime can also be embedded in different languages, so you can use WebAssembly anywhere ✨:
 
-* [**Rust**](https://github.com/wasmerio/wasmer-rust-example)
+* [🦀 **Rust**](https://github.com/wasmerio/wasmer-rust-example)
 * [**C/C++**](https://github.com/wasmerio/wasmer-c-api)
 * [**🐘 PHP**](https://github.com/wasmerio/php-ext-wasm)
 * [**🐍 Python**](https://github.com/wasmerio/python-ext-wasm)
 * [**💎 Ruby**](https://github.com/wasmerio/ruby-ext-wasm)
+* [**🐹 Go**](https://github.com/wasmerio/go-ext-wasm)
 
 ### Usage
 

SECURITY.md

@@ -0,0 +1,19 @@
+# Security Policy
+
+## Supported Versions
+
+While in beta, the latest published version of `wasmer` (`0.x`) will be supported with security updates.
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 0.x   | :white_check_mark: |
+
+## Reporting a Vulnerability
+
+The Wasmer team and community take security bugs in Wasmer seriously.
+We appreciate your efforts to responsibly disclose your findings, and will make every effort to acknowledge your contributions.
+
+To report a security issue, email security@wasmer.io and include the word "SECURITY" in the subject line.
+
+The Wasmer team will send a response indicating the next steps in handling your report.
+After the initial reply to your report, the security team will keep you informed of the progress towards a fix and full announcement, and may ask for additional information or guidance.

lib/emscripten/Cargo.toml

@@ -9,14 +9,15 @@ edition = "2018"
 build = "build/mod.rs"
 
 [dependencies]
-wasmer-runtime-core = { path = "../runtime-core", version = "0.4.2" }
+byteorder = "1"
+hashbrown = "0.1"
 lazy_static = "1.2.0"
 libc = "0.2.49"
-byteorder = "1"
 time = "0.1.41"
 wasmer-clif-backend = { path = "../clif-backend", version = "0.4.2" }
-wasmer-singlepass-backend = { path = "../singlepass-backend", version = "0.4.2", optional = true }
 wasmer-llvm-backend = { path = "../llvm-backend", version = "0.4.2", optional = true }
+wasmer-runtime-core = { path = "../runtime-core", version = "0.4.2" }
+wasmer-singlepass-backend = { path = "../singlepass-backend", version = "0.4.2", optional = true }
 
 [target.'cfg(windows)'.dependencies]
 rand = "0.6"

lib/emscripten/src/env/mod.rs

@@ -10,6 +10,8 @@ pub use self::unix::*;
 #[cfg(windows)]
 pub use self::windows::*;
 
+use libc::c_char;
+
 use crate::{allocate_on_stack, EmscriptenData};
 use std::os::raw::c_int;
 use wasmer_runtime_core::vm::Ctx;
@@ -112,3 +114,41 @@ pub fn ___assert_fail(_ctx: &mut Ctx, _a: c_int, _b: c_int, _c: c_int, _d: c_int
     // TODO: Implement like emscripten expects regarding memory/page size
     // TODO raise an error
 }
+
+pub fn _pathconf(ctx: &mut Ctx, path_addr: c_int, name: c_int) -> c_int {
+    debug!(
+        "emscripten::_pathconf {} {} - UNIMPLEMENTED",
+        path_addr, name
+    );
+    let _path = emscripten_memory_pointer!(ctx.memory(0), path_addr) as *const c_char;
+    match name {
+        0 => 32000,
+        1 | 2 | 3 => 255,
+        4 | 5 | 16 | 17 | 18 => 4096,
+        6 | 7 | 20 => 1,
+        8 => 0,
+        9 | 10 | 11 | 12 | 14 | 15 | 19 => -1,
+        13 => 64,
+        _ => {
+            // ___setErrNo(22);
+            -1
+        }
+    }
+}
+
+pub fn _fpathconf(_ctx: &mut Ctx, _fildes: c_int, name: c_int) -> c_int {
+    debug!("emscripten::_fpathconf {} {}", _fildes, name);
+    match name {
+        0 => 32000,
+        1 | 2 | 3 => 255,
+        4 | 5 | 16 | 17 | 18 => 4096,
+        6 | 7 | 20 => 1,
+        8 => 0,
+        9 | 10 | 11 | 12 | 14 | 15 | 19 => -1,
+        13 => 64,
+        _ => {
+            // ___setErrNo(22);
+            -1
+        }
+    }
+}

lib/emscripten/src/lib.rs

@@ -3,8 +3,10 @@
 #[macro_use]
 extern crate wasmer_runtime_core;
 
+use hashbrown::HashMap;
 use lazy_static::lazy_static;
 use std::cell::UnsafeCell;
+use std::path::PathBuf;
 use std::{f64, ffi::c_void};
 use wasmer_runtime_core::{
     error::CallResult,
@@ -141,10 +143,14 @@ pub struct EmscriptenData<'a> {
     pub stack_save: Option<Func<'a, (), i32>>,
     pub stack_restore: Option<Func<'a, (i32)>>,
     pub set_threw: Option<Func<'a, (i32, i32)>>,
+    pub mapped_dirs: HashMap<String, PathBuf>,
 }
 
 impl<'a> EmscriptenData<'a> {
-    pub fn new(instance: &'a mut Instance) -> EmscriptenData<'a> {
+    pub fn new(
+        instance: &'a mut Instance,
+        mapped_dirs: HashMap<String, PathBuf>,
+    ) -> EmscriptenData<'a> {
         let malloc = instance.func("_malloc").unwrap();
         let free = instance.func("_free").unwrap();
         let memalign = instance.func("_memalign").ok();
@@ -272,6 +278,7 @@ impl<'a> EmscriptenData<'a> {
             stack_save,
             stack_restore,
             set_threw,
+            mapped_dirs,
         }
     }
 }
@@ -282,8 +289,9 @@ pub fn run_emscripten_instance(
     path: &str,
     args: Vec<&str>,
     entrypoint: Option<String>,
+    mapped_dirs: Vec<(String, PathBuf)>,
 ) -> CallResult<()> {
-    let mut data = EmscriptenData::new(instance);
+    let mut data = EmscriptenData::new(instance, mapped_dirs.into_iter().collect());
     let data_ptr = &mut data as *mut _ as *mut c_void;
     instance.context_mut().data = data_ptr;
 
@@ -545,6 +553,8 @@ pub fn generate_emscripten_env(globals: &mut EmscriptenGlobals) -> ImportObject
         "_sysconf" => func!(crate::env::_sysconf),
         "_getaddrinfo" => func!(crate::env::_getaddrinfo),
         "_times" => func!(crate::env::_times),
+        "_pathconf" => func!(crate::env::_pathconf),
+        "_fpathconf" => func!(crate::env::_fpathconf),
 
         // Syscalls
         "___syscall1" => func!(crate::syscalls::___syscall1),
@@ -687,6 +697,7 @@ pub fn generate_emscripten_env(globals: &mut EmscriptenGlobals) -> ImportObject
         "_asctime_r" => func!(crate::time::_asctime_r),
         "_localtime" => func!(crate::time::_localtime),
         "_time" => func!(crate::time::_time),
+        "_timegm" => func!(crate::time::_timegm),
         "_strftime" => func!(crate::time::_strftime),
         "_strftime_l" => func!(crate::time::_strftime_l),
         "_localtime_r" => func!(crate::time::_localtime_r),
@@ -705,6 +716,7 @@ pub fn generate_emscripten_env(globals: &mut EmscriptenGlobals) -> ImportObject
         "_llvm_exp2_f32" => func!(crate::math::_llvm_exp2_f32),
         "_llvm_exp2_f64" => func!(crate::math::_llvm_exp2_f64),
         "_llvm_trunc_f64" => func!(crate::math::_llvm_trunc_f64),
+        "_llvm_fma_f64" => func!(crate::math::_llvm_fma_f64),
         "_emscripten_random" => func!(crate::math::_emscripten_random),
 
         // Jump

lib/emscripten/src/math.rs

@@ -49,6 +49,11 @@ pub fn _llvm_trunc_f64(_ctx: &mut Ctx, value: f64) -> f64 {
     value.trunc()
 }
 
+pub fn _llvm_fma_f64(_ctx: &mut Ctx, value: f64, a: f64, b: f64) -> f64 {
+    debug!("emscripten::_llvm_fma_f64");
+    value.mul_add(a, b)
+}
+
 pub fn _emscripten_random(_ctx: &mut Ctx) -> f64 {
     debug!("emscripten::_emscripten_random");
     -1.0

lib/emscripten/src/syscalls/mod.rs

@@ -10,7 +10,8 @@ pub use self::unix::*;
 #[cfg(windows)]
 pub use self::windows::*;
 
-use super::utils::copy_stat_into_wasm;
+use crate::utils::{copy_stat_into_wasm, get_cstr_path, get_current_directory};
+
 use super::varargs::VarArgs;
 use byteorder::{ByteOrder, LittleEndian};
 /// NOTE: TODO: These syscalls only support wasm_32 for now because they assume offsets are u32
@@ -38,6 +39,7 @@ use libc::{
     // writev,
     stat,
     write,
+    // readlink,
 };
 use wasmer_runtime_core::vm::Ctx;
 
@@ -93,14 +95,20 @@ pub fn ___syscall6(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int
 // chdir
 pub fn ___syscall12(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall12 (chdir) {}", _which);
-    let path_addr: i32 = varargs.get(ctx);
+    let path_ptr = varargs.get_str(ctx);
-    unsafe {
+    let real_path_owned = get_cstr_path(ctx, path_ptr);
-        let path_ptr = emscripten_memory_pointer!(ctx.memory(0), path_addr) as *const i8;
+    let real_path = if let Some(ref rp) = real_path_owned {
-        let _path = std::ffi::CStr::from_ptr(path_ptr);
+        rp.as_c_str().as_ptr()
-        let ret = chdir(path_ptr);
+    } else {
-        debug!("=> path: {:?}, ret: {}", _path, ret);
+        path_ptr
+    };
+    let ret = unsafe { chdir(real_path) };
+    debug!(
+        "=> path: {:?}, ret: {}",
+        unsafe { std::ffi::CStr::from_ptr(real_path) },
         ret
-    }
+    );
+    ret
 }
 
 pub fn ___syscall10(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
@@ -122,15 +130,25 @@ pub fn ___syscall20(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
 // rename
 pub fn ___syscall38(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> i32 {
     debug!("emscripten::___syscall38 (rename)");
-    let old_path_addr: u32 = varargs.get(ctx);
+    let old_path = varargs.get_str(ctx);
-    let new_path_addr: u32 = varargs.get(ctx);
+    let new_path = varargs.get_str(ctx);
-    let old_path = emscripten_memory_pointer!(ctx.memory(0), old_path_addr) as *const i8;
+    let real_old_path_owned = get_cstr_path(ctx, old_path);
-    let new_path = emscripten_memory_pointer!(ctx.memory(0), new_path_addr) as *const i8;
+    let real_old_path = if let Some(ref rp) = real_old_path_owned {
-    let result = unsafe { rename(old_path, new_path) };
+        rp.as_c_str().as_ptr()
+    } else {
+        old_path
+    };
+    let real_new_path_owned = get_cstr_path(ctx, new_path);
+    let real_new_path = if let Some(ref rp) = real_new_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        new_path
+    };
+    let result = unsafe { rename(real_old_path, real_new_path) };
     debug!(
         "=> old_path: {}, new_path: {}, result: {}",
-        unsafe { std::ffi::CStr::from_ptr(old_path).to_str().unwrap() },
+        unsafe { std::ffi::CStr::from_ptr(real_old_path).to_str().unwrap() },
-        unsafe { std::ffi::CStr::from_ptr(new_path).to_str().unwrap() },
+        unsafe { std::ffi::CStr::from_ptr(real_new_path).to_str().unwrap() },
         result
     );
     result
@@ -139,9 +157,14 @@ pub fn ___syscall38(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> i32 {
 // rmdir
 pub fn ___syscall40(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall40 (rmdir)");
-    let pathname: u32 = varargs.get(ctx);
+    let pathname_addr = varargs.get_str(ctx);
-    let pathname_addr = emscripten_memory_pointer!(ctx.memory(0), pathname) as *const i8;
+    let real_path_owned = get_cstr_path(ctx, pathname_addr);
-    unsafe { rmdir(pathname_addr) }
+    let real_path = if let Some(ref rp) = real_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        pathname_addr
+    };
+    unsafe { rmdir(real_path) }
 }
 
 // pipe
@@ -201,9 +224,32 @@ pub fn ___syscall75(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
     -1
 }
 
-pub fn ___syscall85(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
+// readlink
-    debug!("emscripten::___syscall85");
+pub fn ___syscall85(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> i32 {
-    -1
+    debug!("emscripten::___syscall85 (readlink)");
+    let _path = varargs.get_str(ctx);
+    let buf = varargs.get_str(ctx);
+    // let buf_addr: i32 = varargs.get(ctx);
+    let buf_size: i32 = varargs.get(ctx);
+    let fd = 3;
+    let ret = unsafe { read(fd, buf as _, buf_size as _) as i32 };
+    debug!(
+        "=> buf: {}, buf_size: {}, return: {} ",
+        unsafe { std::ffi::CStr::from_ptr(buf as _).to_str().unwrap() },
+        buf_size,
+        ret
+    );
+    // let ret = unsafe {
+    //     readlink(path, buf as _, buf_size as _) as i32
+    // };
+    // debug!("=> path: {}, buf: {}, buf_size: {}, return: {} ",
+    //     unsafe { std::ffi::CStr::from_ptr(path).to_str().unwrap() },
+    //     unsafe { std::ffi::CStr::from_ptr(buf as _).to_str().unwrap() },
+    //     // std::ffi::CStr::from_ptr(buf).to_str().unwrap(),
+    //     // buf,
+    //     buf_size,
+    //     ret);
+    ret
 }
 
 pub fn ___syscall91(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
@@ -224,10 +270,9 @@ pub fn ___syscall110(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
 // getcwd
 pub fn ___syscall183(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> i32 {
     debug!("emscripten::___syscall183");
-    use std::env;
     let buf_offset: c_int = varargs.get(ctx);
     let _size: c_int = varargs.get(ctx);
-    let path = env::current_dir();
+    let path = get_current_directory(ctx);
     let path_string = path.unwrap().display().to_string();
     let len = path_string.len();
     unsafe {
@@ -397,19 +442,23 @@ pub fn ___syscall199(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
 // stat64
 pub fn ___syscall195(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall195 (stat64) {}", _which);
-    let pathname: u32 = varargs.get(ctx);
+    let pathname_addr = varargs.get_str(ctx);
     let buf: u32 = varargs.get(ctx);
 
-    let pathname_addr = emscripten_memory_pointer!(ctx.memory(0), pathname) as *const i8;
+    let real_path_owned = get_cstr_path(ctx, pathname_addr);
+    let real_path = if let Some(ref rp) = real_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        pathname_addr
+    };
 
     unsafe {
         let mut _stat: stat = std::mem::zeroed();
-        let ret = stat(pathname_addr, &mut _stat);
+        let ret = stat(real_path, &mut _stat);
         debug!(
-            "=> pathname: {}, buf: {}, path: {} = {}\nlast os error: {}",
+            "=> pathname: {}, buf: {} = {}, last os error: {}",
-            pathname,
+            std::ffi::CStr::from_ptr(real_path).to_str().unwrap(),
             buf,
-            std::ffi::CStr::from_ptr(pathname_addr).to_str().unwrap(),
             ret,
             Error::last_os_error()
         );
@@ -440,11 +489,6 @@ pub fn ___syscall197(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_in
     0
 }
 
-pub fn ___syscall220(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
-    debug!("emscripten::___syscall220");
-    -1
-}
-
 // fcntl64
 pub fn ___syscall221(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall221 (fcntl64) {}", _which);
@@ -457,7 +501,7 @@ pub fn ___syscall221(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_in
     // |FNONBLOCK - 0x04
     debug!("=> fd: {}, cmd: {}", _fd, cmd);
     match cmd {
-        2 => 0,
+        1 | 2 => 0,
         13 | 14 => 0, // pretend file locking worked
         _ => -1,
     }

lib/emscripten/src/syscalls/unix.rs

@@ -43,6 +43,7 @@ use libc::{
     pid_t,
     pread,
     pwrite,
+    readdir,
     // readv,
     recvfrom,
     recvmsg,
@@ -104,19 +105,23 @@ const SO_NOSIGPIPE: c_int = 0;
 /// open
 pub fn ___syscall5(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall5 (open) {}", _which);
-    let pathname: u32 = varargs.get(ctx);
+    let pathname_addr = varargs.get_str(ctx);
     let flags: i32 = varargs.get(ctx);
     let mode: u32 = varargs.get(ctx);
-    let pathname_addr = emscripten_memory_pointer!(ctx.memory(0), pathname) as *const i8;
+    let real_path_owned = utils::get_cstr_path(ctx, pathname_addr);
-    let _path_str = unsafe { std::ffi::CStr::from_ptr(pathname_addr).to_str().unwrap() };
+    let real_path = if let Some(ref rp) = real_path_owned {
-    let fd = unsafe { open(pathname_addr, flags, mode) };
+        rp.as_c_str().as_ptr()
+    } else {
+        pathname_addr
+    };
+    let _path_str = unsafe { std::ffi::CStr::from_ptr(real_path).to_str().unwrap() };
+    let fd = unsafe { open(real_path, flags, mode) };
     debug!(
-        "=> pathname: {}, flags: {}, mode: {} = fd: {}\npath: {}\nlast os error: {}",
+        "=> path: {}, flags: {}, mode: {} = fd: {}, last os error: {}",
-        pathname,
+        _path_str,
         flags,
         mode,
         fd,
-        _path_str,
         Error::last_os_error(),
     );
     fd
@@ -126,10 +131,8 @@ pub fn ___syscall5(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int
 pub fn ___syscall9(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall9 (link) {}", _which);
 
-    let oldname: c_int = varargs.get(ctx);
+    let oldname_ptr = varargs.get_str(ctx);
-    let newname: c_int = varargs.get(ctx);
+    let newname_ptr = varargs.get_str(ctx);
-    let oldname_ptr = emscripten_memory_pointer!(ctx.memory(0), oldname) as *const i8;
-    let newname_ptr = emscripten_memory_pointer!(ctx.memory(0), newname) as *const i8;
     let result = unsafe { link(oldname_ptr, newname_ptr) };
     debug!(
         "=> oldname: {}, newname: {}, result: {}",
@@ -156,15 +159,25 @@ pub fn ___syscall77(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int
 pub fn ___syscall83(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall83 (symlink) {}", _which);
 
-    let path1_ptr: c_int = varargs.get(ctx);
+    let path1 = varargs.get_str(ctx);
-    let path2_ptr: c_int = varargs.get(ctx);
+    let path2 = varargs.get_str(ctx);
-    let path1 = emscripten_memory_pointer!(ctx.memory(0), path1_ptr) as *mut i8;
+    let real_path1_owned = utils::get_cstr_path(ctx, path1);
-    let path2 = emscripten_memory_pointer!(ctx.memory(0), path2_ptr) as *mut i8;
+    let real_path1 = if let Some(ref rp) = real_path1_owned {
-    let result = unsafe { symlink(path1, path2) };
+        rp.as_c_str().as_ptr()
+    } else {
+        path1
+    };
+    let real_path2_owned = utils::get_cstr_path(ctx, path2);
+    let real_path2 = if let Some(ref rp) = real_path2_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        path2
+    };
+    let result = unsafe { symlink(real_path1, real_path2) };
     debug!(
         "=> path1: {}, path2: {}, result: {}",
-        unsafe { std::ffi::CStr::from_ptr(path1).to_str().unwrap() },
+        unsafe { std::ffi::CStr::from_ptr(real_path1).to_str().unwrap() },
-        unsafe { std::ffi::CStr::from_ptr(path2).to_str().unwrap() },
+        unsafe { std::ffi::CStr::from_ptr(real_path2).to_str().unwrap() },
         result,
     );
     result
@@ -186,14 +199,19 @@ pub fn ___syscall194(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_in
 /// lchown
 pub fn ___syscall198(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall198 (lchown) {}", _which);
-    let path: c_int = varargs.get(ctx);
+    let path_ptr = varargs.get_str(ctx);
+    let real_path_owned = utils::get_cstr_path(ctx, path_ptr);
+    let real_path = if let Some(ref rp) = real_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        path_ptr
+    };
     let uid: uid_t = varargs.get(ctx);
     let gid: gid_t = varargs.get(ctx);
-    let path_ptr = emscripten_memory_pointer!(ctx.memory(0), path) as *const i8;
+    let result = unsafe { lchown(real_path, uid, gid) };
-    let result = unsafe { lchown(path_ptr, uid, gid) };
     debug!(
         "=> path: {}, uid: {}, gid: {}, result: {}",
-        unsafe { std::ffi::CStr::from_ptr(path_ptr).to_str().unwrap() },
+        unsafe { std::ffi::CStr::from_ptr(real_path).to_str().unwrap() },
         uid,
         gid,
         result,
@@ -222,13 +240,17 @@ pub fn ___syscall205(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_in
 pub fn ___syscall212(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall212 (chown) {}", _which);
 
-    let pathname: u32 = varargs.get(ctx);
+    let pathname_addr = varargs.get_str(ctx);
+    let real_path_owned = utils::get_cstr_path(ctx, pathname_addr);
+    let real_path = if let Some(ref rp) = real_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        pathname_addr
+    };
     let owner: u32 = varargs.get(ctx);
     let group: u32 = varargs.get(ctx);
 
-    let pathname_addr = emscripten_memory_pointer!(ctx.memory(0), pathname) as *const i8;
+    unsafe { chown(real_path, owner, group) }
-
-    unsafe { chown(pathname_addr, owner, group) }
 }
 
 /// madvise
@@ -247,13 +269,18 @@ pub fn ___syscall219(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_in
 /// access
 pub fn ___syscall33(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall33 (access) {}", _which);
-    let path_ptr: c_int = varargs.get(ctx);
+    let path = varargs.get_str(ctx);
+    let real_path_owned = utils::get_cstr_path(ctx, path);
+    let real_path = if let Some(ref rp) = real_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        path
+    };
     let amode: c_int = varargs.get(ctx);
-    let path = emscripten_memory_pointer!(ctx.memory(0), path_ptr) as *const i8;
+    let result = unsafe { access(real_path, amode) };
-    let result = unsafe { access(path, amode) };
     debug!(
         "=> path: {}, amode: {}, result: {}",
-        unsafe { std::ffi::CStr::from_ptr(path).to_str().unwrap() },
+        unsafe { std::ffi::CStr::from_ptr(real_path).to_str().unwrap() },
         amode,
         result
     );
@@ -270,10 +297,15 @@ pub fn ___syscall34(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int
 // mkdir
 pub fn ___syscall39(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall39 (mkdir) {}", _which);
-    let pathname: u32 = varargs.get(ctx);
+    let pathname_addr = varargs.get_str(ctx);
+    let real_path_owned = utils::get_cstr_path(ctx, pathname_addr);
+    let real_path = if let Some(ref rp) = real_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        pathname_addr
+    };
     let mode: u32 = varargs.get(ctx);
-    let pathname_addr = emscripten_memory_pointer!(ctx.memory(0), pathname) as *const i8;
+    unsafe { mkdir(real_path, mode as _) }
-    unsafe { mkdir(pathname_addr, mode as _) }
 }
 
 /// dup
@@ -771,9 +803,14 @@ pub fn ___syscall122(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_in
 /// lstat64
 pub fn ___syscall196(ctx: &mut Ctx, _which: i32, mut varargs: VarArgs) -> i32 {
     debug!("emscripten::___syscall196 (lstat64) {}", _which);
-    let path_ptr: c_int = varargs.get(ctx);
+    let path = varargs.get_str(ctx);
+    let real_path_owned = utils::get_cstr_path(ctx, path);
+    let real_path = if let Some(ref rp) = real_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        path
+    };
     let buf_ptr: u32 = varargs.get(ctx);
-    let path = emscripten_memory_pointer!(ctx.memory(0), path_ptr) as *const i8;
     unsafe {
         let mut stat: stat = std::mem::zeroed();
 
@@ -783,9 +820,9 @@ pub fn ___syscall196(ctx: &mut Ctx, _which: i32, mut varargs: VarArgs) -> i32 {
         let stat_ptr = &mut stat as *mut stat;
 
         #[cfg(target_os = "macos")]
-        let ret = lstat64(path, stat_ptr);
+        let ret = lstat64(real_path, stat_ptr);
         #[cfg(not(target_os = "macos"))]
-        let ret = lstat(path, stat_ptr);
+        let ret = lstat(real_path, stat_ptr);
 
         debug!("ret: {}", ret);
         if ret != 0 {
@@ -796,6 +833,45 @@ pub fn ___syscall196(ctx: &mut Ctx, _which: i32, mut varargs: VarArgs) -> i32 {
     0
 }
 
+// getdents
+// dirent structure is
+// i64, i64, u16 (280), i8, [i8; 256]
+pub fn ___syscall220(ctx: &mut Ctx, _which: i32, mut varargs: VarArgs) -> i32 {
+    debug!("emscripten::___syscall220");
+    let fd: i32 = varargs.get(ctx);
+    let dirp_addr: i32 = varargs.get(ctx);
+    let count: u32 = varargs.get(ctx);
+
+    let dirp = emscripten_memory_pointer!(ctx.memory(0), dirp_addr) as *mut u8;
+    // need to persist stream across calls?
+    let dir: *mut libc::DIR = unsafe { libc::fdopendir(fd) };
+
+    let mut pos = 0;
+    let offset = 280;
+    while pos + offset <= count as usize {
+        let dirent = unsafe { readdir(dir) };
+        if dirent.is_null() {
+            break;
+        }
+        #[allow(clippy::cast_ptr_alignment)]
+        unsafe {
+            *(dirp.add(pos) as *mut u64) = (*dirent).d_ino;
+            *(dirp.add(pos + 8) as *mut u64) = pos as u64 + offset as u64;
+            *(dirp.add(pos + 16) as *mut u16) = offset as u16;
+            *(dirp.add(pos + 18) as *mut u8) = (*dirent).d_type;
+            let upper_bound = std::cmp::min((*dirent).d_reclen, 254) as usize;
+            let mut i = 0;
+            while i < upper_bound {
+                *(dirp.add(pos + 19 + i) as *mut i8) = (*dirent).d_name[i];
+                i += 1;
+            }
+            *(dirp.add(pos + 19 + i) as *mut i8) = 0 as i8;
+        }
+        pos += offset;
+    }
+    pos as i32
+}
+
 /// fallocate
 pub fn ___syscall324(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall324 (fallocate) {}", _which);

lib/emscripten/src/syscalls/windows.rs

@@ -1,4 +1,4 @@
-use crate::utils::copy_cstr_into_wasm;
+use crate::utils::{copy_cstr_into_wasm, get_cstr_path};
 use crate::varargs::VarArgs;
 use libc::mkdir;
 use libc::open;
@@ -18,11 +18,16 @@ pub fn ___syscall5(ctx: &mut Ctx, which: c_int, mut varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall5 (open) {}", which);
     #[cfg(not(feature = "debug"))]
     let _ = which;
-    let pathname: u32 = varargs.get(ctx);
+    let pathname_addr = varargs.get_str(ctx);
+    let real_path_owned = get_cstr_path(ctx, pathname_addr);
+    let real_path = if let Some(ref rp) = real_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        pathname_addr
+    };
     let flags: i32 = varargs.get(ctx);
     let mode: u32 = varargs.get(ctx);
-    let pathname_addr = emscripten_memory_pointer!(ctx.memory(0), pathname) as *const i8;
+    let path_str = unsafe { std::ffi::CStr::from_ptr(real_path).to_str().unwrap() };
-    let path_str = unsafe { std::ffi::CStr::from_ptr(pathname_addr).to_str().unwrap() };
     match path_str {
         "/dev/urandom" => {
             // create a fake urandom file for windows, super hacky
@@ -43,15 +48,15 @@ pub fn ___syscall5(ctx: &mut Ctx, which: c_int, mut varargs: VarArgs) -> c_int {
             let fd = unsafe { open(raw_pointer_to_urandom_file, flags, mode) };
             debug!(
                 "=> pathname: {}, flags: {}, mode: {} = fd: {}",
-                pathname, flags, mode, fd
+                path_str, flags, mode, fd
             );
             fd
         }
         _ => {
-            let fd = unsafe { open(pathname_addr, flags, mode) };
+            let fd = unsafe { open(real_path, flags, mode) };
             debug!(
                 "=> pathname: {}, flags: {}, mode: {} = fd: {}\npath: {}",
-                pathname, flags, mode, fd, path_str
+                path_str, flags, mode, fd, path_str
             );
             fd
         }
@@ -95,9 +100,14 @@ pub fn ___syscall39(ctx: &mut Ctx, which: c_int, mut varargs: VarArgs) -> c_int
     debug!("emscripten::___syscall39 (mkdir) {}", which);
     #[cfg(not(feature = "debug"))]
     let _ = which;
-    let pathname: u32 = varargs.get(ctx);
+    let pathname_addr = varargs.get_str(ctx);
-    let pathname_addr = emscripten_memory_pointer!(ctx.memory(0), pathname) as *const i8;
+    let real_path_owned = get_cstr_path(ctx, pathname_addr);
-    unsafe { mkdir(pathname_addr) }
+    let real_path = if let Some(ref rp) = real_path_owned {
+        rp.as_c_str().as_ptr()
+    } else {
+        pathname_addr
+    };
+    unsafe { mkdir(real_path) }
 }
 
 /// dup
@@ -251,6 +261,12 @@ pub fn ___syscall196(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
     -1
 }
 
+// getdents
+pub fn ___syscall220(_ctx: &mut Ctx, _one: i32, _two: i32) -> i32 {
+    debug!("emscripten::___syscall220");
+    -1
+}
+
 /// fchown
 pub fn ___syscall207(_ctx: &mut Ctx, _which: c_int, _varargs: VarArgs) -> c_int {
     debug!("emscripten::___syscall207 (fchown) {}", _which);

lib/emscripten/src/time.rs

@@ -4,7 +4,9 @@ use std::mem;
 use std::time::SystemTime;
 
 #[cfg(not(target_os = "windows"))]
-use libc::{clockid_t, time as libc_time};
+use libc::{clockid_t, time as libc_time, timegm as libc_timegm, tm as libc_tm};
+#[cfg(not(target_os = "windows"))]
+use std::ffi::CString;
 
 #[cfg(target_os = "windows")]
 use libc::time_t;
@@ -298,6 +300,57 @@ pub fn _time(ctx: &mut Ctx, time_p: u32) -> i32 {
     }
 }
 
+/// emscripten: _timegm
+#[cfg(not(target_os = "windows"))]
+#[allow(clippy::cast_ptr_alignment)]
+pub fn _timegm(ctx: &mut Ctx, time_ptr: u32) -> i32 {
+    debug!("emscripten::_timegm {}", time_ptr);
+
+    unsafe {
+        let time_p_addr = emscripten_memory_pointer!(ctx.memory(0), time_ptr) as *mut guest_tm;
+
+        let x: *mut c_char = CString::new("").expect("CString::new failed").into_raw();
+        let mut rust_tm = libc_tm {
+            tm_sec: 0,
+            tm_min: 0,
+            tm_hour: 0,
+            tm_mday: 0,
+            tm_mon: 0,
+            tm_year: 0,
+            tm_wday: 0,
+            tm_yday: 0,
+            tm_isdst: 0,
+            tm_gmtoff: 0,
+            tm_zone: x,
+        };
+
+        let result = libc_timegm(&mut rust_tm) as i32;
+        if result != 0 {
+            (*time_p_addr).tm_sec = rust_tm.tm_sec;
+            (*time_p_addr).tm_min = rust_tm.tm_min;
+            (*time_p_addr).tm_hour = rust_tm.tm_hour;
+            (*time_p_addr).tm_mday = rust_tm.tm_mday;
+            (*time_p_addr).tm_mon = rust_tm.tm_mon;
+            (*time_p_addr).tm_year = rust_tm.tm_year;
+            (*time_p_addr).tm_wday = rust_tm.tm_wday;
+            (*time_p_addr).tm_yday = rust_tm.tm_yday;
+            (*time_p_addr).tm_isdst = rust_tm.tm_isdst;
+            (*time_p_addr).tm_gmtoff = rust_tm.tm_gmtoff as _;
+            (*time_p_addr).tm_zone = 0;
+        }
+        result
+    }
+}
+
+#[cfg(target_os = "windows")]
+pub fn _timegm(_ctx: &mut Ctx, _time_ptr: c_int) -> i32 {
+    debug!(
+        "emscripten::_timegm - UNIMPLEMENTED IN WINDOWS {}",
+        _time_ptr
+    );
+    -1
+}
+
 /// emscripten: _strftime
 pub fn _strftime(
     ctx: &mut Ctx,

lib/emscripten/src/utils.rs

@@ -5,6 +5,7 @@ use libc::stat;
 use std::ffi::CStr;
 use std::mem::size_of;
 use std::os::raw::c_char;
+use std::path::PathBuf;
 use std::slice;
 use wasmer_runtime_core::memory::Memory;
 use wasmer_runtime_core::{
@@ -204,6 +205,61 @@ pub fn read_string_from_wasm(memory: &Memory, offset: u32) -> String {
     String::from_utf8_lossy(&v).to_owned().to_string()
 }
 
+/// This function trys to find an entry in mapdir
+/// translating paths into their correct value
+pub fn get_cstr_path(ctx: &mut Ctx, path: *const i8) -> Option<std::ffi::CString> {
+    use std::collections::VecDeque;
+
+    let path_str = unsafe { std::ffi::CStr::from_ptr(path).to_str().unwrap() }.to_string();
+    let data = get_emscripten_data(ctx);
+    let path = PathBuf::from(path_str);
+    let mut prefix_added = false;
+    let mut components = path.components().collect::<VecDeque<_>>();
+    // TODO(mark): handle absolute/non-canonical/non-relative paths too (this
+    // functionality should be shared among the abis)
+    if components.len() == 1 {
+        components.push_front(std::path::Component::CurDir);
+        prefix_added = true;
+    }
+    let mut cumulative_path = PathBuf::new();
+    for c in components.into_iter() {
+        cumulative_path.push(c);
+        if let Some(val) = data
+            .mapped_dirs
+            .get(&cumulative_path.to_string_lossy().to_string())
+        {
+            let rest_of_path = if !prefix_added {
+                path.strip_prefix(cumulative_path).ok()?
+            } else {
+                &path
+            };
+            let rebased_path = val.join(rest_of_path);
+            return std::ffi::CString::new(rebased_path.to_string_lossy().as_bytes()).ok();
+        }
+    }
+    None
+}
+
+/// gets the current directory
+/// handles mapdir logic
+pub fn get_current_directory(ctx: &mut Ctx) -> Option<PathBuf> {
+    if let Some(val) = get_emscripten_data(ctx).mapped_dirs.get(".") {
+        return Some(val.clone());
+    }
+    std::env::current_dir()
+        .map(|cwd| {
+            if let Some(val) = get_emscripten_data(ctx)
+                .mapped_dirs
+                .get(&cwd.to_string_lossy().to_string())
+            {
+                val.clone()
+            } else {
+                cwd
+            }
+        })
+        .ok()
+}
+
 #[cfg(test)]
 mod tests {
     use super::is_emscripten_module;

lib/emscripten/src/varargs.rs

@@ -1,5 +1,7 @@
 use std::mem;
 use wasmer_runtime_core::{types::WasmExternType, vm::Ctx};
+// use std::ffi::CStr;
+use std::os::raw::c_char;
 
 #[repr(transparent)]
 #[derive(Copy, Clone)]
@@ -13,6 +15,14 @@ impl VarArgs {
         self.pointer += mem::size_of::<T>() as u32;
         unsafe { (ptr as *const T).read() }
     }
+
+    // pub fn getStr<'a>(&mut self, ctx: &mut Ctx) -> &'a CStr {
+    pub fn get_str(&mut self, ctx: &mut Ctx) -> *const c_char {
+        let ptr_addr: u32 = self.get(ctx);
+        let ptr = emscripten_memory_pointer!(ctx.memory(0), ptr_addr) as *const c_char;
+        ptr
+        // unsafe { CStr::from_ptr(ptr) }
+    }
 }
 
 unsafe impl WasmExternType for VarArgs {

lib/emscripten/tests/emtests/_common.rs

@@ -56,6 +56,7 @@ macro_rules! assert_emscripten_output {
             $name,
             $args,
             None,
+            vec![],
         ).expect("run_emscripten_instance finishes");
 
         let output = capturer.end().unwrap().0;

src/bin/wasmer.rs

@@ -445,9 +445,6 @@ fn execute_wasm(options: &Run) -> Result<(), String> {
             .instantiate(&import_object)
             .map_err(|e| format!("Can't instantiate module: {:?}", e))?;
 
-        if !mapped_dirs.is_empty() {
-            eprintln!("WARN: mapdir is not implemented for emscripten targets");
-        }
         wasmer_emscripten::run_emscripten_instance(
             &module,
             &mut instance,
@@ -458,6 +455,7 @@ fn execute_wasm(options: &Run) -> Result<(), String> {
             },
             options.args.iter().map(|arg| arg.as_str()).collect(),
             options.em_entrypoint.clone(),
+            mapped_dirs,
         )
         .map_err(|e| format!("{:?}", e))?;
     } else {