4 files changed, 44 insertions, 27 deletions
diff --git a/compiler/rustc_session/Cargo.toml b/compiler/rustc_session/Cargo.toml
index d8db86c5f62..9e337dde995 100644
--- a/compiler/rustc_session/Cargo.toml
+++ b/compiler/rustc_session/Cargo.toml
@@ -24,5 +24,9 @@ termize = "0.1.1"
 [target.'cfg(unix)'.dependencies]
 libc = "0.2"
 
-[target.'cfg(windows)'.dependencies]
-winapi = { version = "0.3", features = ["libloaderapi"] }
+[target.'cfg(windows)'.dependencies.windows]
+version = "0.46.0"
+features = [
+    "Win32_Foundation",
+    "Win32_System_LibraryLoader",
+]
diff --git a/compiler/rustc_session/src/cstore.rs b/compiler/rustc_session/src/cstore.rs
index 868ffdf0f1d..a262c06d91f 100644
--- a/compiler/rustc_session/src/cstore.rs
+++ b/compiler/rustc_session/src/cstore.rs
@@ -67,12 +67,11 @@ pub enum LinkagePreference {
 #[derive(Debug, Encodable, Decodable, HashStable_Generic)]
 pub struct NativeLib {
     pub kind: NativeLibKind,
-    pub name: Option<Symbol>,
+    pub name: Symbol,
     /// If packed_bundled_libs enabled, actual filename of library is stored.
     pub filename: Option<Symbol>,
     pub cfg: Option<ast::MetaItem>,
     pub foreign_module: Option<DefId>,
-    pub wasm_import_module: Option<Symbol>,
     pub verbatim: Option<bool>,
     pub dll_imports: Vec<DllImport>,
 }
@@ -81,6 +80,10 @@ impl NativeLib {
     pub fn has_modifiers(&self) -> bool {
         self.verbatim.is_some() || self.kind.has_modifiers()
     }
+
+    pub fn wasm_import_module(&self) -> Option<Symbol> {
+        if self.kind == NativeLibKind::WasmImportModule { Some(self.name) } else { None }
+    }
 }
 
 /// Different ways that the PE Format can decorate a symbol name.
diff --git a/compiler/rustc_session/src/filesearch.rs b/compiler/rustc_session/src/filesearch.rs
index f1fbf38217d..e734599cbfc 100644
--- a/compiler/rustc_session/src/filesearch.rs
+++ b/compiler/rustc_session/src/filesearch.rs
@@ -87,35 +87,38 @@ fn current_dll_path() -> Result<PathBuf, String> {
     use std::ffi::OsString;
     use std::io;
     use std::os::windows::prelude::*;
-    use std::ptr;
 
-    use winapi::um::libloaderapi::{
-        GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
+    use windows::{
+        core::PCWSTR,
+        Win32::Foundation::HINSTANCE,
+        Win32::System::LibraryLoader::{
+            GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
+        },
     };
 
+    let mut module = HINSTANCE::default();
     unsafe {
-        let mut module = ptr::null_mut();
-        let r = GetModuleHandleExW(
+        GetModuleHandleExW(
             GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
-            current_dll_path as usize as *mut _,
+            PCWSTR(current_dll_path as *mut u16),
             &mut module,
-        );
-        if r == 0 {
-            return Err(format!("GetModuleHandleExW failed: {}", io::Error::last_os_error()));
-        }
-        let mut space = Vec::with_capacity(1024);
-        let r = GetModuleFileNameW(module, space.as_mut_ptr(), space.capacity() as u32);
-        if r == 0 {
-            return Err(format!("GetModuleFileNameW failed: {}", io::Error::last_os_error()));
-        }
-        let r = r as usize;
-        if r >= space.capacity() {
-            return Err(format!("our buffer was too small? {}", io::Error::last_os_error()));
-        }
-        space.set_len(r);
-        let os = OsString::from_wide(&space);
-        Ok(PathBuf::from(os))
+        )
     }
+    .ok()
+    .map_err(|e| e.to_string())?;
+
+    let mut filename = vec![0; 1024];
+    let n = unsafe { GetModuleFileNameW(module, &mut filename) } as usize;
+    if n == 0 {
+        return Err(format!("GetModuleFileNameW failed: {}", io::Error::last_os_error()));
+    }
+    if n >= filename.capacity() {
+        return Err(format!("our buffer was too small? {}", io::Error::last_os_error()));
+    }
+
+    filename.truncate(n);
+
+    Ok(OsString::from_wide(&filename).into())
 }
 
 pub fn sysroot_candidates() -> SmallVec<[PathBuf; 2]> {
diff --git a/compiler/rustc_session/src/utils.rs b/compiler/rustc_session/src/utils.rs
index b996d36a318..3b3d4ca5d6b 100644
--- a/compiler/rustc_session/src/utils.rs
+++ b/compiler/rustc_session/src/utils.rs
@@ -37,6 +37,10 @@ pub enum NativeLibKind {
     /// Argument which is passed to linker, relative order with libraries and other arguments
     /// is preserved
     LinkArg,
+
+    /// Module imported from WebAssembly
+    WasmImportModule,
+
     /// The library kind wasn't specified, `Dylib` is currently used as a default.
     Unspecified,
 }
@@ -50,7 +54,10 @@ impl NativeLibKind {
             NativeLibKind::Dylib { as_needed } | NativeLibKind::Framework { as_needed } => {
                 as_needed.is_some()
             }
-            NativeLibKind::RawDylib | NativeLibKind::Unspecified | NativeLibKind::LinkArg => false,
+            NativeLibKind::RawDylib
+            | NativeLibKind::Unspecified
+            | NativeLibKind::LinkArg
+            | NativeLibKind::WasmImportModule => false,
         }
     }