1 files changed, 10 insertions, 7 deletions
diff --git a/cortex-m-rt/macros/src/lib.rs b/cortex-m-rt/macros/src/lib.rs
index 579e566..f9ae17e 100644
--- a/cortex-m-rt/macros/src/lib.rs
+++ b/cortex-m-rt/macros/src/lib.rs
@@ -6,6 +6,7 @@ extern crate rand;
 extern crate quote;
 extern crate core;
 extern crate proc_macro2;
+#[macro_use]
 extern crate syn;
 
 use proc_macro2::Span;
@@ -77,7 +78,7 @@ use proc_macro::TokenStream;
 /// ```
 #[proc_macro_attribute]
 pub fn entry(args: TokenStream, input: TokenStream) -> TokenStream {
-    let f: ItemFn = syn::parse(input).expect("`#[entry]` must be applied to a function");
+    let f = parse_macro_input!(input as ItemFn);
 
     // check the function signature
     assert!(
@@ -105,6 +106,7 @@ pub fn entry(args: TokenStream, input: TokenStream) -> TokenStream {
 
     // XXX should we blacklist other attributes?
     let attrs = f.attrs;
+    let unsafety = f.unsafety;
     let hash = random_ident();
     let (statics, stmts) = extract_static_muts(f.block.stmts);
 
@@ -131,7 +133,7 @@ pub fn entry(args: TokenStream, input: TokenStream) -> TokenStream {
     quote!(
         #[export_name = "main"]
         #(#attrs)*
-        pub fn #hash() -> ! {
+        pub #unsafety fn #hash() -> ! {
             #(#vars)*
 
             #(#stmts)*
@@ -252,7 +254,7 @@ pub fn entry(args: TokenStream, input: TokenStream) -> TokenStream {
 /// ```
 #[proc_macro_attribute]
 pub fn exception(args: TokenStream, input: TokenStream) -> TokenStream {
-    let f: ItemFn = syn::parse(input).expect("`#[exception]` must be applied to a function");
+    let f = parse_macro_input!(input as ItemFn);
 
     assert!(
         args.to_string() == "",
@@ -282,6 +284,7 @@ pub fn exception(args: TokenStream, input: TokenStream) -> TokenStream {
     let attrs = f.attrs;
     let block = f.block;
     let stmts = block.stmts;
+    let unsafety = f.unsafety;
 
     let hash = random_ident();
     match exn {
@@ -313,7 +316,7 @@ pub fn exception(args: TokenStream, input: TokenStream) -> TokenStream {
             quote!(
                 #[export_name = #ident_s]
                 #(#attrs)*
-                pub extern "C" fn #hash() {
+                pub #unsafety extern "C" fn #hash() {
                     extern crate core;
 
                     const SCB_ICSR: *const u32 = 0xE000_ED04 as *const u32;
@@ -362,7 +365,7 @@ pub fn exception(args: TokenStream, input: TokenStream) -> TokenStream {
             quote!(
                 #[export_name = "UserHardFault"]
                 #(#attrs)*
-                pub extern "C" fn #hash(#arg) -> ! {
+                pub #unsafety extern "C" fn #hash(#arg) -> ! {
                     extern crate cortex_m_rt;
 
                     // further type check of the input argument
@@ -418,7 +421,7 @@ pub fn exception(args: TokenStream, input: TokenStream) -> TokenStream {
             quote!(
                 #[export_name = #ident_s]
                 #(#attrs)*
-                pub fn #hash() {
+                pub #unsafety extern "C" fn #hash() {
                     extern crate cortex_m_rt;
 
                     // check that this exception actually exists
@@ -457,7 +460,7 @@ pub fn exception(args: TokenStream, input: TokenStream) -> TokenStream {
 /// ```
 #[proc_macro_attribute]
 pub fn pre_init(args: TokenStream, input: TokenStream) -> TokenStream {
-    let f: ItemFn = syn::parse(input).expect("`#[pre_init]` must be applied to a function");
+    let f = parse_macro_input!(input as ItemFn);
 
     // check the function signature
     assert!(