bring back error type

crates/nsis-fn/src/lib.rs

@@ -1,6 +1,7 @@
 use proc_macro::TokenStream;
+use proc_macro2::Span;
 use quote::quote;
-use syn::{parse::Parse, parse_macro_input, ItemFn};
+use syn::{parse::Parse, parse_macro_input, Ident, ItemFn};
 
 struct NsisFn {
     func: ItemFn,
@@ -22,7 +23,12 @@ pub fn nsis_fn(_attr: TokenStream, tokens: TokenStream) -> TokenStream {
     let block = func.block;
     let attrs = func.attrs;
 
+    let new_ident = Ident::new(&format!("__{}", ident.to_string()), Span::call_site());
+
     quote! {
+        #[inline(always)]
+        pub unsafe fn #new_ident() -> Result<(), ::nsis_plugin_api::Error> #block
+
         #(#attrs)*
         #[no_mangle]
         #[allow(non_standard_style)]
@@ -33,7 +39,9 @@ pub fn nsis_fn(_attr: TokenStream, tokens: TokenStream) -> TokenStream {
             stacktop: *mut *mut ::nsis_plugin_api::stack_t,
         ) {
             ::nsis_plugin_api::exdll_init(string_size, variables, stacktop);
-            #block
+            if let Err(e) = #new_ident() {
+                e.push_err();
+            }
         }
     }
     .into()

crates/nsis-plugin-api/src/lib.rs

@@ -37,10 +37,11 @@ pub struct stack_t {
     pub text: [wchar_t; 1],
 }
 
-static mut G_STRINGSIZE: c_int = 0;
-static mut G_VARIABLES: *mut wchar_t = core::ptr::null_mut();
-static mut G_STACKTOP: *mut *mut stack_t = core::ptr::null_mut();
+pub static mut G_STRINGSIZE: c_int = 0;
+pub static mut G_VARIABLES: *mut wchar_t = core::ptr::null_mut();
+pub static mut G_STACKTOP: *mut *mut stack_t = core::ptr::null_mut();
 
+#[inline(always)]
 pub unsafe fn exdll_init(string_size: c_int, variables: *mut wchar_t, stacktop: *mut *mut stack_t) {
     G_STRINGSIZE = string_size;
     G_VARIABLES = variables;
@@ -51,43 +52,71 @@ pub const ONE: [u16; 2] = [49, 0];
 pub const ZERO: [u16; 2] = [48, 0];
 pub const NEGATIVE_ONE: [u16; 3] = [45, 49, 0];
 
-pub unsafe fn push(bytes: &[u16]) {
+#[derive(Debug)]
+pub enum Error {
+    StackIsNull,
+    ParseIntError,
+}
+
+impl Error {
+    const fn description(&self) -> &str {
+        match self {
+            Error::StackIsNull => "Stack is null",
+            Error::ParseIntError => "Failed to parse integer",
+        }
+    }
+    pub fn push_err(&self) {
+        let _ = unsafe { pushstr(&self.description()) };
+    }
+}
+
+pub unsafe fn push(bytes: &[u16]) -> Result<(), Error> {
     if G_STACKTOP.is_null() {
-        return;
+        return Err(Error::StackIsNull);
     }
 
     let n = size_of::<stack_t>() + G_STRINGSIZE as usize * 2;
     let th = GlobalAlloc(GPTR, n) as *mut stack_t;
     lstrcpyW((*th).text.as_ptr() as _, bytes.as_ptr());
     (*th).next = *G_STACKTOP;
     *G_STACKTOP = th;
+
+    Ok(())
 }
 
-pub unsafe fn pushstr(str: &str) {
+pub unsafe fn pushstr(str: &str) -> Result<(), Error> {
     let bytes = encode_wide(str);
     push(&bytes)
 }
 
-pub unsafe fn pushint(int: i32) {
+pub unsafe fn pushint(int: i32) -> Result<(), Error> {
     let str = int.to_string();
     pushstr(&str)
 }
 
-pub unsafe fn pop(out: &mut [u16]) {
+pub unsafe fn pop() -> Result<Vec<u16>, Error> {
     if G_STACKTOP.is_null() || (*G_STACKTOP).is_null() {
-        return;
+        return Err(Error::StackIsNull);
     }
 
+    let mut out = vec![0_u16; G_STRINGSIZE as _];
+
     let th: *mut stack_t = *G_STACKTOP;
     lstrcpyW(out.as_mut_ptr(), (*th).text.as_ptr() as _);
     *G_STACKTOP = (*th).next;
     GlobalFree(th as _);
+
+    Ok(out)
+}
+
+pub unsafe fn popstr() -> Result<String, Error> {
+    let bytes = pop()?;
+    Ok(decode_wide(&bytes))
 }
 
-pub unsafe fn popstring() -> String {
-    let mut bytes = vec![0_u16; G_STRINGSIZE as _];
-    pop(&mut bytes);
-    decode_wide(&bytes)
+pub unsafe fn popint() -> Result<i32, Error> {
+    let str = popstr()?;
+    str.parse().map_err(|_| Error::ParseIntError)
 }
 
 pub fn encode_wide(str: &str) -> Vec<u16> {

crates/nsis-process/src/lib.rs

@@ -30,13 +30,13 @@ nsis_plugin!();
 ///
 /// This function always expects 1 string on the stack ($1: name) and will panic otherwise.
 #[nsis_fn]
-fn FindProcess() {
-    let name = popstring();
+fn FindProcess() -> Result<(), Error> {
+    let name = popstr()?;
 
     if !get_processes(&name).is_empty() {
-        push(&ZERO);
+        push(&ZERO)
     } else {
-        push(&ONE);
+        push(&ONE)
     }
 }
 
@@ -46,8 +46,8 @@ fn FindProcess() {
 ///
 /// This function always expects 1 string on the stack ($1: name) and will panic otherwise.
 #[nsis_fn]
-fn FindProcessCurrentUser() {
-    let name = popstring();
+fn FindProcessCurrentUser() -> Result<(), Error> {
+    let name = popstr()?;
 
     let processes = get_processes(&name);
 
@@ -56,15 +56,15 @@ fn FindProcessCurrentUser() {
             .into_iter()
             .any(|pid| belongs_to_user(user_sid, pid))
         {
-            push(&ZERO);
+            push(&ZERO)
         } else {
-            push(&ONE);
+            push(&ONE)
         }
     // Fall back to perMachine checks if we can't get current user id
     } else if processes.is_empty() {
-        push(&ONE);
+        push(&ONE)
     } else {
-        push(&ZERO);
+        push(&ZERO)
     }
 }
 
@@ -74,15 +74,15 @@ fn FindProcessCurrentUser() {
 ///
 /// This function always expects 1 string on the stack ($1: name) and will panic otherwise.
 #[nsis_fn]
-fn KillProcess() {
-    let name = popstring();
+fn KillProcess() -> Result<(), Error> {
+    let name = popstr()?;
 
     let processes = get_processes(&name);
 
     if !processes.is_empty() && processes.into_iter().map(kill).all(|b| b) {
-        push(&ZERO);
+        push(&ZERO)
     } else {
-        push(&ONE);
+        push(&ONE)
     }
 }
 
@@ -92,14 +92,13 @@ fn KillProcess() {
 ///
 /// This function always expects 1 string on the stack ($1: name) and will panic otherwise.
 #[nsis_fn]
-fn KillProcessCurrentUser() {
-    let name = popstring();
+fn KillProcessCurrentUser() -> Result<(), Error> {
+    let name = popstr()?;
 
     let processes = get_processes(&name);
 
     if processes.is_empty() {
-        push(&ONE);
-        return;
+        return push(&ONE);
     }
 
     let success = if let Some(user_sid) = get_sid(GetCurrentProcessId()) {

crates/nsis-semvercompare/src/lib.rs

@@ -15,16 +15,18 @@ nsis_plugin!();
 ///
 /// This function always expects 2 strings on the stack ($v1, $v2) and will panic otherwise.
 #[nsis_fn]
-fn SemverCompare() {
-    let v1 = popstring();
-    let v2 = popstring();
+fn SemverCompare() -> Result<(), Error> {
+    let v1 = popstr()?;
+    let v2 = popstr()?;
 
     match compare(&v1, &v2) {
-        -1 => push(&NEGATIVE_ONE),
-        0 => push(&ZERO),
-        1 => push(&ONE),
+        -1 => push(&NEGATIVE_ONE)?,
+        0 => push(&ZERO)?,
+        1 => push(&ONE)?,
         _ => unreachable!(),
     }
+
+    Ok(())
 }
 
 fn compare(v1: &str, v2: &str) -> i32 {

demo.nsi

@@ -4,11 +4,8 @@ Unicode true
 ShowInstDetails show
 
 !addplugindir ".\target\i686-pc-windows-msvc\release"
-!addplugindir ".\target\i686-pc-windows-msvc\debug"
 !addplugindir "$%CARGO_TARGET_DIR%\i686-pc-windows-msvc\release"
-!addplugindir "$%CARGO_TARGET_DIR%\i686-pc-windows-msvc\debug"
 !addplugindir "$%CARGO_BUILD_TARGET_DIR%\i686-pc-windows-msvc\release"
-!addplugindir "$%CARGO_BUILD_TARGET_DIR%\i686-pc-windows-msvc\debug"
 
 !include "MUI2.nsh"