update changelog and version bump

0.2.3

Changelog.md

@@ -1,5 +1,17 @@
 # Changelog
 
+[0.2.4]
+
+- Groundwork laid to collect and track source maps
+- IC Housing will now display the `Slang` source error line (if available)
+  instead of the `IC10` source error line
+
+[0.2.3]
+
+- Fixed stack underflow with function invocations
+  - They are still "heavy", but they should work as expected now
+- Fixed issue where syscall functions were not allowed as infix operators
+
 [0.2.2]
 
 - Fixed some formatting issues when converting Markdown to Text Mesh Pro for

ModData/About/About.xml

@@ -2,7 +2,7 @@
 <ModMetadata xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <Name>Slang</Name>
   <Author>JoeDiertay</Author>
-  <Version>0.2.2</Version>
+  <Version>0.2.4</Version>
   <Description>
 [h1]Slang: High-Level Programming for Stationeers[/h1]
 

csharp_mod/Extensions.cs

@@ -113,6 +113,34 @@ public static unsafe class SlangExtensions
         return toReturn;
     }
 
+    public static unsafe List<SourceMapEntry> ToList(this Vec_FfiSourceMapEntry_t vec)
+    {
+        var toReturn = new List<SourceMapEntry>((int)vec.len);
+
+        var currentPtr = vec.ptr;
+
+        for (int i = 0; i < (int)vec.len; i++)
+        {
+            var item = currentPtr[i];
+
+            toReturn.Add(
+                new SourceMapEntry
+                {
+                    Ic10Line = item.line_number,
+                    SlangSource = new Range
+                    {
+                        EndCol = item.span.end_col,
+                        EndLine = item.span.end_line,
+                        StartCol = item.span.start_col,
+                        StartLine = item.span.start_line,
+                    },
+                }
+            );
+        }
+
+        return toReturn;
+    }
+
     private static uint GetColorForKind(uint kind)
     {
         switch (kind)

csharp_mod/FfiGlue.cs

@@ -71,18 +71,6 @@ public unsafe struct Vec_uint8_t {
     public UIntPtr cap;
 }
 
-public unsafe partial class Ffi {
-    /// <summary>
-    /// C# handles strings as UTF16. We do NOT want to allocate that memory in C# because
-    /// we want to avoid GC. So we pass it to Rust to handle all the memory allocations.
-    /// This should result in the ability to compile many times without triggering frame drops
-    /// from the GC from a <c>GetBytes()</c> call on a string in C#.
-    /// </summary>
-    [DllImport(RustLib, ExactSpelling = true)] public static unsafe extern
-    Vec_uint8_t compile_from_string (
-        slice_ref_uint16_t input);
-}
-
 [StructLayout(LayoutKind.Sequential, Size = 16)]
 public unsafe struct FfiRange_t {
     public UInt32 start_col;
@@ -94,6 +82,44 @@ public unsafe struct FfiRange_t {
     public UInt32 end_line;
 }
 
+[StructLayout(LayoutKind.Sequential, Size = 20)]
+public unsafe struct FfiSourceMapEntry_t {
+    public UInt32 line_number;
+
+    public FfiRange_t span;
+}
+
+/// <summary>
+/// Same as [<c>Vec<T></c>][<c>rust::Vec</c>], but with guaranteed <c>#[repr(C)]</c> layout
+/// </summary>
+[StructLayout(LayoutKind.Sequential, Size = 24)]
+public unsafe struct Vec_FfiSourceMapEntry_t {
+    public FfiSourceMapEntry_t * ptr;
+
+    public UIntPtr len;
+
+    public UIntPtr cap;
+}
+
+[StructLayout(LayoutKind.Sequential, Size = 48)]
+public unsafe struct FfiCompilationResult_t {
+    public Vec_uint8_t output_code;
+
+    public Vec_FfiSourceMapEntry_t source_map;
+}
+
+public unsafe partial class Ffi {
+    /// <summary>
+    /// C# handles strings as UTF16. We do NOT want to allocate that memory in C# because
+    /// we want to avoid GC. So we pass it to Rust to handle all the memory allocations.
+    /// This should result in the ability to compile many times without triggering frame drops
+    /// from the GC from a <c>GetBytes()</c> call on a string in C#.
+    /// </summary>
+    [DllImport(RustLib, ExactSpelling = true)] public static unsafe extern
+    FfiCompilationResult_t compile_from_string (
+        slice_ref_uint16_t input);
+}
+
 [StructLayout(LayoutKind.Sequential, Size = 48)]
 public unsafe struct FfiDiagnostic_t {
     public Vec_uint8_t message;
@@ -146,6 +172,12 @@ public unsafe partial class Ffi {
         Vec_FfiDocumentedItem_t v);
 }
 
+public unsafe partial class Ffi {
+    [DllImport(RustLib, ExactSpelling = true)] public static unsafe extern
+    void free_ffi_compilation_result (
+        FfiCompilationResult_t input);
+}
+
 public unsafe partial class Ffi {
     [DllImport(RustLib, ExactSpelling = true)] public static unsafe extern
     void free_ffi_diagnostic_vec (

csharp_mod/GlobalCode.cs

@@ -15,11 +15,59 @@ public static class GlobalCode
     // so that save file data is smaller
     private static Dictionary<Guid, string> codeDict = new();
 
+    // This Dictionary stores the source maps for the given SLANG_REF, where
+    // the key is the IC10 line, and the value is a List of Slang ranges where that
+    // line would have come from
+    private static Dictionary<Guid, Dictionary<uint, List<Range>>> sourceMaps = new();
+
     public static void ClearCache()
     {
         codeDict.Clear();
     }
 
+    public static void SetSourceMap(Guid reference, List<SourceMapEntry> sourceMapEntries)
+    {
+        var builtDictionary = new Dictionary<uint, List<Range>>();
+
+        foreach (var entry in sourceMapEntries)
+        {
+            if (!builtDictionary.ContainsKey(entry.Ic10Line))
+            {
+                builtDictionary[entry.Ic10Line] = new();
+            }
+            builtDictionary[entry.Ic10Line].Add(entry.SlangSource);
+        }
+
+        sourceMaps[reference] = builtDictionary;
+    }
+
+    public static bool GetSlangErrorLineFromICError(
+        Guid reference,
+        uint icErrorLine,
+        out uint slangSrc,
+        out Range slangSpan
+    )
+    {
+        slangSrc = icErrorLine;
+        slangSpan = new Range { };
+
+        if (!sourceMaps.ContainsKey(reference))
+        {
+            return false;
+        }
+
+        var foundRange = sourceMaps[reference][icErrorLine];
+
+        if (foundRange is null)
+        {
+            return false;
+        }
+
+        slangSrc = foundRange[0].StartLine;
+        slangSpan = foundRange[0];
+        return true;
+    }
+
     public static string GetSource(Guid reference)
     {
         if (!codeDict.ContainsKey(reference))

csharp_mod/Marshal.cs

@@ -10,10 +10,23 @@ using StationeersIC10Editor;
 
 public struct Range
 {
-    public uint StartCol;
-    public uint EndCol;
-    public uint StartLine;
-    public uint EndLine;
+    public uint StartCol = 0;
+    public uint EndCol = 0;
+    public uint StartLine = 0;
+    public uint EndLine = 0;
+
+    public Range(uint startLine, uint startCol, uint endLine, uint endCol)
+    {
+        StartLine = startLine;
+        StartCol = startCol;
+        EndLine = endLine;
+        EndCol = endCol;
+    }
+
+    public override string ToString()
+    {
+        return $"L{StartLine}C{StartCol} - L{EndLine}C{EndCol}";
+    }
 }
 
 public struct Diagnostic
@@ -23,6 +36,17 @@ public struct Diagnostic
     public Range Range;
 }
 
+public struct SourceMapEntry
+{
+    public Range SlangSource;
+    public uint Ic10Line;
+
+    public override string ToString()
+    {
+        return $"IC10: {Ic10Line} Slang: `{SlangSource}`";
+    }
+}
+
 public static class Marshal
 {
     private static IntPtr _libraryHandle = IntPtr.Zero;
@@ -78,11 +102,16 @@ public static class Marshal
         }
     }
 
-    public static unsafe bool CompileFromString(string inputString, out string compiledString)
+    public static unsafe bool CompileFromString(
+        string inputString,
+        out string compiledString,
+        out List<SourceMapEntry> sourceMapEntries
+    )
     {
         if (String.IsNullOrEmpty(inputString) || !EnsureLibLoaded())
         {
             compiledString = String.Empty;
+            sourceMapEntries = new();
             return false;
         }
 
@@ -95,19 +124,16 @@ public static class Marshal
             };
 
             var result = Ffi.compile_from_string(input);
+
             try
             {
-                if ((ulong)result.len < 1)
-                {
-                    compiledString = String.Empty;
-                    return false;
-                }
-                compiledString = result.AsString();
+                sourceMapEntries = result.source_map.ToList();
+                compiledString = result.output_code.AsString();
                 return true;
             }
             finally
             {
-                result.Drop();
+                Ffi.free_ffi_compilation_result(result);
             }
         }
     }

csharp_mod/Patches.cs

@@ -1,12 +1,34 @@
 namespace Slang;
 
 using System;
+using System.Runtime.CompilerServices;
 using Assets.Scripts.Objects;
 using Assets.Scripts.Objects.Electrical;
 using Assets.Scripts.Objects.Motherboards;
 using Assets.Scripts.UI;
 using HarmonyLib;
 
+class LineErrorData
+{
+    public AsciiString SourceRef;
+    public uint IC10ErrorSource;
+    public string SlangErrorReference;
+    public Range SlangErrorSpan;
+
+    public LineErrorData(
+        AsciiString sourceRef,
+        uint ic10ErrorSource,
+        string slangErrorRef,
+        Range slangErrorSpan
+    )
+    {
+        this.SourceRef = sourceRef;
+        this.IC10ErrorSource = ic10ErrorSource;
+        this.SlangErrorReference = slangErrorRef;
+        this.SlangErrorSpan = slangErrorSpan;
+    }
+}
+
 [HarmonyPatch]
 public static class SlangPatches
 {
@@ -14,6 +36,9 @@ public static class SlangPatches
     private static AsciiString? _motherboardCachedCode;
     private static Guid? _currentlyEditingGuid;
 
+    private static ConditionalWeakTable<ProgrammableChip, LineErrorData> _errorReferenceTable =
+        new();
+
     [HarmonyPatch(
         typeof(ProgrammableChipMotherboard),
         nameof(ProgrammableChipMotherboard.InputFinished)
@@ -26,7 +51,7 @@ public static class SlangPatches
         // guard to ensure we have valid IC10 before continuing
         if (
             !SlangPlugin.IsSlangSource(ref result)
-            || !Marshal.CompileFromString(result, out string compiled)
+            || !Marshal.CompileFromString(result, out var compiled, out var sourceMap)
             || string.IsNullOrEmpty(compiled)
         )
         {
@@ -37,6 +62,7 @@ public static class SlangPatches
 
         // Ensure we cache this compiled code for later retreival.
         GlobalCode.SetSource(thisRef, result);
+        GlobalCode.SetSourceMap(thisRef, sourceMap);
 
         _currentlyEditingGuid = null;
 
@@ -140,6 +166,100 @@ public static class SlangPatches
         chipData.SourceCode = code;
     }
 
+    [HarmonyPatch(
+        typeof(ProgrammableChip),
+        nameof(ProgrammableChip.ErrorLineNumberString),
+        MethodType.Getter
+    )]
+    [HarmonyPostfix]
+    public static void pgc_ErrorLineNumberString(ProgrammableChip __instance, ref string __result)
+    {
+        if (
+            String.IsNullOrEmpty(__result)
+            || !uint.TryParse(__result.Trim(), out var ic10ErrorLineNumber)
+        )
+        {
+            return;
+        }
+
+        var sourceAscii = __instance.GetSourceCode();
+
+        if (_errorReferenceTable.TryGetValue(__instance, out var cache))
+        {
+            if (cache.SourceRef.Equals(sourceAscii) && cache.IC10ErrorSource == ic10ErrorLineNumber)
+            {
+                __result = cache.SlangErrorReference;
+                return;
+            }
+        }
+
+        var source = System.Text.Encoding.UTF8.GetString(
+            System.Text.Encoding.ASCII.GetBytes(__instance.GetSourceCode())
+        );
+
+        var slangIndex = source.LastIndexOf(GlobalCode.SLANG_REF);
+
+        if (
+            slangIndex < 0
+            || !Guid.TryParse(
+                source
+                    .Substring(
+                        source.LastIndexOf(GlobalCode.SLANG_REF) + GlobalCode.SLANG_REF.Length
+                    )
+                    .Trim(),
+                out var slangGuid
+            )
+            || !GlobalCode.GetSlangErrorLineFromICError(
+                slangGuid,
+                ic10ErrorLineNumber,
+                out var slangErrorLineNumber,
+                out var slangSpan
+            )
+        )
+        {
+            return;
+        }
+
+        L.Warning($"IC error at: {__result} -- Slang source error line: {slangErrorLineNumber}");
+        __result = slangErrorLineNumber.ToString();
+        _errorReferenceTable.Remove(__instance);
+        _errorReferenceTable.Add(
+            __instance,
+            new LineErrorData(
+                sourceAscii,
+                ic10ErrorLineNumber,
+                slangErrorLineNumber.ToString(),
+                slangSpan
+            )
+        );
+    }
+
+    [HarmonyPatch(
+        typeof(ProgrammableChip),
+        nameof(ProgrammableChip.SetSourceCode),
+        new Type[] { typeof(string) }
+    )]
+    [HarmonyPostfix]
+    public static void pgc_SetSourceCode_string(ProgrammableChip __instance, string sourceCode)
+    {
+        _errorReferenceTable.Remove(__instance);
+    }
+
+    [HarmonyPatch(
+        typeof(ProgrammableChip),
+        nameof(ProgrammableChip.SetSourceCode),
+        new Type[] { typeof(string), typeof(ICircuitHolder) }
+    )]
+    [HarmonyPostfix]
+    public static void pgc_SetSourceCode_string_parent(
+        ProgrammableChip __instance,
+        string sourceCode,
+        ICircuitHolder parent
+    )
+    {
+        _errorReferenceTable.Remove(__instance);
+    }
+
     [HarmonyPatch(
         typeof(ProgrammableChipMotherboard),
         nameof(ProgrammableChipMotherboard.SerializeSave)

csharp_mod/Plugin.cs

@@ -41,7 +41,7 @@ namespace Slang
     {
         public const string PluginGuid = "com.biddydev.slang";
         public const string PluginName = "Slang";
-        public const string PluginVersion = "0.1.1";
+        public const string PluginVersion = "0.2.4";
 
         public static Mod MOD = new Mod(PluginName, PluginVersion);
 

csharp_mod/stationeersSlang.csproj

@@ -5,7 +5,7 @@
     <Nullable>enable</Nullable>
     <AssemblyName>StationeersSlang</AssemblyName>
     <Description>Slang Compiler Bridge</Description>
-    <Version>0.2.2</Version>
+    <Version>0.2.4</Version>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <LangVersion>latest</LangVersion>
   </PropertyGroup>

rust_compiler/Cargo.lock

@@ -571,6 +571,7 @@ dependencies = [
  "helpers",
  "lsp-types",
  "pretty_assertions",
+ "safer-ffi",
  "thiserror",
  "tokenizer",
 ]
@@ -909,7 +910,7 @@ checksum = "e3a9fe34e3e7a50316060351f37187a3f546bce95496156754b601a5fa71b76e"
 
 [[package]]
 name = "slang"
-version = "0.2.2"
+version = "0.2.4"
 dependencies = [
  "anyhow",
  "clap",

rust_compiler/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "slang"
-version = "0.2.2"
+version = "0.2.4"
 edition = "2021"
 
 [workspace]

rust_compiler/libs/compiler/src/lib.rs

@@ -3,4 +3,4 @@ mod test;
 mod v1;
 mod variable_manager;
 
-pub use v1::{Compiler, CompilerConfig, Error};
+pub use v1::{CompilationResult, Compiler, CompilerConfig, Error};

rust_compiler/libs/compiler/src/test/binary_expression.rs

@@ -52,6 +52,8 @@ fn nested_binary_expressions() -> Result<()> {
             add r1 r10 r9
             mul r2 r1 r8
             move r15 r2
+            j L1
+            L1:
             sub r0 sp 1
             get ra db r0
             sub sp sp 1

rust_compiler/libs/compiler/src/test/declaration_function_invocation.rs

@@ -17,6 +17,7 @@ fn no_arguments() -> anyhow::Result<()> {
         j main
         doSomething:
         push ra
+        L1:
         sub r0 sp 1
         get ra db r0
         sub sp sp 1
@@ -34,14 +35,17 @@ fn no_arguments() -> anyhow::Result<()> {
 
 #[test]
 fn let_var_args() -> anyhow::Result<()> {
-    // !IMPORTANT this needs to be stabilized as it currently incorrectly calculates sp offset at
-    // both ends of the cleanup lifecycle
     let compiled = compile! {
         debug
         "
-        fn doSomething(arg1) {};
-        let arg1 = 123;
-        let i = doSomething(arg1);
+        fn mul2(arg1) {
+            return arg1 * 2;
+        };
+        loop {
+            let arg1 = 123;
+            let i = mul2(arg1);
+            i = i ** 2;
+        }
         "
     };
 
@@ -50,23 +54,31 @@ fn let_var_args() -> anyhow::Result<()> {
         indoc! {
             "
             j main
-            doSomething:
+            mul2:
             pop r8 #arg1
             push ra
+            mul r1 r8 2
+            move r15 r1
+            j L1
+            L1:
             sub r0 sp 1
             get ra db r0
             sub sp sp 1
             j ra
             main:
+            L2:
             move r8 123 #arg1
             push r8
             push r8
-            jal doSomething
+            jal mul2
             sub r0 sp 1
             get r8 db r0
             sub sp sp 1
             move r9 r15 #i
-            sub sp sp 1
+            pow r1 r9 2
+            move r9 r1 #i
+            j L2
+            L3:
             "
         }
     );
@@ -97,7 +109,9 @@ fn inline_literal_args() -> anyhow::Result<()> {
     let compiled = compile! {
         debug
         "
-        fn doSomething(arg1, arg2) {};
+        fn doSomething(arg1, arg2) {
+            return 5;
+        };
         let thisVariableShouldStayInPlace = 123;
         let returnedValue = doSomething(12, 34);
         "
@@ -112,6 +126,9 @@ fn inline_literal_args() -> anyhow::Result<()> {
             pop r8 #arg2
             pop r9 #arg1
             push ra
+            move r15 5 #returnValue
+            j L1
+            L1:
             sub r0 sp 1
             get ra db r0
             sub sp sp 1
@@ -126,7 +143,6 @@ fn inline_literal_args() -> anyhow::Result<()> {
             get r8 db r0
             sub sp sp 1
             move r9 r15 #returnedValue
-            sub sp sp 1
             "
         }
     );
@@ -154,6 +170,7 @@ fn mixed_args() -> anyhow::Result<()> {
             pop r8 #arg2
             pop r9 #arg1
             push ra
+            L1:
             sub r0 sp 1
             get ra db r0
             sub sp sp 1
@@ -168,7 +185,6 @@ fn mixed_args() -> anyhow::Result<()> {
             get r8 db r0
             sub sp sp 1
             move r9 r15 #returnValue
-            sub sp sp 1
             "
         }
     );
@@ -198,6 +214,8 @@ fn with_return_statement() -> anyhow::Result<()> {
             pop r8 #arg1
             push ra
             move r15 456 #returnValue
+            j L1
+            L1:
             sub r0 sp 1
             get ra db r0
             sub sp sp 1
@@ -233,6 +251,7 @@ fn with_negative_return_literal() -> anyhow::Result<()> {
             doSomething:
             push ra
             move r15 -1 #returnValue
+            L1:
             sub r0 sp 1
             get ra db r0
             sub sp sp 1

rust_compiler/libs/compiler/src/test/declaration_literal.rs

@@ -120,7 +120,7 @@ fn test_boolean_return() -> anyhow::Result<()> {
         fn getTrue() {
             return true;
         };
-        
+
         let val = getTrue();
         "
     };
@@ -133,6 +133,8 @@ fn test_boolean_return() -> anyhow::Result<()> {
             getTrue:
             push ra
             move r15 1 #returnValue
+            j L1
+            L1:
             sub r0 sp 1
             get ra db r0
             sub sp sp 1

rust_compiler/libs/compiler/src/test/function_declaration.rs

@@ -21,6 +21,7 @@ fn test_function_declaration_with_spillover_params() -> anyhow::Result<()> {
             pop r13 #arg4
             pop r14 #arg3
             push ra
+            L1:
             sub r0 sp 1
             get ra db r0
             sub sp sp 3
@@ -31,6 +32,48 @@ fn test_function_declaration_with_spillover_params() -> anyhow::Result<()> {
     Ok(())
 }
 
+#[test]
+fn test_early_return() -> anyhow::Result<()> {
+    let compiled = compile!(debug r#"
+        // This is a test function declaration with no body
+        fn doSomething() {
+            if (1 == 1) {
+                return;
+            }
+            let i = 1 + 2;
+            return;
+        };
+        doSomething();
+    "#);
+
+    assert_eq!(
+        compiled,
+        indoc! {
+            "
+            j main
+            doSomething:
+            push ra
+            seq r1 1 1
+            beq r1 0 L2
+            j L1
+            L2:
+            move r8 3 #i
+            j L1
+            L1:
+            sub r0 sp 1
+            get ra db r0
+            sub sp sp 1
+            j ra
+            main:
+            jal doSomething
+            move r1 r15 #__binary_temp_2
+            "
+        }
+    );
+
+    Ok(())
+}
+
 #[test]
 fn test_function_declaration_with_register_params() -> anyhow::Result<()> {
     let compiled = compile!(debug r#"
@@ -47,6 +90,7 @@ fn test_function_declaration_with_register_params() -> anyhow::Result<()> {
             pop r8 #arg2
             pop r9 #arg1
             push ra
+            L1:
             sub r0 sp 1
             get ra db r0
             sub sp sp 1

rust_compiler/libs/compiler/src/test/mod.rs

@@ -26,7 +26,7 @@ macro_rules! compile {
             &mut writer,
             Some(crate::CompilerConfig { debug: true }),
         );
-        compiler.compile()
+        compiler.compile().errors
     }};
 
     (debug $source:expr) => {{

rust_compiler/libs/compiler/src/variable_manager.rs

@@ -94,19 +94,21 @@ impl<'a, 'b> VariableScope<'a, 'b> {
     pub const RETURN_REGISTER: u8 = 15;
     pub const TEMP_STACK_REGISTER: u8 = 0;
 
-    pub fn registers(&self) -> impl Iterator<Item = &u8> {
-        self.var_lookup_table
-            .values()
-            .filter(|val| {
-                matches!(
-                    val,
-                    VariableLocation::Temporary(_) | VariableLocation::Persistant(_)
-                )
-            })
-            .map(|loc| match loc {
-                VariableLocation::Persistant(reg) | VariableLocation::Temporary(reg) => reg,
-                _ => unreachable!(),
-            })
+    pub fn registers(&self) -> Vec<u8> {
+        let mut used = Vec::new();
+
+        for r in TEMP {
+            if !self.temporary_vars.contains(&r) {
+                used.push(r);
+            }
+        }
+
+        for r in PERSIST {
+            if !self.persistant_vars.contains(&r) {
+                used.push(r);
+            }
+        }
+        used
     }
 
     pub fn scoped(parent: &'b VariableScope<'a, 'b>) -> Self {

rust_compiler/libs/parser/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2024"
 tokenizer = { path = "../tokenizer" }
 helpers = { path = "../helpers" }
 lsp-types = { workspace = true }
+safer-ffi = { workspace = true }
 thiserror = { workspace = true }
 
 

rust_compiler/libs/parser/src/lib.rs

@@ -766,6 +766,7 @@ impl<'a> Parser<'a> {
             Expression::Binary(_)
             | Expression::Logical(_)
             | Expression::Invocation(_)
+            | Expression::Syscall(_)
             | Expression::Priority(_)
             | Expression::Literal(_)
             | Expression::Variable(_)
@@ -1225,18 +1226,34 @@ impl<'a> Parser<'a> {
             // Need to capture return span
             let ret_start_span = Self::token_to_span(&current_token);
             self.assign_next()?;
-            let expression = self.expression()?.ok_or(Error::UnexpectedEOF)?;
+
+            let expr = if token_matches!(
+                self.current_token.as_ref().ok_or(Error::UnexpectedEOF)?,
+                TokenType::Symbol(Symbol::Semicolon)
+            ) {
+                // rewind 1 token so we can check for the semicolon at the bottom of this function.
+                self.tokenizer.seek(SeekFrom::Current(-1))?;
+                None
+            } else {
+                Some(self.expression()?.ok_or(Error::UnexpectedEOF)?)
+            };
 
             let ret_span = Span {
                 start_line: ret_start_span.start_line,
                 start_col: ret_start_span.start_col,
-                end_line: expression.span.end_line,
-                end_col: expression.span.end_col,
+                end_line: expr
+                    .as_ref()
+                    .map(|e| e.span.end_line)
+                    .unwrap_or(ret_start_span.end_line),
+                end_col: expr
+                    .as_ref()
+                    .map(|e| e.span.end_col)
+                    .unwrap_or(ret_start_span.end_col),
             };
 
             let return_expr = Spanned {
                 span: ret_span,
-                node: Expression::Return(boxed!(expression)),
+                node: Expression::Return(expr.map(Box::new)),
             };
             expressions.push(return_expr);
 

rust_compiler/libs/parser/src/tree_node.rs

@@ -1,5 +1,6 @@
 use super::sys_call::SysCall;
 use crate::sys_call;
+use safer_ffi::prelude::*;
 use std::{borrow::Cow, ops::Deref};
 use tokenizer::token::Number;
 
@@ -381,7 +382,7 @@ pub enum Expression<'a> {
     MethodCall(Spanned<MethodCallExpression<'a>>),
     Negation(Box<Spanned<Expression<'a>>>),
     Priority(Box<Spanned<Expression<'a>>>),
-    Return(Box<Spanned<Expression<'a>>>),
+    Return(Option<Box<Spanned<Expression<'a>>>>),
     Syscall(Spanned<SysCall<'a>>),
     Ternary(Spanned<TernaryExpression<'a>>),
     Variable(Spanned<Cow<'a, str>>),
@@ -409,7 +410,15 @@ impl<'a> std::fmt::Display for Expression<'a> {
             Expression::MethodCall(e) => write!(f, "{}", e),
             Expression::Negation(e) => write!(f, "(-{})", e),
             Expression::Priority(e) => write!(f, "({})", e),
-            Expression::Return(e) => write!(f, "(return {})", e),
+            Expression::Return(e) => write!(
+                f,
+                "(return {})",
+                if let Some(e) = e {
+                    e.to_string()
+                } else {
+                    "".to_string()
+                }
+            ),
             Expression::Syscall(e) => write!(f, "{}", e),
             Expression::Ternary(e) => write!(f, "{}", e),
             Expression::Variable(id) => write!(f, "{}", id),

rust_compiler/src/ffi/mod.rs

@@ -1,6 +1,6 @@
-use compiler::Compiler;
+use compiler::{CompilationResult, Compiler};
 use helpers::Documentation;
-use parser::{sys_call::SysCall, Parser};
+use parser::{sys_call::SysCall, tree_node::Span, Parser};
 use safer_ffi::prelude::*;
 use std::io::BufWriter;
 use tokenizer::{
@@ -8,6 +8,20 @@ use tokenizer::{
     Tokenizer,
 };
 
+#[derive_ReprC]
+#[repr(C)]
+pub struct FfiSourceMapEntry {
+    pub line_number: u32,
+    pub span: FfiRange,
+}
+
+#[derive_ReprC]
+#[repr(C)]
+pub struct FfiCompilationResult {
+    pub output_code: safer_ffi::String,
+    pub source_map: safer_ffi::Vec<FfiSourceMapEntry>,
+}
+
 #[derive_ReprC]
 #[repr(C)]
 pub struct FfiToken {
@@ -34,6 +48,17 @@ pub struct FfiDocumentedItem {
     docs: safer_ffi::String,
 }
 
+impl From<Span> for FfiRange {
+    fn from(value: Span) -> Self {
+        Self {
+            start_line: value.start_line as u32,
+            end_line: value.end_line as u32,
+            start_col: value.start_col as u32,
+            end_col: value.end_col as u32,
+        }
+    }
+}
+
 impl From<lsp_types::Range> for FfiRange {
     fn from(value: lsp_types::Range) -> Self {
         Self {
@@ -69,6 +94,11 @@ impl From<lsp_types::Diagnostic> for FfiDiagnostic {
     }
 }
 
+#[ffi_export]
+pub fn free_ffi_compilation_result(input: FfiCompilationResult) {
+    drop(input)
+}
+
 #[ffi_export]
 pub fn free_ffi_token_vec(v: safer_ffi::Vec<FfiToken>) {
     drop(v)
@@ -94,7 +124,7 @@ pub fn free_docs_vec(v: safer_ffi::Vec<FfiDocumentedItem>) {
 /// This should result in the ability to compile many times without triggering frame drops
 /// from the GC from a `GetBytes()` call on a string in C#.
 #[ffi_export]
-pub fn compile_from_string(input: safer_ffi::slice::Ref<'_, u16>) -> safer_ffi::String {
+pub fn compile_from_string(input: safer_ffi::slice::Ref<'_, u16>) -> FfiCompilationResult {
     let res = std::panic::catch_unwind(|| {
         let input = String::from_utf16_lossy(input.as_slice());
         let mut writer = BufWriter::new(Vec::new());
@@ -103,19 +133,45 @@ pub fn compile_from_string(input: safer_ffi::slice::Ref<'_, u16>) -> safer_ffi::
         let parser = Parser::new(tokenizer);
         let compiler = Compiler::new(parser, &mut writer, None);
 
-        if !compiler.compile().is_empty() {
-            return safer_ffi::String::EMPTY;
+        let res = compiler.compile();
+
+        if !res.errors.is_empty() {
+            return (safer_ffi::String::EMPTY, res.source_map);
         }
 
         let Ok(compiled_vec) = writer.into_inner() else {
-            return safer_ffi::String::EMPTY;
+            return (safer_ffi::String::EMPTY, res.source_map);
         };
 
         // Safety: I know the compiler only outputs valid utf8
-        safer_ffi::String::from(unsafe { String::from_utf8_unchecked(compiled_vec) })
+        (
+            safer_ffi::String::from(unsafe { String::from_utf8_unchecked(compiled_vec) }),
+            res.source_map,
+        )
     });
 
-    res.unwrap_or("".into())
+    if let Ok((res_str, source_map)) = res {
+        FfiCompilationResult {
+            source_map: source_map
+                .into_iter()
+                .flat_map(|(k, v)| {
+                    v.into_iter()
+                        .map(|span| FfiSourceMapEntry {
+                            span: span.into(),
+                            line_number: k as u32,
+                        })
+                        .collect::<Vec<_>>()
+                })
+                .collect::<Vec<_>>()
+                .into(),
+            output_code: res_str,
+        }
+    } else {
+        FfiCompilationResult {
+            output_code: "".into(),
+            source_map: vec![].into(),
+        }
+    }
 }
 
 #[ffi_export]
@@ -184,7 +240,9 @@ pub fn diagnose_source(input: safer_ffi::slice::Ref<'_, u16>) -> safer_ffi::Vec<
         let tokenizer = Tokenizer::from(input.as_str());
         let compiler = Compiler::new(Parser::new(tokenizer), &mut writer, None);
 
-        let diagnosis = compiler.compile();
+        let CompilationResult {
+            errors: diagnosis, ..
+        } = compiler.compile();
 
         let mut result_vec: Vec<FfiDiagnostic> = Vec::with_capacity(diagnosis.len());
 

rust_compiler/src/main.rs

@@ -1,7 +1,7 @@
 #![allow(clippy::result_large_err)]
 
 use clap::Parser;
-use compiler::Compiler;
+use compiler::{CompilationResult, Compiler};
 use parser::Parser as ASTParser;
 use std::{
     fs::File,
@@ -90,7 +90,7 @@ fn run_logic<'a>() -> Result<(), Error<'a>> {
 
     let compiler = Compiler::new(parser, &mut writer, None);
 
-    let errors = compiler.compile();
+    let CompilationResult { errors, .. } = compiler.compile();
 
     if !errors.is_empty() {
         let mut std_error = stderr();