Return multiple values from Patio functions

6 files changed, 24 insertions, 39 deletions

diff --git a/patio-to-cranelift/src/codegen/mod.rs b/patio-to-cranelift/src/codegen/mod.rs
index bfa9a82a..97414753 100644
--- a/patio-to-cranelift/src/codegen/mod.rs
+++ b/patio-to-cranelift/src/codegen/mod.rs
@@ -19,8 +19,8 @@ use crate::{
             PatioBlock, PatioBoolToInt, PatioCall, PatioCallPointer, PatioDataPtrToInt, PatioIf,
             PatioInstruction, PatioIntAdd, PatioIntEquals, PatioIntNotEqual, PatioIntSub,
             PatioIntToBool, PatioIntToDataPtr, PatioLocalStore, PatioLoop, PatioLoopBreak,
-            PatioLoopContinue, PatioMemoryLoad, PatioMemoryStore, PatioReturn, PatioReturnVoid,
-            PatioSwitch, PatioUnreachable, PatioVarLoad, PatioVarStore,
+            PatioLoopContinue, PatioMemoryLoad, PatioMemoryStore, PatioReturn, PatioSwitch,
+            PatioUnreachable, PatioVarLoad, PatioVarStore,
         },
         operands::{PatioLocalRef, PatioOperand},
         types::PatioType,
@@ -200,7 +200,7 @@ fn declare_function_declaration(
 ) {
     let cranelift_signature = cranelift_signature(
         function_declaration.params.iter(),
-        function_declaration.return_type,
+        function_declaration.return_types.iter(),
         &context.target_triple,
     );
 
@@ -216,8 +216,8 @@ fn declare_function_definition(
     context: &mut CompilerContext,
 ) {
     let cranelift_signature = cranelift_signature(
-        function_definition.locals.iter().map(Into::into),
-        function_definition.return_type,
+        function_definition.locals.iter(),
+        function_definition.return_types.iter(),
         &context.target_triple,
     );
 
@@ -235,8 +235,8 @@ fn define_function_definition(
     context: &mut CompilerContext,
 ) {
     let cranelift_signature = cranelift_signature(
-        function_definition.locals.iter().map(Into::into),
-        function_definition.return_type,
+        function_definition.locals.iter(),
+        function_definition.return_types.iter(),
         &context.target_triple,
     );
 
@@ -360,10 +360,6 @@ fn compile_instruction(instruction: &PatioInstruction, context: &mut CompilerFun
             compile_return(return_, context);
         }
 
-        PatioInstruction::ReturnVoid(return_void) => {
-            compile_return_void(return_void, context);
-        }
-
         PatioInstruction::Switch(switch) => {
             compile_switch(switch, context);
         }
@@ -682,13 +678,13 @@ fn compile_memory_store(
 }
 
 fn compile_return(return_: &PatioReturn, context: &mut CompilerFunctionContext<'_>) {
-    let cranelift_value = compile_operand(&return_.value, context);
-
-    context.function_builder.ins().return_(&[cranelift_value]);
-}
+    let cranelift_values: Vec<_> = return_
+        .values
+        .iter()
+        .map(|value| compile_operand(value, context))
+        .collect();
 
-fn compile_return_void(_return_void: &PatioReturnVoid, context: &mut CompilerFunctionContext<'_>) {
-    context.function_builder.ins().return_(&[]);
+    context.function_builder.ins().return_(&cranelift_values);
 }
 
 fn compile_switch(switch: &PatioSwitch, context: &mut CompilerFunctionContext<'_>) {
@@ -886,7 +882,7 @@ fn new_cranelift_signature() -> cranelift::prelude::Signature {
 
 fn cranelift_signature<'a>(
     locals: impl Iterator<Item = &'a PatioLocal>,
-    return_type: PatioType,
+    return_types: impl Iterator<Item = &'a PatioType>,
     target_triple: &target_lexicon::Triple,
 ) -> cranelift::prelude::Signature {
     let mut signature = new_cranelift_signature();
@@ -899,9 +895,9 @@ fn cranelift_signature<'a>(
         }
     }
 
-    if return_type != PatioType::Void {
+    for return_type in return_types {
         let cranelift_return_type =
-            types::patio_type_to_cranelift_type(return_type, &target_triple);
+            types::patio_type_to_cranelift_type(*return_type, &target_triple);
         let returns = cranelift::prelude::AbiParam::new(cranelift_return_type);
         signature.returns.push(returns);
     }
diff --git a/patio-to-cranelift/src/codegen/types.rs b/patio-to-cranelift/src/codegen/types.rs
index 38cc6b2e..21833f3f 100644
--- a/patio-to-cranelift/src/codegen/types.rs
+++ b/patio-to-cranelift/src/codegen/types.rs
@@ -16,8 +16,6 @@ pub(crate) fn patio_type_to_cranelift_type(
         PatioType::Int => cranelift_int_type(target_triple),
 
         PatioType::Int32 => CRANELIFT_INT_32_TYPE,
-
-        PatioType::Void => todo!(),
     }
 }
 
diff --git a/patio-to-cranelift/src/patio/compilation_unit.rs b/patio-to-cranelift/src/patio/compilation_unit.rs
index ecf80558..af8b4d3f 100644
--- a/patio-to-cranelift/src/patio/compilation_unit.rs
+++ b/patio-to-cranelift/src/patio/compilation_unit.rs
@@ -36,14 +36,14 @@ pub(crate) struct PatioDataElementMutableDeclaration {
 pub(crate) struct PatioFunctionDeclaration {
     pub(crate) name: String,
     pub(crate) params: Vec<PatioLocal>,
-    pub(crate) return_type: PatioType,
+    pub(crate) return_types: Vec<PatioType>,
 }
 
 pub(crate) struct PatioFunctionDefinition {
     pub(crate) name: String,
     pub(crate) visibility: PatioVisibility,
     pub(crate) locals: Vec<PatioLocal>,
-    pub(crate) return_type: PatioType,
+    pub(crate) return_types: Vec<PatioType>,
     pub(crate) body: Vec<PatioInstruction>,
 }
 
diff --git a/patio-to-cranelift/src/patio/flatbuffers.rs b/patio-to-cranelift/src/patio/flatbuffers.rs
index 5622259a..35226614 100644
--- a/patio-to-cranelift/src/patio/flatbuffers.rs
+++ b/patio-to-cranelift/src/patio/flatbuffers.rs
@@ -10,8 +10,8 @@ use crate::{
             PatioBlock, PatioBoolToInt, PatioCall, PatioCallPointer, PatioDataPtrToInt, PatioIf,
             PatioInstruction, PatioIntAdd, PatioIntEquals, PatioIntNotEqual, PatioIntSub,
             PatioIntToBool, PatioIntToDataPtr, PatioLocalStore, PatioLoop, PatioLoopBreak,
-            PatioLoopContinue, PatioMemoryLoad, PatioMemoryStore, PatioReturn, PatioReturnVoid,
-            PatioSwitch, PatioSwitchCase, PatioUnreachable, PatioVarLoad, PatioVarStore,
+            PatioLoopContinue, PatioMemoryLoad, PatioMemoryStore, PatioReturn, PatioSwitch,
+            PatioSwitchCase, PatioUnreachable, PatioVarLoad, PatioVarStore,
         },
         operands::{PatioLocalRef, PatioOperand},
         types::{PatioDataLayout, PatioType},
@@ -77,7 +77,7 @@ impl From<patio_generated::patio::PatioCompilationUnitElement<'_>> for PatioComp
                         .iter()
                         .map(Into::into)
                         .collect(),
-                    return_type: function_declaration.return_type().into(),
+                    return_types: function_declaration.return_types().iter().map(Into::into).collect(),
                 })
             }
 
@@ -92,7 +92,7 @@ impl From<patio_generated::patio::PatioCompilationUnitElement<'_>> for PatioComp
                         .iter()
                         .map(Into::into)
                         .collect(),
-                    return_type: function_definition.return_type().into(),
+                    return_types: function_definition.return_types().iter().map(Into::into).collect(),
                     body: function_definition.body().iter().map(Into::into).collect(),
                 })
             }
@@ -314,14 +314,10 @@ impl From<patio_generated::patio::PatioInstruction<'_>> for PatioInstruction {
                 let return_ = value.value_as_patio_return().unwrap();
 
                 Self::Return(PatioReturn {
-                    value: return_.value().into(),
+                    values: return_.values().iter().map(Into::into).collect(),
                 })
             }
 
-            patio_generated::patio::PatioInstructionValue::PatioReturnVoid => {
-                Self::ReturnVoid(PatioReturnVoid)
-            }
-
             patio_generated::patio::PatioInstructionValue::PatioSwitch => {
                 let switch = value.value_as_patio_switch().unwrap();
 
@@ -509,7 +505,6 @@ impl From<patio_generated::patio::PatioType<'_>> for PatioType {
             PatioTypeValue::PatioFunctionPtrType => Self::FunctionPtr,
             PatioTypeValue::PatioIntType => Self::Int,
             PatioTypeValue::PatioInt32Type => Self::Int32,
-            PatioTypeValue::PatioVoidType => Self::Void,
 
             type_type => {
                 todo!(
diff --git a/patio-to-cranelift/src/patio/instructions.rs b/patio-to-cranelift/src/patio/instructions.rs
index af354117..804ee93d 100644
--- a/patio-to-cranelift/src/patio/instructions.rs
+++ b/patio-to-cranelift/src/patio/instructions.rs
@@ -23,7 +23,6 @@ pub(crate) enum PatioInstruction {
     MemoryLoad(PatioMemoryLoad),
     MemoryStore(PatioMemoryStore),
     Return(PatioReturn),
-    ReturnVoid(PatioReturnVoid),
     Switch(PatioSwitch),
     Unreachable(PatioUnreachable),
     VarLoad(PatioVarLoad),
@@ -126,11 +125,9 @@ pub(crate) struct PatioMemoryStore {
 }
 
 pub(crate) struct PatioReturn {
-    pub(crate) value: PatioOperand,
+    pub(crate) values: Vec<PatioOperand>,
 }
 
-pub(crate) struct PatioReturnVoid;
-
 pub(crate) struct PatioSwitch {
     pub(crate) destinations: Vec<PatioLocalRef>,
     pub(crate) value: PatioOperand,
diff --git a/patio-to-cranelift/src/patio/types.rs b/patio-to-cranelift/src/patio/types.rs
index c513ed4e..49bce09a 100644
--- a/patio-to-cranelift/src/patio/types.rs
+++ b/patio-to-cranelift/src/patio/types.rs
@@ -6,7 +6,6 @@ pub(crate) enum PatioType {
     FunctionPtr,
     Int,
     Int32,
-    Void,
 }
 
 #[derive(Clone, Debug, PartialEq)]