2 files changed, 40 insertions, 25 deletions

diff --git a/patio-to-cranelift/src/codegen/context.rs b/patio-to-cranelift/src/codegen/context.rs
index a9333e26..bc551944 100644
--- a/patio-to-cranelift/src/codegen/context.rs
+++ b/patio-to-cranelift/src/codegen/context.rs
@@ -103,6 +103,7 @@ impl CompilerContext {
             local_name_to_type: Default::default(),
             var_name_to_variable: Default::default(),
             loop_blocks: Default::default(),
+            unreachable: false,
         };
         generate_function_body(&mut context);
 
@@ -161,6 +162,7 @@ pub(crate) struct CompilerFunctionContext<'a> {
     local_name_to_type: HashMap<String, cranelift_codegen::ir::Type>,
     var_name_to_variable: HashMap<String, cranelift::prelude::Variable>,
     loop_blocks: Vec<Loop>,
+    unreachable: bool,
 }
 
 impl<'a> CompilerFunctionContext<'a> {
@@ -217,6 +219,7 @@ impl<'a> CompilerFunctionContext<'a> {
 
     pub(crate) fn switch_to_block(&mut self, block: cranelift_codegen::ir::Block) {
         self.function_builder.switch_to_block(block);
+        self.unreachable = false;
     }
 
     pub(crate) fn seal_block(&mut self, block: cranelift_codegen::ir::Block) {
@@ -245,6 +248,14 @@ impl<'a> CompilerFunctionContext<'a> {
     pub(crate) fn exit_loop(&mut self) {
         self.loop_blocks.pop();
     }
+
+    pub(crate) fn mark_unreachable(&mut self) {
+        self.unreachable = true
+    }
+
+    pub(crate) fn is_reachable(&self) -> bool {
+        !self.unreachable
+    }
 }
 
 pub(crate) enum Mutability {
diff --git a/patio-to-cranelift/src/codegen/mod.rs b/patio-to-cranelift/src/codegen/mod.rs
index 438a0893..1e898123 100644
--- a/patio-to-cranelift/src/codegen/mod.rs
+++ b/patio-to-cranelift/src/codegen/mod.rs
@@ -494,17 +494,21 @@ fn compile_if(if_: &PatioIf, context: &mut CompilerFunctionContext<'_>) {
 
     context.switch_to_block(cranelift_then_block);
     let cranelift_then_results = compile_block(&if_.true_body, context);
-    context.function_builder.ins().jump(
-        cranelift_end_block,
-        cranelift_block_args(cranelift_then_results).iter(),
-    );
+    if context.is_reachable() {
+        context.function_builder.ins().jump(
+            cranelift_end_block,
+            cranelift_block_args(cranelift_then_results).iter(),
+        );
+    }
 
     context.switch_to_block(cranelift_else_block);
     let cranelift_else_results = compile_block(&if_.false_body, context);
-    context.function_builder.ins().jump(
-        cranelift_end_block,
-        cranelift_block_args(cranelift_else_results).iter(),
-    );
+    if context.is_reachable() {
+        context.function_builder.ins().jump(
+            cranelift_end_block,
+            cranelift_block_args(cranelift_else_results).iter(),
+        );
+    }
 
     context.seal_block(cranelift_end_block);
     context.switch_to_block(cranelift_end_block);
@@ -603,7 +607,9 @@ fn compile_loop(loop_: &PatioLoop, context: &mut CompilerFunctionContext<'_>) {
     }
     context.exit_loop();
     context.seal_block(cranelift_loop_block);
-    context.function_builder.ins().jump(cranelift_end_block, []);
+    if context.is_reachable() {
+        context.function_builder.ins().jump(cranelift_end_block, []);
+    }
 
     context.seal_block(cranelift_end_block);
     context.switch_to_block(cranelift_end_block);
@@ -615,10 +621,7 @@ fn compile_loop_break(_: &PatioLoopBreak, context: &mut CompilerFunctionContext<
         .function_builder
         .ins()
         .jump(cranelift_loop_end_block, []);
-
-    // TODO: avoid creating orphaned blocks
-    let cranelift_unreachable_block = context.create_block();
-    context.switch_to_block(cranelift_unreachable_block);
+    context.mark_unreachable();
 }
 
 fn compile_loop_continue(_: &PatioLoopContinue, context: &mut CompilerFunctionContext<'_>) {
@@ -627,10 +630,7 @@ fn compile_loop_continue(_: &PatioLoopContinue, context: &mut CompilerFunctionCo
         .function_builder
         .ins()
         .jump(cranelift_loop_start_block, []);
-
-    // TODO: avoid creating orphaned blocks
-    let cranelift_unreachable_block = context.create_block();
-    context.switch_to_block(cranelift_unreachable_block);
+    context.mark_unreachable();
 }
 
 fn compile_memory_load(memory_load: &PatioMemoryLoad, context: &mut CompilerFunctionContext<'_>) {
@@ -738,19 +738,23 @@ fn compile_switch(switch: &PatioSwitch, context: &mut CompilerFunctionContext<'_
     for (case, case_block) in switch.cases.iter().zip(&case_blocks) {
         context.switch_to_block(*case_block);
         let end_args = compile_block(&case.body, context);
-        context
-            .function_builder
-            .ins()
-            .jump(end_block, &cranelift_block_args(end_args));
+        if context.is_reachable() {
+            context
+                .function_builder
+                .ins()
+                .jump(end_block, &cranelift_block_args(end_args));
+        }
     }
 
     {
         context.switch_to_block(default_block);
         let end_args = compile_block(&switch.default_body, context);
-        context
-            .function_builder
-            .ins()
-            .jump(end_block, &cranelift_block_args(end_args));
+        if context.is_reachable() {
+            context
+                .function_builder
+                .ins()
+                .jump(end_block, &cranelift_block_args(end_args));
+        }
     }
 
     context.seal_block(end_block);