fix: breaking in loops

Signed-off-by: Henry Gressmann <mail@henrygressmann.de>

crates/tinywasm/src/runtime/executor/mod.rs

@@ -198,25 +198,8 @@ fn exec_one(
         }
 
         If(args, else_offset, end_offset) => {
-            if stack.values.pop_t::<i32>()? == 0 {
-                if let Some(else_offset) = else_offset {
-                    log::debug!("entering else at {}", cf.instr_ptr + *else_offset);
-                    cf.enter_label(
-                        LabelFrame {
-                            instr_ptr: cf.instr_ptr + *else_offset,
-                            end_instr_ptr: cf.instr_ptr + *end_offset,
-                            stack_ptr: stack.values.len(), // - params,
-                            args: crate::LabelArgs::new(*args, module)?,
-                            ty: BlockType::Else,
-                        },
-                        &mut stack.values,
-                    );
-                    cf.instr_ptr += *else_offset;
-                } else {
-                    log::info!("skipping if");
-                    cf.instr_ptr += *end_offset
-                }
-            } else {
+            // truthy value is on the top of the stack, so enter the then block
+            if stack.values.pop_t::<i32>()? != 0 {
                 log::trace!("entering then");
                 cf.enter_label(
                     LabelFrame {
@@ -227,7 +210,26 @@ fn exec_one(
                         ty: BlockType::If,
                     },
                     &mut stack.values,
-                )
+                );
+                return Ok(ExecResult::Ok);
+            }
+
+            // falsy value is on the top of the stack
+            if let Some(else_offset) = else_offset {
+                log::debug!("entering else at {}", cf.instr_ptr + *else_offset);
+                cf.enter_label(
+                    LabelFrame {
+                        instr_ptr: cf.instr_ptr + *else_offset,
+                        end_instr_ptr: cf.instr_ptr + *end_offset,
+                        stack_ptr: stack.values.len(), // - params,
+                        args: crate::LabelArgs::new(*args, module)?,
+                        ty: BlockType::Else,
+                    },
+                    &mut stack.values,
+                );
+                cf.instr_ptr += *else_offset;
+            } else {
+                cf.instr_ptr += *end_offset;
             }
         }
 
@@ -285,7 +287,7 @@ fn exec_one(
 
         Br(v) => break_to!(cf, stack, v),
         BrIf(v) => {
-            if stack.values.pop_t::<i32>()? > 0 {
+            if stack.values.pop_t::<i32>()? != 0 {
                 break_to!(cf, stack, v);
             }
         }

crates/tinywasm/src/runtime/executor/traits.rs

@@ -16,7 +16,6 @@ macro_rules! impl_wasm_float_ops {
         impl WasmFloatOps for $t {
             // https://webassembly.github.io/spec/core/exec/numerics.html#op-fnearest
             fn wasm_nearest(self) -> Self {
-                log::info!("wasm_nearest: {}", self);
                 match self {
                     x if x.is_nan() => x,
                     x if x.is_infinite() || x == 0.0 => x,

crates/tinywasm/src/runtime/stack/call_stack.rs

@@ -75,21 +75,28 @@ impl CallFrame {
     /// Returns `None` if there is no block at the given index (e.g. if we need to return, this is handled by the caller)
     #[inline]
     pub(crate) fn break_to(&mut self, break_to_relative: u32, value_stack: &mut super::ValueStack) -> Option<()> {
+        log::debug!("break_to_relative: {}", break_to_relative);
         let break_to = self.labels.get_relative_to_top(break_to_relative as usize)?;
-        value_stack.break_to(break_to.stack_ptr, break_to.args.results);
 
         // instr_ptr points to the label instruction, but the next step
         // will increment it by 1 since we're changing the "current" instr_ptr
         match break_to.ty {
             BlockType::Loop => {
                 // this is a loop, so we want to jump back to the start of the loop
+                // We also want to push the params to the stack
+                value_stack.break_to(break_to.stack_ptr, break_to.args.params);
+
                 self.instr_ptr = break_to.instr_ptr;
 
                 // we also want to trim the label stack to the loop (but not including the loop)
                 self.labels.truncate(self.labels.len() - break_to_relative as usize);
             }
             BlockType::Block | BlockType::If | BlockType::Else => {
-                // this is a block, so we want to jump to the next instruction after the block ends (the inst_ptr will be incremented by 1 before the next instruction is executed)
+                // this is a block, so we want to jump to the next instruction after the block ends
+                // We also want to push the block's results to the stack
+                value_stack.break_to(break_to.stack_ptr, break_to.args.results);
+
+                // (the inst_ptr will be incremented by 1 before the next instruction is executed)
                 self.instr_ptr = break_to.end_instr_ptr;
 
                 // we also want to trim the label stack, including the block

crates/tinywasm/src/runtime/stack/value_stack.rs

@@ -92,6 +92,7 @@ impl ValueStack {
     }
 
     pub(crate) fn break_to(&mut self, new_stack_size: usize, result_count: usize) {
+        assert!(self.top >= result_count);
         self.stack.copy_within((self.top - result_count)..self.top, new_stack_size);
         self.top = new_stack_size + result_count;
         self.stack.truncate(self.top);

crates/tinywasm/tests/test-mvp.rs

@@ -17,16 +17,11 @@ fn test_mvp() -> Result<()> {
 
     TestSuite::set_log_level(log::LevelFilter::Off);
     test_suite.run_spec_group(wasm_testsuite::MVP_TESTS)?;
-
     test_suite.save_csv("./tests/generated/mvp.csv", env!("CARGO_PKG_VERSION"))?;
 
     if test_suite.failed() {
         println!();
-        Err(eyre!(format!(
-            "{}:\n{:#?}",
-            "failed one or more tests".red().bold(),
-            test_suite,
-        )))
+        Err(eyre!(format!("{}:\n{:#?}", "failed one or more tests".red().bold(), test_suite,)))
     } else {
         println!("\n\npassed all tests:\n{:#?}", test_suite);
         Ok(())

crates/tinywasm/tests/test-wast.rs

@@ -20,11 +20,7 @@ fn main() -> Result<()> {
     let cwd = std::env::current_dir()?;
 
     // if current dir is crates/tinywasm, then we want to go up 2 levels
-    let mut wast_file = if cwd.ends_with("crates/tinywasm") {
-        PathBuf::from("../../")
-    } else {
-        PathBuf::from("./")
-    };
+    let mut wast_file = if cwd.ends_with("crates/tinywasm") { PathBuf::from("../../") } else { PathBuf::from("./") };
 
     wast_file.push(&args[2]);
     let wast_file = cwd.join(wast_file);
@@ -34,7 +30,7 @@ fn main() -> Result<()> {
 }
 
 fn test_wast(wast_file: &str) -> Result<()> {
-    TestSuite::set_log_level(log::LevelFilter::Info);
+    TestSuite::set_log_level(log::LevelFilter::Debug);
 
     let args = std::env::args().collect::<Vec<_>>();
     println!("args: {:?}", args);
@@ -48,11 +44,7 @@ fn test_wast(wast_file: &str) -> Result<()> {
         println!();
         test_suite.print_errors();
         println!();
-        Err(eyre!(format!(
-            "{}:\n{:#?}",
-            "failed one or more tests".red().bold(),
-            test_suite,
-        )))
+        Err(eyre!(format!("{}:\n{:#?}", "failed one or more tests".red().bold(), test_suite,)))
     } else {
         println!("\n\npassed all tests:\n{:#?}", test_suite);
         Ok(())