fix: stack overflow with iterative tree traversal

.github/workflows/general.yml

@@ -23,7 +23,7 @@ jobs:
           components: rustfmt, clippy
 
       - name: cargo test
-        run: cargo test
+        run: RUST_MIN_STACK=8388608 cargo test
 
       - name: cargo fmt
         run: cargo fmt --all -- --check

Cargo.toml

@@ -24,6 +24,9 @@ ethers-solc = { git = "https://github.com/gakonst/ethers-rs", features = ["full"
 paste = "1.0.12"
 rlp = "0.5.2"
 serde = "1.0.164"
+backtrace-on-stack-overflow = "0.3.0"
+justerror = "1.1.0"
+thiserror = "1.0.44"
 
 [target.'cfg(any(target_os = "windows", target_os = "macos"))'.dependencies]
 z3 = {version = "0.11.2", features = ["static-link-z3"]}

examples/simple_token.rs

@@ -8,7 +8,6 @@ use z3::ast::*;
 pub const SIMPLE_TOKEN: &str = r#"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"#;
 
 fn main() {
-    unsafe {backtrace_on_stack_overflow::enable();}
     let pgm = Parser::with_pgm(SIMPLE_TOKEN).parse();
     let mut evm = Evm::new(pgm);
 

src/instruction/mod.rs

@@ -27,7 +27,6 @@ use super::smt::*;
 #[Error]
 pub enum InstructionError {
     StackEmpty{
-        instruction: Instruction,
         pc: usize,
     }
 }
@@ -252,16 +251,16 @@ impl Instruction {
 }
 impl<'ctx> MachineInstruction<'ctx, 32> for Instruction {
     type Error = InstructionError;
-    fn exec(&self, mach: &EvmState) -> Result<MachineRecord<32>, InstructionError> {
+    fn exec(&self, mach: &EvmState) -> MachineRecord<32> {
         match self {
-            Instruction::Stop => Ok(MachineRecord {
+            Instruction::Stop => MachineRecord {
                 halt: true,
                 stack: None,
                 mem: None,
                 constraints: None,
                 storage: None,
                 pc: (mach.pc(), mach.pc()),
-            }),
+            },
             Instruction::Add => {
                 let stack = mach.stack();
                 let [stack_top, stack_top2] = stack.peek_top().unwrap();

src/traits.rs

@@ -43,7 +43,7 @@ pub trait Machine<const STACK_ITEM_SZ: usize> {
 
 pub trait MachineInstruction<'ctx, const SZ: usize> {
     type Error;
-    fn exec(&self, mach: &EvmState) -> Result<MachineRecord<SZ>, Self::Error>;
+    fn exec(&self, mach: &EvmState) -> MachineRecord<SZ>;
 }
 
 pub trait MachineComponent {

tests/lib.rs

@@ -33,8 +33,12 @@ fn can_run_simple_storage_pgm() {
 
     let execution = evm.exec();
     let leaf = execution.states.leaves();
-    assert_eq!(2, leaf.len());
-    eprintln!("LEAVES: {:#?}", leaf);
+
+    {
+        let leaf = execution.states.leaves();
+        // as seen here https://bytegraph.xyz/bytecode/e5987a6f24f8af926faddae88de7980f/graph
+        assert_eq!(7, leaf.len());
+    }
     let final_tree = leaf.get(1).unwrap().clone();
     // eprintln!("FINAL TREE: {:#?}", final_tree);
     let mut mem_val = final_tree.val.mem_read(bvi(64));