feat: add env var-based trace options: looks simpler than adding cli params

.envrc

@@ -0,0 +1,16 @@
+# shellcheck shell=bash
+if ! has nix_direnv_version || ! nix_direnv_version 3.0.4; then
+  source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/3.0.4/direnvrc" "sha256-DzlYZ33mWF/Gs8DDeyjr8mnVmQGx7ASYqA5WlxwvBG4="
+fi
+
+dotenv_if_exists
+
+# watch_file "$(find ./nix -name "*.nix" -type f)"
+
+OS_AND_SYSTEM=$(uname -a)
+
+if [[ "${NO_NIX:-}" == "1" || $OS_AND_SYSTEM == "Darwin"* ]]; then
+  source non-nix-build/env.sh
+else
+  use flake
+fi

.gitignore

@@ -8,3 +8,6 @@ spec/target
 **/fuzz/artifacts/
 **/fuzz/crash-inputs/
 **/fuzz/Cargo.lock
+
+*.wasm
+.direnv/

Cargo.toml

@@ -10,7 +10,8 @@ members = [
     "crates/ir",
     "crates/fuzz",
     "crates/wast",
-    "fuzz",
+    "fuzz", "crates/tracer",
+    # "wasm-test",
 ]
 exclude = []
 resolver = "2"
@@ -39,6 +40,7 @@ wasmi_c_api_impl = { version = "0.44.0", path = "crates/c_api" }
 wasmi_c_api_macros = { version = "0.44.0", path = "crates/c_api/macro" }
 wasmi_fuzz = { version = "0.44.0", path = "crates/fuzz" }
 wasmi_wast = { version = "0.44.0", path = "crates/wast" }
+wasmi_tracer = { version = "0.1.0", path = "crates/tracer" }
 
 # wasm-tools dependencies
 wat = { version = "1.227.1", default-features = false }

crates/tracer/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "wasmi_tracer"
+version = "0.1.0"
+authors.workspace = true
+repository.workspace = true
+# version.workspace = true
+rust-version.workspace = true
+edition.workspace = true
+readme.workspace = true
+license.workspace = true
+keywords.workspace = true
+categories.workspace = true
+exclude.workspace = true
+
+[dependencies]

crates/tracer/src/lib.rs

@@ -0,0 +1,74 @@
+use std::path::{Path, PathBuf};
+use std::println;
+
+pub fn add(left: u64, right: u64) -> u64 {
+    left + right
+}
+
+// TODO
+#[derive(Debug, Clone)]
+struct DebugInfo {
+    // for now minimal info here
+    wasm_exe_path: std::path::PathBuf,
+    // TODO eventually dwarf/gimli stuff, not sure
+    // TODO: eventually the tracer from runtime_tracer but maybe DebugInfo is just PDO for debug info?A
+    // maybe there are several kinds, e.g. frame-based, maybe others
+    // so maybe our fn-s will know how to deal with them
+    // TODO: local_variables: HashMap<VariableId, DebugLocation>,
+}
+
+impl DebugInfo {
+    fn new(wasm_exe_path: &Path) -> Self {
+        DebugInfo { wasm_exe_path: PathBuf::from(wasm_exe_path) }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct WasmTracer {
+    debug_info: DebugInfo,
+    // TODO: tracer: runtime_tracing.Tracer,
+    // etc
+}
+
+// just to make it build so we can branch-out
+
+impl WasmTracer {
+    pub fn new(wasm_exe_path: &Path) -> Self {
+        WasmTracer {
+            debug_info: DebugInfo::new(wasm_exe_path),
+        }
+    }
+
+    pub fn load_local_variables(&mut self, address: usize) { // -> ???
+        println!("load_local_variables {address}");
+        // e.g. here we might call something like
+        // some kind of check if we already have the info for the current context
+        // let cached = TODO;
+        let cached = false;
+
+        if !cached {
+            // TODO etc
+            // load debuginfo etc
+        }
+    }
+}
+
+    // load wasm file
+    // find out its subprogram and scope for a certain address and somehow
+    // 
+    // print mapping with expr => relevant location
+    // x <- 0x000A7321
+    // ip; (debuginfo address of some code(?))
+    //
+    // 
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let result = add(2, 2);
+        assert_eq!(result, 4);
+    }
+}

crates/wasmi/Cargo.toml

@@ -19,9 +19,16 @@ exclude = [
 ]
 
 [dependencies]
+
+# Dwarf utilities
+gimli = "0.31.1"
+object = { "version" = "0.36.7", "features" = ["elf", "wasm"] }
+memmap2 = "0.9.5"
+
 wasmi_core = { workspace = true }
 wasmi_collections = { workspace = true }
 wasmi_ir = { workspace = true }
+wasmi_tracer = { workspace = true }
 wasmparser = { workspace = true, features = ["validate", "features"] }
 wat = { workspace = true, optional = true }
 spin = { version = "0.9", default-features = false, features = [

crates/wasmi/src/engine/executor/instrs.rs

@@ -2,6 +2,7 @@
 
 pub use self::call::{dispatch_host_func, ResumableHostError};
 use super::{cache::CachedInstance, InstructionPtr, Stack};
+use wasmi_tracer::WasmTracer;
 use crate::{
     core::{hint, wasm, ReadAs, TrapCode, UntypedVal, WriteAs},
     engine::{
@@ -91,6 +92,9 @@ struct Executor<'engine> {
     ///
     /// [`Engine`]: crate::Engine
     code_map: &'engine CodeMap,
+
+    // debug:
+    // TODO tracer: &'engine mut WasmTracer,
 }
 
 impl<'engine> Executor<'engine> {
@@ -110,12 +114,14 @@ impl<'engine> Executor<'engine> {
         //         valid for all register indices used by the associated function body.
         let sp = unsafe { stack.values.stack_ptr_at(frame.base_offset()) };
         let ip = frame.instr_ptr();
+
         Self {
             sp,
             ip,
             cache,
             stack,
             code_map,
+            // TODO tracer: &mut tracer, // probably were not gonna make it
         }
     }
 
@@ -124,6 +130,22 @@ impl<'engine> Executor<'engine> {
     fn execute<T>(mut self, store: &mut Store<T>) -> Result<(), Error> {
         use Instruction as Instr;
         loop {
+            // TODO: change that, just startting from somewehre
+            // Args: path : Path, instruction address(?) , step?
+            // TODO: good way to take address
+            //let address = usize::from(self.ip.get());
+            let address = 0x000000010; // should be in the main subprogram >= low_pc
+            //std::println!("address of {:?}: {:?}", *self.ip.get(), address);
+            // TODO: make this be a field with correct lifetime
+            let mut tracer = WasmTracer::new(std::path::Path::new("/home/pesho/code/codetracer-wasmi-recorder/wasm_test.wasm")); // "<path to test.wasm>: for now hardcoded TODO pass");
+            tracer.load_local_variables(address);
+
+            // load debuginfo from gimli <- for this ip;
+            // -> find out current scope and vars in it:
+            //   some kind of mapping between them and locations
+            // -> load them with some general(for us) mechanism from wasmi's memory(?)
+            // e.g. load_expression(expr, location, ..) -> ValueRecord
+            // (to be iterated on, just an idea)
             match *self.ip.get() {
                 Instr::Trap { trap_code } => self.execute_trap(trap_code)?,
                 Instr::ConsumeFuel { block_fuel } => {