From 2403cdb7ee077c1762a4d3dff2f7c128fbe5e694 Mon Sep 17 00:00:00 2001
From: XFFXFF <1247714429@qq.com>
Date: Tue, 19 Sep 2023 08:55:00 +0800
Subject: [PATCH] add a step_inspect to vm.interpret for debugging

---
 components/lox-execute/src/execute.rs |  6 ++---
 components/lox-execute/src/lib.rs     |  1 +
 components/lox-execute/src/vm.rs      | 10 ++++++--
 lox_tests/arithmetic.output           | 36 +++++++++++++++++++++++++--
 lox_tests/boolean.output              | 11 ++++++--
 src/main.rs                           | 13 +++++++---
 6 files changed, 65 insertions(+), 12 deletions(-)

diff --git a/components/lox-execute/src/execute.rs b/components/lox-execute/src/execute.rs
index 15411e1..a526dd7 100644
--- a/components/lox-execute/src/execute.rs
+++ b/components/lox-execute/src/execute.rs
@@ -1,10 +1,10 @@
 use lox_compile::compile;
-use lox_ir::input_file::InputFile;
+use lox_ir::{input_file::InputFile, bytecode};
 
 use crate::vm::{VM, Value};
 
-pub fn execute_file(db: &impl crate::Db, input_file: InputFile) -> Value {
+pub fn execute_file(db: &impl crate::Db, input_file: InputFile, step_inspect: Option<impl FnMut(bytecode::Code, &VM)>) -> Value {
     let chunk = compile::compile_file(db, input_file);
     let mut vm = VM::new(chunk);
-    vm.interpret()
+    vm.interpret(step_inspect)
 }
diff --git a/components/lox-execute/src/lib.rs b/components/lox-execute/src/lib.rs
index 4395c78..85b3838 100644
--- a/components/lox-execute/src/lib.rs
+++ b/components/lox-execute/src/lib.rs
@@ -4,6 +4,7 @@ pub mod execute;
 pub mod vm;
 
 pub use execute::execute_file;
+pub use vm::VM;
 
 #[salsa::jar(db = Db)]
 pub struct Jar();
diff --git a/components/lox-execute/src/vm.rs b/components/lox-execute/src/vm.rs
index 6021d0b..f9beccf 100644
--- a/components/lox-execute/src/vm.rs
+++ b/components/lox-execute/src/vm.rs
@@ -67,7 +67,7 @@ pub struct VM {
     chunk: bytecode::Chunk,
     ip: usize,
 
-    stack: Vec<Value>,
+    pub stack: Vec<Value>,
 }
 
 impl VM {
@@ -79,7 +79,10 @@ impl VM {
         }
     }
 
-    pub fn interpret(&mut self) -> Value {
+    // `step_inspect` is a callback that is called after each instruction is executed.
+    //  It is useful for debugging.
+    pub fn interpret<F>(&mut self, mut step_inspect: Option<F>) -> Value
+        where F: FnMut(bytecode::Code, &VM) {
         loop {
             if self.chunk.len() <= self.ip {
                 break;
@@ -117,6 +120,9 @@ impl VM {
                     self.push(false);
                 },
             }
+            if let Some(step_inspect) = &mut step_inspect {
+                step_inspect(instruction, self);
+            }
         }
         self.stack.pop().unwrap()
     }
diff --git a/lox_tests/arithmetic.output b/lox_tests/arithmetic.output
index 06980d6..5ebcd5d 100644
--- a/lox_tests/arithmetic.output
+++ b/lox_tests/arithmetic.output
@@ -1,3 +1,35 @@
-Number(
+execute: Constant(
+    F64(
+        1.0,
+    ),
+)
+stack: [
+    Number(
+        1.0,
+    ),
+]
+
+execute: Constant(
+    F64(
+        2.0,
+    ),
+)
+stack: [
+    Number(
+        1.0,
+    ),
+    Number(
+        2.0,
+    ),
+]
+
+execute: Add
+stack: [
+    Number(
+        3.0,
+    ),
+]
+
+output: Number(
     3.0,
-)
\ No newline at end of file
+)
diff --git a/lox_tests/boolean.output b/lox_tests/boolean.output
index 3da3958..7011a24 100644
--- a/lox_tests/boolean.output
+++ b/lox_tests/boolean.output
@@ -1,3 +1,10 @@
-Boolean(
+execute: True
+stack: [
+    Boolean(
+        true,
+    ),
+]
+
+output: Boolean(
     true,
-)
\ No newline at end of file
+)
diff --git a/src/main.rs b/src/main.rs
index 0beb03c..09640da 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -48,7 +48,7 @@ impl TestCase {
 }
 
 use expect_test::expect_file;
-use lox_ir::{diagnostic::Diagnostics, input_file::InputFile, word::Word};
+use lox_ir::{diagnostic::Diagnostics, input_file::InputFile, word::Word, bytecode};
 
 #[salsa::db(
     lox_parse::Jar,
@@ -113,7 +113,14 @@ fn main() {
         expect_file![case.bytecode].assert_eq(&format!("{:#?}", chunk));
 
         // test execute
-        let output = lox_execute::execute_file(&db, input_file);
-        expect_file![case.output].assert_eq(&format!("{:#?}", output));
+        let mut buf = String::new();
+        let step_inspect = |code: bytecode::Code, vm: &lox_execute::VM| {
+            buf.push_str(&format!("execute: {:#?}\n", code));
+            buf.push_str(&format!("stack: {:#?}\n", vm.stack));
+            buf.push('\n');
+        };
+        let output = lox_execute::execute_file(&db, input_file, Some(step_inspect));
+        buf.push_str(&format!("output: {:#?}\n", output));
+        expect_file![case.output].assert_eq(&buf);
     }
 }