From 9bc7a5ec5f184695766ba2e74a73d92d9f81c9f7 Mon Sep 17 00:00:00 2001
From: Jan Ferdinand Sauer <ferdinand@neptune.cash>
Date: Thu, 5 Oct 2023 09:16:31 +0200
Subject: [PATCH] feat: add support for `break` debug command

---
 triton-vm/src/instruction.rs |  4 ++++
 triton-vm/src/parser.rs      | 24 +++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/triton-vm/src/instruction.rs b/triton-vm/src/instruction.rs
index c4a06f70..b41d98e7 100644
--- a/triton-vm/src/instruction.rs
+++ b/triton-vm/src/instruction.rs
@@ -49,6 +49,8 @@ pub enum LabelledInstruction {
 
     /// Labels look like "`<name>:`" and are translated into absolute addresses.
     Label(String),
+
+    Breakpoint,
 }
 
 impl LabelledInstruction {
@@ -77,6 +79,7 @@ impl Display for LabelledInstruction {
         match self {
             LabelledInstruction::Instruction(instr) => write!(f, "{instr}"),
             LabelledInstruction::Label(label_name) => write!(f, "{label_name}:"),
+            LabelledInstruction::Breakpoint => write!(f, "break"),
         }
     }
 }
@@ -469,6 +472,7 @@ pub(crate) fn build_label_to_address_map(program: &[LabelledInstruction]) -> Has
                 }
             },
             Instruction(instruction) => instruction_pointer += instruction.size() as u64,
+            Breakpoint => (),
         }
     }
     label_map
diff --git a/triton-vm/src/parser.rs b/triton-vm/src/parser.rs
index bb2368dd..7f28eac7 100644
--- a/triton-vm/src/parser.rs
+++ b/triton-vm/src/parser.rs
@@ -36,6 +36,7 @@ pub struct ParseError<'a> {
 pub enum InstructionToken<'a> {
     Instruction(AnInstruction<String>, &'a str),
     Label(String, &'a str),
+    Breakpoint(&'a str),
 }
 
 impl<'a> Display for InstructionToken<'a> {
@@ -43,6 +44,7 @@ impl<'a> Display for InstructionToken<'a> {
         match self {
             InstructionToken::Instruction(instr, _) => write!(f, "{instr}"),
             InstructionToken::Label(label_name, _) => write!(f, "{label_name}:"),
+            InstructionToken::Breakpoint(_) => write!(f, "break"),
         }
     }
 }
@@ -60,6 +62,7 @@ impl<'a> InstructionToken<'a> {
         match self {
             InstructionToken::Instruction(_, token_str) => token_str,
             InstructionToken::Label(_, token_str) => token_str,
+            InstructionToken::Breakpoint(token_str) => token_str,
         }
     }
 
@@ -68,6 +71,7 @@ impl<'a> InstructionToken<'a> {
         match self {
             Instruction(instr, _) => LabelledInstruction::Instruction(instr.to_owned()),
             Label(label, _) => LabelledInstruction::Label(label.to_owned()),
+            Breakpoint(_) => LabelledInstruction::Breakpoint,
         }
     }
 }
@@ -187,7 +191,7 @@ type ParseResult<'input, Out> = IResult<&'input str, Out, VerboseError<&'input s
 ///
 pub fn tokenize(s: &str) -> ParseResult<Vec<InstructionToken>> {
     let (s, _) = comment_or_whitespace0(s)?;
-    let (s, instructions) = many0(alt((label, labelled_instruction)))(s)?;
+    let (s, instructions) = many0(alt((label, labelled_instruction, breakpoint)))(s)?;
     let (s, _) = context("expecting label, instruction or eof", eof)(s)?;
 
     Ok((s, instructions))
@@ -213,6 +217,11 @@ fn label(label_s: &str) -> ParseResult<InstructionToken> {
     Ok((s, InstructionToken::Label(addr, label_s)))
 }
 
+fn breakpoint(breakpoint_s: &str) -> ParseResult<InstructionToken> {
+    let (s, _) = token1("break")(breakpoint_s)?;
+    Ok((s, InstructionToken::Breakpoint(breakpoint_s)))
+}
+
 fn an_instruction(s: &str) -> ParseResult<AnInstruction<String>> {
     // OpStack manipulation
     let pop = instruction("pop", Pop);
@@ -1063,4 +1072,17 @@ pub(crate) mod tests {
         let expected_instructions = vec![Instruction(Divine); DIGEST_LENGTH];
         assert_eq!(expected_instructions, instructions);
     }
+
+    #[test]
+    fn break_gets_turned_into_labelled_instruction() {
+        let instructions = triton_asm![break];
+        let expected_instructions = vec![Breakpoint];
+        assert_eq!(expected_instructions, instructions);
+    }
+
+    #[test]
+    fn break_does_not_propagate_to_full_program() {
+        let program = triton_program! { break halt break };
+        assert_eq!(1, program.instructions.len());
+    }
 }