From 6cf4d48802287b720d919dd701ac4495a0c83499 Mon Sep 17 00:00:00 2001
From: Patrick LaFontaine <32135464+Pat-Lafon@users.noreply.github.com>
Date: Thu, 25 Jul 2024 21:16:33 -0700
Subject: [PATCH 1/3] minor cleanup

---
 brilirs/src/basic_block.rs | 20 ++++----------------
 1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/brilirs/src/basic_block.rs b/brilirs/src/basic_block.rs
index 7294f58c..d82ac304 100644
--- a/brilirs/src/basic_block.rs
+++ b/brilirs/src/basic_block.rs
@@ -220,23 +220,11 @@ impl BBFunction {
           }
           curr_block.label = Some(label);
         }
-        bril_rs::Code::Instruction(bril_rs::Instruction::Effect {
-          op,
-          args,
-          funcs,
-          labels,
-          pos,
-        }) if op == bril_rs::EffectOps::Jump
-          || op == bril_rs::EffectOps::Branch
-          || op == bril_rs::EffectOps::Return =>
+        bril_rs::Code::Instruction(i @ bril_rs::Instruction::Effect { op, .. })
+          if op == bril_rs::EffectOps::Jump
+            || op == bril_rs::EffectOps::Branch
+            || op == bril_rs::EffectOps::Return =>
         {
-          let i = bril_rs::Instruction::Effect {
-            op,
-            args,
-            funcs,
-            labels,
-            pos,
-          };
           curr_block.numified_instrs.push(NumifiedInstruction::new(
             &i,
             &mut num_of_vars,

From 3368738d67f9901356c2f86dd79c9c97ad57444e Mon Sep 17 00:00:00 2001
From: Patrick LaFontaine <32135464+Pat-Lafon@users.noreply.github.com>
Date: Thu, 25 Jul 2024 21:34:17 -0700
Subject: [PATCH 2/3] Add the new label, not the old one for simplicity

---
 brilirs/src/basic_block.rs | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/brilirs/src/basic_block.rs b/brilirs/src/basic_block.rs
index d82ac304..3d17f058 100644
--- a/brilirs/src/basic_block.rs
+++ b/brilirs/src/basic_block.rs
@@ -212,12 +212,10 @@ impl BBFunction {
       match instr {
         bril_rs::Code::Label { label, pos: _ } => {
           if !curr_block.instrs.is_empty() || curr_block.label.is_some() {
-            if let Some(old_label) = curr_block.label.as_ref() {
-              label_map.insert(old_label.to_string(), blocks.len());
-            }
             blocks.push(curr_block);
             curr_block = BasicBlock::new();
           }
+          label_map.insert(label.to_string(), blocks.len());
           curr_block.label = Some(label);
         }
         bril_rs::Code::Instruction(i @ bril_rs::Instruction::Effect { op, .. })
@@ -232,9 +230,6 @@ impl BBFunction {
             func_map,
           )?);
           curr_block.instrs.push(i);
-          if let Some(l) = curr_block.label.as_ref() {
-            label_map.insert(l.to_string(), blocks.len());
-          }
           blocks.push(curr_block);
           curr_block = BasicBlock::new();
         }
@@ -251,9 +246,6 @@ impl BBFunction {
     }
 
     if !curr_block.instrs.is_empty() || curr_block.label.is_some() {
-      if let Some(l) = curr_block.label.as_ref() {
-        label_map.insert(l.to_string(), blocks.len());
-      }
       blocks.push(curr_block);
     }
 

From 1158ba57d7e9dc6bb025f3f0b0bf17b3e4158cda Mon Sep 17 00:00:00 2001
From: Patrick LaFontaine <32135464+Pat-Lafon@users.noreply.github.com>
Date: Thu, 25 Jul 2024 22:00:14 -0700
Subject: [PATCH 3/3] Check and error on duplicate labels

---
 brilirs/src/basic_block.rs | 6 ++++--
 brilirs/src/error.rs       | 2 ++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/brilirs/src/basic_block.rs b/brilirs/src/basic_block.rs
index 3d17f058..bb38d9c6 100644
--- a/brilirs/src/basic_block.rs
+++ b/brilirs/src/basic_block.rs
@@ -210,12 +210,14 @@ impl BBFunction {
     let mut curr_block = BasicBlock::new();
     for instr in func.instrs {
       match instr {
-        bril_rs::Code::Label { label, pos: _ } => {
+        bril_rs::Code::Label { label, pos } => {
           if !curr_block.instrs.is_empty() || curr_block.label.is_some() {
             blocks.push(curr_block);
             curr_block = BasicBlock::new();
           }
-          label_map.insert(label.to_string(), blocks.len());
+          if label_map.insert(label.to_string(), blocks.len()).is_some() {
+            return Err(InterpError::DuplicateLabel(label).add_pos(pos));
+          }
           curr_block.label = Some(label);
         }
         bril_rs::Code::Instruction(i @ bril_rs::Instruction::Effect { op, .. })
diff --git a/brilirs/src/error.rs b/brilirs/src/error.rs
index 7aaa3d03..5d34e010 100644
--- a/brilirs/src/error.rs
+++ b/brilirs/src/error.rs
@@ -25,6 +25,8 @@ pub enum InterpError {
   NotOneChar,
   #[error("multiple functions of the same name found")]
   DuplicateFunction,
+  #[error("duplicate label `{0}` found")]
+  DuplicateLabel(String),
   #[error("Expected empty return for `{0}`, found value")]
   NonEmptyRetForFunc(String),
   #[error("cannot allocate `{0}` entries")]