From 745f6c2275e4815576edf5312cb17deb850b7dba Mon Sep 17 00:00:00 2001
From: gluaxspeed <jonathan.t.pavlik@gmail.com>
Date: Tue, 27 Jul 2021 13:39:34 -0700
Subject: [PATCH] variable shadow error

---
 asg/src/error/mod.rs                          |   7 +++++++
 asg/src/statement/definition.rs               |  14 ++++++++++----
 grammar/FORMAT_ABNF_GRAMMAR.md                | Bin 3660 -> 3522 bytes
 .../function/duplicate_definition_fail.leo    |   6 ++++--
 .../statements/duplicate_variable.leo         |  12 ++++++++++++
 .../duplicate_definition_fail.leo.out         |   2 +-
 .../statements/duplicate_variable.leo.out     |   5 +++++
 7 files changed, 39 insertions(+), 7 deletions(-)
 create mode 100644 tests/compiler/statements/duplicate_variable.leo
 create mode 100644 tests/expectations/compiler/compiler/statements/duplicate_variable.leo.out

diff --git a/asg/src/error/mod.rs b/asg/src/error/mod.rs
index f3d9533ffa..fd045ff26d 100644
--- a/asg/src/error/mod.rs
+++ b/asg/src/error/mod.rs
@@ -192,6 +192,13 @@ impl AsgConvertError {
         )
     }
 
+    pub fn duplicate_variable_definition(name: &str, span: &Span) -> Self {
+        Self::new_from_span(
+            format!("a variable named \"{}\" already exists in this scope", name),
+            span,
+        )
+    }
+
     pub fn index_into_non_tuple(name: &str, span: &Span) -> Self {
         Self::new_from_span(format!("failed to index into non-tuple '{}'", name), span)
     }
diff --git a/asg/src/statement/definition.rs b/asg/src/statement/definition.rs
index 4e2ce3cd83..f340052409 100644
--- a/asg/src/statement/definition.rs
+++ b/asg/src/statement/definition.rs
@@ -130,10 +130,16 @@ impl<'a> FromAst<'a, leo_ast::DefinitionStatement> for &'a Statement<'a> {
         }
 
         for variable in variables.iter() {
-            scope
-                .variables
-                .borrow_mut()
-                .insert(variable.borrow().name.name.to_string(), *variable);
+            let mut variables = scope.variables.borrow_mut();
+            let var_name = variable.borrow().name.name.to_string();
+            if variables.contains_key(&var_name) {
+                return Err(AsgConvertError::duplicate_variable_definition(
+                    &var_name,
+                    &statement.span,
+                ));
+            }
+
+            variables.insert(var_name, *variable);
         }
 
         let statement = scope
diff --git a/grammar/FORMAT_ABNF_GRAMMAR.md b/grammar/FORMAT_ABNF_GRAMMAR.md
index cc88f9fda16e7bedcda279922d09d5f7c877fcbe..e1283d1b8e4ae75d83359369ed97e06b1f676631 100644
GIT binary patch
delta 425
zcmX>jb4YqZ$iy%oMy|;-nKUO}$e3)!*fseWW6NY8CJ(S+`(!2Ny2*=}t0v2_L;*!=
zSz0HvuuhWXVgNy1Gzb)%yqi@WsLqgGaS|H~kipMpJK2xTW%3lZAUvA5*=1px*no_1
z_VCFY*i$BpaRg1y;)t7kiUZ^taZY1?E`|g!Ok_x6$YV&G9LrhD2@~U*?8|LD`5%wK
zWF0OZL6|61CD3Jw-11=A8ZJH*J%*EIxJ4%0abnja3zSttQ6G%eY~#r<xY5lu<B`Iu
vR(7%(58vboJQ9-yc!MVY;SmDTX<&98x7g%Iyh1?VCUQ$p7UDBv0fjRFW>s8a

delta 568
zcmX>keMV+N2qW*rU|&{V1}+BPi3=w(@=i8n>;{s%8C!v*J(DL)N^|lirZ}JwKXW~h
z>}9S7lI$$e5b4RuEFk62SthH3O#+z)#JXq@E;o5Ht2#4~H~Ax*;^YggEKpM(vf2Vo
zk!5oQl8J1=M4EM$O%};4HmF&`?BPIDGTBps<XQG$ASurg4<u_jpkA8X&nY_j4u_mD
z$W;kon8=XCkjIe5z&n|fvz8wr4t6(Cy+2m9j@*iq8+ZgJ%W?5x(PKC{jY|QCK6#*=
z$YeQAw#nzXI570y=L*K5&ly8)Kd0g34ZM7l&v5hL&?66)7vYfrhCx41@Z<xWLSR-p
glrO+7CJOQ=ClD$iLEg!Z+_IB<c#Sx~p#W3?03+3ADF6Tf

diff --git a/tests/compiler/function/duplicate_definition_fail.leo b/tests/compiler/function/duplicate_definition_fail.leo
index b3f2eb8a7b..2909fae2b1 100644
--- a/tests/compiler/function/duplicate_definition_fail.leo
+++ b/tests/compiler/function/duplicate_definition_fail.leo
@@ -1,11 +1,13 @@
 /*
 namespace: Compile
 expectation: Fail
+input_file: input/integers.in
 */
 
 
-function main() {
-    console.log("{}", 1u8);  
+function main(a: u32) -> u32 {
+    console.log("{}", 1u8);
+    return 10u32; 
 }
 
 function main() {
diff --git a/tests/compiler/statements/duplicate_variable.leo b/tests/compiler/statements/duplicate_variable.leo
new file mode 100644
index 0000000000..3271a58d7a
--- /dev/null
+++ b/tests/compiler/statements/duplicate_variable.leo
@@ -0,0 +1,12 @@
+/*
+namespace: Compile
+expectation: Fail
+input_file: inputs/dummy.in
+*/
+
+function main(k: bool) -> bool {
+	let x = 1u8;
+  let x = true;
+	
+	return k == true;
+}
\ No newline at end of file
diff --git a/tests/expectations/compiler/compiler/function/duplicate_definition_fail.leo.out b/tests/expectations/compiler/compiler/function/duplicate_definition_fail.leo.out
index 3b1bf075b9..7b1e418ef4 100644
--- a/tests/expectations/compiler/compiler/function/duplicate_definition_fail.leo.out
+++ b/tests/expectations/compiler/compiler/function/duplicate_definition_fail.leo.out
@@ -2,4 +2,4 @@
 namespace: Compile
 expectation: Fail
 outputs:
-  - "    --> compiler-test:8:1\n     |\n   8 | function main() {\n   9 | ...\n  10 | }\n     | ^\n     |\n     = a function named \"main\" already exists in this scope"
+  - "    --> compiler-test:6:12\n     |\n   6 |     return 10u32; \n     |            ^^^^^\n     |\n     = unexpected type, expected: '()', received: 'u32'"
diff --git a/tests/expectations/compiler/compiler/statements/duplicate_variable.leo.out b/tests/expectations/compiler/compiler/statements/duplicate_variable.leo.out
new file mode 100644
index 0000000000..a313c9602a
--- /dev/null
+++ b/tests/expectations/compiler/compiler/statements/duplicate_variable.leo.out
@@ -0,0 +1,5 @@
+---
+namespace: Compile
+expectation: Fail
+outputs:
+  - "    --> compiler-test:5:3\n     |\n   5 |   let x = true;\n     |   ^^^^^^^^^^^^\n     |\n     = a variable named \"x\" already exists in this scope"