Merge pull request #108 from lambdaclass/for-lowering

For lowering

crates/concrete_driver/tests/examples.rs

@@ -18,6 +18,8 @@ mod common;
 #[test_case(include_str!("../../../examples/malloc.con"), "malloc", false, 5 ; "malloc.con")]
 #[test_case(include_str!("../../../examples/while_if_false.con"), "while_if_false", false, 7 ; "while_if_false.con")]
 #[test_case(include_str!("../../../examples/if_if_false.con"), "if_if_false", false, 7 ; "if_if_false.con")]
+#[test_case(include_str!("../../../examples/for.con"), "for", false, 10 ; "for.con")]
+#[test_case(include_str!("../../../examples/for_while.con"), "for_while", false, 10 ; "for_while.con")]
 fn example_tests(source: &str, name: &str, is_library: bool, status_code: i32) {
     assert_eq!(
         status_code,

crates/concrete_ir/src/lowering.rs

@@ -9,7 +9,7 @@ use concrete_ast::{
     },
     functions::{FunctionDecl, FunctionDef},
     modules::{Module, ModuleDefItem},
-    statements::{self, AssignStmt, LetStmt, LetStmtTarget, ReturnStmt, WhileStmt},
+    statements::{self, AssignStmt, ForStmt, LetStmt, LetStmtTarget, ReturnStmt, WhileStmt},
     structs::StructDecl,
     types::{TypeQualifier, TypeSpec},
     Program,
@@ -291,6 +291,24 @@ fn lower_func(
                 }
                 LetStmtTarget::Destructure(_) => todo!(),
             }
+        } else if let statements::Statement::For(info) = stmt {
+            if let Some(info) = &info.init {
+                match &info.target {
+                    LetStmtTarget::Simple { name, r#type } => {
+                        let ty = lower_type(&builder.ctx, r#type, builder.local_module)?;
+                        builder
+                            .name_to_local
+                            .insert(name.name.clone(), builder.body.locals.len());
+                        builder.body.locals.push(Local::new(
+                            Some(name.span),
+                            LocalKind::Temp,
+                            ty,
+                            Some(name.name.clone()),
+                        ));
+                    }
+                    LetStmtTarget::Destructure(_) => todo!(),
+                }
+            }
         }
     }
 
@@ -363,7 +381,10 @@ fn lower_statement(
     match info {
         statements::Statement::Assign(info) => lower_assign(builder, info)?,
         statements::Statement::Match(_) => todo!(),
-        statements::Statement::For(_) => todo!(),
+        statements::Statement::For(info) => {
+            lower_for(builder, info)?;
+            assert!(builder.statements.is_empty());
+        }
         statements::Statement::If(info) => {
             lower_if_statement(builder, info)?;
             assert!(builder.statements.is_empty());
@@ -460,6 +481,107 @@ fn lower_while(builder: &mut FnBodyBuilder, info: &WhileStmt) -> Result<(), Lowe
     Ok(())
 }
 
+fn lower_for(builder: &mut FnBodyBuilder, info: &ForStmt) -> Result<(), LoweringError> {
+    if let Some(init) = &info.init {
+        lower_let(builder, init)?;
+    }
+
+    let statements = std::mem::take(&mut builder.statements);
+    builder.body.basic_blocks.push(BasicBlock {
+        statements,
+        terminator: Box::new(Terminator {
+            span: None,
+            kind: TerminatorKind::Goto {
+                target: builder.body.basic_blocks.len() + 1,
+            },
+        }),
+    });
+
+    let (discriminator, discriminator_type, _disc_span) = if let Some(condition) = &info.condition {
+        let (discriminator, discriminator_type, span) = lower_expression(builder, condition, None)?;
+
+        (discriminator, discriminator_type, Some(span))
+    } else {
+        // todo: don't use discriminator when no loop condition
+        let discriminator_type = Ty {
+            span: None,
+            kind: TyKind::Bool,
+        };
+
+        let discriminator = Rvalue::Use(Operand::Const(ConstData {
+            ty: discriminator_type.clone(),
+            data: ConstKind::Value(ValueTree::Leaf(ConstValue::Bool(true))),
+        }));
+
+        (discriminator, discriminator_type, None)
+    };
+
+    let local = builder.add_temp_local(TyKind::Bool);
+    let place = Place {
+        local,
+        projection: vec![],
+    };
+
+    builder.statements.push(Statement {
+        span: None,
+        kind: StatementKind::Assign(place.clone(), discriminator),
+    });
+
+    // keep idx to change terminator
+    let check_block_idx = builder.body.basic_blocks.len();
+
+    let statements = std::mem::take(&mut builder.statements);
+    builder.body.basic_blocks.push(BasicBlock {
+        statements,
+        terminator: Box::new(Terminator {
+            span: None,
+            kind: TerminatorKind::Unreachable,
+        }),
+    });
+
+    // keep idx for switch targets
+    let first_then_block_idx = builder.body.basic_blocks.len();
+
+    for stmt in &info.contents {
+        lower_statement(
+            builder,
+            stmt,
+            builder.body.locals[builder.ret_local].ty.clone(),
+        )?;
+    }
+
+    if let Some(post) = &info.post {
+        lower_assign(builder, post)?;
+    }
+
+    builder.body.basic_blocks.len();
+    let statements = std::mem::take(&mut builder.statements);
+    builder.body.basic_blocks.push(BasicBlock {
+        statements,
+        terminator: Box::new(Terminator {
+            span: None,
+            kind: TerminatorKind::Goto {
+                target: check_block_idx,
+            },
+        }),
+    });
+
+    let otherwise_block_idx = builder.body.basic_blocks.len();
+
+    let targets = SwitchTargets {
+        values: vec![discriminator_type.kind.get_falsy_value()],
+        targets: vec![otherwise_block_idx, first_then_block_idx],
+    };
+
+    let kind = TerminatorKind::SwitchInt {
+        discriminator: Operand::Place(place),
+        targets,
+    };
+    builder.body.basic_blocks[check_block_idx].terminator.kind = kind;
+
+    Ok(())
+}
+
 fn lower_if_statement(builder: &mut FnBodyBuilder, info: &IfExpr) -> Result<(), LoweringError> {
     let (discriminator, discriminator_type, _disc_span) =
         lower_expression(builder, &info.value, None)?;

examples/for_loop.con

@@ -7,11 +7,6 @@ mod Example {
         let mut result: i64 = 0;
 
         let n: i64 = 1;
-        for (;;) {
-            result = result + n;
-            n = n + 1;
-        }
-
         for {
             result = result + n;
             n = n + 1;

examples/for_while.con

@@ -7,12 +7,6 @@ mod Example {
         let mut result: i64 = 0;
 
         let n: i64 = 1;
-        for (; n <= limit ;) {
-            result = result + n;
-            n = n + 1;
-        }
-
-        n = 1;
         for (n <= limit) {
             result = result + n;
             n = n + 1;