add different variants of addition

cli/src/lib.rs

@@ -210,6 +210,12 @@ fn build_file(
             "host.rs",
             "-o",
             binary_path.as_path().to_str().unwrap(),
+            // ensure we don't make a position-independent executable
+            "-C",
+            "link-arg=-no-pie",
+            // explicitly link in the c++ stdlib, for exceptions
+            "-C",
+            "link-arg=-lc++",
         ])
         .current_dir(cwd)
         .spawn()

compiler/builtins/bitcode/src/lib.rs

@@ -36,3 +36,12 @@ pub fn pow_int_(mut base: i64, mut exp: i64) -> i64 {
 
     acc
 }
+
+/// Adapted from Rust's core::num module, by the Rust core team,
+/// licensed under the Apache License, version 2.0 - https://www.apache.org/licenses/LICENSE-2.0
+///
+/// Thank you, Rust core team!
+#[no_mangle]
+pub fn is_finite_(num: f64) -> bool {
+    f64::is_finite(num)
+}

compiler/builtins/src/std.rs

@@ -188,8 +188,8 @@ pub fn types() -> MutMap<Symbol, (SolvedType, Region)> {
     );
 
     // addChecked or (+) : Num a, Num a -> Result (Num a) [ IntOverflow ]*
-    let int_overflow = SolvedType::TagUnion(
+    let overflow = SolvedType::TagUnion(
-        vec![(TagName::Global("IntOverflow".into()), vec![])],
+        vec![(TagName::Global("Overflow".into()), vec![])],
         Box::new(SolvedType::Wildcard),
     );
 
@@ -197,7 +197,7 @@ pub fn types() -> MutMap<Symbol, (SolvedType, Region)> {
         Symbol::NUM_ADD_CHECKED,
         SolvedType::Func(
             vec![num_type(flex(TVAR1)), num_type(flex(TVAR1))],
-            Box::new(result_type(num_type(flex(TVAR1)), int_overflow)),
+            Box::new(result_type(num_type(flex(TVAR1)), overflow)),
         ),
     );
 

compiler/builtins/src/unique.rs

@@ -275,8 +275,8 @@ pub fn types() -> MutMap<Symbol, (SolvedType, Region)> {
     });
 
     // addChecked or (+) : Num a, Num a -> Result (Num a) [ IntOverflow ]*
-    let int_overflow = SolvedType::TagUnion(
+    let overflow = SolvedType::TagUnion(
-        vec![(TagName::Global("IntOverflow".into()), vec![])],
+        vec![(TagName::Global("Overflow".into()), vec![])],
         Box::new(SolvedType::Wildcard),
     );
 
@@ -284,7 +284,7 @@ pub fn types() -> MutMap<Symbol, (SolvedType, Region)> {
         let_tvars! { u, v, w, num, result, star };
         unique_function(
             vec![num_type(u, num), num_type(v, num)],
-            result_type(result, num_type(w, num), lift(star, int_overflow)),
+            result_type(result, num_type(w, num), lift(star, overflow)),
         )
     });
 

compiler/can/src/builtins.rs

@@ -258,7 +258,7 @@ fn num_add_checked(symbol: Symbol, var_store: &mut VarStore) -> Def {
     //
     // if arg_3.b then
     //  # overflow
-    //  Err IntOverflow
+    //  Err Overflow
     // else
     //  # all is well
     //  Ok arg_3.a
@@ -281,7 +281,7 @@ fn num_add_checked(symbol: Symbol, var_store: &mut VarStore) -> Def {
             // overflow!
             no_region(tag(
                 "Err",
-                vec![tag("DivByZero", Vec::new(), var_store)],
+                vec![tag("Overflow", Vec::new(), var_store)],
                 var_store,
             )),
         )],

compiler/gen/src/llvm/build.rs

@@ -990,8 +990,8 @@ pub fn build_exp_expr<'a, 'ctx, 'env>(
                 }
             }
 
-            // TODO verify that this is required (better safe than sorry)
             if filler > 0 {
+                // TODO verify that this is required (better safe than sorry)
                 field_types.push(env.context.i8_type().array_type(filler).into());
             }
 
@@ -1381,15 +1381,6 @@ pub fn build_exp_stmt<'a, 'ctx, 'env>(
 
                     builder.build_conditional_branch(value, then_block, else_block);
 
-                    // build then block
-                    builder.position_at_end(then_block);
-                    let then_val = build_exp_stmt(env, layout_ids, scope, parent, pass_stmt);
-                    if then_block.get_terminator().is_none() {
-                        builder.build_unconditional_branch(cont_block);
-                        let then_block = builder.get_insert_block().unwrap();
-                        blocks.push((&then_val, then_block));
-                    }
-
                     // build else block
                     builder.position_at_end(else_block);
                     let else_val = build_exp_stmt(env, layout_ids, scope, parent, fail_stmt);
@@ -1399,6 +1390,15 @@ pub fn build_exp_stmt<'a, 'ctx, 'env>(
                         blocks.push((&else_val, else_block));
                     }
 
+                    // build then block
+                    builder.position_at_end(then_block);
+                    let then_val = build_exp_stmt(env, layout_ids, scope, parent, pass_stmt);
+                    if then_block.get_terminator().is_none() {
+                        builder.build_unconditional_branch(cont_block);
+                        let then_block = builder.get_insert_block().unwrap();
+                        blocks.push((&then_val, then_block));
+                    }
+
                     // emit merge block
                     if blocks.is_empty() {
                         // SAFETY there are no other references to this block in this case
@@ -2115,7 +2115,7 @@ fn run_low_level<'a, 'ctx, 'env>(
             list_join(env, inplace, parent, list, outer_list_layout)
         }
         NumAbs | NumNeg | NumRound | NumSqrtUnchecked | NumSin | NumCos | NumCeiling | NumFloor
-        | NumToFloat => {
+        | NumToFloat | NumIsFinite => {
             debug_assert_eq!(args.len(), 1);
 
             let (arg, arg_layout) = load_symbol_and_layout(env, scope, &args[0]);
@@ -2250,6 +2250,7 @@ fn run_low_level<'a, 'ctx, 'env>(
                         ),
                         Float128 | Float64 | Float32 | Float16 => build_float_binop(
                             env,
+                            parent,
                             lhs_arg.into_float_value(),
                             lhs_layout,
                             rhs_arg.into_float_value(),
@@ -2504,6 +2505,7 @@ fn call_bitcode_fn<'a, 'ctx, 'env>(
 
 fn build_float_binop<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,
+    parent: FunctionValue<'ctx>,
     lhs: FloatValue<'ctx>,
     _lhs_layout: &Layout<'a>,
     rhs: FloatValue<'ctx>,
@@ -2516,9 +2518,60 @@ fn build_float_binop<'a, 'ctx, 'env>(
     let bd = env.builder;
 
     match op {
-        NumAdd => bd.build_float_add(lhs, rhs, "add_float").into(),
+        NumAdd => {
+            let builder = env.builder;
+            let context = env.context;
+
+            let result = bd.build_float_add(lhs, rhs, "add_float");
+
+            let is_finite =
+                call_bitcode_fn(NumIsFinite, env, &[result.into()], "is_finite_").into_int_value();
+
+            let then_block = context.append_basic_block(parent, "then_block");
+            let throw_block = context.append_basic_block(parent, "throw_block");
+
+            builder.build_conditional_branch(is_finite, then_block, throw_block);
+
+            builder.position_at_end(throw_block);
+
+            throw_exception(env, "float addition overflowed!");
+
+            builder.position_at_end(then_block);
+
+            result.into()
+        }
+        NumAddChecked => {
+            let builder = env.builder;
+            let context = env.context;
+
+            let result = bd.build_float_add(lhs, rhs, "add_float");
+
+            let is_finite =
+                call_bitcode_fn(NumIsFinite, env, &[result.into()], "is_finite_").into_int_value();
+            let is_infinite = bd.build_not(is_finite, "negate");
+
+            let struct_type = context.struct_type(
+                &[context.f64_type().into(), context.bool_type().into()],
+                false,
+            );
+
+            let struct_value = {
+                let v1 = struct_type.const_zero();
+
+                let v2 = builder
+                    .build_insert_value(v1, result, 0, "set_result")
+                    .unwrap();
+
+                let v3 = builder
+                    .build_insert_value(v2, is_infinite, 1, "set_is_infinite")
+                    .unwrap();
+
+                v3.into_struct_value()
+            };
+
+            struct_value.into()
+        }
         NumAddWrap => unreachable!("wrapping addition is not defined on floats"),
-        NumAddChecked => bd.build_float_add(lhs, rhs, "add_float_checked").into(),
         NumSub => bd.build_float_sub(lhs, rhs, "sub_float").into(),
         NumMul => bd.build_float_mul(lhs, rhs, "mul_float").into(),
         NumGt => bd.build_float_compare(OGT, lhs, rhs, "float_gt").into(),
@@ -2622,6 +2675,7 @@ fn build_float_unary_op<'a, 'ctx, 'env>(
             env.context.i64_type(),
             "num_floor",
         ),
+        NumIsFinite => call_bitcode_fn(NumIsFinite, env, &[arg.into()], "is_finite_"),
         _ => {
             unreachable!("Unrecognized int unary operation: {:?}", op);
         }
@@ -2632,7 +2686,6 @@ fn define_global_str<'a, 'ctx, 'env>(
     env: &Env<'a, 'ctx, 'env>,
     message: &str,
 ) -> inkwell::values::GlobalValue<'ctx> {
-    let context = env.context;
     let module = env.module;
 
     // hash the name so we don't re-define existing messages
@@ -2644,29 +2697,12 @@ fn define_global_str<'a, 'ctx, 'env>(
         message.hash(&mut hasher);
         let hash = hasher.finish();
 
-        format!("message_{}", hash)
+        format!("_Error_message_{}", hash)
     };
 
     match module.get_global(&name) {
         Some(current) => current,
-        None => {
+        None => unsafe { env.builder.build_global_string(message, name.as_str()) },
-            let i8_type = context.i8_type();
-
-            // define the error message as a global constant
-            let message_global =
-                module.add_global(i8_type.array_type(message.len() as u32), None, &name);
-
-            let mut message_bytes = Vec::with_capacity_in(message.len(), env.arena);
-
-            for c in message.chars() {
-                message_bytes.push(i8_type.const_int(c as u64, false));
-            }
-
-            let const_array = i8_type.const_array(&message_bytes);
-            message_global.set_initializer(&const_array);
-
-            message_global
-        }
     }
 }
 

compiler/gen/tests/gen_num.rs

@@ -701,34 +701,34 @@ mod gen_num {
     }
 
     #[test]
-    fn add_checked() {
+    fn int_add_checked() {
         assert_evals_to!(
             indoc!(
                 r#"
                 when Num.addChecked 1 2 is
-                    Ok 3 -> True
+                    Ok v -> v
-                    _ -> False
+                    _ -> -1
                 "#
             ),
-            true,
+            3,
-            bool
+            i64
         );
 
         assert_evals_to!(
             indoc!(
                 r#"
                 when Num.addChecked 9_223_372_036_854_775_807 1 is
-                    Err IntOverflow -> True
+                    Err Overflow -> -1
-                    _ -> False
+                    Ok v -> v
                 "#
             ),
-            true,
+            -1,
-            bool
+            i64
         );
     }
 
     #[test]
-    fn add_wrap() {
+    fn int_add_wrap() {
         assert_evals_to!(
             indoc!(
                 r#"
@@ -741,11 +741,42 @@ mod gen_num {
     }
 
     #[test]
+    fn float_add_checked_pass() {
+        assert_evals_to!(
+            indoc!(
+                r#"
+                when Num.addChecked 1.0 0.0 is 
+                    Ok v -> v
+                    Err Overflow -> -1.0
+                "#
+            ),
+            1.0,
+            f64
+        );
+    }
+
+    #[test]
+    fn float_add_checked_fail() {
+        assert_evals_to!(
+            indoc!(
+                r#"
+                when Num.addChecked 1.7976931348623157e308 1.7976931348623157e308 is
+                    Err Overflow -> -1
+                    Ok v -> v
+                "#
+            ),
+            -1.0,
+            f64
+        );
+    }
+
+    #[test]
+    #[should_panic(expected = r#"Roc failed with message: "float addition overflowed!"#)]
     fn float_overflow() {
         assert_evals_to!(
             indoc!(
                 r#"
-                1.7976931348623157E+308 + 1
+                1.7976931348623157e308 + 1.7976931348623157e308
                 "#
             ),
             0.0,

compiler/module/src/low_level.rs

@@ -42,6 +42,7 @@ pub enum LowLevel {
     NumCeiling,
     NumPowInt,
     NumFloor,
+    NumIsFinite,
     Eq,
     NotEq,
     And,

compiler/mono/src/borrow.rs

@@ -526,6 +526,6 @@ pub fn lowlevel_borrow_signature(arena: &Bump, op: LowLevel) -> &[bool] {
         | NumPowInt => arena.alloc_slice_copy(&[irrelevant, irrelevant]),
 
         NumAbs | NumNeg | NumSin | NumCos | NumSqrtUnchecked | NumRound | NumCeiling | NumFloor
-        | NumToFloat | Not => arena.alloc_slice_copy(&[irrelevant]),
+        | NumToFloat | Not | NumIsFinite => arena.alloc_slice_copy(&[irrelevant]),
     }
 }