Merge remote-tracking branch 'origin/trunk' into precedence-error

BUILDING_FROM_SOURCE.md

@@ -32,7 +32,9 @@ Create `~/.config/cargo` and add this to it:
 
 ```
 [build]
-rustflags = ["-C", "link-arg=-fuse-ld=lld"]
+# Link with lld, per https://github.com/rust-lang/rust/issues/39915#issuecomment-538049306
+# Use target-cpu=native, per https://deterministic.space/high-performance-rust.html
+rustflags = ["-C", "link-arg=-fuse-ld=lld", "-C", "target-cpu=native"]
 ```
 
 Then install `lld` version 9 (e.g. with `$ sudo apt-get install lld-9`)

Cargo.lock

@@ -568,6 +568,10 @@ dependencies = [
  "roc_types",
 ]
 
+[[package]]
+name = "roc_builtins_bitcode"
+version = "0.1.0"
+
 [[package]]
 name = "roc_can"
 version = "0.1.0"

Cargo.toml

@@ -10,6 +10,7 @@ members = [
     "compiler/types",
     "compiler/uniq",
     "compiler/builtins",
+    "compiler/builtins/bitcode",
     "compiler/constrain",
     "compiler/unify",
     "compiler/solve",
@@ -23,3 +24,7 @@ members = [
     "cli"
 ]
 
+# Optimizations based on https://deterministic.space/high-performance-rust.html
+[profile.release]
+lto = "fat"
+codegen-units = 1

ci/enable-lld.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
 mkdir -p $HOME/.cargo
-echo -e "[build]\nrustflags = [\"-C\", \"link-arg=-fuse-ld=lld\"]" > $HOME/.cargo/config
+echo -e "[build]\nrustflags = [\"-C\", \"link-arg=-fuse-ld=lld\", \"-C\", \"target-cpu=native\"]" > $HOME/.cargo/config
 
 ln -s /usr/bin/lld-8 /usr/local/bin/ld.lld

cli/src/main.rs

@@ -8,7 +8,9 @@ use inkwell::passes::PassManager;
 use inkwell::types::BasicType;
 use inkwell::OptimizationLevel;
 use roc_collections::all::ImMap;
-use roc_gen::llvm::build::{build_proc, build_proc_header, get_call_conventions};
+use roc_gen::llvm::build::{
+    build_proc, build_proc_header, get_call_conventions, module_from_builtins,
+};
 use roc_gen::llvm::convert::basic_type_from_layout;
 use roc_mono::expr::{Expr, Procs};
 use roc_mono::layout::Layout;
@@ -65,7 +67,7 @@ fn gen(src: &str, target: Triple, dest_filename: &Path) {
     let (content, mut subs) = infer_expr(subs, &mut unify_problems, &constraint, var);
 
     let context = Context::create();
-    let module = context.create_module("app");
+    let module = module_from_builtins(&context, "app");
     let builder = context.create_builder();
     let fpm = PassManager::create(&module);
 
@@ -74,17 +76,14 @@ fn gen(src: &str, target: Triple, dest_filename: &Path) {
     fpm.initialize();
 
     // Compute main_fn_type before moving subs to Env
-    let pointer_bytes = target.pointer_width().unwrap().bytes() as u32;
-    let layout = Layout::from_content(&arena, content, &subs, pointer_bytes)
-    .unwrap_or_else(|err| panic!("Code gen error in test: could not convert to layout. Err was {:?} and Subs were {:?}", err, subs));
+    let ptr_bytes = target.pointer_width().unwrap().bytes() as u32;
+    let layout = Layout::from_content(&arena, content, &subs, ptr_bytes).unwrap_or_else(|err| {
+        panic!(
+            "Code gen error in test: could not convert to layout. Err was {:?} and Subs were {:?}",
+            err, subs
+        )
+    });
 
-    let execution_engine = module
-        .create_jit_execution_engine(OptimizationLevel::None)
-        .expect("Error creating JIT execution engine for test");
-
-    let ptr_bytes = execution_engine
-        .get_target_data()
-        .get_pointer_byte_size(None);
     let main_fn_type =
         basic_type_from_layout(&arena, &context, &layout, ptr_bytes).fn_type(&[], false);
     let main_fn_name = "$Test.main";
@@ -109,7 +108,7 @@ fn gen(src: &str, target: Triple, dest_filename: &Path) {
         &mut procs,
         home,
         &mut ident_ids,
-        pointer_bytes,
+        ptr_bytes,
     );
 
     // Put this module's ident_ids back in the interns, so we can use them in env.

compiler/builtins/bitcode/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "roc_builtins_bitcode"
+version = "0.1.0"
+authors = ["Richard Feldman <richard.t.feldman@gmail.com>"]
+repository = "https://github.com/rtfeldman/roc"
+readme = "README.md"
+edition = "2018"
+description = "Generate LLVM bitcode for Roc builtins"
+license = "Apache-2.0"
+
+
+[build]
+target-dir="~/code/roc/copmiler/builtins/bitcode/"

compiler/builtins/bitcode/README.md

@@ -0,0 +1,56 @@
+# Bitcode for Builtins
+
+Roc's builtins are implemented in the compiler using LLVM only.
+When their implementations are simple enough (e.g. addition), they
+can be implemented directly in Inkwell.
+
+When their implementations are complex enough, it's nicer to
+implement them in a higher-level language like Rust, compile the
+result to LLVM bitcode, and import that bitcode into the compiler.
+
+Here is the process for doing that.
+
+## Building the bitcode
+
+The source we'll use to generate the bitcode is in `src/lib.rs` in this directory.
+
+To generate the bitcode, `cd` into `compiler/builtins/bitcode/` and run:
+
+```bash
+$ cargo rustc --release --lib -- --emit=llvm-bc
+```
+
+Then look in the root `roc` source directory under `target/release/deps/` for a file
+with a name like `roc_builtins_bitcode-8da0901c58a73ebf.bc` - except
+probably with a different hash before the `.bc`. If there's more than one
+`*.bc` file in that directory, delete the whole `deps/` directory and re-run
+the `cargo rustc` command above to regenerate it.
+
+> If you want to take a look at the human-readable LLVM IR rather than the
+> bitcode, run this instead and look for a `.ll` file instead of a `.bc` file:
+>
+> ```bash
+> $ cargo rustc --release --lib -- --emit=llvm-ir
+> ```
+
+## Importing the bitcode
+
+The bitcode is a bunch of bytes that aren't particularly human-readable.
+Since Roc is designed to be distributed as a single binary, these bytes
+need to be included in the raw source somewhere.
+
+The `llvm/src/build.rs` file statically imports these raw bytes
+using the [`include_bytes!` macro](https://doc.rust-lang.org/std/macro.include_bytes.html),
+so we just need to move the `.bc` file from the previous step to the correct
+location.
+
+The current `.bc` file is located at:
+
+```
+compiler/gen/src/llvm/builtins.bc
+```
+
+...so you want to overwrite it with the new `.bc` file in `target/deps/`
+
+Once that's done, `git status` should show that the `builtins.bc` file
+has been changed. Commit that change and you're done!

compiler/builtins/bitcode/src/lib.rs

@@ -0,0 +1,10 @@
+#![crate_type = "lib"]
+#![no_std]
+
+// TODO replace this with a normal Inkwell build_cast call - this was just
+// used as a proof of concept for getting bitcode importing working!
+
+#[no_mangle]
+pub fn i64_to_f64_(num: i64) -> f64 {
+    num as f64
+}

compiler/gen/src/llvm/build.rs

@@ -2,6 +2,7 @@ use bumpalo::collections::Vec;
 use bumpalo::Bump;
 use inkwell::builder::Builder;
 use inkwell::context::Context;
+use inkwell::memory_buffer::MemoryBuffer;
 use inkwell::module::{Linkage, Module};
 use inkwell::passes::PassManager;
 use inkwell::types::{BasicTypeEnum, IntType, StructType};
@@ -47,6 +48,14 @@ impl<'a, 'ctx, 'env> Env<'a, 'ctx, 'env> {
     }
 }
 
+pub fn module_from_builtins<'ctx>(ctx: &'ctx Context, module_name: &str) -> Module<'ctx> {
+    let memory_buffer =
+        MemoryBuffer::create_from_memory_range(include_bytes!("builtins.bc"), module_name);
+
+    Module::parse_bitcode_from_buffer(&memory_buffer, ctx)
+        .unwrap_or_else(|err| panic!("Unable to import builtins bitcode. LLVM error: {:?}", err))
+}
+
 pub fn add_passes(fpm: &PassManager<FunctionValue<'_>>) {
     // tail-call elimination is always on
     fpm.add_instruction_combining_pass();
@@ -1069,6 +1078,31 @@ fn call_with_args<'a, 'ctx, 'env>(
 
             BasicValueEnum::IntValue(int_val)
         }
+        Symbol::NUM_TO_FLOAT => {
+            // TODO specialize this to be not just for i64!
+            let builtin_fn_name = "i64_to_f64_";
+
+            let fn_val = env
+                .module
+                .get_function(builtin_fn_name)
+                .unwrap_or_else(|| panic!("Unrecognized builtin function: {:?} - if you're working on the Roc compiler, do you need to rebuild the bitcode? See compiler/builtins/bitcode/README.md", builtin_fn_name));
+
+            let mut arg_vals: Vec<BasicValueEnum> = Vec::with_capacity_in(args.len(), env.arena);
+
+            for (arg, _layout) in args.iter() {
+                arg_vals.push(*arg);
+            }
+
+            let call = env
+                .builder
+                .build_call(fn_val, arg_vals.into_bump_slice(), "call_builtin");
+
+            call.set_call_convention(DEFAULT_CALLING_CONVENTION);
+
+            call.try_as_basic_value()
+                .left()
+                .unwrap_or_else(|| panic!("LLVM error: Invalid call for builtin {:?}", symbol))
+        }
         Symbol::FLOAT_EQ => {
             debug_assert!(args.len() == 2);
 

compiler/gen/tests/gen_builtins.rs

@@ -344,4 +344,17 @@ mod gen_builtins {
             i64
         );
     }
+
+    #[test]
+    fn int_to_float() {
+        assert_evals_to!(
+            indoc!(
+                r#"
+                    Num.toFloat 0x9
+                "#
+            ),
+            9.0,
+            f64
+        );
+    }
 }

compiler/gen/tests/helpers/eval.rs

@@ -10,7 +10,7 @@ macro_rules! assert_llvm_evals_to {
         let (content, mut subs) = infer_expr(subs, &mut unify_problems, &constraint, var);
 
         let context = Context::create();
-        let module = context.create_module("app");
+        let module = roc_gen::llvm::build::module_from_builtins(&context, "app");
         let builder = context.create_builder();
         let fpm = inkwell::passes::PassManager::create(&module);
 
@@ -142,7 +142,7 @@ macro_rules! assert_opt_evals_to {
         let (content, mut subs) = infer_expr(subs, &mut unify_problems, &constraint, var);
 
         let context = Context::create();
-        let module = context.create_module("app");
+        let module = roc_gen::llvm::build::module_from_builtins(&context, "app");
         let builder = context.create_builder();
         let fpm = PassManager::create(&module);
 

compiler/parse/src/operator.rs

@@ -133,6 +133,6 @@ impl std::fmt::Display for BinOp {
             Pizza => "|>",
         };
 
-        write!(f, "({})", as_str)
+        write!(f, "{}", as_str)
     }
 }

compiler/reporting/Cargo.toml

@@ -8,6 +8,7 @@ edition = "2018"
 roc_collections = { path = "../collections" }
 roc_region = { path = "../region" }
 roc_module = { path = "../module" }
+roc_parse = { path = "../parse" }
 roc_problem = { path = "../problem" }
 roc_types = { path = "../types" }
 roc_load = { path = "../load" }
@@ -15,7 +16,6 @@ roc_can = { path = "../can" }
 roc_solve = { path = "../solve" }
 inlinable_string = "0.1.0"
 
-
 [dev-dependencies]
 roc_constrain = { path = "../constrain" }
 roc_builtins = { path = "../builtins" }

compiler/reporting/src/report.rs

@@ -1,4 +1,4 @@
-use crate::report::ReportText::{Batch, Module, Region, Value};
+use crate::report::ReportText::{Batch, BinOp, Module, Region, Value};
 use roc_can::expected::{Expected, PExpected};
 use roc_module::symbol::{Interns, ModuleId, Symbol};
 use roc_problem::can::PrecedenceProblem::BothNonAssociative;
@@ -27,6 +27,7 @@ pub struct Palette {
     pub line_number: Color,
     pub gutter_bar: Color,
     pub module_name: Color,
+    pub binop: Color,
 }
 
 #[derive(Copy, Clone)]
@@ -52,6 +53,7 @@ pub const TEST_PALETTE: Palette = Palette {
     line_number: Color::Cyan,
     gutter_bar: Color::Magenta,
     module_name: Color::Green,
+    binop: Color::Green,
 };
 
 impl Color {
@@ -314,10 +316,21 @@ pub fn can_problem(filename: PathBuf, problem: Problem) -> Report {
             texts.push(plain_text("\". Adding an underscore at the start of a variable name is a way of saying that the variable is not used."));
         }
         Problem::PrecedenceProblem(BothNonAssociative(region, left_bin_op, right_bin_op)) => {
-            texts.push(plain_text(&*format!(
-                "You cannot mix {} and {} without parentheses",
-                left_bin_op.value, right_bin_op.value
-            )));
+            if left_bin_op.value == right_bin_op.value {
+                texts.push(plain_text("Using more than one "));
+                texts.push(BinOp(left_bin_op.value));
+                texts.push(plain_text(
+                    " like this requires parentheses, to clarify how things should be grouped.",
+                ))
+            } else {
+                texts.push(plain_text("Using "));
+                texts.push(BinOp(left_bin_op.value));
+                texts.push(plain_text(" and "));
+                texts.push(BinOp(right_bin_op.value));
+                texts.push(plain_text(
+                    " together requires parentheses, to clarify how they should be grouped.",
+                ))
+            }
             texts.push(Region(region));
         }
         Problem::UnsupportedPattern(_pattern_type, _region) => {
@@ -371,6 +384,8 @@ pub enum ReportText {
     /// The documentation for this symbol.
     Docs(Symbol),
 
+    BinOp(roc_parse::operator::BinOp),
+
     /// Many ReportText that should be concatenated together.
     Batch(Vec<ReportText>),
 }
@@ -575,6 +590,9 @@ impl ReportText {
                     report_text.render_ci(buf, subs, home, src_lines, interns);
                 }
             }
+            BinOp(bin_op) => {
+                buf.push_str(bin_op.to_string().as_str());
+            }
         }
     }
 
@@ -716,6 +734,9 @@ impl ReportText {
                     report_text.render_color_terminal(buf, subs, home, src_lines, interns, palette);
                 }
             }
+            BinOp(bin_op) => {
+                buf.push_str(&palette.binop.render(bin_op.to_string().as_str()));
+            }
             _ => panic!("TODO implement more ReportTexts in render color terminal"),
         }
     }

compiler/reporting/tests/test_reporting.rs

@@ -304,23 +304,22 @@ mod test_reporting {
         )
     }
 
-    // hits a TODO in reporting
-    //    #[test]
-    //    fn report_shadow() {
-    //        report_problem_as(
-    //            indoc!(
-    //                r#"
-    //                i = 1
+    // #[test]
+    // fn report_shadow() {
+    //     report_problem_as(
+    //         indoc!(
+    //             r#"
+    //            i = 1
     //
-    //                s = \i ->
-    //                    i + 1
+    //            s = \i ->
+    //                i + 1
     //
-    //                s i
-    //            "#
-    //            ),
-    //            indoc!(r#"     "#),
-    //        )
-    //    }
+    //            s i
+    //        "#
+    //         ),
+    //         indoc!(r#"     "#),
+    //     )
+    // }
 
     // #[test]
     // fn report_unsupported_top_level_def() {
@@ -355,7 +354,7 @@ mod test_reporting {
             ),
             indoc!(
                 r#"
-                You cannot mix (!=) and (==) without parentheses
+                Using != and == together requires parentheses, to clarify how they should be grouped.
 
                 3 ┆      if selectedId != thisId == adminsId then
                   ┆         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -372,7 +371,7 @@ mod test_reporting {
                 r#"
                 if
                     1
-                        != 2
+                        == 2
                         == 3
                 then
                     2
@@ -383,10 +382,10 @@ mod test_reporting {
             ),
             indoc!(
                 r#"
-                You cannot mix (!=) and (==) without parentheses
+                Using more than one == like this requires parentheses, to clarify how things should be grouped.
 
                 2 ┆>      1
-                3 ┆>          != 2
+                3 ┆>          == 2
                 4 ┆>          == 3
 
                 "#

compiler/solve/tests/test_solve.rs

@@ -9,7 +9,9 @@ mod helpers;
 
 #[cfg(test)]
 mod test_solve {
-    use crate::helpers::{assert_correct_variable_usage, can_expr, infer_expr, CanExprOut};
+    use crate::helpers::{
+        assert_correct_variable_usage, can_expr, infer_expr, with_larger_debug_stack, CanExprOut,
+    };
     use roc_types::pretty_print::{content_to_string, name_all_type_vars};
     use roc_types::subs::Subs;
 
@@ -2220,9 +2222,10 @@ mod test_solve {
 
     #[test]
     fn quicksort_partition() {
-        infer_eq_without_problem(
-            indoc!(
-                r#"
+        with_larger_debug_stack(|| {
+            infer_eq_without_problem(
+                indoc!(
+                    r#"
                 swap : Int, Int, List a -> List a
                 swap = \i, j, list ->
                     when Pair (List.get list i) (List.get list j) is
@@ -2261,9 +2264,10 @@ mod test_solve {
 
                 partition
             "#
-            ),
-            "Int, Int, List Int -> [ Pair Int (List Int) ]",
-        );
+                ),
+                "Int, Int, List Int -> [ Pair Int (List Int) ]",
+            );
+        });
     }
 
     #[test]

compiler/types/src/types.rs

@@ -792,7 +792,7 @@ fn write_error_type_help(
             }
         }
         Function(arguments, result) => {
-            let use_parens = parens != Parens::Unnecessary;
+            let write_parens = parens != Parens::Unnecessary;
 
             if write_parens {
                 buf.push(')');
@@ -815,10 +815,10 @@ fn write_error_type_help(
                 buf.push(')');
             }
         }
-        Record(fields, ext) { 
-                buf.push('{');
-                buf.push('}');
-                write_ext(ext, buf);
+        Record(fields, ext) => {
+            buf.push('{');
+            buf.push('}');
+            write_type_ext(ext, buf);
         }
 
         Infinite => {
@@ -836,6 +836,16 @@ pub enum TypeExt {
     RigidOpen(Lowercase),
 }
 
+fn write_type_ext(ext: TypeExt, buf: &mut String) {
+    use TypeExt::*;
+    match ext {
+        Closed => {}
+        FlexOpen(lowercase) | RigidOpen(lowercase) => {
+            buf.push_str(lowercase.as_str());
+        }
+    }
+}
+
 static THE_LETTER_A: u32 = 'a' as u32;
 
 pub fn name_type_var(letters_used: u32, taken: &mut MutSet<Lowercase>) -> (Lowercase, u32) {

examples/hello-world/README.md

@@ -15,7 +15,7 @@ in our imaginations...so Rube Goldberg it is!)
 1. `cd` into `examples/hello-world/`
 2. Run `cargo run hello.roc` to compile the Roc source code into a `hello.o` file.
 3. Run `gcc -shared hello.o -o libhello_from_roc.so` to generate `libhello_from_roc.so`. (This filename must begin with `lib` and end in `.so` or else `host.rs` won't be able to find it!)
-4. Move `libhello_from_roc.so` onto the system library path, e.g. with `sudo mv libhello_from_roc.so /usr/local/lib/`
+4. Move `libhello_from_roc.so` onto the system library path, e.g. with `sudo mv libhello_from_roc.so /usr/local/lib/` on macOS, or `sudo mv libhello_from_roc.so /usr/local/lib /usr/lib` on Linux.
 5. Run `rustc host.rs -o hello` to generate the `hello` executable.
 6. Run `./hello` to see the greeting!