Merge branch 'trunk' into zig9-to-zig

cli/src/build.rs

@@ -240,7 +240,7 @@ pub fn build_file<'a>(
             app_o_file.to_str().unwrap(),
         ];
         if matches!(opt_level, OptLevel::Development) {
-            inputs.push(bitcode::OBJ_PATH);
+            inputs.push(bitcode::BUILTINS_HOST_OBJ_PATH);
         }
 
         let (mut child, _) =  // TODO use lld

compiler/build/src/link.rs

@@ -97,7 +97,7 @@ pub fn build_zig_host_native(
             "build-exe",
             "-fPIE",
             shared_lib_path.to_str().unwrap(),
-            bitcode::OBJ_PATH,
+            bitcode::BUILTINS_HOST_OBJ_PATH,
         ]);
     } else {
         command.args(&["build-obj", "-fPIC"]);
@@ -186,7 +186,7 @@ pub fn build_zig_host_native(
             "build-exe",
             "-fPIE",
             shared_lib_path.to_str().unwrap(),
-            bitcode::OBJ_PATH,
+            bitcode::BUILTINS_HOST_OBJ_PATH,
         ]);
     } else {
         command.args(&["build-obj", "-fPIC"]);
@@ -282,7 +282,7 @@ pub fn build_c_host_native(
     if let Some(shared_lib_path) = shared_lib_path {
         command.args(&[
             shared_lib_path.to_str().unwrap(),
-            bitcode::OBJ_PATH,
+            bitcode::BUILTINS_HOST_OBJ_PATH,
             "-fPIE",
             "-pie",
             "-lm",

compiler/builtins/bitcode/build.zig

@@ -59,8 +59,9 @@ fn generateLlvmIrFile(
 
 // Generate Object File
 // TODO: figure out how to get this to emit symbols that are only scoped to linkage (global but hidden).
-// Also, zig has -ffunction-sections, but I am not sure how to add it here.
-// With both of those changes, unused zig functions will be cleaned up by the linker saving around 100k.
+// @bhansconnect: I believe anything with global scope will still be preserved by the linker even if it
+// is never called. I think it could theoretically be called by a dynamic lib that links to the executable
+// or something similar.
 fn generateObjectFile(
     b: *Builder,
     mode: std.builtin.Mode,
@@ -75,6 +76,7 @@ fn generateObjectFile(
     obj.setOutputDir(".");
     obj.strip = true;
     obj.target = target;
+    obj.link_function_sections = true;
     const obj_step = b.step(step_name, "Build object file for linking");
     obj_step.dependOn(&obj.step);
 }

compiler/builtins/src/bitcode.rs

@@ -1,10 +1,15 @@
 use std::ops::Index;
 
-pub const OBJ_PATH: &str = env!(
+pub const BUILTINS_HOST_OBJ_PATH: &str = env!(
     "BUILTINS_HOST_O",
     "Env var BUILTINS_HOST_O not found. Is there a problem with the build script?"
 );
 
+pub const BUILTINS_WASM32_OBJ_PATH: &str = env!(
+    "BUILTINS_WASM32_O",
+    "Env var BUILTINS_WASM32_O not found. Is there a problem with the build script?"
+);
+
 #[derive(Debug, Default)]
 pub struct IntrinsicName {
     pub options: [&'static str; 14],

compiler/gen_wasm/src/backend.rs

@@ -11,7 +11,8 @@ use roc_mono::layout::{Layout, LayoutIds};
 use crate::layout::WasmLayout;
 use crate::storage::{Storage, StoredValue, StoredValueKind};
 use crate::wasm_module::linking::{
-    DataSymbol, LinkingSection, RelocationSection, WasmObjectSymbol, WASM_SYM_UNDEFINED,
+    DataSymbol, LinkingSection, RelocationSection, WasmObjectSymbol, WASM_SYM_BINDING_WEAK,
+    WASM_SYM_UNDEFINED,
 };
 use crate::wasm_module::sections::{
     CodeSection, DataMode, DataSection, DataSegment, ExportSection, FunctionSection, GlobalSection,
@@ -21,7 +22,10 @@ use crate::wasm_module::{
     code_builder, BlockType, CodeBuilder, ConstExpr, Export, ExportType, Global, GlobalType,
     LocalId, Signature, SymInfo, ValueType,
 };
-use crate::{copy_memory, CopyMemoryConfig, Env, PTR_TYPE};
+use crate::{
+    copy_memory, CopyMemoryConfig, Env, BUILTINS_IMPORT_MODULE_NAME, MEMORY_NAME, PTR_TYPE,
+    STACK_POINTER_NAME,
+};
 
 /// The memory address where the constants data will be loaded during module instantiation.
 /// We avoid address zero and anywhere near it. They're valid addresses but maybe bug-prone.
@@ -31,8 +35,6 @@ const CONST_SEGMENT_BASE_ADDR: u32 = 1024;
 /// Index of the data segment where we store constants
 const CONST_SEGMENT_INDEX: usize = 0;
 
-const IMPORT_MODULE_BUILTINS: &str = "builtins";
-
 pub struct WasmBackend<'a> {
     env: &'a Env<'a>,
 
@@ -66,7 +68,7 @@ impl<'a> WasmBackend<'a> {
         let num_procs = proc_symbols.len();
 
         exports.push(Export {
-            name: "__linear_memory".to_string(),
+            name: MEMORY_NAME.to_string(),
             ty: ExportType::Mem,
             index: 0,
         });
@@ -78,10 +80,17 @@ impl<'a> WasmBackend<'a> {
             },
             init: ConstExpr::I32(MEMORY_INIT_SIZE as i32),
         };
-        linker_symbols.push(SymInfo::Global(WasmObjectSymbol::Defined {
-            flags: 0,
+
+        exports.push(Export {
+            name: STACK_POINTER_NAME.to_string(),
+            ty: ExportType::Global,
             index: 0,
-            name: "__stack_pointer".to_string(),
+        });
+
+        linker_symbols.push(SymInfo::Global(WasmObjectSymbol::Defined {
+            flags: WASM_SYM_BINDING_WEAK,
+            index: 0,
+            name: STACK_POINTER_NAME.to_string(),
         }));
 
         let const_segment = DataSegment {
@@ -759,7 +768,7 @@ impl<'a> WasmBackend<'a> {
 
                 let import_index = self.module.import.entries.len() as u32;
                 let import = Import {
-                    module: IMPORT_MODULE_BUILTINS,
+                    module: BUILTINS_IMPORT_MODULE_NAME,
                     name: name.to_string(),
                     description: ImportDesc::Func { signature_index },
                 };

compiler/gen_wasm/src/lib.rs

@@ -21,6 +21,9 @@ const PTR_TYPE: ValueType = ValueType::I32;
 
 pub const STACK_POINTER_GLOBAL_ID: u32 = 0;
 pub const FRAME_ALIGNMENT_BYTES: i32 = 16;
+pub const MEMORY_NAME: &str = "memory";
+pub const BUILTINS_IMPORT_MODULE_NAME: &str = "builtins";
+pub const STACK_POINTER_NAME: &str = "__stack_pointer";
 
 pub struct Env<'a> {
     pub arena: &'a Bump,

compiler/test_gen/src/gen_num.rs

@@ -1330,7 +1330,7 @@ fn pow_int() {
 }
 
 #[test]
-#[cfg(any(feature = "gen-llvm", feature = "gen-dev"))]
+#[cfg(any(feature = "gen-llvm", feature = "gen-dev", feature = "gen-wasm"))]
 fn atan() {
     assert_evals_to!("Num.atan 10", 1.4711276743037347, f64);
 }

compiler/test_gen/src/helpers/dev.rs

@@ -193,7 +193,10 @@ pub fn helper(
         app_o_file.clone(),
         // Long term we probably want a smarter way to link in zig builtins.
         // With the current method all methods are kept and it adds about 100k to all outputs.
-        &[app_o_file.to_str().unwrap(), bitcode::OBJ_PATH],
+        &[
+            app_o_file.to_str().unwrap(),
+            bitcode::BUILTINS_HOST_OBJ_PATH,
+        ],
         LinkType::Dylib,
     )
     .expect("failed to link dynamic library");

compiler/test_gen/src/helpers/wasm.rs

@@ -4,8 +4,12 @@ use std::hash::{Hash, Hasher};
 
 use crate::helpers::from_wasm32_memory::FromWasm32Memory;
 use crate::helpers::wasm32_test_result::Wasm32TestResult;
+use roc_builtins::bitcode;
 use roc_can::builtins::builtin_defs_map;
 use roc_collections::all::{MutMap, MutSet};
+use roc_gen_wasm::MEMORY_NAME;
+
+use tempfile::tempdir;
 
 const TEST_WRAPPER_NAME: &str = "test_wrapper";
 
@@ -143,8 +147,43 @@ pub fn helper_wasm<'a, T: Wasm32TestResult>(
     use wasmer::{Instance, Module, Store};
 
     let store = Store::default();
-    // let module = Module::from_file(&store, &test_wasm_path).unwrap();
-    let wasmer_module = Module::from_binary(&store, &module_bytes).unwrap();
+
+    let wasmer_module = {
+        let dir = tempdir().unwrap();
+        let dirpath = dir.path();
+        let final_wasm_file = dirpath.join("final.wasm");
+        let app_o_file = dirpath.join("app.o");
+
+        // write the module to a file so the linker can access it
+        std::fs::write(&app_o_file, &module_bytes).unwrap();
+
+        std::process::Command::new("zig")
+            .args(&[
+                "wasm-ld",
+                // input files
+                app_o_file.to_str().unwrap(),
+                bitcode::BUILTINS_WASM32_OBJ_PATH,
+                // output
+                "-o",
+                final_wasm_file.to_str().unwrap(),
+                // we don't define `_start`
+                "--no-entry",
+                // If you only specify test_wrapper, it will stop at the call to UserApp_main_1
+                // But if you specify both exports, you get all the dependencies.
+                //
+                // It seems that it will not write out an export you didn't explicitly specify,
+                // even if it's a dependency of another export!
+                // In our case we always export main and test_wrapper so that's OK.
+                "--export",
+                "test_wrapper",
+                "--export",
+                "#UserApp_main_1",
+            ])
+            .output()
+            .unwrap();
+
+        Module::from_file(&store, &final_wasm_file).unwrap()
+    };
 
     // First, we create the `WasiEnv`
     use wasmer_wasi::WasiState;
@@ -171,7 +210,7 @@ where
 
     let instance = crate::helpers::wasm::helper_wasm(&arena, src, stdlib, &expected);
 
-    let memory = instance.exports.get_memory("__linear_memory").unwrap();
+    let memory = instance.exports.get_memory(MEMORY_NAME).unwrap();
 
     let test_wrapper = instance.exports.get_function(TEST_WRAPPER_NAME).unwrap();