Add preliminary support for imports

Cargo.lock

@@ -329,6 +329,15 @@ name = "glob"
 version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "hashbrown"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "indicatif"
 version = "0.10.3"
@@ -894,6 +903,7 @@ dependencies = [
  "errno 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "field-offset 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hashbrown 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "indicatif 0.10.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.44 (git+https://github.com/rust-lang/libc)",
  "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -978,6 +988,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum gcc 0.3.55 (registry+https://github.com/rust-lang/crates.io-index)" = "8f5f3913fa0bfe7ee1fd8248b6b9f42a5af4b9d65ec2dd2c3c26132b950ecfc2"
 "checksum glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "8be18de09a56b60ed0edf84bc9df007e30040691af7acd1c41874faac5895bfb"
+"checksum hashbrown 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "64b7d419d0622ae02fe5da6b9a5e1964b610a65bb37923b976aeebb6dbb8f86e"
 "checksum indicatif 0.10.3 (registry+https://github.com/rust-lang/crates.io-index)" = "40ecd1e2ee08e6c255ce890f5a99d17000850e664e7acf119fb03b25b0575bfe"
 "checksum itoa 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "1306f3464951f30e30d12373d31c79fbd52d236e5e896fd92f96ec7babbbe60b"
 "checksum lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1"

Cargo.toml

@@ -50,6 +50,7 @@ byteorder = "1"
 indicatif = "0.10"
 console = "0.7.1"
 field-offset = "0.1.1"
+hashbrown = "0.1"
 
 [build-dependencies]
 wabt = "0.7.2"

src/runtime/backend.rs

@@ -5,11 +5,12 @@ use crate::runtime::{
     module::Module,
     types::FuncIndex,
 };
+use std::sync::Arc;
 
 pub trait Compiler {
-    fn compile(wasm: &[u8]) -> Box<Module>;
+    fn compile(&self, wasm: &[u8]) -> Result<Arc<Module>, String>;
 }
 
 pub trait FuncResolver {
-    pub fn resolve(&self, index: FuncIndex) -> *const vm::Func;
+    pub fn resolve(&self, index: FuncIndex) -> Option<*const vm::Func>;
 }

src/runtime/backing.rs

@@ -1,16 +1,12 @@
-use super::vm;
-use crate::module::Module;
-use super::table::{TableBacking, TableScheme};
-use super::memory::LinearMemory;
-use super::instance::{InstanceOptions, InstanceABI};
-use std::mem;
-
 use crate::runtime::{
     vm,
     module::Module,
     table::TableBacking,
     types::{Val, GlobalInit},
+    memory::LinearMemory,
+    instance::{Imports, Import},
 };
+use std::{ptr, mem};
 
 
 #[derive(Debug)]
@@ -24,9 +20,9 @@ pub struct LocalBacking {
 }
 
 impl LocalBacking {
-    pub fn new(module: &Module, imports: &ImportBacking, options: &InstanceOptions) -> Self {
-        let mut memories = Self::generate_memories(module, options);
-        let mut tables = Self::generate_tables(module, options);
+    pub fn new(module: &Module, imports: &ImportBacking) -> Self {
+        let mut memories = Self::generate_memories(module);
+        let mut tables = Self::generate_tables(module);
         let globals = Self::generate_globals(module);
 
         Self {
@@ -39,7 +35,7 @@ impl LocalBacking {
         }
     }
 
-    fn generate_memories(module: &Module, options: &InstanceOptions) -> Box<[LinearMemory]> {
+    fn generate_memories(module: &Module) -> Box<[LinearMemory]> {
         let mut memories = Vec::with_capacity(module.memories.len());
 
         for (_, mem) in &module.memories {
@@ -63,7 +59,7 @@ impl LocalBacking {
         memories.into_boxed_slice()
     }
 
-    fn finalize_memories(module: &Module, memories: &mut [LinearMemory], options: &InstanceOptions) -> Box<[vm::LocalMemory]> {
+    fn finalize_memories(module: &Module, memories: &mut [LinearMemory]) -> Box<[vm::LocalMemory]> {
         for init in &module.data_initializers {
             debug_assert!(init.base.is_none(), "globalvar base not supported yet");
             let offset = init.offset;
@@ -78,16 +74,10 @@ impl LocalBacking {
             to_init.copy_from_slice(&init.data);
         }
 
-        if options.abi == InstanceABI::Emscripten {
-            debug!("emscripten::setup memory");
-            crate::apis::emscripten::emscripten_set_up_memory(&mut memories[0]);
-            debug!("emscripten::finish setup memory");
-        }
-
         memories.iter_mut().map(|mem| mem.into_vm_memory()).collect::<Vec<_>>().into_boxed_slice()
     }
 
-    fn generate_tables(module: &Module, options: &InstanceOptions) -> Box<[TableBacking]> {
+    fn generate_tables(module: &Module) -> Box<[TableBacking]> {
         let mut tables = Vec::with_capacity(module.tables.len());
 
         for table in &module.tables {
@@ -98,7 +88,7 @@ impl LocalBacking {
         tables.into_boxed_slice()
     }
 
-    fn finalize_tables(module: &Module, tables: &[TableBacking], options: &InstanceOptions) -> Box<[vm::LocalTable]> {
+    fn finalize_tables(module: &Module, tables: &[TableBacking]) -> Box<[vm::LocalTable]> {
         tables.iter().map(|table| table.into_vm_table()).collect::<Vec<_>>().into_boxed_slice()
     }
 
@@ -196,4 +186,59 @@ pub struct ImportBacking {
     memories: Box<[vm::ImportedMemory]>,
     tables: Box<[vm::ImportedTable]>,
     globals: Box<[vm::ImportedGlobal]>,
+}
+
+impl ImportBacking {
+    pub fn new(module: &Module, imports: &Imports) -> Result<Self, String> {
+        assert!(module.imported_memories.len() == 0, "imported memories not yet supported");
+        assert!(module.imported_tables.len() == 0, "imported tables not yet supported");
+
+        let mut functions = Vec::with_capacity(module.imported_functions.len());
+        for (index, (mod_name, item_name)) in &module.imported_functions {
+            let expected_sig = module.signatures[index];
+            let import = imports.get(mod_name, item_name);
+            if let Import::Func(func, signature) = import {
+                if expected_sig == signature {
+                    functions.push(vm::ImportedFunc {
+                        func,
+                        vmctx: ptr::null_mut(),
+                    });
+                } else {
+                    return Err(format!("unexpected signature for {}:{}", mod_name, item_name));
+                }
+            } else {
+                return Err(format!("incorrect type for {}:{}", mod_name, item_name));
+            }
+        }
+
+        let mut globals = Vec::with_capacity(module.imported_globals.len());
+        for (_, ((mod_name, item_name), global_desc)) in &module.imported_globals {
+            let import = imports.get(mod_name, item_name);
+            if let Import::Global(val) = import {
+                if val.ty() == global_desc.ty {
+                    globals.push(vm::ImportedGlobal {
+                        global: vm::LocalGlobal {
+                            data: match val {
+                                Val::I32(n) => n as u64,
+                                Val::I64(n) => n as u64,
+                                Val::F32(n) => n as u64,
+                                Val::F64(n) => n,
+                            },
+                        },
+                    });
+                } else {
+                    return Err(format!("unexpected global type for {}:{}", mod_name, item_name));
+                }
+            } else {
+                return Err(format!("incorrect type for {}:{}", mod_name, item_name));
+            }
+        }
+
+        Ok(ImportBacking {
+            functions: functions.into_boxed_slice(),
+            memories: vec![].into_boxed_slice(),
+            tables: vec![].into_boxed_slice(),
+            globals: globals.into_boxed_slice(),
+        })
+    }
 }

src/runtime/instance.rs

@@ -1,26 +1,63 @@
 use crate::runtime::{
     vm,
     backing::{LocalBacking, ImportBacking},
+    module::{ModuleName, ItemName},
+    types::{Val, Memory, Table, Global, FuncSig},
+    table::TableBacking,
+    memory::LinearMemory,
 };
 use std::sync::Arc;
+use hashbrown::{HashMap, Entry};
 
 pub struct Instance {
     pub vmctx: vm::Ctx,
 
-    pub finalized_funcs: Box<[*const vm::Func]>,
-
-    pub backing: LocalBacking,
-    pub imports: ImportBacking,
+    backing: LocalBacking,
+    imports: ImportBacking,
 
     pub module: Arc<Module>,
 }
 
 impl Instance {
-    pub fn new(module: Arc<Module>) -> Box<Instance> {
+    pub fn new(module: Arc<Module>, imports: &Imports) -> Result<Box<Instance>, String> {
+        let mut import_backing = ImportBacking::new(&*module, imports)?;
+        let mut backing = LocalBacking::new(&*module, &import_backing);
+
+        let vmctx = vm::Ctx::new(&mut backing, &mut imports);
         
-        Box::new(Instance {
+        Ok(Box::new(Instance {
             vmctx,
-            finalized_funcs
-        })
+            backing,
+            import_backing,
+            module,
+        }))
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum Import {
+    Func(*const vm::Func, FuncSig),
+    Table(Arc<TableBacking>, Table),
+    Memory(Arc<LinearMemory>, Memory),
+    Global(Val),
+}
+
+pub struct Imports {
+    map: HashMap<ModuleName, HashMap<ItemName, Import>>,
+}
+
+impl Imports {
+    pub fn new() -> Self {
+        Self {
+            map: HashMap::new(),
+        }
+    }
+
+    pub fn add(&mut self, module: ModuleName, name: ItemName, import: Import) {
+        self.map.entry(module).or_insert(HashMap::new()).insert(name, import)
+    }
+
+    pub fn get(&self, module: ModuleName, name: ItemName) -> Option<&Import> {
+        self.map.get().and_then(|m| m.get(name))
     }
 }

src/runtime/memory.rs

@@ -238,9 +238,4 @@ impl DerefMut for LinearMemory {
             )
         }
     }
-}
-
-fn round_up_to_page_size(size: usize) -> usize {
-    let page_size = region::page::size();
-    (size + (page_size - 1)) & !(page_size - 1)
 }

src/runtime/mod.rs

@@ -1,9 +1,20 @@
 
 pub mod vm;
-pub mod backing;
-pub mod types;
-pub mod memory;
-pub mod backend;
-pub mod module;
-pub mod instance;
-pub mod table;
+mod backing;
+mod types;
+mod memory;
+mod backend;
+mod module;
+mod instance;
+mod table;
+mod sig_registry;
+
+pub use backend::Compiler;
+pub use instance::{Instance, Imports, Import};
+pub use module::{ModuleName, ItemName, Module};
+
+/// Compile a webassembly module using the provided compiler and linked with the provided imports.
+pub fn compile(compiler: &dyn Compiler, wasm: &[u8], imports: &Imports) -> Result<Box<Instance>, String> {
+    let module = compiler.compile(wasm)?;
+    Instance::new(module, imports)
+}

src/runtime/module.rs

@@ -1,7 +1,7 @@
 use crate::runtime::types::{
     Map,
     FuncIndex, MemoryIndex, TableIndex, GlobalIndex,
-    Memory, Globals, GlobalDesc, Func, Table,
+    Memory, Globals, GlobalDesc, FuncSig, Table,
 };
 use crate::runtime::backend::FuncResolver;
 
@@ -13,7 +13,7 @@ pub struct Module {
     pub globals: Map<Global, GlobalIndex>,
     pub tables: Map<Table, TableIndex>,
     
-    pub imported_functions: Map<(ImportName, Func), FuncIndex>,
+    pub imported_functions: Map<ImportName, FuncIndex>,
     pub imported_memories: Map<(ImportName, Memory), MemoryIndex>,
     pub imported_tables: Map<(ImportName, Table), TableIndex>,
     pub imported_globals: Map<(ImportName, GlobalDesc), GlobalIndex>,
@@ -23,7 +23,7 @@ pub struct Module {
     pub data_initializers: Vec<DataInitializer>,
     pub start_func: FuncIndex,
 
-    pub signatures: Map<Func, FuncIndex>,
+    pub signatures: Map<FuncSig, FuncIndex>,
 }
 
 pub type ModuleName = Vec<u8>;

src/runtime/sig_registry.rs

@@ -0,0 +1,5 @@
+
+
+pub struct SignatureRegistry {
+    
+}

src/runtime/types.rs

@@ -25,6 +25,17 @@ pub enum Val {
     F64(u64),
 }
 
+impl Val {
+    pub fn ty(&self) -> Type {
+        match self {
+            Val::I32(_) => Type::I32,
+            Val::I64(_) => Type::I64,
+            Val::F32(_) => Type::F32,
+            Val::F64(_) => Type::F64,
+        }
+    }
+}
+
 impl From<i32> for Val {
     fn from(n: i32) -> Self {
         Self::I32(n)
@@ -105,8 +116,8 @@ impl Memory {
 }
 
 /// A wasm func.
-#[derive(Debug)]
-pub struct Func {
+#[derive(Debug, PartialEq, Eq)]
+pub struct FuncSig {
     pub params: Vec<Type>,
     pub returns: Vec<Type>,
 }

src/runtime/vm.rs

@@ -1,19 +1,22 @@
 use std::{ptr, mem};
-use crate::runtime::types::{
-    MemoryIndex, TableIndex, GlobalIndex, FuncIndex,
-    SignatureIndex,
+use crate::runtime::{
+    types::{
+        MemoryIndex, TableIndex, GlobalIndex, FuncIndex,
+        SignatureIndex,
+    },
+    backing::{LocalBacking, ImportBacking},
 };
 
 #[derive(Debug)]
 #[repr(C)]
 pub struct Ctx<'a> {
-    /// A pointer to an array of locally-defined memories, indexed by `DefinedMemoryIndex`.
+    /// A pointer to an array of locally-defined memories, indexed by `MemoryIndex`.
     pub memories: *mut LocalMemory,
 
-    /// A pointer to an array of locally-defined tables, indexed by `DefinedTableIndex`.
+    /// A pointer to an array of locally-defined tables, indexed by `TableIndex`.
     pub tables: *mut LocalTable,
 
-    /// A pointer to an array of locally-defined globals, indexed by `DefinedGlobalIndex`.
+    /// A pointer to an array of locally-defined globals, indexed by `GlobalIndex`.
     pub globals: *mut LocalGlobal,
 
     /// A pointer to an array of imported memories, indexed by `MemoryIndex,
@@ -34,23 +37,19 @@ pub struct Ctx<'a> {
 
 impl Ctx {
     pub fn new(
-        memories: *mut LocalMemory,
-        tables: *mut LocalTable,
-        globals: *mut LocalGlobal,
-        imported_memories: *mut ImportedMemory,
-        imported_tables: *mut ImportedTable,
-        imported_globals: *mut ImportedGlobal,
-        imported_funcs: *mut ImportedFunc,
+        local_backing: &mut LocalBacking,
+        import_backing: &mut ImportBacking,
         sig_ids: *mut SigId,
     ) -> Self {
         Self {
-            memories,
-            tables,
-            globals,
-            imported_memories,
-            imported_tables,
-            imported_globals,
-            imported_funcs,
+            memories: local_backing.vm_memories.as_mut_ptr(),
+            tables: local_backing.vm_tables.as_mut_ptr(),
+            globals: local_backing.vm_globals.as_mut_ptr(),
+
+            imported_memories: import_backing.memories.as_mut_ptr(),
+            imported_tables: import_backing.tables.as_mut_ptr(),
+            imported_funcs: import_backing.functions.as_mut_ptr(),
+            
             sig_ids,
         }
     }
@@ -98,17 +97,12 @@ pub enum Func {}
 #[repr(C)]
 pub struct ImportedFunc {
     pub func: *const Func,
-    pub vmctx: *mut Ctx,
 }
 
 impl ImportedFunc {
     pub fn offset_func() -> u8 {
         0 * (mem::size_of::<usize>() as u8)
     }
-
-    pub fn offset_vmctx() -> u8 {
-        1 * (mem::size_of::<usize>() as u8)
-    }
 }
 
 /// Definition of a table used by the VM. (obviously)
@@ -205,11 +199,11 @@ impl LocalGlobal {
 #[derive(Debug, Clone)]
 #[repr(C)]
 pub struct ImportedGlobal {
-    pub global: *mut LocalGlobal,
+    pub global: LocalGlobal,
 }
 
 impl ImportedGlobal {
-    pub fn offset_global() -> u8 {
+    pub fn offset_data() -> u8 {
         0 * (mem::size_of::<usize>() as u8)
     }
 }
@@ -314,10 +308,10 @@ mod vm_offset_tests {
             offset_of!(ImportedFunc => func).get_byte_offset(),
         );
 
-        assert_eq!(
-            ImportedFunc::offset_vmctx() as usize,
-            offset_of!(ImportedFunc => vmctx).get_byte_offset(),
-        );
+        // assert_eq!(
+        //     ImportedFunc::offset_vmctx() as usize,
+        //     offset_of!(ImportedFunc => vmctx).get_byte_offset(),
+        // );
     }
 
     #[test]
@@ -378,8 +372,8 @@ mod vm_offset_tests {
     #[test]
     fn imported_global() {
         assert_eq!(
-            ImportedGlobal::offset_global() as usize,
-            offset_of!(ImportedGlobal => global).get_byte_offset(),
+            ImportedGlobal::offset_data() as usize,
+            offset_of!(ImportedGlobal => global: LocalGlobal => data).get_byte_offset(),
         );
     }