Upgrade libm and make no-std config testable (#241)

* Make everything build and test without 'std' feature

Signed-off-by: Brian Anderson <[email protected]>

* Use faster constructor in vec_bytebuf.

`vec![0; len]` uses a specialized intrinsic codepath, which, at least in debug
mode, is extremely faster than `resize`.

This makes the `alloc` test pass instantaneously instead of taking minutes.

Signed-off-by: Brian Anderson <[email protected]>

* Fix a comment about core+mmap

Signed-off-by: Brian Anderson <[email protected]>

* Don't use traits to call libm functions

These no longer exist in the latest revision of libm.

Signed-off-by: Brian Anderson <[email protected]>

* Upgrade libm to 0.2.1

Fixes #240

Signed-off-by: Brian Anderson <[email protected]>

* Remove warning from readme about debug-mode panics from libm

Signed-off-by: Brian Anderson <[email protected]>

* Test no-std configuration under travis

Signed-off-by: Brian Anderson <[email protected]>

* rustfmt

Signed-off-by: Brian Anderson <[email protected]>

Author: brson

.travis.yml

@@ -30,6 +30,7 @@ script:
 # Check that `vec_memory` feature works.
 - cargo check --features vec_memory
 - travis_wait 60 ./test.sh
+- TEST_NO_STD=1 travis_wait 60 ./test.sh
 - ./doc.sh
 
 after_success: |

Cargo.toml

@@ -15,7 +15,7 @@ exclude = [ "/res/*", "/tests/*", "/fuzz/*", "/benches/*" ]
 validation = { package = "wasmi-validation", version = "0.3", path = "validation", default-features = false }
 parity-wasm = { version = "0.41.0", default-features = false }
 memory_units = "0.3.0"
-libm = { version = "0.1.2", optional = true }
+libm = { version = "0.2.1", optional = true }
 num-rational = { version = "0.2.2", default-features = false }
 num-traits = { version = "0.2.8", default-features = false }
 libc = { version = "0.2.58", optional = true}
@@ -41,7 +41,7 @@ std = [
 ]
 # Enable for no_std support
 core = [
-    # `core` doesn't support vec_memory
+    # `core` doesn't support mmaped memory
     "vec_memory",
     "validation/core",
     "libm"

README.md

@@ -35,9 +35,6 @@ wasmi = {
 
 When the `core` feature is enabled, code related to `std::error` is disabled.
 
-Floating point operations in `no_std` use [`libm`](https://crates.io/crates/libm), which sometimes panics in debug mode (https://github.com/japaric/libm/issues/4).
-So make sure to either use release builds or avoid WASM with floating point operations, for example by using [`deny_floating_point`](https://docs.rs/wasmi/0.4.0/wasmi/struct.Module.html#method.deny_floating_point).
-
 # License
 
 `wasmi` is primarily distributed under the terms of both the MIT

examples/invoke.rs

@@ -3,7 +3,7 @@ extern crate wasmi;
 
 use std::env::args;
 
-use parity_wasm::elements::{External, FunctionType, Internal, Type, ValueType};
+use parity_wasm::elements::{External, FunctionType, Internal, Module, Type, ValueType};
 use wasmi::{ImportsBuilder, ModuleInstance, NopExternals, RuntimeValue};
 
 fn main() {
@@ -15,7 +15,7 @@ fn main() {
     let func_name = &args[2];
     let (_, program_args) = args.split_at(3);
 
-    let module = parity_wasm::deserialize_file(&args[1]).expect("File to be deserialized");
+    let module = load_module(&args[1]);
 
     // Extracts call arguments from command-line arguments
     let args = {
@@ -118,3 +118,14 @@ fn main() {
             .expect("")
     );
 }
+
+#[cfg(feature = "std")]
+fn load_module(file: &str) -> Module {
+    parity_wasm::deserialize_file(file).expect("File to be deserialized")
+}
+
+#[cfg(not(feature = "std"))]
+fn load_module(file: &str) -> Module {
+    let mut buf = std::fs::read(file).expect("Read file");
+    parity_wasm::deserialize_buffer(&mut buf).expect("Deserialize module")
+}

src/memory/mod.rs

@@ -542,7 +542,7 @@ mod tests {
     use super::{MemoryInstance, MemoryRef, LINEAR_MEMORY_PAGE_SIZE};
     use crate::memory_units::Pages;
     use crate::Error;
-    use std::rc::Rc;
+    use alloc::rc::Rc;
 
     #[test]
     fn alloc() {

src/memory/vec_bytebuf.rs

@@ -8,8 +8,7 @@ pub struct ByteBuf {
 
 impl ByteBuf {
     pub fn new(len: usize) -> Result<Self, String> {
-        let mut buf = Vec::new();
-        buf.resize(len, 0u8);
+        let buf = vec![0; len];
         Ok(Self { buf })
     }
 

src/prepare/tests.rs

@@ -1,3 +1,9 @@
+// Test-only code importing std for no-std testing
+extern crate std;
+
+use alloc::vec::Vec;
+use std::println;
+
 use super::{compile_module, CompiledModule};
 use crate::isa;
 use parity_wasm::{deserialize_buffer, elements::Module};

src/tests/host.rs

@@ -1,3 +1,6 @@
+// Test-only code importing std for no-std testing
+extern crate std;
+
 use super::parse_wat;
 use crate::memory_units::Pages;
 use crate::types::ValueType;
@@ -6,6 +9,8 @@ use crate::{
     MemoryInstance, MemoryRef, ModuleImportResolver, ModuleInstance, ModuleRef, ResumableError,
     RuntimeArgs, RuntimeValue, Signature, TableDescriptor, TableInstance, TableRef, Trap, TrapKind,
 };
+use alloc::boxed::Box;
+use std::println;
 
 #[derive(Debug, Clone, PartialEq)]
 struct HostErrorWithCode {

src/tests/mod.rs

@@ -8,7 +8,10 @@ use super::Error;
 
 fn assert_send<T: Send>() {}
 fn assert_sync<T: Sync>() {}
+#[cfg(feature = "std")]
 fn assert_std_err_impl<T: ::std::error::Error>() {}
+#[cfg(not(feature = "std"))]
+fn assert_std_err_impl<T>() {}
 
 #[test]
 fn assert_error_properties() {

src/tests/wasm.rs

@@ -1,9 +1,13 @@
+// Test-only code importing std for no-std testing
+extern crate std;
+
 use crate::memory_units::Pages;
 use crate::{
     Error, FuncRef, GlobalDescriptor, GlobalInstance, GlobalRef, ImportsBuilder, MemoryDescriptor,
     MemoryInstance, MemoryRef, Module, ModuleImportResolver, ModuleInstance, NopExternals,
     RuntimeValue, Signature, TableDescriptor, TableInstance, TableRef,
 };
+use alloc::vec::Vec;
 use std::fs::File;
 
 struct Env {