Switch from failure to anyhow

This moves us back to `std::error::Error` compatibility and helps build
times since it doesn't rely on an older version of `syn`

Cargo.toml

@@ -23,7 +23,7 @@ path = "benches/benches.rs"
 harness = false
 
 [dependencies]
-failure = { version = "0.1.5", default-features = false, features = ['std'] }
+anyhow = "1.0"
 id-arena = "2.2.1"
 leb128 = "0.2.4"
 log = "0.4.8"

crates/fuzz-utils/Cargo.toml

@@ -8,7 +8,7 @@ publish = false
 [dependencies]
 rand = { version = "0.7.0", features = ['small_rng'] }
 tempfile = "3.1.0"
-failure = "0.1.5"
+anyhow = "1.0"
 env_logger = "0.7.0"
 
 [dependencies.walrus]

crates/fuzz-utils/src/lib.rs

@@ -2,7 +2,7 @@
 
 #![deny(missing_docs)]
 
-use failure::ResultExt;
+use anyhow::Context;
 use rand::{rngs::SmallRng, Rng, SeedableRng};
 use std::cmp;
 use std::fmt;
@@ -12,8 +12,8 @@ use std::path::Path;
 use std::time;
 use walrus_tests_utils::{wasm_interp, wat2wasm};
 
-/// `Ok(T)` or a `Err(failure::Error)`
-pub type Result<T> = std::result::Result<T, failure::Error>;
+/// `Ok(T)` or a `Err(anyhow::Error)`
+pub type Result<T> = std::result::Result<T, anyhow::Error>;
 
 #[derive(Copy, Clone, Debug)]
 enum ValType {
@@ -139,7 +139,7 @@ where
     pub fn run_one(&mut self) -> Result<()> {
         let wat = self.gen_wat();
         self.test_wat(&wat)
-            .with_context(|_| format!("wat = {}", wat))?;
+            .with_context(|| format!("wat = {}", wat))?;
         Ok(())
     }
 
@@ -436,12 +436,9 @@ impl TestCaseGenerator for WasmOptTtf {
     }
 }
 
-/// Print a `failure::Error` with its chain.
-pub fn print_err(e: &failure::Error) {
-    eprintln!("Error:");
-    for c in e.iter_chain() {
-        eprintln!("  - {}", c);
-    }
+/// Print a `anyhow::Error` with its chain.
+pub fn print_err(e: &anyhow::Error) {
+    eprintln!("Error: {:?}", e);
 }
 
 #[cfg(test)]

crates/tests-utils/Cargo.toml

@@ -7,4 +7,4 @@ publish = false
 
 [dependencies]
 tempfile = "3.1.0"
-failure = "0.1.5"
+anyhow = "1.0"

crates/tests-utils/src/lib.rs

@@ -1,11 +1,11 @@
-use failure::ResultExt;
+use anyhow::{bail, Context};
 use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
 use std::sync::Once;
 
-pub type Result<T> = std::result::Result<T, failure::Error>;
+pub type Result<T> = std::result::Result<T, anyhow::Error>;
 
 pub const FEATURES: &[&str] = &[
     "--enable-threads",
@@ -56,7 +56,7 @@ pub fn wat2wasm(path: &Path, extra_args: &[&str]) -> Result<Vec<u8>> {
     let output = cmd.output().context("could not spawn wat2wasm")?;
 
     if !output.status.success() {
-        failure::bail!(
+        bail!(
             "wat2wasm exited with status {:?}\n\nstderr = '''\n{}\n'''",
             output.status,
             String::from_utf8_lossy(&output.stderr)
@@ -82,7 +82,7 @@ pub fn wasm2wat(path: &Path) -> Result<String> {
     println!("running: {:?}", cmd);
     let output = cmd.output().context("could not run wasm2wat")?;
     if !output.status.success() {
-        failure::bail!(
+        bail!(
             "wasm2wat exited with status {:?}\n\nstderr = '''\n{}\n'''",
             output.status,
             String::from_utf8_lossy(&output.stderr)
@@ -111,7 +111,7 @@ pub fn wasm_interp(path: &Path) -> Result<String> {
     println!("running: {:?}", cmd);
     let output = cmd.output().context("could notrun wasm-interp")?;
     if !output.status.success() {
-        failure::bail!(
+        bail!(
             "wasm-interp exited with status {:?}\n\nstderr = '''\n{}\n'''",
             output.status,
             String::from_utf8_lossy(&output.stderr)
@@ -151,7 +151,7 @@ where
     println!("running: {:?}", cmd);
     let output = cmd.output().context("could not run wasm-opt")?;
     if !output.status.success() {
-        failure::bail!(
+        bail!(
             "wasm-opt exited with status {:?}\n\nstderr = '''\n{}\n'''",
             output.status,
             String::from_utf8_lossy(&output.stderr)
@@ -174,17 +174,11 @@ impl TestResult for () {
     fn handle(self) {}
 }
 
-impl TestResult for std::result::Result<(), failure::Error> {
+impl TestResult for Result<()> {
     fn handle(self) {
-        let err = match self {
-            Ok(()) => return,
-            Err(e) => e,
-        };
-        eprintln!("got an error:");
-        for c in err.iter_chain() {
-            eprintln!("  {}", c);
+        match self {
+            Ok(()) => {}
+            Err(e) => panic!("got an error: {:?}", e),
         }
-        eprintln!("{}", err.backtrace());
-        panic!("test failed");
     }
 }

crates/tests/Cargo.toml

@@ -9,7 +9,7 @@ publish = false
 walkdir = "2.2.9"
 
 [dev-dependencies]
-failure = "0.1.5"
+anyhow = "1.0"
 walrus = { path = "../.." }
 walrus-tests-utils = { path = "../tests-utils" }
 tempfile = "3.1.0"

crates/tests/tests/function_imports.rs

@@ -1,7 +1,7 @@
 use std::path::Path;
 use walrus_tests_utils::wat2wasm;
 
-fn run(wat_path: &Path) -> Result<(), failure::Error> {
+fn run(wat_path: &Path) -> Result<(), anyhow::Error> {
     static INIT_LOGS: std::sync::Once = std::sync::Once::new();
     INIT_LOGS.call_once(|| {
         env_logger::init();

crates/tests/tests/invalid.rs

@@ -1,7 +1,7 @@
 use std::path::Path;
 use std::sync::Once;
 
-fn run(wat: &Path) -> Result<(), failure::Error> {
+fn run(wat: &Path) -> Result<(), anyhow::Error> {
     static INIT_LOGS: Once = Once::new();
     INIT_LOGS.call_once(|| {
         env_logger::init();
@@ -12,12 +12,9 @@ fn run(wat: &Path) -> Result<(), failure::Error> {
     // NB: reading the module will do the validation.
     match walrus::Module::from_buffer(&wasm) {
         Err(e) => {
-            eprintln!("Got error, as expected:");
-            for c in e.iter_chain() {
-                eprintln!("  - {}", c);
-            }
+            eprintln!("Got error, as expected: {:?}", e);
         }
-        Ok(_) => failure::bail!("expected {} to be invalid, but it was valid", wat.display()),
+        Ok(_) => anyhow::bail!("expected {} to be invalid, but it was valid", wat.display()),
     }
 
     Ok(())

crates/tests/tests/round_trip.rs

@@ -2,7 +2,7 @@ use std::env;
 use std::path::Path;
 use walrus_tests_utils::{wasm2wat, wat2wasm};
 
-fn run(wat_path: &Path) -> Result<(), failure::Error> {
+fn run(wat_path: &Path) -> Result<(), anyhow::Error> {
     static INIT_LOGS: std::sync::Once = std::sync::Once::new();
     INIT_LOGS.call_once(|| {
         env_logger::init();

crates/tests/tests/spec-tests.rs

@@ -1,4 +1,4 @@
-use failure::ResultExt;
+use anyhow::Context;
 use std::fs;
 use std::path::Path;
 use std::process::Command;
@@ -10,7 +10,7 @@ struct Test {
     commands: Vec<serde_json::Value>,
 }
 
-fn run(wast: &Path) -> Result<(), failure::Error> {
+fn run(wast: &Path) -> Result<(), anyhow::Error> {
     static INIT_LOGS: std::sync::Once = std::sync::Once::new();
     INIT_LOGS.call_once(|| {
         env_logger::init();
@@ -145,7 +145,7 @@ fn run(wast: &Path) -> Result<(), failure::Error> {
     Ok(())
 }
 
-fn run_spectest_interp(cwd: &Path, extra_args: &[&str]) -> Result<(), failure::Error> {
+fn run_spectest_interp(cwd: &Path, extra_args: &[&str]) -> Result<(), anyhow::Error> {
     let output = Command::new("spectest-interp")
         .current_dir(cwd)
         .arg("foo.json")

crates/tests/tests/valid.rs

@@ -2,7 +2,7 @@ use std::env;
 use std::path::Path;
 use std::sync::Once;
 
-fn run(wat: &Path) -> Result<(), failure::Error> {
+fn run(wat: &Path) -> Result<(), anyhow::Error> {
     static INIT_LOGS: Once = Once::new();
     INIT_LOGS.call_once(|| {
         env_logger::init();

src/error.rs

@@ -1,10 +1,10 @@
 //! Error types and utilities.
 
-pub use failure::Error;
+pub use anyhow::Error;
 use std::fmt;
 
 /// Either `Ok(T)` or `Err(failure::Error)`.
-pub type Result<T> = ::std::result::Result<T, failure::Error>;
+pub type Result<T> = ::std::result::Result<T, anyhow::Error>;
 
 /// A leaf wasm error type.
 ///

src/init_expr.rs

@@ -4,7 +4,7 @@ use crate::emit::{Emit, EmitContext};
 use crate::ir::Value;
 use crate::parse::IndicesToIds;
 use crate::{GlobalId, Result};
-use failure::bail;
+use anyhow::bail;
 
 /// A constant which is produced in WebAssembly, typically used in global
 /// initializers or element/data offsets.

src/module/data.rs

@@ -5,7 +5,7 @@ use crate::ir::Value;
 use crate::parse::IndicesToIds;
 use crate::tombstone_arena::{Id, Tombstone, TombstoneArena};
 use crate::{GlobalId, InitExpr, MemoryId, Module, Result, ValType};
-use failure::{bail, ResultExt};
+use anyhow::{bail, Context};
 
 /// A passive element segment identifier
 pub type DataId = Id<Data>;
@@ -217,7 +217,7 @@ impl Module {
                     memory.data_segments.insert(data.id);
 
                     let offset = InitExpr::eval(&init_expr, ids)
-                        .with_context(|_e| format!("in segment {}", i))?;
+                        .with_context(|| format!("in segment {}", i))?;
                     data.kind = DataKind::Active(ActiveData {
                         memory: memory_id,
                         location: match offset {

src/module/elements.rs

@@ -5,7 +5,7 @@ use crate::ir::Value;
 use crate::parse::IndicesToIds;
 use crate::tombstone_arena::{Id, Tombstone, TombstoneArena};
 use crate::{FunctionId, InitExpr, Module, Result, TableKind, ValType};
-use failure::{bail, ResultExt};
+use anyhow::{bail, Context};
 
 /// A passive element segment identifier
 pub type ElementId = Id<Element>;
@@ -92,7 +92,7 @@ impl Module {
                     };
 
                     let offset = InitExpr::eval(&init_expr, ids)
-                        .with_context(|_e| format!("in segment {}", i))?;
+                        .with_context(|| format!("in segment {}", i))?;
                     let functions = segment.items.get_items_reader()?.into_iter().map(|func| {
                         let func = func?;
                         ids.get_func(func)

src/module/functions/local_function/context.rs

@@ -7,7 +7,7 @@ use crate::module::Module;
 use crate::parse::IndicesToIds;
 use crate::ty::ValType;
 use crate::{ModuleTypes, TypeId};
-use failure::Fail;
+use anyhow::Context;
 
 #[derive(Debug)]
 pub(crate) struct ControlFrame {
@@ -173,7 +173,7 @@ impl<'a> ValidationContext<'a> {
 
     pub fn control(&self, n: usize) -> Result<&ControlFrame> {
         if n >= self.controls.len() {
-            failure::bail!("jump to nonexistent control block");
+            anyhow::bail!("jump to nonexistent control block");
         }
         let idx = self.controls.len() - n - 1;
         Ok(&self.controls[idx])
@@ -217,9 +217,8 @@ fn impl_pop_operand(
                 log::trace!("pop operand: None");
                 return Ok(None);
             }
-            return Err(ErrorKind::InvalidWasm
-                .context("popped operand past control frame height in non-unreachable code")
-                .into());
+            return Err(ErrorKind::InvalidWasm)
+                .context("popped operand past control frame height in non-unreachable code");
         }
     }
     let op = operands.pop().unwrap();
@@ -237,10 +236,9 @@ fn impl_pop_operand_expected(
         (actual, None) => Ok(actual),
         (Some(actual), Some(expected)) => {
             if actual != expected {
-                Err(ErrorKind::InvalidWasm
+                Err(ErrorKind::InvalidWasm)
                     .context(format!("expected type {}", expected))
                     .context(format!("found type {}", actual))
-                    .into())
             } else {
                 Ok(Some(actual))
             }
@@ -275,7 +273,7 @@ fn impl_push_control(
     end_types: Box<[ValType]>,
 ) -> Result<InstrSeqId> {
     let ty = InstrSeqType::existing(types, &start_types, &end_types).ok_or_else(|| {
-        failure::format_err!(
+        anyhow::anyhow!(
             "attempted to push a control frame for an instruction \
              sequence with a type that does not exist"
         )
@@ -330,19 +328,18 @@ fn impl_pop_control(
     controls: &mut ControlStack,
     operands: &mut OperandStack,
 ) -> Result<ControlFrame> {
-    let frame = controls.last().ok_or_else(|| {
-        ErrorKind::InvalidWasm.context("attempted to pop a frame from an empty control stack")
-    })?;
+    let frame = controls
+        .last()
+        .ok_or_else(|| ErrorKind::InvalidWasm)
+        .context("attempted to pop a frame from an empty control stack")?;
     impl_pop_operands(operands, controls, &frame.end_types)?;
     if operands.len() != frame.height {
-        return Err(ErrorKind::InvalidWasm
-            .context(format!(
-                "incorrect number of operands on the stack at the end of a control frame; \
-                 found {}, expected {}",
-                operands.len(),
-                frame.height
-            ))
-            .into());
+        return Err(ErrorKind::InvalidWasm).context(format!(
+            "incorrect number of operands on the stack at the end of a control frame; \
+             found {}, expected {}",
+            operands.len(),
+            frame.height
+        ));
     }
     let frame = controls.pop().unwrap();
     Ok(frame)

src/module/functions/local_function/mod.rs

@@ -12,7 +12,7 @@ use crate::parse::IndicesToIds;
 use crate::{
     Data, DataId, FunctionBuilder, FunctionId, Module, Result, TableKind, TypeId, ValType,
 };
-use failure::{bail, ResultExt};
+use anyhow::{bail, Context};
 use std::collections::BTreeMap;
 use wasmparser::Operator;
 
@@ -308,7 +308,7 @@ fn validate_instruction(ctx: &mut ValidationContext, inst: Operator) -> Result<(
 
     let mem_arg = |arg: &wasmparser::MemoryImmediate| -> Result<MemArg> {
         if arg.flags >= 32 {
-            failure::bail!("invalid alignment");
+            bail!("invalid alignment");
         }
         Ok(MemArg {
             align: 1 << (arg.flags as i32),

src/module/functions/mod.rs

@@ -11,7 +11,7 @@ use crate::parse::IndicesToIds;
 use crate::tombstone_arena::{Id, Tombstone, TombstoneArena};
 use crate::ty::TypeId;
 use crate::ty::ValType;
-use failure::bail;
+use anyhow::bail;
 use std::cmp;
 
 #[cfg(feature = "parallel")]