new feature flag: deterministic

Makefile

@@ -192,6 +192,12 @@ check: check-bench
 	# as default, and test a minimal set of features with only one backend
 	# at a time.
 	cargo check --manifest-path lib/runtime/Cargo.toml
+	# Check some of the cases where deterministic execution could matter
+	cargo check --manifest-path lib/runtime/Cargo.toml --features "deterministic-execution"
+	cargo check --manifest-path lib/runtime/Cargo.toml --no-default-features \
+		--features=default-backend-singlepass,deterministic-execution
+	cargo check --manifest-path lib/runtime/Cargo.toml --no-default-features \
+		--features=default-backend-llvm,deterministic-execution
 	cargo check --release --manifest-path lib/runtime/Cargo.toml
 
 	$(RUNTIME_CHECK) \

lib/runtime-core/Cargo.toml

@@ -57,3 +57,4 @@ trace = ["debug"]
 "backend-singlepass" = []
 "backend-llvm" = []
 managed = []
+deterministic-execution = ["wasmparser/deterministic"]

lib/runtime-core/src/codegen.rs

@@ -186,6 +186,9 @@ pub fn validating_parser_config(features: &Features) -> wasmparser::ValidatingPa
             enable_simd: features.simd,
             enable_bulk_memory: false,
             enable_multi_value: false,
+
+            #[cfg(feature = "deterministic-execution")]
+            deterministic_only: true,
         },
     }
 }

lib/runtime-core/src/lib.rs

@@ -159,6 +159,9 @@ pub fn validate_and_report_errors_with_features(
             enable_multi_value: false,
             enable_reference_types: false,
             enable_threads: features.threads,
+
+            #[cfg(feature = "deterministic-execution")]
+            deterministic_only: true,
         },
     };
     let mut parser = wasmparser::ValidatingParser::new(wasm, Some(config));

lib/runtime/Cargo.toml

@@ -44,6 +44,7 @@ singlepass = ["wasmer-singlepass-backend"]
 default-backend-singlepass = ["singlepass"]
 default-backend-llvm = ["llvm"]
 default-backend-cranelift = ["cranelift"]
+deterministic-execution = ["wasmer-singlepass-backend/deterministic-execution", "wasmer-runtime-core/deterministic-execution"]
 
 [[bench]]
 name = "nginx"

lib/runtime/src/lib.rs

@@ -71,7 +71,7 @@
 //!     let value = add_one.call(42)?;
 //!
 //!     assert_eq!(value, 43);
-//!     
+//!
 //!     Ok(())
 //! }
 //! ```
@@ -246,14 +246,26 @@ pub fn compiler_for_backend(backend: Backend) -> Option<Box<dyn Compiler>> {
         #[cfg(feature = "cranelift")]
         Backend::Cranelift => Some(Box::new(wasmer_clif_backend::CraneliftCompiler::new())),
 
-        #[cfg(feature = "singlepass")]
+        #[cfg(any(feature = "singlepass"))]
         Backend::Singlepass => Some(Box::new(
             wasmer_singlepass_backend::SinglePassCompiler::new(),
         )),
 
         #[cfg(feature = "llvm")]
         Backend::LLVM => Some(Box::new(wasmer_llvm_backend::LLVMCompiler::new())),
 
+        Backend::Auto => {
+            #[cfg(feature = "default-backend-singlepass")]
+            return Some(Box::new(
+                wasmer_singlepass_backend::SinglePassCompiler::new(),
+            ));
+            #[cfg(feature = "default-backend-cranelift")]
+            return Some(Box::new(wasmer_clif_backend::CraneliftCompiler::new()));
+            #[cfg(feature = "default-backend-llvm")]
+            return Some(Box::new(wasmer_llvm_backend::LLVMCompiler::new()));
+        }
+
+        #[cfg(not(all(feature = "llvm", feature = "singlepass", feature = "cranelift")))]
         _ => None,
     }
 }

lib/singlepass-backend/Cargo.toml

@@ -22,3 +22,7 @@ smallvec = "0.6"
 serde = "1.0"
 serde_derive = "1.0"
 bincode = "1.2"
+
+[features]
+default = []
+deterministic-execution = ["wasmer-runtime-core/deterministic-execution"]