From 038101e93da2b9a748ed035aa00f21f2a657281c Mon Sep 17 00:00:00 2001
From: Manos Pitsidianakis <el13635@mail.ntua.gr>
Date: Wed, 27 Jul 2022 20:19:25 +0300
Subject: [PATCH] compiler: move MetadataHeader to wasmer-types

---
 .../src/artifact_builders/artifact_builder.rs |  2 +-
 lib/compiler/src/engine/artifact.rs           |  3 +-
 lib/compiler/src/traits.rs                    | 73 +------------------
 3 files changed, 5 insertions(+), 73 deletions(-)

diff --git a/lib/compiler/src/artifact_builders/artifact_builder.rs b/lib/compiler/src/artifact_builders/artifact_builder.rs
index 9558c0b2dc2..82df23855ac 100644
--- a/lib/compiler/src/artifact_builders/artifact_builder.rs
+++ b/lib/compiler/src/artifact_builders/artifact_builder.rs
@@ -4,7 +4,6 @@
 #[cfg(feature = "engine_compilation")]
 use super::trampoline::{libcall_trampoline_len, make_libcall_trampolines};
 use crate::Features;
-use crate::MetadataHeader;
 use crate::{ArtifactCreate, EngineBuilder};
 #[cfg(feature = "engine_compilation")]
 use crate::{ModuleEnvironment, ModuleMiddlewareChain};
@@ -13,6 +12,7 @@ use std::mem;
 use wasmer_types::entity::PrimaryMap;
 #[cfg(feature = "engine_compilation")]
 use wasmer_types::CompileModuleInfo;
+use wasmer_types::MetadataHeader;
 use wasmer_types::SerializeError;
 use wasmer_types::{
     CompileError, CpuFeature, CustomSection, Dwarf, FunctionIndex, LocalFunctionIndex, MemoryIndex,
diff --git a/lib/compiler/src/engine/artifact.rs b/lib/compiler/src/engine/artifact.rs
index 1409ecde6f5..977674a5486 100644
--- a/lib/compiler/src/engine/artifact.rs
+++ b/lib/compiler/src/engine/artifact.rs
@@ -10,12 +10,13 @@ use crate::Features;
 use crate::ModuleEnvironment;
 use crate::{
     register_frame_info, resolve_imports, FunctionExtent, GlobalFrameInfoRegistration,
-    InstantiationError, MetadataHeader, RuntimeError, Tunables,
+    InstantiationError, RuntimeError, Tunables,
 };
 use enumset::EnumSet;
 use std::sync::Arc;
 use std::sync::Mutex;
 use wasmer_types::entity::{BoxedSlice, PrimaryMap};
+use wasmer_types::MetadataHeader;
 use wasmer_types::{
     CompileError, CpuFeature, DataInitializer, DeserializeError, FunctionIndex, LocalFunctionIndex,
     MemoryIndex, ModuleInfo, OwnedDataInitializer, SerializableModule, SerializeError,
diff --git a/lib/compiler/src/traits.rs b/lib/compiler/src/traits.rs
index e8da762451e..8b0cb748794 100644
--- a/lib/compiler/src/traits.rs
+++ b/lib/compiler/src/traits.rs
@@ -3,14 +3,13 @@
 use crate::Features;
 use enumset::EnumSet;
 use std::any::Any;
-use std::convert::TryInto;
+use std::fs;
 use std::path::Path;
-use std::{fs, mem};
 use wasmer_types::entity::PrimaryMap;
+use wasmer_types::SerializeError;
 use wasmer_types::{
     CpuFeature, MemoryIndex, MemoryStyle, ModuleInfo, OwnedDataInitializer, TableIndex, TableStyle,
 };
-use wasmer_types::{DeserializeError, SerializeError};
 
 /// An `Artifact` is the product that the `Engine`
 /// implementation produce and use.
@@ -87,71 +86,3 @@ impl dyn ArtifactCreate + 'static {
         self.upcast_any_mut().downcast_mut::<T>()
     }
 }
-
-/// Metadata header which holds an ABI version and the length of the remaining
-/// metadata.
-#[repr(C)]
-#[derive(Clone, Copy)]
-pub struct MetadataHeader {
-    magic: [u8; 8],
-    version: u32,
-    len: u32,
-}
-
-impl MetadataHeader {
-    /// Current ABI version. Increment this any time breaking changes are made
-    /// to the format of the serialized data.
-    const CURRENT_VERSION: u32 = 1;
-
-    /// Magic number to identify wasmer metadata.
-    const MAGIC: [u8; 8] = *b"WASMER\0\0";
-
-    /// Length of the metadata header.
-    pub const LEN: usize = 16;
-
-    /// Alignment of the metadata.
-    pub const ALIGN: usize = 16;
-
-    /// Creates a new header for metadata of the given length.
-    pub fn new(len: usize) -> Self {
-        Self {
-            magic: Self::MAGIC,
-            version: Self::CURRENT_VERSION,
-            len: len.try_into().expect("metadata exceeds maximum length"),
-        }
-    }
-
-    /// Convert the header into its bytes representation.
-    pub fn into_bytes(self) -> [u8; 16] {
-        unsafe { mem::transmute(self) }
-    }
-
-    /// Parses the header and returns the length of the metadata following it.
-    pub fn parse(bytes: &[u8]) -> Result<usize, DeserializeError> {
-        if bytes.as_ptr() as usize % 16 != 0 {
-            return Err(DeserializeError::CorruptedBinary(
-                "misaligned metadata".to_string(),
-            ));
-        }
-        let bytes: [u8; 16] = bytes
-            .get(..16)
-            .ok_or_else(|| {
-                DeserializeError::CorruptedBinary("invalid metadata header".to_string())
-            })?
-            .try_into()
-            .unwrap();
-        let header: Self = unsafe { mem::transmute(bytes) };
-        if header.magic != Self::MAGIC {
-            return Err(DeserializeError::Incompatible(
-                "The provided bytes were not serialized by Wasmer".to_string(),
-            ));
-        }
-        if header.version != Self::CURRENT_VERSION {
-            return Err(DeserializeError::Incompatible(
-                "The provided bytes were serialized by an incompatible version of Wasmer"
-                    .to_string(),
-            ));
-        }
-        Ok(header.len as usize)
-    }
-}