Move asset hashing into the CLI (#3988)

* Fix deduping assets

* hash assets in the linker

* fix extracting assets

* Fix the hashed asset name

* deserialize the asset back from the link section

* prevent the read from being inlined

* remove some extra logs

* Fix liveview routing

* Only look for direct dependencies on dioxus features

* fix wasm split test

* On wasm, create a new object file with the asset information

* Fix multiple assets

* add a regression test for 3467

* fix image link

* fix linker out file

* fix linux linker args

* add windows linker command

* fix linux link args

* fix windows target triple

* Expose an option to build assets in the linker intercept

* Fix the standalone optimizer and document it in the dx help command

* include the cli opt version in the hash

* fix clippy

* fix ssg port

* add a safety note to the read_volatile call

* move found assets log

* fix some merge conflicts

* fix build

* make most env var for the linker optional

* guess the target triple when dx acts as the linker intercept

* automatically find the linker for normal builds

* use the right linker in wasm mode

* fix mac linker

* look inside archive files (rlibs)

* remove out.txt

* fix clippy

* fix typo

* fix clippy

* fix build

* fix dx link name in docs

* ignore libcompiler_builtins warnings

* fix playwright

* pass typocheck

* fix printing sysroot

* Modify final binary

* fix wasm assets

* remove old link section logic

* fix tests

* forward manganis export args

* fail to evaluate relocatable address

* retain all exports in the same pattern as other platforms

* Fix adding assets during a wasm hot patch

* less nesting and remove logs

* fix clippy

* log pdb files

* read from pdb

* print data section contents

* print with object

* normal windows builds working

* fix hot patch windows

* clean up logs

* fix clippy

* clean up assets

* use the most recent pdb

* fix doc test

* fix typo

* tiny nits

* make bundled a reference instead of a pointer

* add helpful comment to impl

* match on file format

* Fix asset hashing comment

---------

Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>

packages/manganis/manganis-macro/src/asset.rs

@@ -1,9 +1,11 @@
 use crate::{resolve_path, AssetParseError};
 use macro_string::MacroString;
-use manganis_core::hash::AssetHash;
 use proc_macro2::TokenStream as TokenStream2;
 use quote::{quote, ToTokens, TokenStreamExt};
-use std::path::PathBuf;
+use std::{
+    hash::{DefaultHasher, Hash, Hasher},
+    path::PathBuf,
+};
 use syn::{
     parse::{Parse, ParseStream},
     spanned::Spanned as _,
@@ -72,24 +74,19 @@ impl ToTokens for AssetParser {
                 return;
             }
         };
-        let asset_str = asset.to_string_lossy();
-        let mut asset_str = proc_macro2::Literal::string(&asset_str);
+        let asset_string = asset.to_string_lossy();
+        let mut asset_str = proc_macro2::Literal::string(&asset_string);
         asset_str.set_span(self.path_expr.span());
 
-        let hash = match AssetHash::hash_file_contents(asset) {
-            Ok(hash) => hash,
-            Err(err) => {
-                let err = err.to_string();
-                tokens.append_all(quote! { compile_error!(#err) });
-                return;
-            }
-        };
-
-        let hash = hash.bytes();
+        let mut hash = DefaultHasher::new();
+        format!("{:?}", self.options.span()).hash(&mut hash);
+        format!("{:?}", self.options.to_string()).hash(&mut hash);
+        asset_string.hash(&mut hash);
+        let asset_hash = format!("{:016x}", hash.finish());
 
         // Generate the link section for the asset
         // The link section includes the source path and the output path of the asset
-        let link_section = crate::generate_link_section(quote!(__ASSET));
+        let link_section = crate::generate_link_section(quote!(__ASSET), &asset_hash);
 
         // generate the asset::new method to deprecate the `./assets/blah.css` syntax
         let constructor = if asset.is_relative() {
@@ -106,21 +103,25 @@ impl ToTokens for AssetParser {
 
         tokens.extend(quote! {
             {
-                // We keep a hash of the contents of the asset for cache busting
-                const __ASSET_HASH: &[u8] = &[#(#hash),*];
                 // The source is used by the CLI to copy the asset
                 const __ASSET_SOURCE_PATH: &'static str = #asset_str;
                 // The options give the CLI info about how to process the asset
                 // Note: into_asset_options is not a trait, so we cannot accept the options directly
                 // in the constructor. Stable rust doesn't have support for constant functions in traits
                 const __ASSET_OPTIONS: manganis::AssetOptions = #options.into_asset_options();
+                // The input token hash is used to uniquely identify the link section for this asset
+                const __ASSET_HASH: &'static str = #asset_hash;
                 // Create the asset that the crate will use. This is used both in the return value and
                 // added to the linker for the bundler to copy later
-                const __ASSET: manganis::BundledAsset = manganis::macro_helpers::#constructor(__ASSET_SOURCE_PATH, __ASSET_HASH, __ASSET_OPTIONS);
+                const __ASSET: manganis::BundledAsset = manganis::macro_helpers::#constructor(__ASSET_SOURCE_PATH, __ASSET_OPTIONS);
 
                 #link_section
 
-                manganis::Asset::new(__ASSET, __keep_link_section)
+                static __REFERENCE_TO_LINK_SECTION: &'static [u8] = &__LINK_SECTION;
+
+                manganis::Asset::new(
+                    __REFERENCE_TO_LINK_SECTION
+                )
             }
         })
     }

packages/manganis/manganis-macro/src/linker.rs

@@ -6,12 +6,9 @@ use quote::ToTokens;
 /// We force rust to store a serialized representation of the asset description
 /// inside a particular region of the binary, with the label "manganis".
 /// After linking, the "manganis" sections of the different object files will be merged.
-pub fn generate_link_section(asset: impl ToTokens) -> TokenStream2 {
+pub fn generate_link_section(asset: impl ToTokens, asset_hash: &str) -> TokenStream2 {
     let position = proc_macro2::Span::call_site();
-    let section_name = syn::LitStr::new(
-        manganis_core::linker::LinkSection::CURRENT.link_section,
-        position,
-    );
+    let export_name = syn::LitStr::new(&format!("__MANGANIS__{}", asset_hash), position);
 
     quote::quote! {
         // First serialize the asset into a constant sized buffer
@@ -22,12 +19,7 @@ pub fn generate_link_section(asset: impl ToTokens) -> TokenStream2 {
         const __LEN: usize = __BYTES.len();
 
         // Now that we have the size of the asset, copy the bytes into a static array
-        #[link_section = #section_name]
-        #[used]
-        static __LINK_SECTION: [u8; __LEN] = manganis::macro_helpers::copy_bytes(__BYTES);
-
-        fn __keep_link_section() -> u8 {
-            unsafe { std::ptr::read_volatile(__LINK_SECTION.as_ptr()) }
-        }
+        #[unsafe(export_name = #export_name)]
+        static __LINK_SECTION: [u8; __LEN]  = manganis::macro_helpers::copy_bytes(__BYTES);
     }
 }