WIP: weval support.

(Stacked on top of bytecodealliance#90.)

When built with:

```
$ mkdir build/; cd build/
$ cmake .. -DCMAKE_BUILD_TYPE=Release -DUSE_WASM_OPT=OFF -DWEVAL=ON
$ make
```

This PR will result in a `starling.wasm`, a prebuilt compilation cache
of ICs in `starling-ics.wevalcache` (~1.8MiB), and a `componentize.sh`
that takes a `--aot` option.

I haven't yet quite worked out how to successfully use componentize.sh,
so I can't claim this is end-to-end tested yet, but it is invoking weval
successfully and ICs are wevaled at least.

CMakeLists.txt

@@ -28,6 +28,7 @@ include("init-corrosion")
 include("wasm-tools")
 include("binaryen")
 include("wizer")
+include("weval")
 include("wasmtime")
 
 include("fmt")
@@ -96,6 +97,22 @@ configure_file("componentize.sh" "${CMAKE_CURRENT_BINARY_DIR}/componentize.sh" C
 configure_file(${ADAPTER} "${CMAKE_CURRENT_BINARY_DIR}/${ADAPTER_FILE}" COPYONLY)
 configure_file(spin.toml spin.toml COPYONLY)
 
+# build a compilation cache of ICs
+if(WEVAL)
+    include("weval")
+    file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/null.js "function main() {}")
+    add_custom_target(
+        starling-ics.wevalcache
+        ALL
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+        COMMAND rm -f starling-ics.wevalcache
+        COMMAND echo ./null.js | ${WEVAL_BIN} weval --dir . --show-stats --cache starling-ics.wevalcache -w -i starling.wasm -o /dev/null
+        DEPENDS starling.wasm
+        VERBATIM
+    )
+    set(WEVAL_CACHE_FILE "starling-ics.wevalcache")
+endif()
+
 function(componentize OUTPUT)
     set(options)
     set(oneValueArgs)
@@ -105,13 +122,23 @@ function(componentize OUTPUT)
     list(JOIN ARG_SOURCES " " SOURCES)
     get_target_property(RUNTIME_DIR starling.wasm BINARY_DIR)
 
-    add_custom_command(
-            OUTPUT ${OUTPUT}.wasm
-            WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-            COMMAND ${CMAKE_COMMAND} -E env "PATH=${WASM_TOOLS_DIR};${WIZER_DIR};$ENV{PATH}" ${RUNTIME_DIR}/componentize.sh ${SOURCES} -o ${OUTPUT}.wasm
-            DEPENDS ${ARG_SOURCES} ${RUNTIME_DIR}/componentize.sh starling.wasm
-            VERBATIM
-    )
+    if(WEVAL)
+        add_custom_command(
+                OUTPUT ${OUTPUT}.wasm
+                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+                COMMAND ${CMAKE_COMMAND} -E env "PATH=${WASM_TOOLS_DIR};${WEVAL_DIR};$ENV{PATH}" ${RUNTIME_DIR}/componentize.sh ${SOURCES} --aot -o ${OUTPUT}.wasm
+                DEPENDS ${ARG_SOURCES} ${RUNTIME_DIR}/componentize.sh starling.wasm starling-ics.wevalcache
+                VERBATIM
+        )
+    else()
+        add_custom_command(
+                OUTPUT ${OUTPUT}.wasm
+                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+                COMMAND ${CMAKE_COMMAND} -E env "PATH=${WASM_TOOLS_DIR};${WIZER_DIR};$ENV{PATH}" ${RUNTIME_DIR}/componentize.sh ${SOURCES} -o ${OUTPUT}.wasm
+                DEPENDS ${ARG_SOURCES} ${RUNTIME_DIR}/componentize.sh starling.wasm
+                VERBATIM
+        )
+    endif()
     add_custom_target(${OUTPUT} DEPENDS ${OUTPUT}.wasm)
 endfunction()
 

cmake/spidermonkey.cmake

@@ -1,10 +1,18 @@
-set(SM_REV ffbf1c4641440e74174199def6558c710b3ac323)
+set(SM_REV bbaee9532ff88b38c31c7f38d0aba1204a6aa9d6)
 
 if (CMAKE_BUILD_TYPE STREQUAL "Debug")
     set(SM_BUILD_TYPE debug)
 else()
     set(SM_BUILD_TYPE release)
 endif()
+set(SM_BUILD_TYPE_DASH ${SM_BUILD_TYPE})
+
+option(WEVAL "Build with a SpiderMonkey variant that supports weval-based AOT compilation" OFF)
+
+if (WEVAL)
+    set(SM_BUILD_TYPE_DASH "${SM_BUILD_TYPE}-weval")
+    set(SM_BUILD_TYPE "${SM_BUILD_TYPE}_weval")
+endif()
 
 # If the developer has specified an alternate local set of SpiderMonkey
 # artifacts, use them. This allows for local/in-tree development without

cmake/weval.cmake

@@ -0,0 +1,6 @@
+set(WEVAL_VERSION v0.2.4)
+
+set(WEVAL_URL https://github.com/cfallin/weval/releases/download/${WEVAL_VERSION}/weval-${WEVAL_VERSION}-${HOST_ARCH}-${HOST_OS}.tar.xz)
+CPMAddPackage(NAME weval URL ${WEVAL_URL} DOWNLOAD_ONLY TRUE)
+set(WEVAL_DIR ${CPM_PACKAGE_weval_SOURCE_DIR})
+set(WEVAL_BIN ${WEVAL_DIR}/weval)

componentize.sh

@@ -6,7 +6,7 @@ wizer="${WIZER:-wizer}"
 wasm_tools="${WASM_TOOLS:-wasm-tools}"
 
 usage() {
-  echo "Usage: $(basename "$0") [input.js] [-o output.wasm]"
+  echo "Usage: $(basename "$0") [input.js] [--aot] [-o output.wasm]"
   echo "       Providing an input file but no output uses the input base name with a .wasm extension"
   echo "       Providing an output file but no input creates a component without running any top-level script"
   exit 1
@@ -19,6 +19,7 @@ fi
 
 IN_FILE=""
 OUT_FILE=""
+AOT=0
 
 while [ $# -gt 0 ]
 do
@@ -27,6 +28,10 @@ do
             OUT_FILE="$2"
             shift 2
             ;;
+        --aot)
+            AOT=1
+            shift
+            ;;
         *)
             if [ -n "$IN_FILE" ] && [ -z "$OUT_FILE" ] && [ $# -eq 1 ]
             then
@@ -62,8 +67,15 @@ else
   echo "Creating runtime-script component $OUT_FILE"
 fi
 
-
-echo "$IN_FILE" | WASMTIME_BACKTRACE_DETAILS=1 $wizer --allow-wasi --wasm-bulk-memory true \
-     --inherit-stdio true --inherit-env true $PREOPEN_DIR -o "$OUT_FILE" \
-     -- "$(dirname "$0")/starling.wasm"
+if [[ $AOT -ne 0 ]]; then
+    echo "$IN_FILE" | WASMTIME_BACKTRACE_DETAILS=1 weval weval -w $PREOPEN_DIR \
+         --cache-ro "$(dirname "$0")/starling-ics.wevalcache" \
+         --show-stats \
+         -o "$OUT_FILE" \
+         -i "$(dirname "$0")/starling.wasm"
+else
+    echo "$IN_FILE" | WASMTIME_BACKTRACE_DETAILS=1 $wizer --allow-wasi --wasm-bulk-memory true \
+         --inherit-stdio true --inherit-env true $PREOPEN_DIR -o "$OUT_FILE" \
+         -- "$(dirname "$0")/starling.wasm"
+fi
 $wasm_tools component new -v --adapt "wasi_snapshot_preview1=$(dirname "$0")/preview1-adapter.wasm" --output "$OUT_FILE" "$OUT_FILE"