Support gzipped WASM inputs in utils::parse_wasm and `utils::parse_…

…wasm_file` (#55)

Cargo.toml

@@ -22,6 +22,7 @@ walrus = "0.20.1"
 candid = "0.10"
 rustc-demangle = "0.1"
 thiserror = "1.0.35"
+libflate = "1.3.0"
 
 wasm-opt = { version = "0.113.0", optional = true }
 tempfile = { version = "3.5.0", optional = true }

src/utils.rs

@@ -1,26 +1,49 @@
 use crate::Error;
+use libflate::gzip;
+use std::borrow::Cow;
 use std::collections::HashMap;
+use std::io::{self, Read};
 use walrus::*;
 
+pub const WASM_MAGIC_BYTES: &[u8] = &[0, 97, 115, 109];
+
+pub const GZIPPED_WASM_MAGIC_BYTES: &[u8] = &[31, 139, 8, 0];
+
 fn wasm_parser_config(keep_name_section: bool) -> ModuleConfig {
     let mut config = walrus::ModuleConfig::new();
     config.generate_name_section(keep_name_section);
     config.generate_producers_section(false);
     config
 }
 
-pub fn parse_wasm(wasm: &[u8], keep_name_section: bool) -> Result<Module, Error> {
+fn decompress(bytes: &[u8]) -> Result<Vec<u8>, std::io::Error> {
+    let mut decoder = gzip::Decoder::new(bytes)?;
+    let mut decoded_data = Vec::new();
+    decoder.read_to_end(&mut decoded_data)?;
+    Ok(decoded_data)
+}
+
+pub fn parse_wasm(bytes: &[u8], keep_name_section: bool) -> Result<Module, Error> {
+    let wasm = if bytes.starts_with(WASM_MAGIC_BYTES) {
+        Ok(Cow::Borrowed(bytes))
+    } else if bytes.starts_with(GZIPPED_WASM_MAGIC_BYTES) {
+        decompress(bytes).map(Cow::Owned)
+    } else {
+        Err(io::Error::new(
+            io::ErrorKind::InvalidInput,
+            "Input must be either gzipped or uncompressed WASM.",
+        ))
+    }
+    .map_err(Error::IO)?;
     let config = wasm_parser_config(keep_name_section);
     config
-        .parse(wasm)
+        .parse(&wasm)
         .map_err(|e| Error::WasmParse(e.to_string()))
 }
 
 pub fn parse_wasm_file(file: std::path::PathBuf, keep_name_section: bool) -> Result<Module, Error> {
-    let config = wasm_parser_config(keep_name_section);
-    config
-        .parse_file(file)
-        .map_err(|e| Error::WasmParse(e.to_string()))
+    let bytes = std::fs::read(file).map_err(Error::IO)?;
+    parse_wasm(&bytes[..], keep_name_section)
 }
 
 #[derive(Clone, Copy, PartialEq, Eq)]

tests/tests.rs

@@ -60,6 +60,11 @@ fn instrumentation() {
         .assert()
         .success();
     assert_wasm("wat-instrument.wasm");
+    wasm_input("wat.wasm.gz", true)
+        .arg("instrument")
+        .assert()
+        .success();
+    assert_wasm("wat-instrument.wasm");
     wasm_input("rust.wasm", true)
         .arg("instrument")
         .assert()
@@ -86,6 +91,11 @@ fn shrink() {
         .assert()
         .success();
     assert_wasm("wat-shrink.wasm");
+    wasm_input("wat.wasm.gz", true)
+        .arg("shrink")
+        .assert()
+        .success();
+    assert_wasm("wat-shrink.wasm");
     wasm_input("rust.wasm", true)
         .arg("shrink")
         .assert()
@@ -147,6 +157,14 @@ fn resource() {
         .assert()
         .success();
     assert_wasm("wat-limit.wasm");
+    wasm_input("wat.wasm.gz", true)
+        .arg("resource")
+        .arg("--remove-cycles-transfer")
+        .arg("--limit-stable-memory-page")
+        .arg("32")
+        .assert()
+        .success();
+    assert_wasm("wat-limit.wasm");
     wasm_input("rust.wasm", true)
         .arg("resource")
         .arg("--remove-cycles-transfer")
@@ -213,6 +231,11 @@ Custom sections with size: []
         .assert()
         .stdout(expected)
         .success();
+    wasm_input("wat.wasm.gz", false)
+        .arg("info")
+        .assert()
+        .stdout(expected)
+        .success();
 }
 
 #[test]
@@ -256,6 +279,12 @@ fn json_info() {
         .assert()
         .stdout(expected)
         .success();
+    wasm_input("wat.wasm.gz", false)
+        .arg("info")
+        .arg("--json")
+        .assert()
+        .stdout(expected)
+        .success();
 }
 
 #[test]