Add gen-c-header option

lib/cli/src/cli.rs

@@ -11,7 +11,8 @@ use crate::commands::CreateObj;
 #[cfg(feature = "wast")]
 use crate::commands::Wast;
 use crate::commands::{
-    Add, Cache, Config, Init, Inspect, List, Login, Publish, Run, SelfUpdate, Validate, Whoami,
+    Add, Cache, Config, GenCHeader, Init, Inspect, List, Login, Publish, Run, SelfUpdate, Validate,
+    Whoami,
 };
 use crate::error::PrettyError;
 use clap::{CommandFactory, ErrorKind, Parser};
@@ -128,6 +129,9 @@ enum WasmerCLIOptions {
     #[structopt(name = "create-obj", verbatim_doc_comment)]
     CreateObj(CreateObj),
 
+    /// Generate the C static_defs.h header file for the input .wasm module
+    GenCHeader(GenCHeader),
+
     /// Get various configuration information needed
     /// to compile programs which use Wasmer
     Config(Config),
@@ -177,6 +181,7 @@ impl WasmerCLIOptions {
             Self::List(list) => list.execute(),
             Self::Login(login) => login.execute(),
             Self::Publish(publish) => publish.execute(),
+            Self::GenCHeader(gen_heder) => gen_heder.execute(),
             #[cfg(feature = "wast")]
             Self::Wast(wast) => wast.execute(),
             #[cfg(target_os = "linux")]
@@ -235,8 +240,8 @@ fn wasmer_main_inner() -> Result<(), anyhow::Error> {
     } else {
         match command.unwrap_or(&"".to_string()).as_ref() {
             "add" | "cache" | "compile" | "config" | "create-obj" | "create-exe" | "help"
-            | "inspect" | "init" | "run" | "self-update" | "validate" | "wast" | "binfmt"
-            | "list" | "login" | "publish" => WasmerCLIOptions::parse(),
+            | "gen-c-header" | "inspect" | "init" | "run" | "self-update" | "validate" | "wast"
+            | "binfmt" | "list" | "login" | "publish" => WasmerCLIOptions::parse(),
             _ => {
                 WasmerCLIOptions::try_parse_from(args.iter()).unwrap_or_else(|e| {
                     match e.kind() {

lib/cli/src/commands.rs

@@ -10,6 +10,7 @@ mod config;
 mod create_exe;
 #[cfg(feature = "static-artifact-create")]
 mod create_obj;
+mod gen_c_header;
 mod init;
 mod inspect;
 mod list;
@@ -34,8 +35,8 @@ use serde::{Deserialize, Serialize};
 #[cfg(feature = "wast")]
 pub use wast::*;
 pub use {
-    add::*, cache::*, config::*, init::*, inspect::*, list::*, login::*, publish::*, run::*,
-    self_update::*, validate::*, whoami::*,
+    add::*, cache::*, config::*, gen_c_header::*, init::*, inspect::*, list::*, login::*,
+    publish::*, run::*, self_update::*, validate::*, whoami::*,
 };
 
 /// The kind of object format to emit.

lib/cli/src/commands/create_exe.rs

@@ -504,7 +504,7 @@ pub(super) fn compile_pirita_into_directory(
 
 /// Prefix map used during compilation of object files
 #[derive(Debug, Default, PartialEq)]
-struct PrefixMapCompilation {
+pub(crate) struct PrefixMapCompilation {
     /// Sha256 hashes for the input files
     input_hashes: BTreeMap<String, String>,
     /// Manual prefixes for input files (file:prefix)
@@ -638,7 +638,7 @@ impl PrefixMapCompilation {
         }
     }
 
-    fn hash_for_bytes(bytes: &[u8]) -> String {
+    pub(crate) fn hash_for_bytes(bytes: &[u8]) -> String {
         use sha2::{Digest, Sha256};
         let mut hasher = Sha256::new();
         hasher.update(bytes);
@@ -992,7 +992,7 @@ fn get_module_infos(
 }
 
 /// Create the static_defs.h header files in the /include directory
-fn create_header_files_in_dir(
+pub(crate) fn create_header_files_in_dir(
     directory: &Path,
     entrypoint: &mut Entrypoint,
     atoms: &[(String, Vec<u8>)],

lib/cli/src/commands/gen_c_header.rs

@@ -0,0 +1,69 @@
+use crate::store::CompilerOptions;
+use anyhow::Context;
+use clap::Parser;
+use std::path::PathBuf;
+use wasmer::Target;
+use wasmer_compiler::Artifact;
+use wasmer_types::compilation::symbols::ModuleMetadataSymbolRegistry;
+
+use super::normalize_path;
+
+#[derive(Debug, Parser)]
+/// The options for the `wasmer gen-c-header` subcommand
+pub struct GenCHeader {
+    /// Input file
+    #[clap(name = "FILE", parse(from_os_str))]
+    path: PathBuf,
+
+    /// Prefix hash (default: SHA256 of input .wasm file)
+    #[clap(long)]
+    prefix: Option<String>,
+
+    /// Output file
+    #[clap(name = "OUTPUT PATH", short = 'o', parse(from_os_str))]
+    output: PathBuf,
+}
+
+impl GenCHeader {
+    /// Runs logic for the `gen-c-header` subcommand
+    pub fn execute(&self) -> Result<(), anyhow::Error> {
+        let path = crate::commands::normalize_path(&format!("{}", self.path.display()));
+        let file = std::fs::read(&path)
+            .map_err(|e| anyhow::anyhow!("{e}"))
+            .with_context(|| anyhow::anyhow!("{path}"))?;
+        let prefix = match self.prefix.as_deref() {
+            Some(s) => s.to_string(),
+            None => crate::commands::PrefixMapCompilation::hash_for_bytes(&file),
+        };
+        let (store, _) = CompilerOptions::default().get_store_for_target(Target::default())?;
+        let module_name = format!("WASMER_{}_METADATA", prefix.to_uppercase());
+        let engine = store.engine();
+        let engine_inner = engine.inner();
+        let compiler = engine_inner.compiler()?;
+        let features = engine_inner.features();
+        let tunables = store.tunables();
+        let (compile_info, _, _, _) =
+            Artifact::generate_metadata(&file, compiler, tunables, features)?;
+        let module_info = compile_info.module;
+
+        let metadata_length = 0;
+
+        let header_file_src = crate::c_gen::staticlib_header::generate_header_file(
+            &prefix,
+            &module_name,
+            &module_info,
+            &ModuleMetadataSymbolRegistry {
+                prefix: prefix.clone(),
+            },
+            metadata_length as usize,
+        );
+
+        let output = normalize_path(&self.output.display().to_string());
+
+        std::fs::write(&output, &header_file_src)
+            .map_err(|e| anyhow::anyhow!("{e}"))
+            .with_context(|| anyhow::anyhow!("{output}"))?;
+
+        Ok(())
+    }
+}

lib/compiler/src/engine/artifact.rs

@@ -412,7 +412,7 @@ impl Artifact {
     #[allow(clippy::type_complexity)]
     #[cfg(feature = "static-artifact-create")]
     /// Generate a compilation
-    fn generate_metadata<'data>(
+    pub fn generate_metadata<'data>(
         data: &'data [u8],
         compiler: &dyn Compiler,
         tunables: &dyn Tunables,

tests/integration/cli/tests/gen_c_header.rs

@@ -0,0 +1,54 @@
+use std::path::PathBuf;
+use std::process::Command;
+use wasmer_integration_tests_cli::get_wasmer_path;
+use wasmer_integration_tests_cli::C_ASSET_PATH;
+
+fn create_exe_wabt_path() -> String {
+    format!("{}/{}", C_ASSET_PATH, "wabt-1.0.37.wasmer")
+}
+
+fn create_exe_python_wasmer() -> String {
+    format!("{}/{}", C_ASSET_PATH, "python-0.1.0.wasmer")
+}
+
+fn create_exe_test_wasm_path() -> String {
+    format!("{}/{}", C_ASSET_PATH, "qjs.wasm")
+}
+
+#[test]
+fn gen_c_header_works() -> anyhow::Result<()> {
+    let temp_dir = tempfile::tempdir()?;
+    let operating_dir: PathBuf = temp_dir.path().to_owned();
+
+    let wasm_path = operating_dir.join(create_exe_test_wasm_path());
+    let out_path = temp_dir.path().join("header.h");
+
+    let _ = Command::new(get_wasmer_path())
+        .arg("gen-c-header")
+        .arg(&wasm_path)
+        .arg("-o")
+        .arg(&out_path)
+        .output()
+        .unwrap();
+
+    let file = std::fs::read_to_string(&out_path).expect("no header.h file");
+    assert!(file.contains("wasmer_function_6f62a6bc5c8f8e3e12a54e2ecbc5674ccfe1c75f91d8e4dd6ebb3fec422a4d6c_0"), "no wasmer_function_6f62a6bc5c8f8e3e12a54e2ecbc5674ccfe1c75f91d8e4dd6ebb3fec422a4d6c_0 in file");
+
+    let cmd = Command::new(get_wasmer_path())
+        .arg("gen-c-header")
+        .arg(&wasm_path)
+        .arg("-o")
+        .arg(&out_path)
+        .arg("--prefix")
+        .arg("abc123")
+        .output()
+        .unwrap();
+
+    let file = std::fs::read_to_string(&out_path).expect("no header.h file");
+    assert!(
+        file.contains("wasmer_function_abc123_0"),
+        "no wasmer_function_abc123_0 in file"
+    );
+
+    Ok(())
+}