Compile C runtime to Web Assembly using Emscripten

src/runtime/c/gu/exn.c

@@ -18,12 +18,24 @@ gu_exn_is_raised(GuExn* err) {
 	return err && (err->state == GU_EXN_RAISED);
 }
 
+GU_API_DECL void
+gu_exn_clear(GuExn* err) {
+	err->caught = NULL;
+	err->state = GU_EXN_OK;
+}
+
 GU_API bool
 gu_exn_caught_(GuExn* err, const char* type)
 {
 	return (err->caught && strcmp(err->caught, type) == 0);
 }
 
+GU_API_DECL void*
+gu_exn_caught_data(GuExn* err)
+{
+	return err->data.data;
+}
+
 GU_API void
 gu_exn_block(GuExn* err)
 {

src/runtime/c/gu/exn.h

@@ -71,23 +71,27 @@ gu_new_exn(GuPool* pool);
 GU_API_DECL bool
 gu_exn_is_raised(GuExn* err);
 
-static inline void
-gu_exn_clear(GuExn* err) {
-	err->caught = NULL;
-	err->state = GU_EXN_OK;
-}
+// static inline void
+// gu_exn_clear(GuExn* err) {
+// 	err->caught = NULL;
+// 	err->state = GU_EXN_OK;
+// }
+GU_API_DECL void
+gu_exn_clear(GuExn* err);
 
 #define gu_exn_caught(err, type) \
 	(err->caught && strcmp(err->caught, #type) == 0)
 
 GU_API_DECL bool
 gu_exn_caught_(GuExn* err, const char* type);
 
-static inline const void*
-gu_exn_caught_data(GuExn* err)
-{
-	return err->data.data;
-}
+// static inline const void*
+// gu_exn_caught_data(GuExn* err)
+// {
+// 	return err->data.data;
+// }
+GU_API_DECL void*
+gu_exn_caught_data(GuExn* err);
 
 /// Temporarily block a raised exception.
 GU_API_DECL void

src/runtime/c/pgf/jit.c

@@ -26,6 +26,16 @@ PGF_INTERNAL void
 pgf_jit_predicate(PgfReader* rdr, PgfAbstr* abstr,
                   PgfAbsCat* abscat)
 {
+    size_t n_funs = pgf_read_len(rdr);
+	gu_return_on_exn(rdr->err, );
+
+    for (size_t i = 0; i < n_funs; i++) {
+        gu_in_f64be(rdr->in, rdr->err);  // ignore
+        gu_return_on_exn(rdr->err, );
+
+        PgfCId name = pgf_read_cid(rdr, rdr->tmp_pool);
+        gu_return_on_exn(rdr->err, );
+    }
 }
 
 PGF_INTERNAL void

src/runtime/c/pgf/reader.c

@@ -1326,7 +1326,7 @@ pgf_read_concretes(PgfReader* rdr, PgfAbstr* abstr, bool with_content)
 PGF_INTERNAL PgfPGF*
 pgf_read_pgf(PgfReader* rdr) {
 	PgfPGF* pgf = gu_new(PgfPGF, rdr->opool);
-	
+
 	pgf->major_version = gu_in_u16be(rdr->in, rdr->err);
 	gu_return_on_exn(rdr->err, NULL);
 
@@ -1335,7 +1335,7 @@ pgf_read_pgf(PgfReader* rdr) {
 
 	pgf->gflags = pgf_read_flags(rdr);
 	gu_return_on_exn(rdr->err, NULL);
-		
+
 	pgf_read_abstract(rdr, &pgf->abstract);
 	gu_return_on_exn(rdr->err, NULL);
 

src/runtime/javascript/.gitignore

@@ -0,0 +1 @@
+.libs/

src/runtime/javascript/Dockerfile

@@ -0,0 +1,48 @@
+FROM emscripten/emsdk:latest
+
+RUN apt update
+RUN apt install -y autoconf automake libtool make
+
+WORKDIR /tmp/c
+COPY gu/*.c gu/*.h /tmp/c/gu/
+COPY pgf/*.c pgf/*.h /tmp/c/pgf/
+COPY pgf/lightning/i386/*.h /tmp/c/pgf/lightning/i386/
+COPY pgf/lightning/*.h /tmp/c/pgf/lightning/
+COPY \
+    Makefile.am \
+    configure.ac \
+    lib*.pc.in \
+    /tmp/c/
+RUN autoreconf -i
+RUN emconfigure ./configure
+RUN emmake make
+RUN emcc .libs/libgu.a .libs/libpgf.a -o pgf.js \
+    -sALLOW_MEMORY_GROWTH \
+    -sEXPORTED_FUNCTIONS="\
+        _pgf_read,\
+        _pgf_abstract_name,\
+        _pgf_read_expr,\
+        _pgf_print_expr,\
+        _pgf_expr_arity,\
+        _gu_new_pool,\
+        _gu_new_exn,\
+        _gu_data_in,\
+        _gu_exn_is_raised,\
+        _gu_exn_caught_,\
+        _gu_exn_caught_data,\
+        _gu_exn_clear,\
+        _gu_new_string_buf,\
+        _gu_string_buf_out,\
+        _gu_string_buf_data,\
+        _malloc,\
+        _free\
+        "\
+    -sEXPORTED_RUNTIME_METHODS="\
+        ccall,\
+        FS,\
+        getValue,\
+        AsciiToString,\
+        stringToUTF8,\
+        UTF8ToString,\
+        allocateUTF8\
+        "

src/runtime/javascript/README.md

@@ -0,0 +1,11 @@
+# JavaScript runtime using Web Assembly
+
+This folder contains very early work experimenting with a pure JavaScript runtime,
+compiled to Web Assembly (WASM) using [Emscripten](https://emscripten.org/).
+
+1. Compile the WASM files (inside Docker) using `build-wasm.sh`, placing them in `.libs/`
+2. Test in Node.js by running `node test-node.js [path to PGF]`
+3. Test in a web browser
+    1. Start a server with `npx serve -l 41296`
+    2. Browse to `http://localhost:41296/test-web.html`
+    3. Check JavaScript console

src/runtime/javascript/build-wasm.sh

@@ -0,0 +1,10 @@
+#! /usr/bin/env bash
+set -e
+
+# Build inside Docker image
+IMAGE="gf/build-c-runtime-wasm"
+docker build ../c --file Dockerfile --tag $IMAGE
+
+# Copy bulit files from container to host
+mkdir -p .libs
+docker run --rm --volume "$PWD":/tmp/host $IMAGE bash -c "cp pgf.js pgf.wasm /tmp/host/.libs/"