updated render_cpp script to work

Author: Soybean44

.gitignore

@@ -1 +1,2 @@
 /.quarto/
+/__pycache__/

_quarto.yml

@@ -1,6 +1,7 @@
 project:
   type: website
   pre-render: scripts/render_cpp.py
+  resources: "*.wasm"
 
 execute:
   freeze: auto

scripts/includes/wasm.h

@@ -0,0 +1,2 @@
+#define WASM_EXPORT __attribute__((visibility("default"))) extern "C"
+#define WASM_IMPORT extern "C"

scripts/render_cpp.py

@@ -6,12 +6,40 @@
              and compile them to wasm for use in quarto web pages.
 """
 
+import ctypes
 import os
+import shutil
 import subprocess
 import sys
 
 import exdown
 
+# --- CONSTANTS --- #
+CFLAGS = [
+    "-Wall",
+    "--target=wasm32",
+    "-I./scripts/includes/",  # this includes the wasm.h file
+    "-Os",
+    "-flto",
+    "--no-standard-libraries",
+    "-fvisibility=hidden",
+    "-std=c++14",
+    "-ffunction-sections",  # This makes the function names normal
+    "-fdata-sections",
+]
+
+LDFLAGS = [
+    "--no-entry",
+    "--strip-all",
+    "--export-dynamic",
+    "--allow-undefined",  # This allows for external definitions in js
+    "--initial-memory=131072",
+    "--error-limit=0",
+    "--lto-O3",
+    "-O3",
+    "--gc-sections",
+]
+
 file_str = os.getenv("QUARTO_PROJECT_INPUT_FILES")
 if file_str is None:
     print("Error: needs to be run as a pre-render script", file=sys.stderr)
@@ -29,34 +57,39 @@ def has_cpp(filename: str) -> bool:
     return False
 
 
+# Get all the files to be compiled to
 cpp_files = [file for file in files if has_cpp(file)]
 
 if cpp_files == []:
     print("Note: No cpp code blocks to render")
     sys.exit(0)
 
 
-def compile_cpp(filename: str, directory: str) -> None:
-    command = [
-        "clang",
-        "--target=wasm32",
-        "--no-standard-libraries",
-        "-Wl,--export-all",
-        "-Wl,--no-entry",
-        "-o",
-        f"{directory}/{filename}.wasm",
-        f"{directory}/{filename}.cpp",
-    ]
+def compile_cpp(filepath: str) -> None:
+    command = (
+        ["clang"]
+        + CFLAGS
+        + [f"-Wl,{flag}" for flag in LDFLAGS]
+        + [
+            "-o",
+            f"{filepath}.wasm",
+            f"{filepath}.cpp",
+        ]
+    )
     subprocess.run(command, check=True)
 
 
 for file in cpp_files:
     print(f"Parsing: {file}")
-    cpp_code = "\n".join(line[0] for line in exdown.extract(file, syntax_filter="cpp"))
-    if (filename := os.path.basename(file)) is not None:
-        filename = filename.split(".")[0]
-    directory = os.path.dirname(file)
-    with open(f"{directory}/{filename}.cpp", "w", encoding="UTF-8") as f:
-        f.write(cpp_code)
-    # TODO: Implement compilation to wasm
-    # compile_cpp(filename, directory)
+
+    # check if the file exists and get the filename
+    if file is not None:
+        # Extract cpp code from qmd codeblocks
+        cpp_code = "\n".join(
+            line[0] for line in exdown.extract(file, syntax_filter="cpp")
+        )
+        filename = file.split(".")[0]
+
+        with open(f"{filename}.cpp", "w", encoding="UTF-8") as f:
+            f.write(cpp_code)
+        compile_cpp(filename)