Compile a C Function to Wasm and Inspect the Binary

Compiling C to Wasm

WebAssembly is a portable binary ISA. LLVM's \`clang --target=wasm32\` plus \`wasm-ld\` turns C into a \`.wasm\` module browsers and standalone runtimes can load.

Toolchain Steps

Pipeline:

1. \`clang --target=wasm32 -c add.c -o add.o\`
2. \`wasm-ld add.o -o add.wasm --export=add\`
3. \`wasm2wat add.wasm\` for readable WAT

C symbols are hidden by default. Export with \`attribute((visibility("default")))\` or a linker \`--export\` flag so JavaScript or WASI can call \`add\`.

For example:

\`\`\`c attribute((export_name("add"))) int add(int a, int b) { return a + b; } \`\`\`

compiles to \`i32.add\` on two parameters in the Wasm stack machine.

Binary starts with magic \`\\0asm\` and version bytes, then type, function, export, and code sections.

Design Notes

Inspect both WAT and the raw binary hex for the same module. Seeing `00 61 73 6D` at offset zero confirms you are looking at Wasm, not a mislabeled object file from a wrong target triple.

For This Exercise

This exercise asks you to document the clang/wasm-ld pipeline for a simple \`add\` function. You will show C source, linker commands, and the resulting WAT so you can read what the compiler produced.

You will use the same mental model here when reading production interpreter source later in the track. Sketch one concrete input on paper, predict the outcome, then confirm with code. That discipline catches logic errors early and makes debugging far faster when you extend the implementation in follow-on tasks.