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Parse a Wasm Binary Module: Sections, Types, Function Bodies

hard2/7

Compile a C Function to Wasm and Inspect the Binary Implement a Wasm Stack Machine Interpreter for a Subset of Instructions

Language

Compiler

2.0s Limit 256MB

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Implementation

Write a C program that parses a minimal Wasm binary module and prints section headers, types, and export names.

Requirements:

Define a hardcoded minimal Wasm binary byte array
Verify the magic bytes (0x00 0x61 0x73 0x6D)
Verify the version (0x01 0x00 0x00 0x00)
Parse section headers (ID and size using LEB128)
Print each section name and size
Parse the type section to show function signatures
Parse the export section to show export names
Include the terms: Wasm binary, section, LEB128, magic

Why This Matters

This section-by-section layout is specified precisely in the WebAssembly binary format spec, and it's exactly what tools like wasm2wat and wasm-objdump from the WABT toolkit parse to produce human-readable output. LEB128 decoding is the same variable-length integer trick DWARF debug info and Git's packfile format use, so this skill transfers well beyond WebAssembly.

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Validation Suite

main.c

Workspace 1.0

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