Debugging Tool Objdump

objdump

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GNU objdump inspects sections, symbols, relocations, and disassembly in the exact optimized xemu binary.

Property	Details
Supported OS	Windows, Linux, macOS.
Install	Install GNU Binutils or use the project pinned MinGW toolchain.
Verify	x86_64-w64-mingw32-objdump --version
Primary output	See the workflow below.

When to use it

x86_64-w64-mingw32-objdump is useful when you need to understand the exact optimized binary around a hot address or build a bounded symbol map.

GNU reference: https://sourceware.org/binutils/docs/binutils/objdump.html

Inspect PE/section layout

x86_64-w64-mingw32-objdump -h xemu.exe

Look at section VMAs/sizes and confirm the address/RVA belongs to executable text.

Inspect defined symbols

x86_64-w64-mingw32-objdump -t -C xemu.exe

This is useful for building or checking a defined-text symbol map when full source-line DWARF is not available to the analysis stage.

Disassemble a function

x86_64-w64-mingw32-objdump -d -C --disassemble=tlb_reset_dirty_range_all xemu.exe

If source/debug interleave is available:

x86_64-w64-mingw32-objdump -S -C --disassemble=tlb_reset_dirty_range_all xemu-dwarf.exe

Read the data

Use disassembly to answer questions such as:

• Did LTO inline this helper?
• Is the sampled address in the loop body or call setup?
• Did the compiler vectorize/unroll the code?
• Is an apparently expensive C helper only a few machine instructions here?
• Does a proposed source change actually alter the generated hot loop?

Do not infer invocation frequency from static disassembly. It tells you what code exists, not how often runtime execution reached it.

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Boundaries and common mistakes

Static disassembly shows what machine code exists. It does not prove the code executed or establish call frequency. Pair it with runtime evidence.

Use the exact build because LTO, inlining, target ISA, and link order can materially change addresses and instruction sequences.

Evidence to retain

• Tool name and exact version.
• Source commit/tree and executable SHA-256.
• The complete command or saved profile used.
• Input artifact hashes and the explicitly selected time or address range.
• Raw output plus any derived report; do not retain only a screenshot or conclusion.
• Admission failures, warnings, dropped events, incomplete rows, or unsupported operations.

Official references

• GNU objdump

Related xemu guides

• Debugging Tools and Commands
• Debugging Lag and Hot Paths
• Performance Methodology