[LAB6] 313554033

[Chun-Ching-Hsu]

Description

I implemented a custom LLVM pass that, at the very start of the compilation pipeline, rewrites both the argc and argv[1] values in the main function so that:

debug(48763) is injected immediately at the top of main.

I grab the argc and argv arguments from main’s entry block.

I build a global constant string "hayaku... motohayaku!" and then:

Store its pointer directly into the argv[1] slot (so that any subsequent printf(argv[1]) sees the new value).

Scan through every instruction, replacing any use of the original argc SSA value with the constant 48763.

I also locate all LoadInst operations loading argv[1] (using a stripped‐cast GEP check) and strcmp calls, and replace their operands or uses with my constant string pointer, then erase the old loads.

Finally, I register this pass via the registerPipelineStartEPCallback so it runs unconditionally on every build configuration (O0 through O2).

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