ewe

ewe is a compiler wrapper toolset that extracts metadata from C code and stores it in addition to the binaries as .ewe files.

Its primary purpose is to tackle the information loss problem during compilation and reconstruct basic block boundaries in machine code. This enables CFG reconstruction from C code making use of the goto* extension.

Toolchain

The ewe tools are part of squid's toolchain and can be found in the /ewe/ directory inside the docker container. The following tools are available:

• /ewe/gcc: A wrapper around riscv64-unknown-linux-gnu-gcc
• /ewe/as: A wrapper around riscv64-unknown-linux-gnu-as
• /ewe/ar: A wrapper around riscv64-unknown-linux-gnu-ar
• /ewe/ld: A wrapper around riscv64-unknown-linux-gnu-ld

Use these programs instead of their RISC-V counterparts whenever your target uses goto* statements.

Integration into squid

squid automatically detects if the binaries it loads have a corresponding .ewe file and uses that for CFG reconstruction. It is important that the .ewe files follow the following convention: For a binary path/to/binary.ext that is loaded by squid the .ewe file must be named path/to/binary.ext.ewe. So, the .ewe extension is appended to the filename in order to signal that this .ewe file belongs to this binary.