This example show how to import an external function written in C in an Heptagon program.
- The .epi file contains the signature of the function in Heptagon.
- Only functions with no side effects can be safely imported.
- The imported function must have the same calling convention as generated code (inputs given by value, outputs in a f_out structure).
- The generated code will include "mathext.h", that should define the step function
To make it work:
heptc mathext.epi
heptc -target c imports.ept
gcc -c -I /usr/local/lib/heptagon/c -I . mathext.c imports_c/*.c
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