CIR Playground

// When a compile-time function declares its argument(s) to take a code object
// (CirCodeId), CIR will pass the raw code (in CIR IR form) into the function.
//
// In this example, we use this capability to examine if a pice of code calls
// any function or not.

#include <stdbool.h>
#include <stdio.h>
#include <cir.h>

// Returns true if the code calls a function, otherwise returns false.
static bool callsAFunction(CirCodeId codeId) {
    // Notice that a simple for loop is sufficient no matter how complex or
    // branchy the piece of code passed into a function is -- CIR's IR was
    // explicitly designed to be flat to make it easy to examine and manipulate
    // in C code.
    for (CirStmtId stmtId = CirCode_getFirstStmt(codeId); stmtId; stmtId = CirStmt_getNext(stmtId)) {
        if (CirStmt_isCall(stmtId))
            return true;
    }
    return false;
}

int main(void) {
    // Evaluates to true
    bool code1_callsAFunction = @callsAFunction(puts("Hi"));

// Evaluates to false
    bool code2_callsAFunction = @callsAFunction(42);

// Evaluates to true
    bool code3_callsAFunction = @callsAFunction(({
        int x = 3, y = 2;
        if (y > x)
            puts("y > x");
    }));
    return 0;
}