Method commit

perfect/src/asm.rs:298–333

Write assembler to backing memory.

(&mut self)

    /// Write assembler to backing memory.
    pub fn commit(&mut self) -> Result<(), &str> {
        if self.cursor() > self.len {
            return Err("Assembled code doesn't fit into backing allocation");
        }
        if let Err(e) = self.encode_relocs() {
            println!("{:?}", e);
            return Err("Failed to encode relocations");
        }

        // Number of bytes in the buffer
        let num_bytes = self.ops.len();

        let src = self.ops.as_ptr();
        let dst = self.ptr as *mut u8;

        // NOTE: Some memcpy implementations *really dislike* when we decide
        // to use the null pointer as virtual address 0. 
        unsafe { 
            // Zero out the whole allocation
            //dst.write_bytes(0, self.len);

            if dst == std::ptr::null_mut() 
            {
                for i in 0..num_bytes { 
                    let b = src.offset(i as _).read();
                    dst.offset(i as _).write_volatile(b);
                }
            } else { 
                dst.write_bytes(0, self.len);
                std::ptr::copy_nonoverlapping(src, dst, num_bytes);
            }
        }

        self.committed = true;
        Ok(())
    }

    /// Clear all bytes in the backing allocation and reset the state 
    /// of this assembler.