Comment by Iv | Hacker News Reader

Comment by Iv | Hacker News Reader

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Uncommon and slightly extreme viewpoint: the best way for a python programmer to learn C is to learn a bit of assembly first.

Python is a high-level language: it provides tools to manipulate abstractions easily. C is a low-level one: it gives you access to chunks of memory (and far enough ropes to hang yourself while shooting yourself in the foot while drowning)

Assembly is not hard to learn. It has a reputation of being hard because it is tedious to use and that optimizations can be very intricate but learning basic assembly does not take long. Learn about MOV, ADD, JMP, INT, a few conditional jumps, learn how negative numbers are represented, what a memory mapping is, what a program counter or a stack counter are.

Then, go back to C. Read a bit about how function calls are made, memory allocated, and you will see that C is actually a high-level assembly language. All the hard parts of C will become obvious: a pointer is a variable that stores an address, a stack overflow, a segfault, a memory leak, all these will make sense very easily within that framework.

Completely agreed!

In the past, I had always avoided C because I didn't understand why many aspects of why it is the way that it is (eg pointers etc). Then I took my university's CPU architecture courses. That sorted that fear right out since I had to go from the ground up, learning everything I'd previously largely avoided or ignored - everything from transistors and the basic logic gates (AND, OR, XOR, NOT, etc) they consist of to full adders, all the way up to pipelined CPUs. Naturally, we learned assembly as part of this.

C made an awful lot more sense after all of this! I still don't like using it, but that's a lot more to do with my understanding of it's dangers (I prefer to let the compiler do the hard work of verifying my programs make sense, a la Rust &c), rather than a fear born of ignorance.

Alternatively write some basic constructs (loops, functions etc.) in C and inspect the generated assembly. You have to fiddle with compiler settings a bit because the optimized output isn't very helpful but for me it was extremely helpful to see what ASM code my compiler tool chain actually produces (to understand the typical function call structure for example).

Doing simple reverse engineering challenges is also a fun and easy way to get a patter matching kind of feeling for assembly.

>Uncommon and slightly extreme viewpoint: the best way for a python programmer to learn C is to learn a bit of assembly first.

I agree. I also sort of learned it that way. The difference was that I learned Turbo Pascal first, before C, and BASIC before TP, but then either while learning TP or C, I also learned some assembly and something about the fundamentals of computer hardware and microprocessors (as related to programming, not electronics) in an interleaved manner. Was lucky to have access to some very good books on all these (and many other topics) from the British Council Library in the city I was in at the time. Gave me a solid grounding in many topics related to computers.

This approach might lead to programmers thinking that they can do things in C because they have a particular mapping to assembly in mind. This might lead to undefined behavior. Casting pointers around for example is no problem in assembly (there are no types...) but has undefined behavior in many circumstances in C.

That doesn't mean that there is no defined behavior to achieve the same thing, though. Platform portability just requires a jump through a few more hoops and then some.

C is high-level language. It's portable across variety of platforms, while low-level languages are tied to hardware platform. Assembler is low level language.

Sounds very reasonable. Any specific books or tutorials you would recommend?

I personally found Programming From The Ground Up[0] to be phenomenal, though a little dated. Alternatively google around for NASM (or MASM if you're on windows) tutorials, such as asmtutor[1].

[0]: http://download.savannah.gnu.org/releases/pgubook/

[1]: http://asmtutor.com/

Any recommendations for assembly learning material?

Why not use LLVM IR instead, which is simpler?

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