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This looks cool, and if you click the "Compile to RISC-V" button you get to a page where a lot of the assembly code has meaningful comments explaining what each

This looks cool, and if you click the "Compile to RISC-V" button you get to a page where a lot of the assembly code has meaningful comments explaining what each instruction does. I wish we had that in every compiler... As for GC, if I read the code correctly it doesn't do any and simply aborts on out of memory. Fair for a first compiler course.

johnisgood 7y ago
> where a lot of the assembly code has meaningful comments explaining what each instruction does Cutter (which is based on Radare2, basically a GUI for r2) can do that under the "Disassembly" tab! It works with executables and source code. You have to configure it to show the additional information though. It is such a neat tool!
- tom_mellior 7y ago
  Sorry, I was probably unclear. I imagine Cutter just tells you what each opcode does, no? gcc.godbolt.org does that too, with links to the ISA docs. But here I mean that in the ChocoPy code you get explanations of what instructions do in the context of the program's semantics, i.e., how they relate to a higher-level view of what's going on. An example: .globl $print $print: # Function print lw a0, 0(sp) # Load arg beq a0, zero, print_6 # None is an illegal argument lw t0, 0(a0) # Get type tag of arg li t1, 1 # Load type tag of `int` beq t0, t1, print_7 # Go to print(int) li t1, 3 # Load type tag of `str` beq t0, t1, print_8 # Go to print(str) li t1, 2 # Load type tag of `bool` beq t0, t1, print_9 # Go to print(bool) print_6: # Invalid argument li a0, 1 # Exit code for: Invalid argument la a1, const_4 # Load error message as str addi a1, a1, @.__str__ # Load address of attribute __str__ j abort # Abort Note that the different occurrences of lw and li explain the meanings of the magic constants in the code. This would be pretty hard to do from disassembly alone.
  - deleted 7y ago
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  - johnisgood 7y ago
    Ah sorry, at first I thought you meant something like: https://i.imgur.com/RZeFKZQ.png https://i.imgur.com/RZeFKZQ.png. I did not try ChocoPy out myself, so I had no idea of the output to what you were referring, which is my fault. In any case, I hope I introduced Cutter/Radare2 to someone at least. :D

johnisgood 7y ago

> where a lot of the assembly code has meaningful comments explaining what each instruction does Cutter (which is based on Radare2, basically a GUI for r2) can do that under the "Disassembly" tab! It works with executables and source code. You have to configure it to show the additional information though. It is such a neat tool!

tom_mellior 7y ago
Sorry, I was probably unclear. I imagine Cutter just tells you what each opcode does, no? gcc.godbolt.org does that too, with links to the ISA docs. But here I mean that in the ChocoPy code you get explanations of what instructions do in the context of the program's semantics, i.e., how they relate to a higher-level view of what's going on. An example: .globl $print $print: # Function print lw a0, 0(sp) # Load arg beq a0, zero, print_6 # None is an illegal argument lw t0, 0(a0) # Get type tag of arg li t1, 1 # Load type tag of `int` beq t0, t1, print_7 # Go to print(int) li t1, 3 # Load type tag of `str` beq t0, t1, print_8 # Go to print(str) li t1, 2 # Load type tag of `bool` beq t0, t1, print_9 # Go to print(bool) print_6: # Invalid argument li a0, 1 # Exit code for: Invalid argument la a1, const_4 # Load error message as str addi a1, a1, @.__str__ # Load address of attribute __str__ j abort # Abort Note that the different occurrences of lw and li explain the meanings of the magic constants in the code. This would be pretty hard to do from disassembly alone.
- deleted 7y ago
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- johnisgood 7y ago
  Ah sorry, at first I thought you meant something like: https://i.imgur.com/RZeFKZQ.png https://i.imgur.com/RZeFKZQ.png. I did not try ChocoPy out myself, so I had no idea of the output to what you were referring, which is my fault. In any case, I hope I introduced Cutter/Radare2 to someone at least. :D