3 ms·

> But to sum up the advantage of C: C is for when you don't want any surprises. It's a very un-surprising language. Actually, judging by the quantity of unspec

> But to sum up the advantage of C: C is for when you don't want any surprises. It's a very un-surprising language. Actually, judging by the quantity of unspecified/undefined/implementation-defined behaviors in the C spec, I'd say C is full of surprises.

mtdewcmu 12y ago
I've seen lists of those, and they are pretty esoteric. I don't think I've ever stepped on one accidentally.
- ahomescu1 12y ago
  How about the problem that the sizes of the basic types aren't exactly specified. All that C requires is that: char < short < int < long < long long and that sizeof(char) >= 8, sizeof(short) >= 16, sizeof(int) >= 16, sizeof(long) >= 32, sizeof(long long) >= 64 (from Wikipedia). The fact that int is allowed to be 16 bits, 32 bits, 64 bits or almost anything else is IMHO very nasty and has produced quite a few problems.
  - mtdewcmu 12y ago
    That is a problem, but doesn't C++ have the same problem? The situation was better before 64-bit became popular, when int == long == 32 bits on any system that mattered (when 16-bit gave way to 32-bits, you couldn't be sorry about that, it was a relief). Somehow the transition to 64 bits got screwed up, and you can hardly trust the basic integer types anymore. I have started using the new stdint.h types wherever size is likely to be an issue.
    - ahomescu1 12y ago
      > That is a problem, but doesn't C++ have the same problem? It does, but that wasn't the point. I wasn't defending C++.
      - mtdewcmu 12y ago
        I guess I don't know what your point was.
        ahomescu1 12y ago
        That C isn't predictable or well-specified, which is a real problem when writing portable or secure code ("oh shit" moments in C code don't just give programmers headaches, but have caused tons of vulnerabilities).
        mtdewcmu 12y ago
        Not predictable or well-specified in comparison to what? Buffer overflows are not caused by the language. They are a well-known risk of developing in native code. Well-known risks are not surprises. Part of being unsurprising is being one of the oldest and most popular programming languages. There's no excuse for being surprised by what's well known.
        ahomescu1 12y ago
        In comparison to Java, for example. Java specifies integer and float semantics exactly, including what happens for things like over/underflow and division by zero. C leaves too much to be decided by the compiler writer or ABI. Buffer overflows aren't the only problem C has. For an interesting discussion and examples of bad behavior that C allows, please take a look at [1] (especially part 2 of that series) and [2] (yes, some of these are compiler shenanigans; the problem is that the C standard allows the compiler to go crazy). 1 - http://blog.llvm.org/2011/05/what-every-c-programmer-should-know.html http://blog.llvm.org/2011/05/what-every-c-programmer-should-... 2 - http://blog.regehr.org/archives/213 http://blog.regehr.org/archives/213

mtdewcmu 12y ago

I've seen lists of those, and they are pretty esoteric. I don't think I've ever stepped on one accidentally.

ahomescu1 12y ago
How about the problem that the sizes of the basic types aren't exactly specified. All that C requires is that: char < short < int < long < long long and that sizeof(char) >= 8, sizeof(short) >= 16, sizeof(int) >= 16, sizeof(long) >= 32, sizeof(long long) >= 64 (from Wikipedia). The fact that int is allowed to be 16 bits, 32 bits, 64 bits or almost anything else is IMHO very nasty and has produced quite a few problems.
- mtdewcmu 12y ago
  That is a problem, but doesn't C++ have the same problem? The situation was better before 64-bit became popular, when int == long == 32 bits on any system that mattered (when 16-bit gave way to 32-bits, you couldn't be sorry about that, it was a relief). Somehow the transition to 64 bits got screwed up, and you can hardly trust the basic integer types anymore. I have started using the new stdint.h types wherever size is likely to be an issue.
  - ahomescu1 12y ago
    > That is a problem, but doesn't C++ have the same problem? It does, but that wasn't the point. I wasn't defending C++.
    - mtdewcmu 12y ago
      I guess I don't know what your point was.
      - ahomescu1 12y ago
        That C isn't predictable or well-specified, which is a real problem when writing portable or secure code ("oh shit" moments in C code don't just give programmers headaches, but have caused tons of vulnerabilities).
        mtdewcmu 12y ago
        Not predictable or well-specified in comparison to what? Buffer overflows are not caused by the language. They are a well-known risk of developing in native code. Well-known risks are not surprises. Part of being unsurprising is being one of the oldest and most popular programming languages. There's no excuse for being surprised by what's well known.
        ahomescu1 12y ago
        In comparison to Java, for example. Java specifies integer and float semantics exactly, including what happens for things like over/underflow and division by zero. C leaves too much to be decided by the compiler writer or ABI. Buffer overflows aren't the only problem C has. For an interesting discussion and examples of bad behavior that C allows, please take a look at [1] (especially part 2 of that series) and [2] (yes, some of these are compiler shenanigans; the problem is that the C standard allows the compiler to go crazy). 1 - http://blog.llvm.org/2011/05/what-every-c-programmer-should-know.html http://blog.llvm.org/2011/05/what-every-c-programmer-should-... 2 - http://blog.regehr.org/archives/213 http://blog.regehr.org/archives/213