How to install Python package from source on Windows

[Steve D'Aprano]

On Fri, 19 May 2017 06:12 am, Chris Angelico wrote:

> On Fri, May 19, 2017 at 5:29 AM, bartc <bc at freeuk.com> wrote:
>> On 18/05/2017 19:50, Chris Angelico wrote:
>>
>>> Now this, however, is more serious. Those warnings scare me, too. (I
>>> just tried it.) Instead of being "gcc is noisy", these are "your code
>>> is sloppy". These are exactly why I tell most people NOT to write in
>>> C. For machine-generated code, this is IMO unacceptable. Maybe
>>> "-Wno-unused" is okay (machine-generated code often has some junk in
>>> it), but all the uninitialized variables? No way. Doesn't matter what
>>> compiler you use, run it in all-warnings-enabled mode at least once as
>>> part of testing your codegen.
>>
>>
>> The rules are different when you are writing in a different language and
>> only use a C compiler to compile the intermediate code.
> 
> Only if your codegen is magically perfect. What happens if you have a
> bug in your compiler? What if it emits incorrect C code?

Oh but this is Bart we're talking about. Of course his code generator is
perfect, it is unthinkable that it emits incorrect code.



>> Before it becomes C, the code has already been largely verified. C might
>> still pick up some things, if the first compiler doesn't check them.
> 
> "largely" verified. Can you be absolutely certain that not one of
> these compiler-detected issues is actually a problem? Would you stake
> your life on it - for example, would you compile this code and put it
> in charge of an airliner that you then ride on?
> 
>> But C is dominated by its ideas of what is undefined behaviour and what
>> is implementation defined, which don't match the model used in the
>> original language. 

Since you are ultimately compiling the code in C, those ideas of undefined
behaviour etc do apply. The behaviour of the C compiler doesn't suddenly,
magically, change just because the code was generated by a program in
another language. If <some code> generates warnings because it relies on
undefined behaviour, it is still undefined behaviour regardless of whether
you typed the code yourself or used a code generator.




-- 
Steve
Emoji: a small, fuzzy, indistinct picture used to replace a clear and
perfectly comprehensible word.