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2
votes
1answer
127 views

C++ design pattern for template instantiation based on run time information?

Say I want to be able to create objects for a range of template parameter template<int a> class Myclass : public MyclassSuper{...}; And I want to create objects like Myclass<...
3
votes
2answers
768 views

What is the difference between a static library and an archive library?

In the comments of a recent answer, I equated a static library with an archive of compiled object files. The response was that they are not the same, so what is the difference? To clarify - gcc ...
2
votes
3answers
274 views

In c++, is there a way inside a function block, to execute cleanup code after the value has been returned?

Backstory (You can skip) I am building an API for managing Files and Directories in a consistent manner across a project. This is for deduplication and consistency when performing a task, and in this ...
0
votes
4answers
248 views

Is it better to use the linker to compile multiple C++ files or better to include them as a header file

Assume we have two files a.cc #include <iostream> int timesTwo(int in); int main(){ std::cout << timesTwo(5) << std::endl; return 0; } b.cc int timesTwo(int in){ return in*2;...
0
votes
1answer
112 views

Is there a way to use and ignore blocks of code, caused by events during runtime?

I'm working in C++14 and trying to figure out a way to put two classes (with the same name) inside the same header file. In this scenario one class would always be ignored as a result of something ...
5
votes
3answers
377 views

Does the output of a compiler depend on the OS you are using?

In the company I am working in we have a management software, written by an external programmer. Let's call the software PK. PK was initially written in the 90s using C++. Since then it was regularely ...
6
votes
1answer
3k views

Is there any use case for using 'L' letter after a number literal in C?

I know that in C code using L after a number tells the compiler that the respective number is L. However I do not see any practical use for this. Do modern compilers still have a use for this ...
8
votes
2answers
9k views

Why C allows multiple global declarations of the same variable but NOT multiple local declarations?

I noticed that if I declare a global variable multiple times the compiler does not even output a warning. However if I declare a local variable in a function multiple times, for example, the gcc ...
60
votes
10answers
11k views

Is it bad practice to use a C++ compiler just for function overloading?

So I am working on a software design using C for a certain processor. The tool-kit includes the ability to compile C as well as C++. For what I am doing, there is no dynamic memory allocation ...
5
votes
4answers
852 views

How does Java improve over C++ in the area of portability?

I was reading through a Java book by author Herbert Schildt and he writes how the advantage of Java over C++ in portabilaty is that while C++ can be run anywhere, it still requires each program to be ...
4
votes
1answer
740 views

Do I need to declare a delay timer variable as volatile even if I access it from another module

This is a question more about using volatile to prevent optimization than about caching write/read of a variable. Particularly timer delay variables since I don't want to declare everything volatile ...
23
votes
1answer
2k views

Why does the documentation on some languages say “equivalent to” rather than “is”?

Why does the documentation on some languages say "equivalent to" rather than "is"? For example, the Python Docs say itertools.chain(*iterables) ... Equivalent to: def chain(*iterables): ...
1
vote
1answer
175 views

Why some compilers do not synthesize the move operations at all per this paragraph in C++ Primer 5th?

In particular, if a class defines its own copy constructor, copy-assignment operator, or destructor, the move constructor and move-assignment operator are not synthesized. —— quote from "13.6.2. Move ...
0
votes
0answers
85 views

Why are datatypes different in terms of bit size based on complier, and OS used

I was reading a tutorial on C++ as I am new to programming, and I was wondering why the sizeof operator gives different output depending on what you're programming with.
4
votes
4answers
45k views

const reference and const pointer. How do they work?

I read a post about how const storage works. How does const storage work? (Item 2, Scott Myers Effective C++) This says that each segment has separate section of write protected memory and const ...
5
votes
1answer
3k views

AST processing and usefulness of visitor pattern

I know the visitor pattern is typically used to traverse a hierarchy of heterogeneous objects (inheriting a same abstract object) and dissociate the processing of these objects from the data within ...
3
votes
2answers
4k views

Is it always safe to shift bool values?

I stumbled about a Cppcheck warning (an inconclusive one), that I mistakenly used & instead of &&: /// @param code identifies the command. Only the lower 16 bits of are being processed ...
5
votes
2answers
2k views

Needs (in principle) C++ parenthesis around if statement condition?

In current C++ when body of if statements contain only one command then: Parenthesis around if condition are mandatory but block are optional. So, both examples are OK: if ( condition ) { return 0; }...
9
votes
2answers
5k views

Isn't there a chicken-and-egg issue since GCC is written in C++ itself?

Since 4.8 release, the C++ compiler GCC (the G++ part of it) is written not in C anymore, but in C++ itself. I have a hypothetical question on this. I wonder how to compile the C++ code of GCC on a ...
-1
votes
2answers
4k views

Does GCC optimize code to remove useless variable read operations? [closed]

I'm using GCC on ununtu 14.04. My program is written in c++ and in a case i need to check the amount of time the program needs to read a large integer array. what is the best way to do this without ...
-2
votes
2answers
86 views

Debug symbols change application execution [closed]

I have to set up remote debugging for a multi threaded application running on a embedded device. C++ is the language. I've gotten so far and got the remote debugging working for a simple application, ...
10
votes
1answer
4k views

Why did GCC switch from Bison to a recursive descent parser for C++ and C?

Was there a language change that required it or some practical reason why Bison was no longer appropriate or optimal? I saw on wikipedia that they switched, referring to the GCC 3.4 and GCC 4.1 ...
7
votes
2answers
478 views

C++ Without Source Files

Bjarne Stroustrup mentions in his book "The C++ Programming Language, 4th Edition" that not all C++ implementations use files to store and compile code: There are systems that do not store, compile,...
-2
votes
2answers
424 views

Does a custom scripting language require it's own compiler/assembler? [closed]

Or is the script generally converted to a known language such as C++ first? And how generally to you integrate a scripting language with the say a game engine?
1
vote
1answer
296 views

LLVM case: is the success due to the algorithms? [closed]

I'm not sure if this is a subjective question, I hope not but I'm not proficient with LLVM so I'm just wondering: how come it's become so popular and so widespread used in the industry? Were the ...
0
votes
4answers
2k views

How does assembly relate to machine/binary code

How does assembly relate to machine/binary code. For example here is how to print to the screen in mikeOS(a small pure assembly OS), mikeOS it uses NASM to assemble. BITS 16 ORG 32768 %...
2
votes
2answers
569 views

What code lays behind C++ exception?

In C and C++ you can return a single variable inside a function. Now in the case that variable is returning data, and not an error code, you can use exceptions. But how is that possible? If you data ...
3
votes
2answers
4k views

Learning YACC nowadays, does it make sense? [closed]

I have a huge project that is using YACC and I would need to fix a bug in it. I might ask someone else who wrote that to fix it but I'm interested in how compilers work. Does it make sense to learn ...
1
vote
2answers
4k views

How would I make a compiler in C++? [closed]

This probably been asked for but I can't google "How to make a compiler in C++" because I will just get "How to compile C++" as the results. Anyway, for my question, I'd like to make a simple ...
8
votes
5answers
924 views

Is it a good idea to read compiler source code? [closed]

I'm a junior in college majoring in Computer Science. Apart from writing lots of code, I want to start reading source code written by others to improve my coding skills and learn better/different ways ...
12
votes
4answers
4k views

Is it possible to use the Intel C/C++ compiler on Linux to create object files to be linked on Windows?

Why? Depending on your source the Intel compiler is likely or most definitely the compiler generating the fastest executables for the x86 architecture (5 to 100 % execution time improvement). Intel ...
19
votes
4answers
75k views

Understanding stack frame of function call in C/C++?

I am trying to understand how stack frames are built and which variables (params) are pushed to stack in what order? Some search results showed that the C/C++ compiler decides based on operations ...
13
votes
3answers
3k views

Why can't a compiler avoid importing a header file twice by its own?

New to C++! So I was reading this: http://www.learncpp.com/cpp-tutorial/110-a-first-look-at-the-preprocessor/ Header guards Because header files can include other header files, it is possible ...
19
votes
6answers
9k views

When to pay for C++ compilers [closed]

Recently I have began to wonder when developers should pay for compilers. Compilers come for free with most platforms or there is a free version easily obtainable. Example: OS X - GCC and Clang/LLVM ...
8
votes
3answers
1k views

Convert an interpreter to a compiler?

First off, I know this is a question asked by MANY other programmers before me. But I couldn't find any useable resource that could help me. Well, I'm creating an programming language called "Light" ...
3
votes
2answers
330 views

What happens when using address before it's allocated?

The very simple piece of C++ code below is incorrect, it's easy to see why and tools like Valgrind will tell you. In running several C++ codes containing this kind of error, I noticed that each time, ...
19
votes
5answers
4k views

Detecting misusage of delete[] vs. delete at compile time

I'd like to know if it's possible to detect the delete error commented below at compile time? Especially, I'd like to hear about g++ compiler. ClassTypeA *abc_ptr = new ClassTypeA[100]; abc_ptr[10]....
42
votes
6answers
32k views

Why does Facebook convert PHP code to C++? [closed]

I read that Facebook started out in PHP, and then to gain speed, they now compile PHP as C++ code. If that's the case why don't they: Just program in c++? Surely there must be SOME errors/bugs when ...
2
votes
1answer
487 views

Brief explanation for executables in a GNU/Clang Toolchain?

I roughly understand that cc, ld and other parts are called in a certain sequence according to schemes like Makefiles etc. Some of those commands are used to generate those configs and Makefiles. And ...
6
votes
6answers
5k views

Can I get a C++ Compiler to instantiate objects at compile time

I am writing some code that has a very large number of reasonably simple objects and I would like them the be created at compile time. I would think that a compiler would be able to do this, but I ...
15
votes
6answers
7k views

Why C++ to write a compiler?

I was wondering why C++ is a good choice to write a compiler. Of course C is good for this purpose too, because many compilers are written either in C or C++ but I am more interested in C++ this time. ...
1
vote
1answer
672 views

what's the most efficient emacs workflow for compilation and interactive execution cycles (C++/makefile)

I try not to cross-post, but the only response I got at stack-exchange was to post here... What's the preferred practice for a compile-run cycle in emacs? Previously, I used alt-x compile (mapped to ...
6
votes
3answers
928 views

Should a standard include header be specified in each file or as a compiler parameter?

I've got a file such as this: #ifndef STDINCLUDE #define STDINCLUDE #include <memory> #include <stdexcept> #endif I want this file to be included in every header file, because I use ...
18
votes
4answers
32k views

Writing a lexer in C++

What are good resources on how to write a lexer in C++ (books, tutorials, documents), what are some good techniques and practices? I have looked on the internet and everyone says to use a lexer ...
1
vote
4answers
501 views

What programs emit C++ code and pass it to mainstream compilers?

I suspect there're programs that instead of emitting machine code instead emit C++ code and then start a mainstream C++ compiler to compile it to machine code. I can't find any notable examples ...
48
votes
4answers
27k views

How could the first C++ compiler be written in C++?

Stroustrup claims that Cfront, the first C++ compiler, was written in C++ (Stroustrup FAQ). However, how is it even possible that the first C++ compiler be written in C++? The code that makes up the ...
19
votes
8answers
2k views

Do you read C or C++ compile errors after the first one?

I never understood why C and C++ compilers try to recover from errors and continue parsing. Almost always, the first error generates a stream of bogus errors that will disappear as soon as the first ...
27
votes
5answers
12k views

Are C++ templates just a kind of glorified macros?

From different comparisons among C++ templates and C#/Java generics like this one- https://stackoverflow.com/questions/31693/what-are-the-differences-between-generics-in-c-and-java-and-templates-in-c/...
2
votes
1answer
544 views

How does compiler handle exceptions that are implicit? Looking for design strategies

Throughout the function handleException, the exception encountered is implicit. How does the compiler handle such implicit passing of exceptions? [For e.g. in C++ methods, this pointer is passed to ...
33
votes
4answers
26k views

JIT compiler for C, C++, and the likes

Is there any just-in-time compiler out there for compiled languages, such as C and C++? (The first names that come to mind are Clang and LLVM! But I don't think they currently support it.) ...