CODEWITHSUNDEEP
c
umlcat
umlcat

Reputation: 4143

plain c using new keyword

Overview:

I'm working with a hobby app. I want my program to be able to stick to "plain C".

For several reasons, I have to use a C++ compiler, and the related programming enviroment program, that supports "Plain C". And, for the same reasons, I cannot change to antoher compiler.

And, there are some C++ features that I have been coded, unintentionally.

For example, I'm not using namespaces or classes. My current programming job, is not "plain c" or "c++", and I haven't used them for some time, so, I may have forgotten which stuff is "plain c" only.

I have browsed in the internet, for "Plain C" examples. I have found that many other developers, have also post mixed "plain c" & "c++" examples, (some of them unintentionally).

I'm using some dynamically allocated structures. I have been using "malloc", but I rather use "new" instead. I thought that some new standard & compiler versions of "plain c" allowed "new", but, seems I'm wrong.

Seems that "new" is a "C++" feature, & if I really want to make a only "plain c", I should use "malloc".

The reason I want to stick to "plain C", it's because I'm working in a cross platform non-gui library / tool.

My current platform is "Windowze", my Development Enviroments, are:

(1) CodeBlocks (MinGW)

(2) Bloodshed DevCPP

(3) Borland CBuilder 6

Although, my goal is to migrate it to Linux, too , and maybe other platforms, and other (command-line) compilers.

Quick not Tested Example:

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>

struct MyData_T
{
  int  MyInt;
  char MyName[512];
  char *MyCharPtr;
};

typedef
  struct MyData_T *MyData_P;

MyData_P newData(char* AName)
{
  MyData_P Result = null;

  Result = malloc(sizeof(MyData_T));

  strcpy(Result->MyName, AName, strlen(AName));
  // do other stuff with fields

  return Result;
} // MyData_P newData(...)

int main(...)
{
  int ErrorCode = 0;

  MyData_P MyDataVar = newData("John Doe");

  // do more stuff with "MyDataVar";

  free(MyDataVar);

  return ErrorCode;
} // int main(...)

Questions

  1. Where I can get a working "plain c only" compiler for x86 (windowze, linux) ?

  2. Should I stick to use "malloc", "calloc", and similar ?

  3. Should I consider to change to "C++" & "new", instead ?

  4. Is it valid to use "new" & "delete" in a "plain c" application ?

  5. Any other suggestion ?

Thanks.

Disclaimer Note: I already spent several hours trying not to post the same question, in Stackoverflow, but, none of the previous answers seem clear to me.

Upvotes: 2

Views: 27144

Answers (7)

M.Calugaru
M.Calugaru

Reputation: 442

It seems that starting with C17 (or the technical name ISO/IEC 9899:2018) the new keyword is being supported. To make this work, if you're using Visual Studio Code, in the c_cpp_properties.json file update:

  • "cStandard": "c17", and
  • "cppStandard": "c++17"

Upvotes: 0

Oliver Charlesworth
Oliver Charlesworth

Reputation: 272527

  1. You can use e.g. GCC as a C compiler. To ensure it's compiling as C, use the -x c option. You can also specify a particular version of the C standard, e.g. -std=c99. To ensure you're not using any GCC-specific extensions, you can use the -pedantic flag. I'm sure other compilers have similar options.

  2. malloc and calloc are indeed how you allocate memory in C.

  3. That's up to you.* You say that you want to be cross-platform, but C++ is essentially just as "cross-platform" as C. However, if you're working on embedded platforms (e.g. microcontrollers or DSPs), you may not find C++ compilers for them.

  4. No, new and delete are not supported in C.

* In my opinion, though, you should strongly consider switching to C++ for any application of non-trivial complexity. C++ has far more powerful high-level constructs than C (e.g. smart pointers, containers, templates) that simplify a lot of the tedious work in C. It takes a while to learn how to use them effectively, but in the long run, they will be worth it.

Upvotes: 4

Cameron Skinner
Cameron Skinner

Reputation: 54326

Remember that C and C++ are actually completely different languages. They share some common syntax, but C is a procedural language and C++ is object oriented, so they are different programming paradigms.

gcc should work just fine as a C compiler. I believe MinGW uses it. It also has flags you can specify to make sure it's using the right version of C (e.g. C99).

If you want to stick with C then you simply won't be able to use new (it's not part of the C language) but there shouldn't be any problems with moving to C++ for a shared library, just so long as you put your Object Oriented hat on when you do.

I'd suggest you just stick with the language you are more comfortable with. The fact that you're using new suggests that will be C++, but it's up to you.

Upvotes: 9

BRPocock
BRPocock

Reputation: 13914

  • GCC has a C compiler. It's the basic one. You can call it with gcc -std=c90 to make sure it doesn't slip in any Gnu or C++ extensions.
  • Yes, malloc/calloc are portable and safe for use in C
  • Only if you have some reason to switch to C++… C is a bit more portable, but not by much, these days.

Upvotes: 1

user1107052
user1107052

Reputation: 91

You don't have to stick with C to create cross platform non-GUI library. You can as well develop that in C++. Since it is hobby, it is OK, but there are such libraries already available.

Upvotes: 0

Keith Nicholas
Keith Nicholas

Reputation: 44298

If using visual studio, just make the file .c (though its not strictly a C compiler, it pretends to be, and for the most, is good enough)

*nix world you can use gcc, as its pretty much the standard.

If you want to do C stick to C, if you want to do C++, use C++

so stick with malloc etc.... in C++ you'd use smart pointers.

Upvotes: 0

Matteo Italia
Matteo Italia

Reputation: 126827

The most important tip is to save your file with a .c extension and disable compiler extensions. On both Visual C++ and gcc (and thus MinGW) this makes them go into C mode, where C++ additions will be disabled.

You can also force C mode using -std=c90 (or c99, depending on the C standard you want to use; these also disable GNU extensions) in gcc, /Tc in VC++ (and here to disable MS extensions you have to use /Za).

Upvotes: 0

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