I have come across a book which contains code written in Fortran 77. I wanted to compile and test some of them, and was wondering how well GNU gfortran supports legacy Fortran. I have Ubuntu 14.04 operating system.
Yes gfortran allows for fortran 77 see the docs standard compile options should work but may give warnings. you can set the flag
-std=legacy
to disable warnings that are caused from fortran77 features.
Related
I purchased a book recently entitled beginning C++20. I was looking to begin learning c++ though I now realize that I can't find a compiler that can run the code in the book as I get an error since the compiler I'm using (xcode) does not support c++ 20. I'm wondering if there are any compilers that I can run on my mac that support c++20.
gcc version 8 and up supports some of C++20; you can try using that.
It should also be noted that Xcode isn't a compiler, but instead an IDE that should be using clang as the actual compiler. Clang also currently has support for some of the C++ 20 features. To use them the -std=c++20 flag will still be needed.
Here can you find the currently implemented feature support of the GCC compiler of the C++20 specification:
GCC Link
But you need to enable it in your console command or add this to your toolchain: "-std=c++20"
I am having trouble understanding the different compilers that are available to me.
I mainly use Xcode for writing and compiling, and in Xcode's preferences, there are all of these options for C++ compilation:
C++ Language Dialect:
C++98[-std=c++98] through C++14[-std=c++14]
GNU++98[-std=gnu++98] through GNU++14[-std=gnu++14]
C++ Standard Library:
libstdc++ (GNU C++ standard library)
libc++ (LLVM C++ standard library with C++11 support)
Can someone explain what exactly all of that ^ is?
I understand that (and correct me if I'm wrong), that apple no longer distributes GCC with Xcode and use Clang instead?
If that were the case, then why does Xcode have the option for GNU C++ standard library? Doesn't GNU make GCC?
What compiler is invoked when I run C++ code in my local terminal with g++ filename.cpp?
Is there any way to make sure that this g++ "compiler" is up to date?
What's the difference between compiling with g++ in the terminal and using Xcode?
Also, what would be the difference if I tried running C++ programs with Clang?
My class requires us to test our programs on the department's server's compiler via ssh from my terminal. The server is a Unix machine and I know that its compiler is GNU's GCC compiler and we also access it using g++. Does this mean that the local g++ in my terminal is also GCC?
edit: Grammar
1.
C++ language dialect
C++98[-std=c++98] through C++14[-std=c++14]
GNU++98[-std=gnu++98] through GNU++14[-std=gnu++14]
The C++ language has evolved over time. These are the various versions of the language that are available to you. If you have to be compatible with something old, you might be forced to use an old one. Otherwise you'd probably want ot use the newest available, which is c++14 in the list above. 14 stands for 2014, 98 for 1998 - it is supposed to represent the year that version of the standard was blessed.
In addition to standard C++ there are non-standard extensions. Gnu is a compiler "manufacturer", the "GNU" above is the non-stanadard extensions as specified by GNU for a particular documented version.
C++ Standard Library:
libstdc++ (GNU C++ standard library)
libc++ (LLVM C++ standard library with C++11 support)
In addition to the base language, the standard library is also a part of the standard. These are two different implementations of the standard library. The first is by GNU, the second by llvm. llvm are a different compiler manufacturer.
On osx you'd probably use libc++ as I believe the llvm compiler (clang++) is now standard there. The llvm compiler will support the gnu extensions if you need them. You probably don't. Just use the latest version of whatever is default.
Yes
two different pieces, the compiler and the standard library. You can use clang++ with libstd++
g++ -v will tell you
not really. Update xcode to the newest or start looking at homebrew or ports to get the latest and greatest they package of whatever compiler you like.
Probably the same compiler, you can set it either to point at any compiler you have installed. So what each points at is your choice.
both g++ and clang++ are standards compliant. You're unlikely to notice much difference. They will complile the same source files into equivalent binaries.
run g++ -v in any terminal to see exactly what it is.
I am currently working on compiling a model with PGI, originally designed for Intel compilers. One of the scripts uses use ifcore which is an Intel-specific command that links in miscellaneous run-time libraries. I am having trouble finding the PGI equivalent (for a linux machine)...any ideas?
I was looking at dflib but that appears to be windows-specific.
I am using mpif90 to compile the model currently.
I had a code that was running perfectly on a machine uses ifort and mpif90
I tried to compile it again on another machine where gfortran is installed instead of ifort
I got errors like those
open(unit=10,name=oldfile,access='APPEND',
1
Error: Syntax error in OPEN statement at (1)
main.f
Does anyone knows how can i solve this?
access='append' is not standard fortran and gfortran does not support it. The ifort manual says what the exact meaning is. The equivalent standard conforming code would be access='sequential', position='append'.
I think the immediate error reported is actually caused by the
name=oldfile
that is an extension. Standard Fortran is
file=oldfile
The incorrect value for access will be checked later.
The overview of the possible specifiers in the openstatements for Intel Fortran is at https://software.intel.com/en-us/node/511247 The green ones are non-standard and will likely not work in other compilers (e.g., gfortran).
Is there a website I can go to to run C++ code online? I have seen a few compilers, but is there one that can also receive input from cin? I want one that can basically host a C++ .exe online, and even more preferable is if it is like the VC++ platform.
You may want to give rextester a try. Currently g++ 4.7.2 with boost libraries and ability to supply compiler args.
Edit
Visual C++ is also supported now.
http://ideone.com/ Can compile several languages, and supports stdin
Yes, Ideone can do that. It's possible to specify stdin there.
Edit: Microsoft's online compiler seems to no longer be active :(
Microsoft research have made an online version of Visual C++ here: http://webcompiler.cloudapp.net/.
It (currently?) only compiles the code and does not run it so you won't be able to check cin though :(
Running code is now supported.
Currently the best online tools seem to be
Special Online Compilers
https://cppinsights.io shows, how C++ introduces conversions, etc. and interprets the source code (current clang based)
https://godbolt.org compare C++ compilers, show disassembly, run (many current compilers including Microsoft VCC and embedded compilers)
http://quick-bench.com create and compare benchmarks (current g++ and clang)
https://www.onlinegdb.com, includes gdb debugger (g++ 7.4.0)
Online Compilers that let you set compile flags
https://wandbox.org (current g++ and clang)
http://coliru.stacked-crooked.com (g++ 9.2.0)
https://repl.it/languages/cpp11 (clang 7.0.0)
https://www.tutorialspoint.com/compile_cpp11_online.php = codingground (g++ 7.1.1)
https://tio.run/#cpp-clang (g++ 8.3.1 and clang 7.0.1)
https://rextester.com/l/cpp_online_compiler_gcc (g++ 7.4.0, clang 6.0.0, VS C++ 2015 Update 1)
Online Compilers that do not let you set compile flags
https://www.jdoodle.com (g++ 9.2.0)
https://www.codechef.com/ide (g++ 9.1.0)
https://ideone.com (g++ 8.3.0 and clang 8.0.0)
https://paiza.io (clang 8.0.0)
https://www.codiva.io/c (clang 7.1.0)
https://code.labstack.com/cpp (g++ 8.3.0)
All listed compilers support C++17 code
Perhaps the following site is what you're aiming for: http://codepad.org/
There is Wandbox.org, which offers GCC and Clang to its latest versions (as of Nov 2018). It has stdin.
I wouldn't say it's a VC++ platform though.
TutorialsPoint's C++ Coding Ground lets you save and compile multiple source files at a time, which can be useful at times, and gives you a GNU bash console to play around with. It's not as convenient for sharing code as sites like Ideone, however.
[Note: While it only has links to C++, C++0x, and C++11 environments, you can compile code for C++14 by specifying the compiler option -std=c++1y. I'm not sure if it has any experimental C++17 support, however.]
repl.it can compile, run, and execute C++ and C++11. It's also interactive and you can ask for user input in realtime.