Question

I have a Qt C++ application that compiles fine with the MSVC compiler. Now I’m trying to compile the same application with MinGW so that I can eventually port it to Mac OSX. However, when doing so I’m getting an error on all the standard includes:

#include <algorithm>
#include <ctime>
#include <map>
#include <sstream>
#include <vector>

And the compiler outputs:

..\trunk\stable.h:29:21: error: algorithm: No such file or directory
..\trunk\stable.h:30:17: error: ctime: No such file or directory
..\trunk\stable.h:31:15: error: map: No such file or directory
..\trunk\stable.h:32:19: error: sstream: No such file or directory
..\trunk\stable.h:33:18: error: vector: No such file or directory

I really don’t understand what could be causing this issue. Any suggestion?

Answer 1

This is one of the more common errors you will see if your source is C++ but is being compiled as C.

This in turn can happen if the source uses .C (note capital C) extension for C++ files. If the source is used in a case-insensitive file system (like all of the windows ones generally) then make probably won’t be able to properly tell whether to compile them as C or C++.

By default, make (including the mingw version) will compile C++ source from extensions .C, .cc and .cpp. (This page has the details).

You have 3 options:

• rename your sources to one of the above extensions. generally .cc and .cpp are the easiest to work with.
• if ALL of the sources in the makefile, you can go CC=mingw32-g++ mingw32-make -f Makefile.Debug

• you can add this to the makefile or one of the included files:

  %.o: %.c++
      $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c -o $@ $<
  

  but this will only work if the makefile(s) haven’t changed the rules for compilation.