Can you tell me why Wolfram Research doesn't support a compiler as widely used as gcc ?
Original developer of CCompilerDriver here. Szabolcs is right (as usual), it's not a question of gcc, which we've supported on Unix from the beginning, but MinGW gcc on Windows 64-bit, which boils down to why doesn't MinGW support gcc on 64-bit, though there is a 64 bit port that you can use, and using that is documented.
What you're reporting is the automatic compiler finding behavior, and also running into the fact that MinGW's C compiler driver is only loaded on 32-bit Windows, for a good reason. At the time this was added, MinGW did not produce 64 bit binaries, and that is required to load the binaries into the Mathematica kernel on a 64 bit OS, which is what happens with CompilationTarget -> "C" option of Compile, or the CreateLibrary function in general.
I've passed this thread on the CCompilerDriver maintainer, to see if anything can be done. But in the interest of helping, here's what I see.
It looks to me like MinGW's gcc still only produces 32 bit binaries. I downloaded MinGW onto my 64-bit Windows 10 machine and compiled hello, world, and it looks to still be 32 bit:
$ file hello
hello: PE32 executable (console) Intel 80386, for MS Windows
You can ignore this and try loading the driver's package:
Needs["CCompilerDriver`MinGWCompiler`"]
For me, after this point CCompilers[] is detecting the compiler. However, it does not work (as expected):
In[6]:= CCompilers[]
Out[6]= {{"Name" -> "Visual Studio", "Compiler" ->
CCompilerDriver`VisualStudioCompiler`VisualStudioCompiler,
"CompilerInstallation" -> "C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\BuildTools",
"CompilerName" -> Automatic}, {"Name" -> "MinGW", "Compiler" -> MinGWCompiler,
"CompilerInstallation" -> "C:\\MinGW\\bin\\gcc.exe", "CompilerName" -> Automatic}}
In[16]:= $CCompiler = Last[CCompilers[]]
Out[16]= {"Name" -> "MinGW", "Compiler" -> MinGWCompiler, "CompilerInstallation" -> "C:\\MinGW\\bin\\gcc.exe", "CompilerName" -> Automatic}
In[17]:= cf = Compile[{{x, _Real}}, Sin[x] + x^2 - 1/(1 + x), CompilationTarget -> "C"]
During evaluation of In[17]:= Compile::nogen: A library could not be generated from the compiled function.
Out[17]= CompiledFunction[{11, 12.1, 5468}, {
Blank[Real]}, {{3, 0, 0}, {3, 0, 1}}, {{1, {2, 0, 0}}}, {0, 1, 5, 0, 0}, {{40, 1, 3, 0, 0, 3, 0, 1}, {40,
56, 3, 0, 0, 3, 0, 2}, {10, 0, 3}, {13, 3, 0, 3}, {40, 60, 3, 0, 3, 3, 0, 4}, {19, 4, 3}, {13, 1, 2, 3, 1}, {1}},
Function[{x}, Sin[x] + x^2 - 1/(1 + x)], Evaluate]
I think, the if you want MinGW/gcc, you need to use the MinGW-w64 project.
The documentation talks about how to use this, look for the section "MinGW for 64-bit targets":
https://reference.wolfram.com/language/CCompilerDriver/tutorial/SpecificCompilers.html
This also shows how to use the "GenericCCompiler" driver, which you can use for any C compiler. It just didn't get found automatically but you can still use it by telling the system where it lives.
