Even though this argument design conflates two separate concepts
(ABI and hardware/software implementation), I chose to go
with it since users are liekly know it from GCC and the
combination of softloat operations with hardfloat ABI makes
no sense.
I didn't implement it for old LLVM versions, as ARM EABI
exception handling requires LLVM 3.3+ anyway, without which
LDC would be useless anyway.
1. Main include corresponding to .cpp file, if any.
2. DMD and LDC includes.
3. LLVM includes.
4. System includes.
Also updated a few include guards to match the default format.
I hope I have untangled the checks for "native" Windows (Triple::Win32)
vs. Windows/MinGW/Cygwin (Triple::isOSWindows) correctly.
MinGW needs some default libraries as well, has to be fixed later.
I removed the copyright notice. I don't think we are obliged to
display it for DMD; on the other hand, if we do, we might also
have to display the libconfig one (LGPL). Thus, this seemed like
the better choice.
The indentation is to align with the registered target output,
which we cannot control.
This is what DMD does, and arguably the expected behavior – otherwise,
there would be no way other than using -od to prevent races if two
compiler instances could ever compile the same file(s) at the same
time (e.g. for debug/release configurations).
Should we transition to assuming -singleobj by default?
A lot of system specific knowledge is already present in LLVM. This is used to populate several fields in global.params instead of hard coded values in main(). Ensures that the frontend and LLVM have always the same values.
The string representation of the data layout is retrieved from the TargetData class (in main) and passed via global.params.dataLayout to the module. Since the gTargetData is also a global variable it makes no sense to pass this information using another global variable.
The Windows linker LINK insists on the .obj extension. The following changes are made:
- CMake uses the same extension as the C compiler
- global.obj_ext_alt (aka .obj) is recognized as objectfile extension
- global.obj_ext_alt is used on Windows
- New functions codeGenOptLevel() and verifyModule() to remove code duplication
- Hidden option no-verify renamed to disable-verify and moved to optimizer (like opt tool)
- Removed global.params.noVerify
This is based on Item 2 of "More Effective C++". In general, the C++ cast operators are more expressive and easy to find,
e.g. by grep. Using const_cast also shuts up some compiler warnings.
