enable C++ EH (no SEH exceptions)
SEH (Structured Exception Handling) is a Windows-specific mechanism for handling system-level exceptions e.g. access violations or hardware faults, using __try, __except and __finally. It is not part of the C++ standard.
cl /EHc
extern "C" defaults to nothrow
Explanation: extern "C" tells the compiler to use C linkage (C-style symbol names, no name mangling), and by virtue of defaulting to "C mode" we don't have exceptions (the C ABI has no concept of exceptions).
So extern "C" functions therefore implicitly move from:
extern "C" void foo();
to:
extern "C" void foo() noexcept;
noexcept was introduced in C++11.
