Extended Description

$ cat msvc-misleading-indent.cpp
int c;

template class MyClass {
public:
void myMethod(int a, int B);
};

template
void MyClass::myMethod(int a, int b) {
if (a)
return;
#ifdef TRY
try {
#endif
c = a + b;
#ifdef TRY
} catch (...) {
}
#endif
}

void myfunc(void) {
MyClass obj;
obj.myMethod(1, 2);
}
$ clang++ -target x86_64-windows-gnu -Wall -c msvc-misleading-indent.cpp
$ clang++ -target x86_64-windows-msvc -Wall -c msvc-misleading-indent.cpp
msvc-misleading-indent.cpp:15:9: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation]
c = a + b;
^
msvc-misleading-indent.cpp:10:5: note: previous statement is here
if (a)
^
1 warning generated.

Here, for targets other than MSVC, the warning about misleading indentation is silenced thanks to the ifdef between the if statement and later line that can be seen as possibly incorrectly indented. However when parsing this code in MSVC mode, the warning about misleading indentation triggers.

It seems to require some amount of templating involved to trigger - for simpler testcases, the warning is silenced due to the ifdef in MSVC mode too.

This triggers in practice in libc++'s sstream header if building with _LIBCPP_NO_EXCEPTIONS.