nvidia answer

Hi Igor,
After checking on our local , we think this is a MSFT cl.exe bug .

nvcc will launch cl -E first before compiling . But in your case , cl -E doesn't process the "\" in macro well and leads to the failure .

See below steps

$ type test.cpp
#define _CRT_STRINGIZE_(x) #x
#define _CRT_STRINGIZE(x) _CRT_STRINGIZE_(x)

#define _WARNING_MESSAGE(NUMBER, MESSAGE) __FILE__ "(" _CRT_STRINGIZE(__LINE__) "): warning " NUMBER ": " MESSAGE
#pragma message(\
_WARNING_MESSAGE("Ok? STL4033", "The contents of are available only with C++20 or later or /await:strict."))

#pragma message(_WARNING_MESSAGE( \
"Bad STL4033", "The contents of are available only with C++20 or later or /await:strict."))

#pragma message(_WARNING_MESSAGE( "Okay STL4033", "The contents of are available only with C++20 or later or /await:strict."))
After preprocessing:

$ cl -E -nologo test.cpp > test.i
test.cpp
#line 1 "test.cpp"

#pragma message(\
"test.cpp" "(" "6" "): warning " "Bad? STL4033" ": " "The contents of are available only with C++20 or later or /await:strict.")

#pragma message(
"test.cpp" "(" "9" "): warning " "Bad STL4033" ": " "The contents of are available only with C++20 or later or /await:strict.")

#pragma message("test.cpp" "(" "11" "): warning " "Okay STL4033" ": " "The contents of are available only with C++20 or later or /await:strict.")

The highlighted lines are not well-formed input to CL.exe:

cl /TP -nologo -c test.i
test.i
test.cpp(6): warning Ok? STL4033: The contents of are available only with C++20 or later or /await:strict.
test.cpp(8): warning C4081: expected 'string'; found 'newline'
test.cpp(9): error C2059: syntax error: 'string'
test.cpp(9): error C2059: syntax error: ')'
test.cpp(11): warning Okay STL4033: The contents of are available only with C++20 or later or /await:strict.

Please reach out to MSFT directly is this is urgent to you and also we will try to contact them as well . The workaround you found is right .

Hope this explains your concern . Let me know if you have extra questions .
Best,
Yuki