llvm-project/clang/test/Preprocessor/stringize_space.c

// RUN: %clang_cc1 -E %s | FileCheck --strict-whitespace %s

#define A(b) -#b  ,  - #b  ,  -# b  ,  - # b
A()

// CHECK: {{^}}-"" , - "" , -"" , - ""{{$}}


#define t(x) #x
t(a
c)

// CHECK: {{^}}"a c"{{$}}