https://issues.dlang.org/show_bug.cgi?id=23622

          Issue ID: 23622
           Summary: ImportC fails to compile files which include math.h
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Keywords: ImportC
          Severity: normal
          Priority: P3
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: krzysztof.jajesnica@student.put.poznan.pl

The following C code fails to compile with DMD 2.101.1:


#include <math.h>

float norm2D(float x, float y) {
    return sqrt(x*x + y*y);
}


DMD error message:

#defines(1074): Error: variable `vec_math.FP_NAN` conflicts with enum member
`__anonymous.FP_NAN` at /usr/include/math.h(936)
#defines(1075): Error: variable `vec_math.FP_INFINITE` conflicts with enum
member `__anonymous.FP_INFINITE` at /usr/include/math.h(939)
#defines(1076): Error: variable `vec_math.FP_ZERO` conflicts with enum member
`__anonymous.FP_ZERO` at /usr/include/math.h(942)
#defines(1077): Error: variable `vec_math.FP_SUBNORMAL` conflicts with enum
member `__anonymous.FP_SUBNORMAL` at /usr/include/math.h(945)
#defines(1078): Error: variable `vec_math.FP_NORMAL` conflicts with enum member
`__anonymous.FP_NORMAL` at /usr/include/math.h(948)


The problem seems to be caused by this strange enum declaration in math.h:

enum
  {
    FP_NAN =
# define FP_NAN 0
      FP_NAN,
    FP_INFINITE =
# define FP_INFINITE 1
      FP_INFINITE,
    FP_ZERO =
# define FP_ZERO 2
      FP_ZERO,
    FP_SUBNORMAL =
# define FP_SUBNORMAL 3
      FP_SUBNORMAL,
    FP_NORMAL =
# define FP_NORMAL 4
      FP_NORMAL
  };

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