Enquire: Everything you wanted to know about your C Compiler and Machine (1993) 

Steven Pemberton, CWI, Amsterdam.

This is a program that determines many properties of the C
compiler and machine that it is run on, such as minimum and
maximum [un]signed char/int/long, many properties of float/ [long]
double, and so on.

As an option it produces the ANSI C float.h and limits.h files.

As a further option, it even checks that the compiler reads the
header files correctly.

It is a good test-case for compilers, since it exercises them with
many limiting values, such as the minimum and maximum floating-point
numbers.

The C source contains a long preamble comment that explains how to
compile and run it.

• The C
  source (Version 5.1a)
• Example output
• Example limits.h file
• Example float.h file
• An
  article describing Enquire.