The C Preprocessor

Last revised March 1997

for GCC version 2

• The C Preprocessor
  • Transformations Made Globally
  • Preprocessing Directives
  • Header Files
    • Uses of Header Files
    • The `#include' Directive
    • How `#include' Works
    • Once-Only Include Files
    • Inheritance and Header Files
  • Macros
    • Simple Macros
    • Macros with Arguments
    • Predefined Macros
      • Standard Predefined Macros
      • Nonstandard Predefined Macros
    • Stringification
    • Concatenation
    • Undefining Macros
    • Redefining Macros
    • Pitfalls and Subtleties of Macros
      • Improperly Nested Constructs
      • Unintended Grouping of Arithmetic
      • Swallowing the Semicolon
      • Duplication of Side Effects
      • Self-Referential Macros
      • Separate Expansion of Macro Arguments
      • Cascaded Use of Macros
    • Newlines in Macro Arguments
  • Conditionals
    • Why Conditionals are Used
    • Syntax of Conditionals
      • The `#if' Directive
      • The `#else' Directive
      • The `#elif' Directive
    • Keeping Deleted Code for Future Reference
    • Conditionals and Macros
    • Assertions
    • The `#error' and `#warning' Directives
  • Combining Source Files
  • Miscellaneous Preprocessing Directives
  • C Preprocessor Output
  • Invoking the C Preprocessor
• Concept Index
• Index of Directives, Macros and Options