| Index Entry |  Section | 
 
  | 
| U |  |  | 
 | undefined variables, warning message | 9.7 Summary of Options | 
 | undefining variable | 6.9 Undefining Variables | 
 | updating archive symbol directories | 11.2.1 Updating Archive Symbol Directories | 
 | updating makefiles | 3.5 How Makefiles Are Remade | 
 | user defined functions | 8.6 The call Function | 
 
  | 
| V |  |  | 
 | value | 6. How to Use Variables | 
 | value, how a variable gets it | 6.4 How Variables Get Their Values | 
 | variable | 6. How to Use Variables | 
 | variable definition | 3.1 What Makefiles Contain | 
 | variable references in recipes | 5.1.2 Using Variables in Recipes | 
 | variables | 2.4 Variables Make Makefiles Simpler | 
 | variables, ‘$’ in name | 6.3.2 Computed Variable Names | 
 | variables, and implicit rule | 10.5.3 Automatic Variables | 
 | variables, appending to | 6.6 Appending More Text to Variables | 
 | variables, automatic | 10.5.3 Automatic Variables | 
 | variables, command line | 9.5 Overriding Variables | 
 | variables, command line, and recursion | 5.7.3 Communicating Options to a Sub-make | 
 | variables, computed names | 6.3.2 Computed Variable Names | 
 | variables, conditional assignment | 6.2 The Two Flavors of Variables | 
 | variables, defining verbatim | 6.8 Defining Multi-Line Variables | 
 | variables, environment | 5.7.2 Communicating Variables to a Sub-make | 
 | variables, environment | 6.10 Variables from the Environment | 
 | variables, exporting | 5.7.2 Communicating Variables to a Sub-make | 
 | variables, flavor of | 8.10 The flavor Function | 
 | variables, flavors | 6.2 The Two Flavors of Variables | 
 | variables, how they get their values | 6.4 How Variables Get Their Values | 
 | variables, how to reference | 6.1 Basics of Variable References | 
 | variables, loops in expansion | 6.2 The Two Flavors of Variables | 
 | variables, modified reference | 6.3.1 Substitution References | 
 | variables, multi-line | 6.8 Defining Multi-Line Variables | 
 | variables, nested references | 6.3.2 Computed Variable Names | 
 | variables, origin of | 8.9 The origin Function | 
 | variables, overriding | 6.7 The override Directive | 
 | variables, overriding with arguments | 9.5 Overriding Variables | 
 | variables, pattern-specific | 6.12 Pattern-specific Variable Values | 
 | variables, recursively expanded | 6.2 The Two Flavors of Variables | 
 | variables, setting | 6.5 Setting Variables | 
 | variables, simply expanded | 6.2 The Two Flavors of Variables | 
 | variables, spaces in values | 6.2 The Two Flavors of Variables | 
 | variables, substituting suffix in | 6.3.1 Substitution References | 
 | variables, substitution reference | 6.3.1 Substitution References | 
 | variables, target-specific | 6.11 Target-specific Variable Values | 
 | variables, unexpanded value | 8.7 The value Function | 
 | variables, warning for undefined | 9.7 Summary of Options | 
 | varying prerequisites | 4.12 Static Pattern Rules | 
 | verbatim variable definition | 6.8 Defining Multi-Line Variables | 
 | vpath | 4.5 Searching Directories for Prerequisites | 
 | VPATH, and implicit rules | 4.5.5 Directory Search and Implicit Rules | 
 | VPATH, and link libraries | 4.5.6 Directory Search for Link Libraries | 
 
  | 
| W |  |  | 
 | warnings, printing | 8.12 Functions That Control Make | 
 | weave | 10.2 Catalogue of Implicit Rules | 
 | weave | 10.3 Variables Used by Implicit Rules | 
 | Web, rule to run | 10.2 Catalogue of Implicit Rules | 
 | what if | 9.3 Instead of Executing Recipes | 
 | whitespace, in variable values | 6.2 The Two Flavors of Variables | 
 | whitespace, stripping | 8.2 Functions for String Substitution and Analysis | 
 | wildcard | 4.4 Using Wildcard Characters in File Names | 
 | wildcard pitfalls | 4.4.2 Pitfalls of Using Wildcards | 
 | wildcard, function | 8.3 Functions for File Names | 
 | wildcard, in archive member | 11.1 Archive Members as Targets | 
 | wildcard, in include | 3.3 Including Other Makefiles | 
 | wildcards and MS-DOS/MS-Windows backslashes | 4.4.2 Pitfalls of Using Wildcards | 
 | Windows, choosing a shell in | Choosing a Shell in DOS and Windows | 
 | word, selecting a | 8.2 Functions for String Substitution and Analysis | 
 | words, extracting first | 8.2 Functions for String Substitution and Analysis | 
 | words, extracting last | 8.2 Functions for String Substitution and Analysis | 
 | words, filtering | 8.2 Functions for String Substitution and Analysis | 
 | words, filtering out | 8.2 Functions for String Substitution and Analysis | 
 | words, finding number | 8.2 Functions for String Substitution and Analysis | 
 | words, iterating over | 8.5 The foreach Function | 
 | words, joining lists | 8.3 Functions for File Names | 
 | words, removing duplicates | 8.2 Functions for String Substitution and Analysis | 
 | words, selecting lists of | 8.2 Functions for String Substitution and Analysis | 
 | writing recipes | 5. Writing Recipes in Rules | 
 | writing rules | 4. Writing Rules | 
 
  | 
| Y |  |  | 
 | yacc | 10.2 Catalogue of Implicit Rules | 
 | yacc | 10.3 Variables Used by Implicit Rules | 
 | Yacc, rule to run | 10.2 Catalogue of Implicit Rules | 
 
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