book

Managing Projects with GNU Make, 3rd Edition

by Robert Mecklenburg

November 2004

Intermediate to advanced

302 pages

9h 7m

English

O'Reilly Media, Inc.

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GNU Make

The Road to the Third EditionWhat’s New in This EditionConventions Used in This BookUsing Code ExamplesComments and QuestionsAcknowledgments
1.1. Targets and Prerequisites1.2. Dependency Checking1.3. Minimizing Rebuilds1.4. Invoking make1.5. Basic Makefile Syntax
2.1. Explicit Rules2.1.1. Wildcards2.1.2. Phony Targets2.1.3. Empty Targets2.2. Variables2.2.1. Automatic Variables2.3. Finding Files with VPATH and vpath2.4. Pattern Rules2.4.1. The Patterns2.4.2. Static Pattern Rules2.4.3. Suffix Rules2.5. The Implicit Rules Database2.5.1. Working with Implicit Rules2.5.2. Rule Structure2.5.3. Implicit Rules for Source Control2.5.4. A Simple Help Command2.6. Special Targets2.7. Automatic Dependency Generation2.8. Managing Libraries2.8.1. Creating and Updating Libraries2.8.2. Using Libraries as Prerequisites2.8.3. Double-Colon Rules
3.1. What Variables Are Used For3.2. Variable Types3.2.1. Other Types of Assignment3.3. Macros3.4. When Variables Are Expanded3.5. Target- and Pattern-Specific Variables3.6. Where Variables Come From3.7. Conditional and include Processing3.7.1. The include Directive3.7.2. include and Dependencies3.8. Standard make Variables
4.1. User-Defined Functions4.2. Built-in Functions4.2.1. String Functions4.2.2. Important Miscellaneous Functions4.2.3. Filename Functions4.2.4. Flow Control4.2.4.1. Style note concerning variables and parentheses4.2.5. Less Important Miscellaneous Functions4.3. Advanced User-Defined Functions4.3.1. eval and value4.3.2. Hooking Functions4.3.3. Passing Parameters

5.1. Parsing Commands5.1.1. Continuing Long Commands5.1.2. Command Modifiers5.1.3. Errors and Interrupts5.1.3.1. Deleting and preserving target files5.2. Which Shell to Use5.3. Empty Commands5.4. Command Environment5.5. Evaluating Commands5.6. Command-Line Limits
6.1. Recursive make6.1.1. Command-Line Options6.1.2. Passing Variables6.1.3. Error Handling6.1.4. Building Other Targets6.1.5. Cross-Makefile Dependencies6.1.6. Avoiding Duplicate Code6.2. Nonrecursive make6.3. Components of Large Systems6.3.1. Requirements6.4. Filesystem Layout6.5. Automating Builds and Testing
7.1. Portability Issues7.2. Cygwin7.2.1. Line Termination7.2.2. Filesystem7.2.3. Program Conflicts7.3. Managing Programs and Files7.3.1. Source Tree Layout7.4. Working with Nonportable Tools7.4.1. A Standard Shell7.5. Automake
8.1. Separating Source and Binary8.1.1. The Easy Way8.1.2. The Hard Way8.2. Read-Only Source8.3. Dependency Generation8.3.1. Tromey’s Way8.3.2. makedepend Programs8.4. Supporting Multiple Binary Trees8.5. Partial Source Trees8.6. Reference Builds, Libraries, and Installers
9.1. Alternatives to make9.1.1. Ant9.1.2. IDEs9.2. A Generic Java Makefile9.3. Compiling Java9.3.1. The Fast Approach: All-in-One Compile9.3.2. Compiling with Dependencies9.3.3. Setting CLASSPATH9.4. Managing Jars9.5. Reference Trees and Third-Party Jars9.6. Enterprise JavaBeans
10.1. Benchmarking10.2. Identifying and Handling Bottlenecks10.2.1. Simple Variables Versus Recursive10.2.2. Disabling @10.2.3. Lazy Initialization10.3. Parallel make10.4. Distributed make
11.1. The Book Makefile11.1.1. Managing Examples11.1.2. XML Preprocessing11.1.3. Generating Output11.1.4. Validating the Source11.2. The Linux Kernel Makefile11.2.1. Command-Line Options11.2.2. Configuration Versus Building11.2.3. Managing Command Echo11.2.4. User-Defined Functions
12.1. Debugging Features of make12.1.1. Command-Line Options12.1.1.1. —just-print12.1.1.2. —print-data-base12.1.1.3. —warn-undefined-variables12.1.2. The —debug Option12.2. Writing Code for Debugging12.2.1. Good Coding Practices12.2.2. Defensive Coding12.2.3. Debugging Techniques12.3. Common Error Messages12.3.1. Syntax Errors12.3.1.1. missing separator12.3.1.2. commands commence before first target12.3.1.3. unterminated variable reference12.3.2. Errors in Command Scripts12.3.3. No Rule to Make Target12.3.4. Overriding Commands for Target
B.1. Data StructuresB.2. Arithmetic
C.1. 0. PREAMBLEC.2. 1. APPLICABILITY AND DEFINITIONSC.3. 2. VERBATIM COPYINGC.4. 3. COPYING IN QUANTITYC.5. 4. MODIFICATIONSC.6. 5. COMBINING DOCUMENTSC.7. 6. COLLECTIONS OF DOCUMENTSC.8. 7. AGGREGATION WITH INDEPENDENT WORKSC.9. 8. TRANSLATIONC.10. 9. TERMINATIONC.11. 10. FUTURE REVISIONS OF THIS LICENSE

Content preview from Managing Projects with GNU Make, 3rd Edition

Chapter 3. Variables and Macros

We’ve been looking at makefile variables for a while now and we’ve seen many examples of how they’re used in both the built-in and user-defined rules. But the examples we’ve seen have only scratched the surface. Variables and macros get much more complicated and give GNU make much of its incredible power.

Before we go any further, it is important to understand that make is sort of two languages in one. The first language describes dependency graphs consisting of targets and prerequisites. (This language was covered in Chapter 2.) The second language is a macro language for performing textual substitution. Other macro languages you may be familiar with are the C preprocessor, m4, TEX, and macro assemblers. Like these other macro languages, make allows you to define a shorthand term for a longer sequence of characters and use the shorthand in your program. The macro processor will recognize your shorthand terms and replace them with their expanded form. Although it is easy to think of makefile variables as traditional programming language variables, there is a distinction between a macro “variable” and a “traditional” variable. A macro variable is expanded “in place” to yield a text string that may then be expanded further. This distinction will become more clear as we proceed.

A variable name can contain almost any characters including most punctuation. Even spaces are allowed, but if you value your sanity you should avoid them. The only characters ...