depends.awk File Reference

Creates a list of dependencies for compiling or linking. More...

Functions
var	testf (var file)
	Tests whether a file can be opened. More...
var	rescape (var str)
	Escape the given string for literal use in a regular expression. More...
var	sescape (var str)
	Escape the given string for command line use. More...
var	extract (var a)
	Returns an arbitrary index from an array and deletes it. More...
var	any (var a)
	Returns whether any of the entries in a given array evalutate to true. More...
var	compact (var path)
	Returns a compacted version of the path. More...
void	filter184 ()
	Perform recursive include and output C/C++ file names. More...

Detailed Description

Creates a list of dependencies for compiling or linking.

The command line arguments are used to produce a CPP command. The given files need to be processed by CPP in order to make sure macros and conditionals are (correctly) expanded.

The output is filtered to only print files in the same directory or subdirectories of the given file. Paths can be added explicitly by using the -I argument.

The following arguments receive special treatment:

Argument	Description
-compile	Choose to produce a dependency list for compiling
-link	Choose to produce a dependency list for linking
-I<path>	Paths are added to the output filter

Modes of Operation

The script can either create a dependency list for compiling or linking.

In any mode the given file (multiple files can be chosen as well, but there is no useful use case) is passed to the CPP. The CPP resolves all includes.

The includes are filtered from the CPP output by this script.

In compile mode all files and includes are output once. In link mode includes are instead checked for heaving a corresponding C/C++ file that ends with the suffix SUFX. Only in that case is the file name printed and also recursively passed to the CPP.

Modes can be combined.

Environment

If the following arguments are not set using AWK's -v argument, they can be set as environment variables.

Variable	Description
DEBUG	If set output debugging information on stderr
CPP	The C/C++ preprocessor command, defaults to cpp
SUFX	The file name suffix for c/c++ files

SUFX

The SUFX variable defaults to the file ending of the first file name given in the arguments.

Non-existing files are ignored during list-creation, this can be used to set the file ending by providing the desired file ending as the first argument:

    awk -f depends.awk .c -link <file>

Function Documentation

testf()

var testf

(

var

file

)

Tests whether a file can be opened.

Parameters

file	The name of the file to test

Return values

1	The file exists and can be read
0	The file cannot be opened

rescape()

var rescape

(

var

str

)

Escape the given string for literal use in a regular expression.

Parameters

str	The string to escape

Returns

The escaped string

sescape()

var sescape

(

var

str

)

Escape the given string for command line use.

Parameters

str	The string to escape

Returns

The escaped string

extract()

var extract

(

var

a

)

Returns an arbitrary index from an array and deletes it.

Parameters

a	The array to fetch an arbitrary index from

Returns

An array index or nothing, if the array is empty

any()

var any

(

var

a

)

Returns whether any of the entries in a given array evalutate to true.

Parameters

a	The array to check for true entries

Return values

0	No true entries
1	At least one entry evaluates to true

compact()

var compact

(

var

path

)

Returns a compacted version of the path.

This gets rid of ../ by removing the previous path.

Parameters

path	The path to compact

Returns

The compacted path

filter184()

void filter184

(

)

Perform recursive include and output C/C++ file names.

• Setup environment setable globals
• Initialize escape tables for the rescape() and sescape() funcitons
• Read command line arguments
  • Assemble the CPP command
  • Collect files to pass to cpp
  • Guess the project paths from the given files
  • Detect SUFX using the first file encountered
• Process files recursively

  Precondition

  BEGIN