2 ======= =======================================================================
4 ?C: Comments for #defines
6 ?D: Set default value for variable
10 ?F: Defines what files are created by this module
12 ?H: Defines the part to be included in the generated config_h.SH
14 To get #ifdefs in config_h.SH, you'll need strange constructs like
16 ?H:?%<:@if USE_SITECUSTOMIZE
17 ?H:?%<:#ifndef USE_SITECUSTOMIZE
18 ?H:?%<:#$usesitecustomize USE_SITECUSTOMIZE /**/
28 ?LINT: tell what is to be expected extern and what is changed
33 ?LINT:use PERL_CONFIG_SH
37 ?MAKE: symbol list: dependency list [+optional]
39 This is the first dependency line. The first "symbol list"
40 should list all the symbols built by this unit (i.e. whose
41 value is computed by the shell section of the unit). Symbols
42 should be space separated. If a defined symbol is for internal
43 use only and should not appear in the generated "config.sh"
44 file, then it should be preceded by a '+' (not to be confused
45 with optional dependencies defined hereafter).
46 The second part of the list (after the middle ':') is the unit
47 dependency. It should list all the needed special units, as
48 well as all the symbols used by the shell implementation. If
49 a symbol is nedded but its configuration value is not critical,
50 it can be preceded by a '+', in which case it is called a
51 conditional dependency: its corresponding unit will be loaded
52 if, and only if, that symbol is otherwise really wanted;
53 otherwise the default value will be used.
57 There can be one or more command lines following the initial
58 dependency lines. Those commands will be executed when the
59 unit is wanted to load them into "Configure".
60 Note that the leading <tab> character is required before the
69 To be used for RCS comments, at the top of the unit.
71 ?S: symbol_name (obsolete symbol list)]:
73 Introduces a shell symbol. This first line names the symbol,
74 optionally followed by a list enclosed between parenthesis and
75 giving the obsolete equivalent. Those obsolete symbols will be
76 remapped to the new "symbol_name" if the -o option is given to
79 ?S: any text, for "Porting/Glossary"
81 Basically a comment describing the shell symbol, which will be
82 extracted by "makegloss" into the Glossary file.
86 Closes the shell symbol comment.
88 ?T: What variables are used as temporary variables
98 General purpose comments. May appear anywhere in the unit but must be
99 left justfied. For RCS comments, please use the ?RCS: comment form.
103 Declare a layout directive for this unit. That directive may be one
104 of the strings "top", "default" or "bottom" (case does not matter,
105 recommended style is to spell them out uppercased). If omitted,
106 "default" is assumed.
108 This directive is only required if you wish to force a unit at the
109 top or the bottom of the generated "Configure" script, as unit
110 dependencies permit it. Important questions may thus be forced
111 at the beginning. Within the same layout class, units are sorted
112 alphabetically with two special cases for d_* and i_* units, forced
113 respectively at the top and bottom of their classes (but these
114 should belong to the default class).
116 It you force at the top a unit whose dependencies require all the
117 other unit to precede it, you achieve nothing interesting. Therefore,
118 that directive should really be used to increase the priority of
119 some interactive units that do not depend on many other user-visible
120 symbols, like path-related questions.
124 lines can be made conditional (see Config_sh.U)