update README_U with info from metalint itself

diff --git a/README_U b/README_U
index 9ce7a27..4141faa 100644 (file)
--- a/README_U
+++ b/README_U
@@ -1,40 +1,9 @@
 Line   Description
 ======= =======================================================================
 
-?C:    Comments for #defines
+?MAKE: The ?MAKE: line records dependencies
 
-?D:    Set default value for variable
-
-       ?D:osname=''
-
-?F:    Defines what files are created by this module
-
-?H:    Defines the part to be included in the generated config_h.SH
-
-       To get #ifdefs in config_h.SH, you'll need strange constructs like
-
-       ?H:?%<:@if USE_SITECUSTOMIZE
-       ?H:?%<:#ifndef USE_SITECUSTOMIZE
-       ?H:?%<:#$usesitecustomize     USE_SITECUSTOMIZE               /**/
-       ?H:?%<:#endif
-       ?H:?%<:@end
-
-?I:    Include
-
-?INIT: ?
-
-?L:    Library
-
-?LINT: tell what is to be expected extern and what is changed
-
-       ?LINT:define fieldn
-       ?LINT:extern CONFIG_H
-       ?LINT:change CONFIG_H
-       ?LINT:use PERL_CONFIG_SH
-
-?M:    Magic
-
-?MAKE: symbol list: dependency list [+optional]
+    ?MAKE:symbol list: dependency list [+optional]
 
        This is the first dependency line. The first "symbol list"
        should list all the symbols built by this unit (i.e. whose
@@ -52,7 +21,7 @@ Line  Description
        if, and only if, that symbol is otherwise really wanted;
        otherwise the default value will be used.
 
-?MAKE: <tab> command
+    ?MAKE: <tab> command
 
        There can be one or more command lines following the initial
        dependency lines.  Those commands will be executed when the
@@ -60,15 +29,85 @@ Line        Description
        Note that the leading <tab> character is required before the
        "command".
 
-?O:    Obsoleted?
+?INIT: Initializations printed verbatim
+
+?LINT: Hints for metalint
+
+       set             Listed variables are set
+           ?LINT:set d_getservprotos
+       describe        Listed shell variables are described
+           ?LINT:describe awk ar bash bison byacc cat chgrp chmod chown
+       create          Listed created files in regular units
+           ?LINT:create mips
+       known           Listed C variables are described
+           ?LINT:known StGiFy
+       change          Shell variable ok to be changed
+           ?LINT:change CONFIG_H
+       extern          Variables known to be externally defined
+           ?LINT:extern CONFIG_H
+       usefile         Files marked as being used
+           ?LINT:usefile foobar
+       use             Variables declared as used by unit
+           ?LINT:use PERL_CONFIG_SH
+       define          Listed variables are defined
+           ?LINT:define fieldn
+       empty           Empty unit file
+           ?LINT:empty
+       unclosed        Unclosed here-documents
+           ?LINT:unclosed EOT
+       nothere         Not a here-document name
+       nocomment       OK if leading unit ': comment' missing
+           ?LINT:nocomment
+
+?RCS:  RCS comments are ignored
 
-?P:    Public
+       To be used for RCS comments, at the top of the unit.
 
-?RCS:  free text
+?C:    C symbols
 
-       To be used for RCS comments, at the top of the unit.
+       Comments for #defines
+
+?D:    Default value for conditional symbols
+
+       ?D:osname=''
+
+?E:    Example of usage
+
+?F:    Produced files
+
+       Defines what files are created by this module
+
+       Files produced in the UU directory and which are identified by the
+       convention ./filename. Files !filename are not produced, i.e. they are
+       temporary or externally provided.
+
+       ?F:cppstdin !testcpp.out !testcpp.c
 
-?S:    symbol_name (obsolete symbol list)]:
+?H:    Process the config.h lines
+
+       Defines the part to be included in the generated config_h.SH
+
+       To get #ifdefs in config_h.SH, you'll need strange constructs like
+
+       ?H:?%<:@if USE_SITECUSTOMIZE
+       ?H:?%<:#ifndef USE_SITECUSTOMIZE
+       ?H:?%<:#$usesitecustomize     USE_SITECUSTOMIZE               /**/
+       ?H:?%<:#endif
+       ?H:?%<:@end
+
+?I:    Added includes
+
+?L:    Added libraries
+
+?M:    Process the confmagic.h lines
+
+?O:    Unit obsolescence
+
+?P:    Location of PD implementation file
+
+?S:    Shell variables
+
+    ?S:symbol_name (obsolete symbol list)]:
 
        Introduces a shell symbol. This first line names the symbol,
        optionally followed by a list enclosed between parenthesis and
@@ -76,29 +115,31 @@ Line       Description
        remapped to the new "symbol_name" if the -o option is given to
        "metaconfig".
 
-?S:    any text, for "Porting/Glossary"
+    ?S: <tab> any text, for "Porting/Glossary"
 
        Basically a comment describing the shell symbol, which will be
        extracted by "makegloss" into the Glossary file.
 
-?S:    .
+    ?S:.
 
        Closes the shell symbol comment.
 
-?T:    What variables are used as temporary variables
+?T:    Shell temporaries used
+
+       What variables are used as temporary variables
 
-?V:    Visible?
+?V:    Visible symbols like 'rp', 'dflt'
 
        ?V:fieldn
 
-?W:    Wanted
+?W:    Wanted value for interpreter
 
-?X:    any text
+?X:    User comment is ignored
 
        General purpose comments. May appear anywhere in the unit but must be
        left justfied. For RCS comments, please use the ?RCS: comment form.
 
-?Y:    layout
+?Y:    User-defined layout preference
 
        Declare a layout directive for this unit. That directive may be one
        of the strings "top", "default" or "bottom" (case does not matter,