Path construction &-expansions, meanings summary:
- In build tree In source tree
- This directory just & &,
- Top level &. implies absolute &;
-
-Adding `@' means "absolute path". This is not needed with &. because
-there is never any need to use &. since it would expand to nothing.
-`/' terminates the escape (needed if the next thing is not a lowercase
-character, or space). `=' means "just the value, no /". Space starts
-multi-word processing.
-
- Recommended In build tree In source tree
- when Relative Absolute Relative Absolute
-
- This lc &file &@file &,file &@,file
- directory any &/file &@/file &,/file &@,/file
- several & f g h &@ f g h &, f g h &@, f g h
-
- Top lc &.file &;file &@;file
- level any file &./file &;/file &@;/file
- several f g h &. f g h &; f g h &@; f g h
- .mk.in file $(abs)/file $(src)/file $(abs_src)/file
+ Relative paths in... Absolute paths in...
+ build source build source
+
+ This directory & &, &@ &@,
+ Top level . &; &@. &@;
+
+Adding `@' means "absolute path". (`&.' is not allowed without @
+because just `&./' is a silly way of writing `.'.) `/' terminates the
+escape (needed if the next thing is not a lowercase character, or
+space). `=' means "just the value, no /". Space starts multi-word
+processing.
+
+In more detail, with the various options for what comes next:
+
+ Recommended Relative paths in... Absolute paths in...
+ for build source build source
+
+ This lc &file &,file &@file &@,file
+ directory any &/file &,/file &@/file &@,/file
+ several & f g h &, f g h &@ f g h &@, f g h
+
+ Top lc file &;file &@.file &@;file
+ level any file &;/file &@./file &@;/file
+ several f g h &; f g h &@. f g h &@; f g h
+ .mk.in file $(src)/file $(abs)/file $(abs_src)/file
Substitution syntax
-------------------
&/ => sub/dir/ or nothing
&=/ => sub/dir or .
-&,lc => $(top_srcdir)/sub/dir/lc
-&,/ => $(top_srcdir)/sub/dir/
+&,lc => $(top_srcdir)/sub/dir/lc &,/ => $(top_srcdir)/sub/dir/
+&;lc => $(top_srcdir)/lc &;/ => $(top_srcdir)/
-&;lc => $(top_srcdir)/sub/dir/lc
-&;/ => $(top_srcdir)/sub/dir/
-
-&@lc => $(PWD)/sub/dir/lc
-&@/ => $(PWD)/sub/dir/
-
-&.lc => $(PWD)/lc
-&./ => $(PWD)/
-
-&@,lc => $(abs_top_srcdir)/sub/dir/lc
-&@,/ => $(abs_top_srcdir)/sub/dir/
-
-&@;lc => $(abs_top_srcdir)/sub/dir/lc
-&@;/ => $(abs_top_srcdir)/sub/dir/
+&@lc => $(PWD)/sub/dir/lc &@/ => $(PWD)/sub/dir/
+&@.lc => $(PWD)/lc &@./ => $(PWD)/
+&@,lc => $(abs_top_srcdir)/sub/dir/lc &@,/ => $(abs_top_srcdir)/sub/dir/
+&@;lc => $(abs_top_srcdir)/lc &@;/ => $(abs_top_srcdir)/
In general:
= return subdir without delimiter (not allowed with `,' `;' `@')
, pathname of this subdirectory in source tree
; pathname of top level of source tree
- . pathname of this directory in build tree, implies absolute pathnames
- @ absolute pathnames (forbidden with `.', must come first)
+ . pathname of this directory in build tree, `@' must be specified
+ @ absolute pathnames
So pathname syntax is a subset of:
'&' [ '@' ] [ ',' | ';' | '.' ] [ lc | '/' ]
To avoid incomprehensible .sd.mk files, some combinations are not
- allowed. For example `&@=./' would mean `$(PWD)/sub/dir' but can
- be spelled `$(PWD)/&=/', but more normally the trailing / can be
- tolerated, so use `&@/'.
+ allowed. For example `&=./' would mean `.' and `&./' would be the
+ empty string. Variations with `=' and one of `@' `,' `;' are
+ uncommon and must be written using make variables instead.
&& => && for convenience in shell runes
\& => & general escaping mechanism
-& thing thing... &
-&. thing thing... & &@. thing thing... &
+& thing thing... & &@ thing thing... &
+ &. thing thing... &
&, thing thing... & &@, thing thing... &
&; thing thing... & &@; thing thing... &
Convenience syntax for prefixing multiple filenames.
Introduced by & followed by lwsp where lc could go.
- Each lwsp-separated non-ws word is prefixed by &/ &./ &@./
+ Each lwsp-separated non-ws word is prefixed by &/ etc.
etc. respectively. No other & escapes are recognised.
This processing continues until & preceded by lwsp,
or until EOL (the end of the line), or \ then EOL.
~ian / subdirmk.git / blobdiff