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- Newsgroups: comp.sources.misc
- subject: v14i023: dmake version 3.5 part 13/21
- From: dvadura@watdragon.waterloo.edu (Dennis Vadura)
- Sender: allbery@uunet.UU.NET (Brandon S. Allbery - comp.sources.misc)
-
- Posting-number: Volume 14, Issue 23
- Submitted-by: dvadura@watdragon.waterloo.edu (Dennis Vadura)
- Archive-name: dmake/part13
-
- #!/bin/sh
- # this is part 13 of a multipart archive
- # do not concatenate these parts, unpack them in order with /bin/sh
- # file man/dmake.nc continued
- #
- CurArch=13
- if test ! -r s2_seq_.tmp
- then echo "Please unpack part 1 first!"
- exit 1; fi
- ( read Scheck
- if test "$Scheck" != $CurArch
- then echo "Please unpack part $Scheck next!"
- exit 1;
- else exit 0; fi
- ) < s2_seq_.tmp || exit 1
- echo "x - Continuing file man/dmake.nc"
- sed 's/^X//' << 'SHAR_EOF' >> man/dmake.nc
- X it the current prerequisite list for the target. The `:'
- X operator with no recipe always modifies the current list of
- X prerequisites. Thus assuming each of the following defini-
- X tions has a recipe attached, then:
- X
- X joe : fred ... (1)
- X joe :: more ... (2)
- X
- X and
- X
- X joe :: fred ... (3)
- X joe :: more ... (4)
- X
- X are legal and mean: add the recipe associated with (2), or
- X (4) to the set of recipes for joe, placing them after exist-
- X ing recipes for making joe. The construct:
- X
- X joe :: fred ... (5)
- X joe : more ... (6)
- X
- X and
- X
- X joe : fred ... (7)
- X joe : more ... (8)
- X
- X are errors since we have two sets of perfectly good recipes
- X for making the target.
- X
- X prerequisites is a possibly empty list of targets that must
- X be brought up to date before making the current target.
- X
- X recipe is a short form and allows the user to specify short
- X rule definitions on a single line. It is taken to be the
- X first recipe line in a larger recipe if additional lines
- X follow the rule definition. If the semi-colon is present
- X but the recipe line is empty (ie. null string) then it is
- X
- X
- X
- XVersion 3.50 UW 16
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X taken to be an empty rule. Any target so defined causes the
- X Don't know how to make ... error message to be suppressed
- X when dmake tries to make the target and fails. This silence
- X is maintained for rules that are terminated by a semicolon
- X and have no following recipe lines, for targets listed on
- X the command line, and for the first target found in the
- X makefile.
- X
- XRECIPES
- X The traditional format used by most versions of Make defines
- X the recipe lines as arbitrary strings that may contain macro
- X expansions. They follow a rule definition line and may be
- X spaced apart by comment or blank lines. The list of recipe
- X lines defining the recipe is terminated by a new target
- X definition, a macro definition, or end-of-file. Each recipe
- X line MUST begin with a <TAB> character which may optionally
- X be followed with one or both of the characters '-@'. The
- X '-' indicates that non-zero exit values (ie. errors) are to
- X be ignored when this recipe line is executed, and the '@'
- X indicates that the recipe line should NOT be echoed to the
- X terminal prior to being executed. Both switches are off by
- X default (ie. by default, errors are significant and commands
- X are echoed). Global settings activated via command line
- X options or special attribute or target names may also affect
- X these settings. An example recipe:
- X
- X target :
- X first recipe line
- X second recipe line, executed independently of the first.
- X @a recipe line that is not echoed
- X -and one that has errors ignored.
- X
- X The second and new format of the recipe block begins the
- X block with the character '[' (the open group character) in
- X the last non-white space position of a line, and terminates
- X the block with the character ']' (the close group character)
- X in the first non-white space position of a line. In this
- X form each recipe line need not have a leading TAB. This is
- X called a recipe group. Groups so defined are fed intact as
- X a single unit to a shell for execution whenever the
- X corresponding target needs to be updated. If the open group
- X character '[' is preceded by one or both of - or @ then they
- X apply to the entire group in the same way that the - and @
- X apply to single recipe lines. See the MAKING TARGETS sec-
- X tion for a description of how dmake invokes recipes. Here
- X is an example of a group recipe:
- X
- X target :
- X [
- X first recipe line
- X second recipe line
- X all of these recipe lines are fed to a
- X
- X
- X
- XVersion 3.50 UW 17
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X single copy of a shell for execution.
- X ]
- X
- X
- XTEXT DIVERSIONS
- X dmake supports the notion of text diversions in recipes. If
- X a recipe line contains the character sequence <+ it is
- X recognized and a text diversion is started. This causes
- X dmake to open a temporary file and to copy into that file
- X all text that is found up to but not including the text
- X diversion termination sequence +>. Any diversions started
- X with a <+ must be terminated with a corresponding +>; the
- X terminating +> may appear on the same or on a subsequent
- X recipe line. Nesting of diversions is not supported.
- X New-lines provided in the recipe that forms the text of a
- X diversion are inserted into the resulting temporary file at
- X the appropriate locations. The diversion text may contain
- X the same escape codes as those described in the MACROS sec-
- X tion.
- X
- X The primary use of diversions is on systems (like MSDOS)
- X that do not support long command lines. The diversion makes
- X it possible to produce a temporary file containing the argu-
- X ments which can then be supplied to a utility via the tem-
- X porary file.
- X
- X Here are some examples:
- X
- X all:
- X cat <+this is a
- X test of the text diversion+>
- X
- X The above will cause dmake to execute the command:
- X
- X cat /tmp/mk12294AA
- X
- X and the contents of the temporary file will be the text
- X found between the <+ and +> strings of the above recipe.
- X
- X OBJ = fred.obj mary.obj joe.obj
- X all : $(OBJ)
- X link @<+$(^:t"+\n")\n+>
- X
- X The result of making `all' in the second example is the com-
- X mand:
- X
- X link @/tmp/mk02394AA
- X
- X where the temporary file contains:
- X
- X fred.obj+
- X mary.obj+
- X
- X
- X
- XVersion 3.50 UW 18
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X joe.obj
- X
- X The last line of the file is terminated by a new-line which
- X is inserted due to the \n placed immediately before the +>
- X text diversion terminator.
- X
- X If the environment variable TMPDIR is defined then the tem-
- X porary file is created in the directory specified by that
- X variable. A makefile can change where temporary files are
- X created by defining a macro named TMPDIR and exporting it
- X using the .EXPORT special target.
- X
- XSPECIAL TARGETS
- X This section describes the special targets that are recog-
- X nized by dmake. Some are affected by attributes and others
- X are not.
- X
- X .ERROR If defined then the recipe associated with
- X this target is executed whenever an error con-
- X dition is detected by dmake. All attributes
- X that can be used with any other target may be
- X used with this target. Any prerequisites of
- X this target will be brought up to date during
- X it's processing. NOTE: errors will be
- X ignored while making this target, in extreme
- X cases this may cause some problems.
- X
- X .EXPORT All prerequisites associated with this target
- X are assumed to correspond to macro names and
- X they and their values are exported to the
- X environment as environment strings at the
- X point in the makefile at which this target
- X appears. Any attributes specified with this
- X target are ignored. Only macros which have
- X been assigned a value in the makefile prior to
- X the export directive are exported, macros as
- X yet undefined are not exported.
- X
- X .IMPORT Prerequisite names specified for this target
- X are searched for in the environment and
- X defined as macros with their value taken from
- X the environment. If the name cannot be found
- X in the environment an error message is issued.
- X .IMPORT accepts the .IGNORE attribute. When
- X given, it causes dmake to ignore the above
- X error. See the MACROS section for a descrip-
- X tion of the processing of imported macro
- X values.
- X
- X .INCLUDE Parse another makefile just as if it had been
- X located at the point of the .INCLUDE in the
- X current makefile. The list of prerequisites
- X
- X
- X
- XVersion 3.50 UW 19
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X gives the list of makefiles to try to read.
- X If the list contains multiple makefiles then
- X they are read in order from left to right.
- X The following search rules are used when try-
- X ing to locate the file. If the filename is
- X surrounded by " or just by itself then it is
- X searched for in the current directory. If it
- X is not found it is then searched for in each
- X of the directories specified for the .INCLU-
- X DEDIRS special target. If the file name is
- X surrounded by < and >, (ie.
- X <my_spiffy_new_makefile>) then it is searched
- X for only in the directories given by the
- X .INCLUDEDIRS special target. In both cases if
- X the file name is a fully qualified name start-
- X ing at the root of the file system then it is
- X only searched for once, and the .INCLUDEDIRS
- X list is ignored. .INCLUDE accepts the .IGNORE
- X and .SETDIR attributes. If .IGNORE attribute
- X is given and the file cannot be found then
- X dmake continues processing, otherwise an error
- X message is generated. The .SETDIR attribute
- X causes dmake to change directories to the
- X specified directory prior to attempting the
- X include operation.
- X
- X .INCLUDEDIRS The list of prerequisites specified for this
- X target defines the set of directories to
- X search when trying to include a makefile.
- X
- X .MAKEFILES The list of prerequisites is the set of files
- X to try to read as the default makefile. By
- X default this target is defined as:
- X
- X .MAKEFILES : makefile.mk Makefile
- X makefile
- X
- X
- X .SOURCE The prerequisite list of this target defines a
- X set of directories to check when trying to
- X locate a target file name. See the section on
- X BINDING of targets for more information.
- X
- X .SOURCE.suff The same as .SOURCE, except that the
- X .SOURCE.suff list is searched first when try-
- X ing to locate a file matching the a target
- X whose name ends in the suffix .suff.
- X
- X .REMOVE The recipe of this target is used whenever
- X dmake needs to remove intermediate targets
- X that were made but do not need to be kept
- X around. Such targets result from the
- X
- X
- X
- XVersion 3.50 UW 20
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X application of transitive closure on the
- X dependency graph.
- X
- X In addition to the special targets above, several other
- X forms of targets are recognized and are considered special,
- X their exact form and use is defined in the sections that
- X follow.
- X
- XSPECIAL MACROS
- X dmake defines a number of special macros. They are divided
- X into two classes: control macros and run-time macros. The
- X control macros are used by dmake to configure it's actions,
- X and are the preferred method of doing so. In the case when
- X a control macro has the same function as a special target or
- X attribute they share the same name as the special target or
- X attribute. The run-time macros are defined when dmake makes
- X targets and may be used by the user inside recipes. We
- X first give the control macros and their meanings.
- X
- X To use the control macros simply assign them a value just
- X like any other macro. The control macros are divided into
- X three groups: string valued macros, character valued macros,
- X and boolean valued macros.
- X
- X The following are all of the string valued macros. This
- X list is also divided into three groups. The first group
- X gives the string valued macros that are defined internally
- X and cannot be directly set by the user.
- X
- X DIRBRKSTR Contains the string of chars used to terminate
- X the name of a directory in a pathname. Under
- X UNIX it's value is "/", under MSDOS it's value
- X is "/\:".
- X
- X INCDEPTH This macro's value is a string of digits
- X representing the current depth of makefile
- X inclusion. In the first makefile level this
- X value is zero.
- X
- X MFLAGS Is the list of flags that were given on the
- X command line including a leading switch char-
- X acter. The -f flag is not included in this
- X list.
- X
- X MAKECMD Is the name with which dmake was invoked.
- X
- X MAKEDIR Is the full path to the initial directory in
- X which dmake was invoked.
- X
- X MAKEFILE Contains the string "-f makefile" where,
- X makefile is the name of initial user makefile
- X that was first read.
- X
- X
- X
- XVersion 3.50 UW 21
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X MAKEFLAGS Is the same as $(MFLAGS) but has no leading
- X switch character. (ie. MFLAGS = -$(MAKEFLAGS))
- X
- X MAKEMACROS Contains the complete list of macro expres-
- X sions that were specified on the command line.
- X
- X MAXPROCESSLIMIT
- X Is a numeric string representing the maximum
- X number of processes that dmake can use when
- X making targets in the parallel mode.
- X
- X NULL Is permanently defined to be the NULL string.
- X This is useful when comparing a conditional
- X expression to an NULL value.
- X
- X PWD Is the full path to the current directory in
- X which make is executing.
- X
- X TMD Stands for "To Make Dir", and is the path from
- X the present directory (value of $(PWD)) to the
- X directory that dmake was started up in (value
- X of $(MAKEDIR)). This macro is modified when
- X .SETDIR attributes are processed.
- X
- X
- X The second group of string valued macros control dmake
- X behavior and may be set by the user.
- X
- X .SETDIR If this macro is assigned a value then dmake
- X will change to the directory given by that
- X value before making any targets. This macro
- X is equivalent to the .SETDIR attribute.
- X Thus the two lines:
- X
- X .SETDIR=fred/hello :
- X
- X .SETDIR := fred/hello
- X
- X are completely equivalent. The difference
- X being that the first is processed as a rule
- X definition and the other as a macro.
- X
- X AUGMAKE If set to a non NULL value will enable the
- X transformation of special meta targets to
- X support special AUGMAKE inferences.
- X
- X DIRSEPSTR Contains the string that is used to separate
- X directory components when path names are
- X constructed. It is defined with a default
- X value at startup.
- X
- X
- X
- X
- X
- XVersion 3.50 UW 22
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X GROUPFLAGS This macro gives the set of flags to pass to
- X the shell when invoking it to execute a
- X group recipe. The value of the macro is the
- X list of flags with a leading switch indica-
- X tor. (ie. `-' under UNIX)
- X
- X GROUPSHELL This macro defines the full path to the exe-
- X cutable image to be used as the shell when
- X processing group recipes. This macro must
- X be defined if group recipes are used. It is
- X assigned a default value in the startup
- X makefile. Under UNIX this value is /bin/sh.
- X
- X GROUPSUFFIX If defined, this macro gives the string to
- X use as a suffix when creating group recipe
- X files to be handed to the command inter-
- X preter. For example, if it is defined as
- X .sh, then all temporary files created by
- X dmake will end in the suffix .sh. Under
- X MSDOS if you are using command.com as your
- X GROUPSHELL, then this suffix must be set to
- X .bat in order for group recipes to work
- X correctly.
- X
- X MAKE It is defined in the startup file by
- X default. The string $(MAKE) is recognized
- X when using the -n option for single line
- X recipes. Initially this macro is defined to
- X have the value "$(MAKECMD) $(MFLAGS)".
- X
- X MAKESTARTUP This macro defines the full path to the ini-
- X tial startup makefile. Use the -V command
- X line option to discover it's initial value.
- X
- X MAXLINELENGTH This macro defines the maximum size of a
- X single line of makefile input text. The
- X size is specified as a number, the default
- X value is defined internally and is shown via
- X the -V option. A buffer of this size plus 2
- X is allocated for reading makefile text. The
- X buffer is freed before any targets are made,
- X thereby allowing files containing long input
- X lines to be processed without consuming
- X memory during the actual make.
- X
- X MAXPROCESS Specify the maximum number of child
- X processes to use when making targets. The
- X default value of this macro is "1" and it's
- X value cannot exceed the value of the macro
- X MAXPROCESSLIMIT. Setting the value of MAX-
- X PROCESS on the command line or in the
- X makefile is equivalent to supplying a
- X
- X
- X
- XVersion 3.50 UW 23
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X corresponding value to the -P flag on the
- X command line.
- X
- X PREP This macro defines the number of iterations
- X to be expanded automatically when processing
- X % rule definitions of the form:
- X
- X % : %.suff
- X
- X See the sections on PERCENT(%) RULES for
- X details on how PREP is used.
- X
- X SHELL This macro defines the full path to the exe-
- X cutable image to be used as the shell when
- X processing single line recipes. This macro
- X must be defined if recipes requiring the
- X shell for execution are to be used. It is
- X assigned a default value in the startup
- X makefile. Under UNIX this value is /bin/sh.
- X
- X SHELLFLAGS This macro gives the set of flags to pass to
- X the shell when invoking it to execute a sin-
- X gle line recipe. The value of the macro is
- X the list of flags with a leading switch
- X indicator. (ie. `-' under UNIX)
- X
- X SHELLMETAS Each time dmake executes a single recipe
- X line (not a group recipe) the line is
- X searched for any occurrence of a character
- X defined in the value of SHELLMETAS. If such
- X a character is found the recipe line is
- X defined to require a shell to ensure it's
- X correct execution. In such instances a
- X shell is used to invoke the recipe line. If
- X no match is found the recipe line is exe-
- X cuted without the use of a shell.
- X
- X
- X There is only one character valued macro defined by dmake:
- X SWITCHAR contains the switch character used to introduce
- X options on command lines. On UNIX it's value is '-', on
- X MSDOS it's value may be '/' or '-'. The macro is internally
- X defined and is not user setable.
- X
- X All boolean macros currently understood by dmake correspond
- X directly to the previously defined attributes. These macros
- X provide a second way to apply global attributes, and
- X represent the preferred method of doing so. They are used
- X by assigning them a value. If the value is not a NULL
- X string then the boolean condition is set to on. If the
- X value is a NULL string then the condition is set to off.
- X There are five conditions defined and they correspond
- X
- X
- X
- XVersion 3.50 UW 24
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X directly to the attributes of the same name. Their meanings
- X are defined in the ATTRIBUTES section above. The macros
- X are: .EPILOG, .IGNORE, .PRECIOUS, .PROLOG, and .SILENT.
- X Assigning any of these a non NULL value will turn on the
- X corresponding attribute on a global scale.
- X
- X The second class of macros is the run-time macros. These
- X macros are defined when dmake is making targets, and may
- X take on different values for each target. $@ is defined to
- X be the full target name, $? is the list of all out of date
- X prerequisites, $& is the list of all prerequisites, $> is
- X the name of the library if the current target is a library
- X member, $< is the list of prerequisites specified in the
- X current rule (this includes any inferred prerequisites), $*
- X is defined as $(@:db) when making targets with explicit
- X recipes and is defined as the value of % when making targets
- X whose recipe is the result of an inference. In the first
- X case $* is the target name with no suffix, and in the latter
- X is the value of the matched % pattern from the associated
- X %-rule. $^ expands to the set of out of date prerequisites
- X taken from the current value of $<. In addition to these,
- X $$ expands to $, {{ expands to {, }} expands to }, and the
- X strings <+ and +> are reserved for use in recipe scripts for
- X starting and terminating a text diversion respectively.
- X
- X The difference between $? and $^ can best be illustrated by
- X an example, consider:
- X
- X fred.out : joe amy hello
- X rules for making fred
- X
- X fred.out : my.c your.h his.h her.h # more prerequisites
- X
- X Assume joe, amy, and my.c are newer then fred.out. When
- X dmake executes the recipe for making fred.out the values of
- X the following macros will be:
- X
- X $@ --> fred.out
- X $* --> fred
- X $? --> joe amy my.c # note the difference between $? and $^
- X $^ --> joe amy
- X $< --> joe amy hello
- X $& --> joe amy hello my.c your.h his.h her.h
- X
- X
- XDYNAMIC PREREQUISITES
- X dmake looks for prerequisites whose names contain macro
- X expansions during target processing. Any such prerequisites
- X are expanded and the result of the expansion is used as the
- X prerequisite name. As an example the line:
- X
- X fred : $$@.c
- X
- X
- X
- XVersion 3.50 UW 25
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X causes the $$@ to be expanded when dmake is making fred, and
- X it resolves to the target fred. This enables dynamic prere-
- X quisites to be generated. The value of @ may be modified by
- X any of the valid macro modifiers. So you can say for exam-
- X ple:
- X
- X fred.out : $$(@:b).c
- X
- X where the $$(@:b) expands to fred. Note the use of $$
- X instead of $ to indicate the dynamic expansion, this is due
- X to the fact that the rule line is expanded when it is ini-
- X tially parsed, and $$ then returns $ which later triggers
- X the dynamic prerequisite expansion. If you really want a $
- X to be part of a prerequisite name you must use $$$$.
- X Dynamic macro expansion is performed in all user defined
- X rules, and the special targets .SOURCE*, and .INCLUDEDIRS.
- X
- XBINDING TARGETS
- X This operation takes a target name and binds it to an exist-
- X ing file, if possible. dmake makes a distinction between
- X the internal target name of a target and it's associated
- X external file name. Thus it is possible for a target's
- X internal name and its external file name to differ. To per-
- X form the binding, the following set of rules is used.
- X Assume that we are trying to bind a target whose name is of
- X the form X.suff, where .suff is the suffix and X is the stem
- X portion (ie. that part which contains the directory and the
- X basename). dmake takes this target name and performs a
- X series of search operations that try to find a suitably
- X named file in the external file system. The search opera-
- X tion is user controlled via the settings of the various
- X .SOURCE targets.
- X
- X 1. If target has the .SYMBOL attribute set then look
- X for it in the library. If found, replace the tar-
- X get name with the library member name and continue
- X with step 2. If the name is not found then
- X return.
- X
- X 2. Extract the suffix portion (that following the
- X `.') of the target name. If the suffix is not
- X null, look up the special target .SOURCE.<suff>
- X (<suff> is the suffix). If the special target
- X exists then search each directory given in the
- X .SOURCE.<suff> prerequisite list for the target.
- X If the target's suffix was null (ie. .suff was
- X empty) then perform the above search but use the
- X special target .SOURCE.NULL instead. If at any
- X point a match is found then terminate the search.
- X If a directory in the prerequisite list is the
- X special name `.NULL ' perform a stat for the full
- X target name without prepending any directory
- X
- X
- X
- XVersion 3.50 UW 26
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X portion (ie. prepend the NULL directory). (a
- X default target of '.SOURCE : .NULL' is defined by
- X dmake at startup, and is user redefinable)
- X
- X 3. The search in step 2. failed. Repeat the same
- X search but this time use the special target
- X .SOURCE.
- X
- X 4. The search in step 3. failed. If the target has
- X the library member attribute (.LIBMEMBER) set then
- X try to find the target in the library which was
- X passed along with the .LIBMEMBER attribute (see
- X the MAKING LIBRARIES section). The bound file
- X name assigned to a target which is successfully
- X located in a library is the same name that would
- X be assigned had the search failed (see 5.).
- X
- X 5. The search failed. Either the target was not
- X found in any of the search directories or no
- X applicable .SOURCE special targets exist. If
- X applicable .SOURCE special targets exist, but the
- X target was not found, then dmake assigns the first
- X name searched as the bound file name. If no
- X applicable .SOURCE special targets exist, then the
- X full original target name becomes the bound file
- X name.
- X
- X There is potential here for a lot of search operations. The
- X trick is to define .SOURCE.x special targets with short
- X search lists and leave .SOURCE as short as possible. The
- X search algorithm has the following useful side effect. When
- X a target having the .LIBMEMBER (library member) attribute is
- X searched for, it is first searched for as an ordinary file.
- X When a number of library members require updating it is
- X desirable to compile all of them first and to update the
- X library at the end in a single operation. If one of the
- X members does not compile and dmake stops, then the user may
- X fix the error and make again. dmake will not remake any of
- X the targets whose object files have already been generated
- X as long as none of their prerequisite files have been modi-
- X fied as a result of the fix.
- X
- X When defining .SOURCE and .SOURCE.x targets the construct
- X
- X .SOURCE :
- X .SOURCE : fred gery
- X
- X is equivalent to
- X
- X .SOURCE :- fred gery
- X
- X
- X
- X
- X
- XVersion 3.50 UW 27
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X dmake correctly handles the UNIX Make variable VPATH. By
- X definition VPATH contains a list of ':' separated direc-
- X tories to search when looking for a target. dmake maps
- X VPATH to the following special rule:
- X
- X .SOURCE :^ $(VPATH:s/:/ /)
- X
- X Which takes the value of VPATH and sets .SOURCE to the same
- X set of directories as specified in VPATH.
- X
- XPERCENT(%) RULES AND MAKING INFERENCES
- X When dmake makes a target it's set of prerequisites (if any)
- X must exist and the target must have a recipe which dmake can
- X use to make it. If the makefile does not specify an expli-
- X cit recipe for the target then dmake uses special rules to
- X try to infer a recipe which it can use to make the target.
- X Previous versions of Make perform this task by using rules
- X that are defined by targets of the form .<suffix>.<suffix>
- X and by using the .SUFFIXES list of suffixes. The exact
- X workings of this mechanism were sometimes difficult to
- X understand and often limiting in their usefulness. Instead,
- X dmake supports the concept of %-meta rules. The syntax and
- X semantics of these rules differ from standard rule lines as
- X follows:
- X
- X <%-target> [<attributes>] <ruleop> [<%-prerequisites>] [;<recipe>]
- X
- X where %-target is a target containing exactly a single `%'
- X sign, attributes is a list (possibly empty) of attributes,
- X ruleop is the standard set of rule operators, %-prere-
- X quisites , if present, is a list of prerequisites containing
- X zero or more `%' signs, and recipe, if present, is the first
- X line of the recipe.
- X
- X The %-target defines a pattern against which a target whose
- X recipe is being inferred gets matched. The pattern match
- X goes as follows: all chars are matched exactly from left to
- X right up to but not including the % sign in the pattern, %
- X then matches the longest string from the actual target name
- X not ending in the suffix given after the % sign in the pat-
- X tern. Consider the following examples:
- X
- X %.c matches fred.c but not joe.c.Z
- X dir/%.c matches dir/fred.c but not dd/fred.c
- X fred/% matches fred/joe.c but not f/joe.c
- X % matches anything
- X
- X In each case the part of the target name that matched the %
- X sign is retained and is substituted for any % signs in the
- X prerequisite list of the %-meta rule when the rule is
- X selected during inference and dmake constructs the depen-
- X dency specified by the %-meta rule for the actual target.
- X
- X
- X
- XVersion 3.50 UW 28
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X As an example the following %-meta rules describe the fol-
- X lowing:
- X
- X %.c : %.y ; recipe...
- X
- X describes how to make any file ending in .c if a correspond-
- X ing file ending in .y can be found.
- X
- X foo%.o : fee%.k ; recipe...
- X
- X is used to describe how to make fooxxxx.o from feexxxx.k.
- X
- X %.a :; recipe...
- X
- X describes how to make a file whose suffix is .a without
- X inferring any prerequisites.
- X
- X %.c : %.y yaccsrc/%.y ; recipe...
- X
- X is a short form for the construct:
- X
- X %.c : %.y ; recipe...
- X %.c : yaccsrc/%.y ; recipe...
- X
- X ie. It is possible to specify the same recipe for two
- X %-rules by giving more than one prerequisite in the prere-
- X quisite list. A more interesting example is:
- X
- X % : RCS/%,v ; co $@
- X
- X which describes how to take any target and check it out of
- X the RCS directory if the corresponding file exists in the
- X RCS directory. The equivalent SCCS rule would be:
- X
- X % : s.% ; get $@
- X
- X
- X The previous RCS example defines an infinite rule, because
- X it says how to make anything from RCS/%,v, and anything also
- X includes RCS/fred.c,v. To limit the size of the graph that
- X results from such rules dmake uses the macro variable PREP
- X (stands for % repetition). By default the value of this
- X variable is 0, which says that no repetitions of a %-rule
- X are to be generated. If it is set to something greater than
- X 0, then that many repetitions of any infinite %-rule are
- X allowed. If in the above example PREP was set to 1, then
- X dmake would generate the dependency graph:
- X
- X % --> RCS/%,v --> RCS/RCS/%,v,v
- X
- X Where each link is assigned the same recipe as the first
- X link. PREP should be used only in special cases, since it
- X
- X
- X
- XVersion 3.50 UW 29
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X may result in a large increase in the number of possible
- X prerequisites tested.
- X
- X dmake supports dynamic prerequisite generation for prere-
- X quisites of %-meta rules. This is best illustrated by an
- X example. The RCS rule shown above can infer how to check
- X out a file from a corresponding RCS file only if the target
- X is a simple file name with no directory information. That
- X is, the above rule can infer how to find RCS/fred.c,v from
- X the target fred.c, but cannot infer how to find
- X srcdir/RCS/fred.c,v from srcdir/fred.c because the above
- X rule will cause dmake to look for RCS/srcdir/fred.c,v; which
- X does not exist (assume that srcdir has it's own RCS direc-
- X tory as is the common case).
- X
- X A more versatile formulation of the above RCS check out rule
- X is the following:
- X
- X % : $$(@:d)RCS/$$(@:f),v : co $@
- X
- X This rule uses the dynamic macro $@ to specify the prere-
- X quisite to try to infer. During inference of this rule the
- X macro $@ is set to the value of the target of the %-meta
- X rule and the appropriate prerequisite is generated by
- X extracting the directory portion of the target name (if
- X any), appending the string RCS/ to it, and appending the
- X target file name with a trailing ,v attached to the previous
- X result.
- X
- X dmake can also infer indirect prerequisites. An inferred
- X target can have a list of prerequisites added that will not
- X show up in the value of $< but will show up in the value of
- X $? and $&. Indirect prerequisites are specified in an
- X inference rule by quoting the prerequisite with single
- X quotes. For example, if you had the explicit dependency:
- X
- X fred.o : fred.c ; rule to make fred.o
- X fred.o : local.h
- X
- X then this can be infered for fred.o from the following
- X inference rule:
- X
- X %.o : %.c 'local.h' ; rule to make a .o from a .c
- X
- X You may infer indirect prerequisites that are a function of
- X the value of '%' in the current rule. The meta-rule:
- X
- X %.o : %.c '$(INC)/%.h' ; rule to make a .o from a .c
- X
- X infers an indirect prerequisite found in the INC directory
- X whose name is the same as the expansion of $(INC), and the
- X prerequisite name depends on the base name of the current
- X
- X
- X
- XVersion 3.50 UW 30
- X
- X
- X
- X
- XDMAKE(p) Unsupported Software DMAKE(p)
- X
- X
- X
- X target. The set of indirect prerequisites is attached to
- X the meta rule in which they are specified and are inferred
- X only if the rule is used to infer a recipe for a target.
- X They do not play an active role in driving the inference
- X algorithm. The construct:
- X
- X %.o : %.c %.f 'local.h'; recipe
- X
- X is equivalent to:
- X
- X %.o : %.c 'local.h' : recipe
- X %.o : %.f 'local.h' : recipe
- X
- X
- X If any of the attributes .SETDIR, .EPILOG, .PROLOG, .SILENT,
- X .PRECIOUS, .LIBRARY, and .IGNORE are given for a %-rule then
- SHAR_EOF
- echo "End of part 13"
- echo "File man/dmake.nc is continued in part 14"
- echo "14" > s2_seq_.tmp
- exit 0
-
-