dvadura@watdragon.waterloo.edu (Dennis Vadura) (06/30/91)
Submitted-by: Dennis Vadura <dvadura@watdragon.waterloo.edu> Posting-number: Volume 20, Issue 82 Archive-name: dmake/patch02g Patch-To: dmake: Volume 19, Issue 22-58 #!/bin/sh # this is dp2.06 (part 6 of a multipart archive) # do not concatenate these parts, unpack them in order with /bin/sh # file dm37p2 continued # if test ! -r _shar_seq_.tmp; then echo 'Please unpack part 1 first!' exit 1 fi (read Scheck if test "$Scheck" != 6; then echo Please unpack part "$Scheck" next! exit 1 else exit 0 fi ) < _shar_seq_.tmp || exit 1 if test ! -f _shar_wnt_.tmp; then echo 'x - still skipping dm37p2' else echo 'x - continuing file dm37p2' sed 's/^X//' << 'SHAR_EOF' >> 'dm37p2' && Xcommand line flag. XIf a prerequisite name cannot be found in the environment Xan error message is issued. X\&.IMPORT accepts the .IGNORE attribute. When given, it causes \fBdmake\fP Xto ignore the above error. XSee the MACROS section for a description of the processing of imported macro Xvalues. X.IP \fB.INCLUDE\fP 1.4i XParse another makefile just as if it had been located at the point of the X\&.INCLUDE in the current makefile. The list of prerequisites gives the list of Xmakefiles to try to read. If the list contains multiple makefiles then they Xare read in order from left to right. The following search rules are used Xwhen trying to locate the file. If the filename is surrounded by " or just Xby itself then it is searched for in the current directory. If it is not Xfound it is then searched for in each of the directories specified for the X\&.INCLUDEDIRS special target. If the file name is surrounded by < and >, (ie. X<my_spiffy_new_makefile>) then it is searched for only in the directories Xgiven by the .INCLUDEDIRS special target. In both cases if the file name is a Xfully qualified name starting at the root of the file system then it is only Xsearched for once, and the .INCLUDEDIRS list is ignored. .INCLUDE accepts Xthe .IGNORE and .SETDIR attributes. If .IGNORE attribute is given and the file Xcannot be found then \fBdmake\fP continues processing, Xotherwise an error message is generated. XThe .SETDIR attribute causes X.B dmake Xto change directories to the specified directory prior to attempting the Xinclude operation. X.IP \fB.INCLUDEDIRS\fP 1.4i XThe list of prerequisites specified for this target defines the set of Xdirectories to search when trying to include a makefile. X.IP \fB.KEEP_STATE\fP 1.4i XThis special target is a synonym for the macro definition X.sp X\&\t.KEEP_STATE := _state.mk X.sp XIt's effect is to turn on STATE keeping and to define \fI_state.mk\fP Xas the state file. X.IP \fB.MAKEFILES\fP 1.4i XThe list of prerequisites is the set of files to try to read as the default Xmakefile. By default this target is defined as: X.sp X\t\&.MAKEFILES : makefile.mk Makefile makefile X.sp X.IP \fB.SOURCE\fP 1.4i XThe prerequisite list of this target defines a set of directories to check Xwhen trying to locate a target file name. See the section on BINDING of Xtargets for more information. X.IP \fB.SOURCE.suff\fP 1.4i XThe same as .SOURCE, except that the .SOURCE.suff list is searched first when Xtrying to locate a file matching the a target whose name ends in the suffix X\&.suff. X.IP \fB.REMOVE\fP 1.4i XThe recipe of this target is used whenever \fBdmake\fP needs to remove Xintermediate targets that were made but do not need to be kept around. XSuch targets result from the application of transitive closure on the Xdependency graph. X.PP XIn addition to the special targets above, Xseveral other forms of targets are recognized and are considered special, Xtheir exact form and use is defined in the sections that follow. X.SH "SPECIAL MACROS" X.B dmake Xdefines a number of special macros. They are divided into three classes: Xcontrol macros, run-time macros, and function macros. XThe control macros are used by X.B dmake Xto configure its actions, and are the preferred method of doing so. XIn the case when a control macro has the same function as a special Xtarget or attribute they share the same name as the special target or Xattribute. XThe run-time macros are defined when X.B dmake Xmakes targets and may be used by the user inside recipes. XThe function macros provide higher level functions dealing with macro Xexpansion and diversion file processing. X.SH "CONTROL MACROS" XTo use the control macros simply assign them a value just like any other Xmacro. The control macros are divided into three groups: Xstring valued macros, character valued macros, and boolean valued macros. X.PP XThe following are all of the string valued macros. XThis list is divided into two groups. The first group gives the string Xvalued macros that are defined internally and cannot be directly set by the Xuser. X.IP \fBDIRBRKSTR\fP 1.4i XContains the string of chars used to terminate Xthe name of a directory in a pathname. XUnder UNIX its value is "/", under MSDOS its value is "/\e:". X.IP \fBINCDEPTH\fP 1.4i XThis macro's value is a string of digits representing Xthe current depth of makefile inclusion. XIn the first makefile level this value is zero. X.IP \fBMFLAGS\fP 1.4i XIs the list of flags Xthat were given on the command line including a leading switch character. XThe \-f flag is not included in this list. X.IP \fBMAKECMD\fP 1.4i XIs the name with which \fBdmake\fP was invoked. X.IP \fBMAKEDIR\fP 1.4i XIs the full path to the initial directory in which X.B dmake Xwas invoked. X.IP \fBMAKEFILE\fP 1.4i XContains the string "\-f \fImakefile\fP" where, \fImakefile\fP is the name Xof initial user makefile that was first read. X.IP \fBMAKEFLAGS\fP 1.4i XIs the same as $(MFLAGS) but has no leading switch Xcharacter. (ie. MFLAGS = \-$(MAKEFLAGS)) X.IP \fBMAKEMACROS\fP 1.4i XContains the complete list of macro expressions that were specified on the Xcommand line. X.IP \fBMAKETARGETS\fP 1.4i XContains the name(s) of the target(s), if any, that were Xspecified on the command line. X.IP \fBMAXPROCESSLIMIT\fP 1.4i XIs a numeric string representing the maximum number of processes that X\fBdmake\fP can use when making targets using parallel mode. X.IP \fBNULL\fP 1.4i XIs permanently defined to be the NULL string. XThis is useful when comparing a conditional expression to an NULL value. X.IP \fBPWD\fP 1.4i XIs the full path to the Xcurrent directory in which make is executing. X.IP \fBTMPFILE\fP 1.4i XIs set to the name of the most recent temporary file opened by \fBdmake\fP. XTemporary files are used for text diversions and for group recipe processing. X.IP \fBTMD\fP 1.4i XStands for "To Make Dir", and Xis the path from the present directory (value of $(PWD)) to the directory Xthat \fBdmake\fP was started up in (value of $(MAKEDIR)). XThis macro is modified when .SETDIR attributes are processed. X.IP \fBUSESHELL\fP 1.4i XThe value of this macro is set to "yes" if the current recipe is forced to Xuse a shell for its execution via the .USESHELL or '+' directives, its value Xis "no" otherwise. X.sp X.PP XThe second group of string valued macros control X.B dmake Xbehavior and may be set by the user. X.IP \fB.NOTABS\fP 1.6i XWhen set to non-NULL enables the use of spaces as well as <tabs> to begin Xrecipe lines. XBy default a non\-group recipe is terminated by a line without any leading Xwhite\-space or by a line not beggining with a <tab> character. XEnabling this mode modifies the first condition of Xthe above termination rule to terminate a Xnon\-group recipe with a line that contains only white\-space. XThis mode does not effect the parsing of group recipes bracketed by []. X.IP \fB.SETDIR\fP 1.6i XIf this macro is assigned a value then \fBdmake\fP will Xchange to the directory given by that value before making any targets. X.IP \fBAUGMAKE\fP 1.6i XIf set to a non NULL value will enable the transformation of special Xmeta targets to support special AUGMAKE inferences (See the COMPATIBILITY Xsection). X.IP \fBDIRSEPSTR\fP 1.6i XContains the string that is used to separate directory components when Xpath names are constructed. It is defined with a default value at startup. X.IP \fBDIVFILE\fP 1.6i XIs defined in the startup file and gives the name that should be returned for Xthe diversion file name when used in X$(mktmp ...) expansions, see the TEXT DIVERSION section for details. X.IP \fB.KEEP_STATE\fP 1.6i XAssigning this macro a value tells X.B dmake Xthe name of the state file to use and turns on the keeping of state Xinformation for any targets that are brought up to date by the make. X.IP \fBGROUPFLAGS\fP 1.6i XThis macro gives the set of flags to pass to the shell when Xinvoking it to execute a group recipe. The value of the macro is the Xlist of flags with a leading switch indicator. (ie. `\-' under UNIX) X.IP \fBGROUPSHELL\fP 1.6i XThis macro defines the full Xpath to the executable image to be used as the shell when Xprocessing group recipes. This macro must be defined if group recipes are Xused. It is assigned a default value in the startup makefile. Under UNIX Xthis value is /bin/sh. X.IP \fBGROUPSUFFIX\fP 1.6i XIf defined, this macro gives the string to use as a suffix Xwhen creating group recipe files to be handed to the command interpreter. XFor example, if it is defined as .sh, then all Xtemporary files created by \fBdmake\fP will end in the suffix .sh. XUnder MSDOS if you are using command.com as your GROUPSHELL, then this suffix Xmust be set to .bat in order for group recipes to function correctly. XThe setting of GROUPSUFFIX and GROUPSHELL is done automatically for Xcommand.com in the startup.mk files. X.IP \fBMAKE\fP 1.6i XIs defined in the startup file by default. XThe string $(MAKE) is recognized when Xusing the \-n option for single line recipes. Initially this macro is defined Xto have the value "$(MAKECMD) $(MFLAGS)". X.IP \fBMAKESTARTUP\fP 1.6i XThis macro defines the full path to the initial startup Xmakefile. Use the \fB\-V\fP command line option to discover its initial Xvalue. X.IP \fBMAXLINELENGTH\fP 1.6i XThis macro defines the maximum size of a single line of Xmakefile input text. The size is specified as a number, the default value Xis defined internally and is shown via the \fB\-V\fP option. XA buffer of this size plus 2 is allocated for reading makefile text. The Xbuffer is freed before any targets are made, thereby allowing files containing Xlong input lines to be processed without consuming memory during the actual Xmake. X.IP \fBMAXPROCESS\fP 1.6i XSpecify the maximum number of child processes to use when making targets. XThe default value of this macro is "1" and its value cannot exceed the value Xof the macro MAXPROCESSLIMIT. Setting the value of MAXPROCESS on the command Xline or in the makefile is equivalent to supplying a corresponding value to Xthe -P flag on the command line. X.IP \fBPREP\fP 1.6i XThis macro defines the number of iterations to be expanded Xautomatically when processing % rule definitions of the form: X.sp X% : %.suff X.sp XSee the sections on PERCENT(%) RULES for details on how PREP is used. X.IP \fBSHELL\fP 1.6i XThis macro defines the full path to the executable Ximage to be used as the shell when Xprocessing single line recipes. This macro must be defined if recipes Xrequiring the shell for execution are to be used. XIt is assigned a default value in the startup makefile. XUnder UNIX this value is /bin/sh. X.IP \fBSHELLFLAGS\fP 1.6i XThis macro gives the set of flags to pass to the shell when Xinvoking it to execute a single line recipe. The value of the macro is the Xlist of flags with a leading switch indicator. (ie. `\-' under UNIX) X.IP \fBSHELLMETAS\fP 1.6i XEach time X.B dmake Xexecutes a single recipe line (not a group recipe) the line is Xsearched for any occurrence of a character defined in the value of SHELLMETAS. XIf such a character is found the recipe line is defined to require a shell Xto ensure its correct execution. In such instances Xa shell is used to invoke the recipe line. XIf no match is found the recipe line is executed without the use of a shell. X.sp X.PP XThere is only one character valued macro defined by \fBdmake\fP: X\fBSWITCHAR\fP contains the switch character used Xto introduce options on command lines. For UNIX its value is `\-', and for XMSDOS its value may be `/' or `\-'. XThe macro is internally defined and is not user setable. XThe MSDOS version of \fBdmake\fP attempts to first extract SWITCHAR from an Xenvironment variable of the same name. If that fails it then attempts to Xuse the undocumented getswitchar system call, and returns the result of Xthat. Under MSDOS version 4.0 you must set the value of the environment Xmacro SWITCHAR to '/' to obtain predictable behavior. X.PP XAll boolean macros currently understood by X.B dmake Xcorrespond directly to the previously defined attributes. XThese macros provide Xa second way to apply global attributes, and represent the Xpreferred method of doing so. They are used by assigning them a Xvalue. If the value is not a NULL string then the boolean condition Xis set to on. XIf the value is a NULL string then the condition is set to off. XThere are five conditions defined and they correspond directly to the Xattributes of the same name. Their meanings are defined in the ATTRIBUTES Xsection above. XThe macros are: X\&\fB.EPILOG\fP, X\&\fB.IGNORE\fP, X\&\fB.MKSARGS\fP, X\&\fB.NOINFER\fP, X\&\fB.PRECIOUS\fP, X\&\fB.PROLOG\fP, X\&\fB.SEQUENTIAL\fP, X\&\fB.SILENT\fP, X\&\fB.SWAP\fP, and X\&\fB.USESHELL\fP. XAssigning any of these a non NULL value will globally set Xthe corresponding attribute to on. X.SH "RUN_TIME MACROS" XThese macros are defined Xwhen \fBdmake\fP is making targets, and may take on different values for each Xtarget. \fB$@\fP is defined to be the full target name, \fB$?\fP is the Xlist of all out of date prerequisites, \fB$&\fP is the list of all Xprerequisites, \fB$>\fP is the name of the library if the current target is a Xlibrary member, and X\fB$<\fP is the list of prerequisites specified in the current rule. XIf the current target had a recipe inferred then \fB$<\fP is the name of the Xinferred prerequisite even if the target had a list of prerequisites supplied Xusing an explicit rule that did not provide a recipe. In such situations X\fB$&\fP gives the full list of prerequisites. X.PP X\fB$*\fP is defined as X\fB$(@:db)\fP when making targets with explicit recipes and is defined as the Xvalue of % when making targets whose recipe is the result of an inference. XIn the first case \fB$*\fP is the target name with no suffix, Xand in the second case, is the value of the matched % pattern from Xthe associated %-rule. X\fB$^\fP expands to the set of out of date prerequisites taken from the Xcurrent value of \fB$<\fP. XIn addition to these, X\fB$$\fP expands to $, \fB{{\fP expands to {, \fB}}\fP expands to }, and the Xstrings \fB<+\fP and \fB+>\fP are recognized Xas respectively starting and terminating a text diversion when they appear Xliterally together in the same input line. X.PP XThe difference between $? and $^ can best be illustrated by an example, Xconsider: X.RS X.sp X.nf Xfred.out : joe amy hello X\trules for making fred XX Xfred.out : my.c your.h his.h her.h # more prerequisites X.fi X.sp X.RE XAssume joe, amy, and my.c are newer then fred.out. When X.B dmake Xexecutes the recipe for making fred.out the values of the following macros Xwill be: X.RS X.sp X.nf X.Is "$@ " X.Ii "$@" X--> fred.out X.Ii "$*" X--> fred X.Ii "$?" X--> joe amy my.c # note the difference between $? and $^ X.Ii "$^" X--> joe amy X.Ii "$<" X--> joe amy hello X.Ii "$&" X--> joe amy hello my.c your.h his.h her.h X.fi X.sp X.RE X.SH "FUNCTION MACROS" X.B dmake Xsupports a full set of functional macros. One of these, the $(mktmp ...) Xmacro, is discussed in detail in the TEXT DIVERSION section and is not Xcovered here. X.RS X.sp X.IP "$(\fBnull\fP,\fItext\fP \fBtrue\fP \fBfalse\fP)" Xexpands the value of X.I text. XIf it is NULL then the macro returns the value of the expansion of \fBtrue\fP Xand the expansion of \fBfalse\fP otherwise. The terms \fBtrue\fP, and X\fBfalse\fP must be strings containing no white\-space. X.IP "$(\fB!null\fP,\fItext\fP \fBtrue\fP \fBfalse\fP)" XBehaves identically to the previous macro except that the X.B true Xstring is chosen if the expansion of X.I text Xis not NULL. X.IP "$(\fBeq\fP,\fItext_a\fP,\fItext_b\fP \fBtrue\fP \fBfalse\fP)" Xexpands X.I text_a Xand X.I text_b Xand compares their results. If equal it returns the result of the expansion Xof the X.B true Xterm, otherwise it returns the expansion of the X.B false Xterm. X.IP "$(\fB!eq\fP,\fItext_a\fP,\fItext_b\fP \fBtrue\fP \fBfalse\fP)" XBehaves identically to the previous macro except that the X.B true Xstring is chosen if the expansions of the two strings are not equal X.IP "$(\fBshell\fP \fBcommand\fP)" XRuns \fIcommand\fP as if it were part of a recipe and returns, Xseparated by a single space, all the non-white Xspace terms written to stdout by the command. XFor example: X.RS X.RS X.sp X$(shell ls *.c) X.sp X.RE Xwill return \fI"a.c b.c c.c d.c"\fP if the files exist in the current Xdirectory. The recipe modification flags \fB[+@%\-]\fP are honored if they Xappear as the first characters in the command. For example: X.RS X.sp X$(shell +ls *.c) X.sp X.RE Xwill run the command using the current shell. X.RE X.IP "$(\fBsort\fP \fBlist\fP)" XWill take all white\-space separated tokens in \fIlist\fP and will Xreturn their sorted equivalent list. X.IP "$(\fBstrip\fP \fBdata\fP)" XWill replace all strings of white\-space in data by a single space. X.IP "$(\fBsubst\fP,\fIpat\fP,\fIreplacement\fP \fBdata\fP)" XWill search for \fIpat\fP in X.B data Xand will replace any occurrence of X.I pat Xwith the X.I replacement Xstring. X.RS XThe expansion X.RS X.sp X$(subst,.o,.c $(OBJECTS)) X.sp X.RE Xis equivalent to: X.RS X.sp X$(OBJECTS:s/.o/.c/) X.sp X.RE X.RE X.SH "DYNAMIC PREREQUISITES" X.B dmake Xlooks for prerequisites whose names contain macro expansions during target Xprocessing. Any such prerequisites are expanded and the result of the Xexpansion is used as the prerequisite name. As an example the line: X.sp X\tfred : $$@.c X.sp Xcauses the $$@ to be expanded when \fBdmake\fP is making fred, and it resolves Xto the target \fIfred\fP. XThis enables dynamic prerequisites to be generated. The value Xof @ may be modified by any of the valid macro modifiers. So you can say for Xexample: X.sp X\tfred.out : $$(@:b).c X.sp Xwhere the $$(@:b) expands to \fIfred\fP. XNote the use of $$ instead of $ to indicate the dynamic expansion, this Xis due to the fact that the rule line is expanded when it is initially parsed, Xand $$ then returns $ which later triggers the dynamic prerequisite expansion. XIf you really want a $ to be part of a prerequisite name you must use $$$$. XDynamic macro expansion is performed in all user defined rules, Xand the special targets .SOURCE*, and .INCLUDEDIRS. X.SH "BINDING TARGETS" XThis operation takes a target name and binds it to an existing file, if Xpossible. X.B dmake Xmakes a distinction between the internal target name of a target and its Xassociated external file name. XThus it is possible for a target's internal name and its external Xfile name to differ. XTo perform the binding, the following set of rules is used. XAssume that we are Xtrying to bind a target whose name is of the form \fIX.suff\fP, Xwhere \fI.suff\fP is the suffix and \fIX\fP is the stem portion X(ie. that part which contains the directory and the basename). X.B dmake Xtakes this target name and performs a series of search operations that try to Xfind a suitably named file in the external file system. XThe search operation is user controlled Xvia the settings of the various .SOURCE targets. X.RS X.IP 1. XIf target has the .SYMBOL attribute set then look for it in the library. XIf found, replace the target name with the library member name and continue Xwith step 2. If the name is not found then return. X.IP 2. XExtract the suffix portion (that following the `.') of the target name. XIf the suffix is not null, look up the special target .SOURCE.<suff> X(<suff> is the suffix). XIf the special target exists then search each directory given in Xthe .SOURCE.<suff> prerequisite list for the target. XIf the target's suffix was null (ie. \fI.suff\fP was empty) then Xperform the above search but use the special target .SOURCE.NULL instead. XIf at any point a match is found then terminate the search. XIf a directory in the prerequisite list is the special name `.NULL ' perform Xa search for the full target name without prepending any directory portion X(ie. prepend the NULL directory). X(a default target of '.SOURCE : .NULL' is defined by \fBdmake\fP at startup, Xand is user redefinable) X.IP 3. XThe search in step 2. failed. Repeat the same search but this time Xuse the special target .SOURCE. X.IP 4. XThe search in step 3. failed. XIf the target has the library member attribute (.LIBMEMBER) Xset then try to find the target in the library which was passed along Xwith the .LIBMEMBER attribute (see the MAKING LIBRARIES section). XThe bound file name assigned to a target which is successfully Xlocated in a library is the same name that would be assigned had the search Xfailed (see 5.). X.IP 5. XThe search failed. Either the target was not found in any of the search Xdirectories or no applicable .SOURCE special targets exist. XIf applicable .SOURCE special targets exist, but the target was not found, Xthen \fBdmake\fP assigns the first name searched as the bound file name. XIf no applicable .SOURCE special targets exist, Xthen the full original target name becomes the bound file name. X.RE X.PP XThere is potential here for a lot of search operations. The trick is to Xdefine .SOURCE.x special targets with short search lists and leave .SOURCE Xas short as possible. XThe search algorithm has the following useful side effect. XWhen a target having the .LIBMEMBER (library member) attribute is searched for, Xit is first searched for as an ordinary file. XWhen a number of library members require updating it is desirable to compile Xall of them first and to update the library at the end in a single operation. XIf one of the members does not compile and \fBdmake\fP stops, then Xthe user may fix the error and make again. \fBdmake\fP will not remake any Xof the targets whose object files have already been generated as long as Xnone of their prerequisite files have been modified as a result of the fix. X.PP XWhen defining .SOURCE and .SOURCE.x targets the construct X.sp X\t.SOURCE : X.br X\t.SOURCE : fred gery X.sp Xis equivalent to X.sp X\t.SOURCE :\- fred gery X.PP X\fBdmake\fP correctly handles the UNIX Make variable VPATH. By definition VPATH Xcontains a list of ':' separated directories to search when looking for a Xtarget. \fBdmake\fP maps VPATH to the following special rule: X.sp X\t.SOURCE :^ $(VPATH:s/:/ /) X.sp XWhich takes the value of VPATH and sets .SOURCE to the same set of directories Xas specified in VPATH. X.SH "PERCENT(%) RULES AND MAKING INFERENCES" XWhen \fBdmake\fP makes a target, the target's set of prerequisites (if any) Xmust exist and the target must have a recipe which \fBdmake\fP Xcan use to make it. XIf the makefile does not specify an explicit recipe for the target then X.B dmake Xuses special rules to try to infer a recipe which it can use Xto make the target. Previous versions of Make perform this task by using Xrules that are defined by targets of the form .<suffix>.<suffix> and by Xusing the .SUFFIXES list of suffixes. The exact workings of this mechanism Xwere sometimes difficult to understand and often limiting in their usefulness. XInstead, \fBdmake\fP supports the concept of \fI%-meta\fP rules. XThe syntax and semantics of these rules differ from standard rule lines as Xfollows: X.sp X.nf X.RS X\fI<%-target>\fP [\fI<attributes>\fP] \fI<ruleop>\fP [\fI<%-prerequisites>\fP] [;\fI<recipe>\fP] X.RE X.fi X.sp Xwhere \fI%-target\fP is a target containing exactly a single `%' sign, X.I attributes Xis a list (possibly empty) of attributes, X.I ruleop Xis the standard set of rule operators, X.I "%-prerequisites" X\&, if present, is a list of prerequisites containing zero or more `%' signs, Xand X.I recipe, Xif present, is the first line of the recipe. X.PP XThe X.I %-target Xdefines a pattern against which a target whose recipe is Xbeing inferred gets matched. The pattern match goes as follows: all chars are Xmatched exactly from left to right up to but not including the % sign in the Xpattern, % then matches the longest string from the actual target name Xnot ending in Xthe suffix given after the % sign in the pattern. XConsider the following examples: X.RS X.sp X.nf X.Is "dir/%.c " X.Ii "%.c" Xmatches fred.c but not joe.c.Z X.Ii "dir/%.c" Xmatches dir/fred.c but not dd/fred.c X.Ii "fred/%" Xmatches fred/joe.c but not f/joe.c X.Ii "%" Xmatches anything X.fi X.sp X.RE XIn each case the part of the target name that matched the % sign is retained Xand is substituted for any % signs in the prerequisite list of the %-meta rule Xwhen the rule is selected during inference and X.B dmake Xconstructs the new dependency. XAs an example the following %-meta rules describe the following: X.RS X.sp X%.c : %.y ; recipe... X.sp X.RE Xdescribes how to make any file ending in .c if a corresponding file ending Xin .y can be found. X.RS X.sp Xfoo%.o : fee%.k ; recipe... X.sp X.RE Xis used to describe how to make fooxxxx.o from feexxxx.k. X.RS X.sp X%.a :; recipe... X.sp X.RE Xdescribes how to make a file whose suffix is .a without inferring any Xprerequisites. X.RS X.sp X%.c : %.y yaccsrc/%.y ; recipe... X.sp X.RE Xis a short form for the construct: X.RS X.sp X%.c : %.y ; recipe... X.br X%.c : yaccsrc/%.y ; recipe... X.sp X.RE Xie. It is possible to specify the same recipe for two %-rules by giving Xmore than one prerequisite in the prerequisite list. XA more interesting example is: X.RS X.sp X% : RCS/%,v ; co $@ X.sp X.RE Xwhich describes how to take any target and check it out of Xthe RCS directory if the corresponding file exists in the RCS directory. XThe equivalent SCCS rule would be: X.RS X.sp X% : s.% ; get $@ X.sp X.RE X.PP XThe previous RCS example defines an infinite rule, because it says how to make X.I anything Xfrom RCS/%,v, and X.I anything Xalso includes RCS/fred.c,v. XTo limit the size of the graph that results from such rules X.B dmake Xuses the macro variable PREP (stands for % repetition). By default the value Xof this variable is 0, which says that no repetitions of a %-rule are to be Xgenerated. If it is set to something greater than 0, then that many Xrepetitions of any infinite %-rule are allowed. If in the above Xexample PREP was set to 1, then \fBdmake\fP would generate the dependency Xgraph: X.RS X.sp X% --> RCS/%,v --> RCS/RCS/%,v,v X.sp X.RE XWhere each link is assigned the same recipe as the first link. XPREP should be used only in special cases, since it may result in Xa large increase in the number of possible prerequisites tested. X.B dmake Xfurther assumes that any target that has no suffix can be made from Xa prerequisite that has at least one suffix. X.PP X.B dmake Xsupports dynamic prerequisite generation for prerequisites of %-meta rules. XThis is best illustrated by an example. The RCS rule shown above can infer Xhow to check out a file from a corresponding RCS file only if the target Xis a simple file name with no directory information. That is, the above rule Xcan infer how to find \fIRCS/fred.c,v\fP from the target \fIfred.c\fP, Xbut cannot infer how to find \fIsrcdir/RCS/fred.c,v\fP from \fIsrcdir/fred.c\fP Xbecause the above rule will cause \fBdmake\fP to look for RCS/srcdir/fred.c,v; Xwhich does not exist (assume that srcdir has its own RCS directory as is the Xcommon case). X.PP XA more versatile formulation of the above RCS check out rule is the following: X.RS X.sp X% : $$(@:d)RCS/$$(@:f),v : co $@ X.sp X.RE XThis rule uses the dynamic macro $@ to specify the prerequisite to try to Xinfer. During inference of this rule the macro $@ is set to the value of Xthe target of the %-meta rule and the appropriate prerequisite is generated by Xextracting the directory portion of the target name (if any), appending the Xstring \fIRCS/\fP to it, and appending the target file name with a trailing X\fI,v\fP attached to the previous result. X.PP X.B dmake Xcan also infer indirect prerequisites. XAn inferred target can have a list of prerequisites added that will not Xshow up in the value of $< but will show up in the value of $? and $&. XIndirect prerequisites are specified in an inference rule by quoting the Xprerequisite with single quotes. For example, if you had the explicit Xdependency: X.RS X.sp X.nf Xfred.o : fred.c ; rule to make fred.o Xfred.o : local.h X.fi X.sp X.RE Xthen this can be inferred for fred.o from the following inference rule: X.RS X.sp X%.o : %.c 'local.h' ; rule to make a .o from a .c X.sp X.RE XYou may infer indirect prerequisites that are a function of the value of '%' Xin the current rule. The meta-rule: X.RS X.sp X%.o : %.c '$(INC)/%.h' ; rule to make a .o from a .c X.sp X.RE Xinfers an indirect prerequisite found in the INC directory whose name is the Xsame as the expansion of $(INC), and the prerequisite name depends on the Xbase name of the current target. XThe set of indirect prerequisites is attached to the meta rule in which they Xare specified and are inferred only if the rule is used to infer a recipe Xfor a target. They do not play an active role in driving the inference Xalgorithm. XThe construct: X.RS X.sp X%.o : %.c %.f 'local.h'; recipe X.sp X.RE Xis equivalent to: X.RS X.sp X.nf X%.o : %.c 'local.h' : recipe X%.o : %.f 'local.h' : recipe X.fi X.sp X.RE X.PP XIf any of the attributes .SETDIR, .EPILOG, .PROLOG, .SILENT, X\&.USESHELL, .SWAP, .PRECIOUS, .LIBRARY, .NOSTATE and .IGNORE Xare given for a %-rule then when that rule is bound to a target Xas the result of an inference, the target's set of attributes is augmented by Xthe attributes from the above set that are specified in the bound %-rule. XOther attributes specified for %-meta rules are not inherited by the target. XThe .SETDIR attribute is treated in a special way. XIf the target already had a .SETDIR attribute set then X.B dmake Xchanges to that directory prior to performing the inference. XDuring inference any .SETDIR attributes for the inferred prerequisite Xare honored. XThe directories must exist for a %-meta rule to be selected as a possible Xinference path. If the directories do not exist no error message is issued, Xinstead the corresponding path in the inference graph is rejected. X.PP X.B dmake Xalso supports the old format special target .<suffix>.<suffix> Xby identifying any rules Xof this form and mapping them to the appropriate %-rule. So for example if Xan old makefile contains the construct: X.RS X.sp X\&.c.o :; cc \-c $< \-o $@ X.sp X.RE X.B dmake Xmaps this into the following %-rule: X.RS X.sp X%.o : %.c; cc \-c $< \-o $@ X.sp X.RE XFurthermore, X.B dmake Xunderstands several SYSV AUGMAKE special targets and maps them into Xcorresponding %-meta rules. These transformation must be enabled by providing Xthe \-A flag on the command line or by setting the value of AUGMAKE to Xnon\-NULL. XThe construct X.RS X.sp X\&.suff :; recipe X.sp X.RE Xgets mapped into: X.RS X.sp X% : %.suff; recipe X.sp X.RE Xand the construct X.RS X.sp X\&.c~.o :; recipe X.sp X.RE Xgets mapped into: X.RS X.sp X%.o : s.%.c ; recipe X.sp X.RE XIn general, a special target of the form .<str>~ is replaced by the %-rule Xconstruct s.%.<str>, thereby providing support for the syntax used by SYSV XAUGMAKE for providing SCCS support. XWhen enabled, these mappings allow processing of existing SYSV Xmakefiles without modifications. X.PP X.B dmake Xbases all of its inferences on the inference graph constructed from the X%-rules defined in the makefile. XIt knows exactly which targets can be made from which prerequisites by Xmaking queries on the inference graph. For this reason .SUFFIXES is not Xneeded and is completely ignored. X.PP XFor a %-meta rule to be inferred as the Xrule whose recipe will be used to make a target, the target's name must match Xthe %-target pattern, and any inferred %-prerequisite must already exist or Xhave an explicit recipe so that the prerequisite can be made. XWithout \fItransitive closure\fP on the inference graph the above rule Xdescribes precisely when an inference match terminates the search. XIf transitive closure is enabled (the usual case), and a prerequisite does Xnot exist or cannot be made, then X.B dmake Xinvokes the inference algorithm recursively on the prerequisite to see if Xthere is some way the prerequisite can be manufactured. For, if the Xprerequisite can be made then the current target can also be made using the Xcurrent %-meta rule. XThis means that there is no longer a need to give a rule Xfor making a .o from a .y if you have already given a rule for making a .o Xfrom a .c and a .c from a .y. In such cases X.B dmake Xcan infer how to make the X\&.o from the .y via the intermediary .c and will remove the .c when the .o is Xmade. Transitive closure can be disabled by giving the \-T switch on the Xcommand line. X.PP XA word of caution. X.B dmake Xbases its transitive closure on the %-meta rule targets. XWhen it performs transitive closure it infers how to make a target from a Xprerequisite by performing a pattern match as if the potential prerequisite Xwere a new target. XThe set of rules: X.RS X.nf X.sp X%.o : %.c :; rule for making .o from .c X%.c : %.y :; rule for making .c from .y X% : RCS/%,v :; check out of RCS file X.fi X.sp X.RE Xwill, by performing transitive closure, allow \fBdmake\fP to infer how to make Xa .o from a .y using a .c as an intermediate temporary file. Additionally Xit will be able to infer how to make a .y from an RCS file, as long as that XRCS file is in the RCS directory and has a name which ends in .y,v. XThe transitivity computation is performed dynamically for each target that Xdoes not have a recipe. This has potential to be costly if the %-meta Xrules are not carefully specified. The .NOINFER attribute is used to mark Xa %-meta node as being a final target during inference. Any node with this Xattribute set will not be used for subsequent inferences. As an example Xthe node RCS/%,v is marked as a final node since we know that if the RCS file Xdoes not exist there likely is no other way to make it. Thus the standard Xstartup makefile contains an entry similar to: X.RS X.nf X\&.NOINFER : RCS/%,v X.fi X.RE XThereby indicating that the RCS file is the end of the inference chain. XX XWhenever the inference algorithm determines that a target can be made from Xmore than one prerequisite and the inference chains for the two methods Xare the same length the algorithm reports an ambiguity and prints the Xambiguous inference chains. X.PP X.B dmake Xtries to Xremove intermediate files resulting from transitive closure if the file Xis not marked as being PRECIOUS, or the \fB\-u\fP flag was not given on the Xcommand line, and if the inferred intermediate did not previously exist. XIntermediate targets that existed prior to being made are never removed. XThis is in keeping with the philosophy that X.B dmake Xshould never remove things from the file system that it did not add. XIf the special target .REMOVE is defined and has a recipe then X.B dmake Xconstructs a list of the intermediate files to be removed and makes them Xprerequisites of .REMOVE. It then makes .REMOVE thereby removing the Xprerequisites if the recipe of .REMOVE says to. Typically .REMOVE is defined Xin the startup file as: X.sp X\t.REMOVE :; $(RM) $< X.SH "MAKING TARGETS" XIn order to update a target \fBdmake\fP must execute a recipe. XWhen a recipe needs to be executed it is first expanded so that any macros Xin the recipe text are expanded, and it is then either executed directly or Xpassed to a shell. X.B dmake Xsupports two types of recipes. The regular recipes and group recipes. X.PP XWhen a regular recipe is invoked \fBdmake\fP executes each line of the recipe Xseparately using a new copy of a shell if a shell is required. XThus effects of commands do not generally persist across recipe lines. X(e.g. cd requests in a recipe line do not carry over to the next recipe line) XThe decision on whether a shell is required to execute a command is based on Xthe value of the macro SHELLMETAS or on the specification of '+' or .USESHELL Xfor the current recipe or target respectively. XIf any character in the value of XSHELLMETAS is found in the expanded recipe text-line or the use of a shell Xis requested explicitly via '+' or .USESHELL then the command is Xexecuted using a shell, otherwise the command is executed directly. XThe shell that is used for execution is given by the value of the macro SHELL. XThe flags that are passed to the shell are given by the value of SHELLFLAGS. XThus \fBdmake\fP constructs the command line: X.sp X\t$(SHELL) $(SHELLFLAGS) $(expanded_recipe_command) X.sp XNormally X.B dmake Xwrites the command line that it is about to invoke to standard output. XIf the .SILENT attribute is set for the target or for Xthe recipe line (via @), then the recipe line is not echoed. X.PP XGroup recipe processing is similar to that of regular recipes, except that Xa shell is always invoked. The shell that is invoked is given by the value of Xthe macro GROUPSHELL, and its flags are taken from the value of the macro XGROUPFLAGS. If a target has the .PROLOG attribute set then X.B dmake Xprepends to the shell script the recipe associated with the special target X\&.GROUPPROLOG, and if the attribute .EPILOG is set as well, then the recipe Xassociated with the special target .GROUPEPILOG is appended to the script Xfile. XThis facility can be used to always prepend a common header and common trailer Xto group recipes. XGroup recipes are echoed to standard output just like standard recipes, but Xare enclosed by lines beginning with [ and ]. X.PP XThe recipe flags [+,\-,%,@] are recognized at the start of a recipe line Xeven if they appear in a macro. For example: X.RS X.sp X.nf XSH = + Xall: X\t$(SH)echo hi X.fi X.sp X.RE Xis completely equivalent to writing X.RS X.sp X.nf XSH = + Xall: X\t+echo hi X.fi X.sp X.RE X.PP XThe last step performed by X.B dmake Xprior to running a recipe is to set the macro CMNDNAME to the name of the Xcommand to execute (determined by finding the first white\-space ending token SHAR_EOF true || echo 'restore of dm37p2 failed' fi echo 'End of part 6' echo 'File dm37p2 is continued in part 7' echo 7 > _shar_seq_.tmp exit 0 exit 0 # Just in case... -- Kent Landfield INTERNET: kent@sparky.IMD.Sterling.COM Sterling Software, IMD UUCP: uunet!sparky!kent Phone: (402) 291-8300 FAX: (402) 291-4362 Please send comp.sources.misc-related mail to kent@uunet.uu.net.