.TH MK 1.SH NAMEmk \- maintain (make) related files.SH SYNOPSIS.B mk[.B -f.I mkfile] ...[.I option ...][.I target ...].SH DESCRIPTION.I Mkuses the dependency rules specified in.I mkfileto control the update (usually by compilation) of.I targets(usually files)from the source files upon which they depend.The.I mkfile(default.LR mkfile )contains a.I rulefor each target that identifies the files and othertargets upon which it depends and a.IR sh (1)script, a.IR recipe ,to update the target.The script is run if the target does not existor if it is older than any of the files it depends on..I Mkfilemay also contain.I meta-rulesthat define actions for updating implicit targets.If no.I targetis specified, the target of the first rule (not meta-rule) in.I mkfileis updated..PPThe environment variable.B $NPROCdetermines how many targets may be updated simultaneously; the default value is 1..PPOptions are:.TP \w'\fL-d[egp]\ 'u.B -aAssume all targets to be out of date.Thus, everything is updated..PD 0.TP.BR -d [ egp ]Produce debugging output.RB ( pis for parsing,.B gfor graph building,.B efor execution)..TP.B -eExplain why each target is made..TP.B -iForce any missing intermediate targets to be made..TP.B -kDo as much work as possible in the face of errors..TP.B -nPrint, but do not execute, the commandsneeded to update the targets..TP.B -sMake the command line arguments sequentially rather than in parallel..TP.B -tTouch (update the modified date of) file targets, withoutexecuting any recipes..TP.BI -w target1 , target2,...Pretend the modify time for each.I targetis the current time; useful in conjunction with.B -nto learn what updates would be triggered bymodifying the.IR targets ..PD.SS The mkfileA.I mkfileconsists of.I assignments(described under `Environment') and.IR rules .A rule contains.I targetsand a.IR tail .A target is a literal stringand is normally a file name.The tail contains zero or more .I prerequisitesand an optional.IR recipe ,which is a.B shscript.Each line of the recipe must begin with white space.A rule takes the form.IP.EXtarget: prereq1 prereq2 sh \f2recipe using\fP prereq1, prereq2 \f2to build\fP target.EE.PPWhen the recipe is executed,the first character on every line is elided..PPAfter the colon on the target line, a rule may specify.IR attributes ,described below..PPA.I meta-rule has a target of the form.IB A % Bwhere.I Aand.I Bare (possibly empty) strings.A meta-rule acts as a rule for any potential target whosename matches.IB A % Bwith.B %replaced by an arbitrary string, called the.IR stem .In interpreting a meta-rule,the stem is substituted for all occurrences of.B %in the prerequisite names.In the recipe of a meta-rule, the environment variable.B $stemcontains the string matched by the.BR % .For example, a meta-rule to compile a limbo program anmd install itmight be:.IP.EX%.dis: %.b limbo $stem.b cp $stem.dis /dis.EE.PPMeta-rules may contain an ampersand.B &rather than a percent sign.BR % .A.B %matches a maximal length string of any characters;an.B &matches a maximal length string of any characters except periodor slash..PPThe text of the.I mkfileis processed as follows.Lines beginning with.B <followed by a file name are replaced by the contents of the namedfile.Blank lines and comments, which run from unquoted.B #characters to the following newline, are deleted.The character sequence backslash-newline is deleted,so long lines in.I mkfilemay be folded.Non-recipe lines are processed by substituting for.BI `{ command }the output of the.I commandwhen run by.IR sh .References to variables are replaced by the variables' values.Special characters may be quoted using single quotes.BR \&''as in.IR sh (1)..PPAssignments and rules are distinguished bythe first unquoted occurrence of.B :(rule)or.B =(assignment)..PPA later rule may modify or override an existing rule under thefollowing conditions:.TP\-If the targets of the rules exactly match and one rulecontains only a prerequisite clause and no recipe, theclause is added to the prerequisites of the other rule.If either or both targets are virtual, the recipe isalways executed..TP\-If the targets of the rules match exactly and theprerequisites do not match and both rulescontain recipes,.I mkreports an ``ambiguous recipe'' error..TP\-If the target and prerequisites of both rules match exactly,the second rule overrides the first..SS EnvironmentRules may make use of.B shenvironment variables.A legal reference of the form.B $OBJor.B ${name}is expanded as in.IR sh (1).A reference of the form.BI ${name: A % B = C\fL%\fID\fL}\fR,where.I A, B, C, Dare (possibly empty) strings,has the value formed by expanding.B $nameand substituting.I Cfor.I Aand.I Dfor.I Bin each word in.B $namethat matches pattern.IB A % B\f1..PPVariables can be set byassignments of the form.I var\fL=\fR[\fIattr\fL=\fR]\fIvalue\fR.brBlanks in the.I valuebreak it into words, as in.I shbut without the surrounding parentheses.Such variables are exportedto the environment ofrecipes as they are executed, unless.BR U ,the only legal attribute.IR attr ,is present.The initial value of a variable istaken from (in increasing order of precedence)the default values below,.I mk'senvironment, the.IR mkfiles ,and any command line assignment as an argument to.IR mk .A variable assignment argument overrides the first (but not any subsequent)assignment to that variable.The variable.B MKFLAGScontains all the option arguments (arguments starting with.L -or containing.LR = )and.B MKARGScontains all the targets in the call to.IR mk ..PPDynamic information may be included in the mkfile by using a line of the form.I \fR<| \fIcommand\fR \fIargs\fR.brThis runs the command .I commandwith the given arguments.I argsand pipes its standard output to.I mkto be included as part of the mkfile. For instance, the file.B /os/sa1100/mkfileuses this techniqueto run a shell command with an awk script and a configuration file as arguments in order forthe.I awkscript to process the file and output a set of variables and their values..SS Execution.PPDuring execution,.I mkdetermines which targets must be updated, and in what order,to build the.I namesspecified on the command line.It then runs the associated recipes..PPA target is considered up to date if it has no prerequisites orif all its prerequisites are up to date and it is newerthan all its prerequisites.Once the recipe for a target has executed, the target isconsidered up to date..PPThe date stampused to determine if a target is up to date is computeddifferently for different types of targets.If a target is.I virtual(the target of a rule with the.B Vattribute),its date stamp is initially zero; when the target isupdated the date stamp is set tothe most recent date stamp of its prerequisites.Otherwise, if a target does not exist as a file,its date stamp is set to the most recent date stamp of its prerequisites,or zero if it has no prerequisites.Otherwise, the target is the name of a file andthe target's date stamp is always that file's modification date.The date stamp is computed when the target is needed inthe execution of a rule; it is not a static value..PPNonexistent targets that have prerequisitesand are themselves prerequisites are treated specially.Such a target.I tis given the date stamp of its most recent prerequisiteand if this causes all the targets which have.I tas a prerequisite to be up to date,.I tis considered up to date.Otherwise,.I tis made in the normal fashion.The.B -iflag overrides this special treatment..PPFiles may be made in any order that respectsthe preceding restrictions..PPA recipe is executed by supplying the recipe as standard input tothe command.B $SHELL -e -I.brwhere the.I SHELLvariable is the appropriate shell on the current platform - typically.B /dis/sh.The appropriate value is automatically supplied in the Inferno build environment.The.B -eis omitted if the.B Eattribute is set. The environment is augmented by the following variables:.TP 14.B $alltargetall the targets of this rule..TP.B $newprereqthe prerequisites that caused this rule to execute..TP.B $nprocthe process slot for this recipe.It satisfies.RB 0≤ $nproc < $NPROC ..TP.B $pidthe process id for the.I mkexecuting the recipe..TP.B $prereqall the prerequisites for this rule..TP.B $stemif this is a meta-rule,.B $stemis the string that matched.B %or.BR & .Otherwise, it is empty.For regular expression meta-rules (see below), the variables.LR stem0 ", ...,".L stem9are set to the corresponding subexpressions..TP.B $targetthe targets for this rule that need to be remade..PPThese variables are available only during the execution of a recipe,not while evaluating the.IR mkfile ..PPUnless the rule has the.B Qattribute,the recipe is printed prior to executionwith recognizable environment variables expanded.Commands returning error statuscause.I mkto terminate..PPRecipes and backquoted.B shcommands in places such as assignmentsexecute in a copy of.I mk'senvironment; changes they make toenvironment variables are not visible from.IR mk ..PPVariable substitution in a rule is done whenthe rule is read; variable substitution in the recipe is donewhen the recipe is executed. For example:.IP.EXbar=a.bfoo: $bar limbo -o foo $barbar=b.b.EE.PPwill compile.B b.binto.BR foo ,if.B a.bis newer than.BR foo ..SS AggregatesNames of the form.IR a ( b )refer to member.I bof the aggregate.IR a .Currently, there are no aggregates supported under Inferno..SS AttributesThe colon separating the target from the prerequisitesmay beimmediately followed by.I attributesand another colon.The attributes are:.TP.B <The standard output of the recipe is read by.I mkas an additional.IR mkfile ..PD 0.TP.B DIf the recipe exits with a non-null status, the target is deleted..TP.B EContinue execution if the recipe draws errors..TP.B NIf there is no recipe, the target has its time updated..TP.B nThe rule is a meta-rule that cannot be a target of a virtual rule.Lines 1–500 of 586. Load more
.TH MK 1 .SH NAME mk \- maintain (make) related files .SH SYNOPSIS .B mk [ .B -f .I mkfile ] ... [ .I option ... ] [ .I target ... ] .SH DESCRIPTION .I Mk uses the dependency rules specified in .I mkfile to control the update (usually by compilation) of .I targets (usually files) from the source files upon which they depend. The .I mkfile (default .LR mkfile ) contains a .I rule for each target that identifies the files and other targets upon which it depends and a .IR sh (1) script, a .IR recipe , to update the target. The script is run if the target does not exist or if it is older than any of the files it depends on. .I Mkfile may also contain .I meta-rules that define actions for updating implicit targets. If no .I target is specified, the target of the first rule (not meta-rule) in .I mkfile is updated. .PP The environment variable .B $NPROC determines how many targets may be updated simultaneously; the default value is 1. .PP Options are: .TP \w'\fL-d[egp]\ 'u .B -a Assume all targets to be out of date. Thus, everything is updated. .PD 0 .TP .BR -d [ egp ] Produce debugging output .RB ( p is for parsing, .B g for graph building, .B e for execution). .TP .B -e Explain why each target is made. .TP .B -i Force any missing intermediate targets to be made. .TP .B -k Do as much work as possible in the face of errors. .TP .B -n Print, but do not execute, the commands needed to update the targets. .TP .B -s Make the command line arguments sequentially rather than in parallel. .TP .B -t Touch (update the modified date of) file targets, without executing any recipes. .TP .BI -w target1 , target2,... Pretend the modify time for each .I target is the current time; useful in conjunction with .B -n to learn what updates would be triggered by modifying the .IR targets . .PD .SS The mkfile A .I mkfile consists of .I assignments (described under `Environment') and .IR rules . A rule contains .I targets and a .IR tail . A target is a literal string and is normally a file name. The tail contains zero or more .I prerequisites and an optional .IR recipe , which is a .B sh script. Each line of the recipe must begin with white space. A rule takes the form .IP .EX target: prereq1 prereq2 sh \f2recipe using\fP prereq1, prereq2 \f2to build\fP target .EE .PP When the recipe is executed, the first character on every line is elided. .PP After the colon on the target line, a rule may specify .IR attributes , described below. .PP A .I meta-rule has a target of the form .IB A % B where .I A and .I B are (possibly empty) strings. A meta-rule acts as a rule for any potential target whose name matches .IB A % B with .B % replaced by an arbitrary string, called the .IR stem . In interpreting a meta-rule, the stem is substituted for all occurrences of .B % in the prerequisite names. In the recipe of a meta-rule, the environment variable .B $stem contains the string matched by the .BR % . For example, a meta-rule to compile a limbo program anmd install it might be: .IP .EX %.dis: %.b limbo $stem.b cp $stem.dis /dis .EE .PP Meta-rules may contain an ampersand .B & rather than a percent sign .BR % . A .B % matches a maximal length string of any characters; an .B & matches a maximal length string of any characters except period or slash. .PP The text of the .I mkfile is processed as follows. Lines beginning with .B < followed by a file name are replaced by the contents of the named file. Blank lines and comments, which run from unquoted .B # characters to the following newline, are deleted. The character sequence backslash-newline is deleted, so long lines in .I mkfile may be folded. Non-recipe lines are processed by substituting for .BI `{ command } the output of the .I command when run by .IR sh . References to variables are replaced by the variables' values. Special characters may be quoted using single quotes .BR \&'' as in .IR sh (1). .PP Assignments and rules are distinguished by the first unquoted occurrence of .B : (rule) or .B = (assignment). .PP A later rule may modify or override an existing rule under the following conditions: .TP \- If the targets of the rules exactly match and one rule contains only a prerequisite clause and no recipe, the clause is added to the prerequisites of the other rule. If either or both targets are virtual, the recipe is always executed. .TP \- If the targets of the rules match exactly and the prerequisites do not match and both rules contain recipes, .I mk reports an ``ambiguous recipe'' error. .TP \- If the target and prerequisites of both rules match exactly, the second rule overrides the first. .SS Environment Rules may make use of .B sh environment variables. A legal reference of the form .B $OBJ or .B ${name} is expanded as in .IR sh (1). A reference of the form .BI ${name: A % B = C\fL%\fID\fL}\fR, where .I A, B, C, D are (possibly empty) strings, has the value formed by expanding .B $name and substituting .I C for .I A and .I D for .I B in each word in .B $name that matches pattern .IB A % B\f1. .PP Variables can be set by assignments of the form .I var\fL=\fR[\fIattr\fL=\fR]\fIvalue\fR .br Blanks in the .I value break it into words, as in .I sh but without the surrounding parentheses. Such variables are exported to the environment of recipes as they are executed, unless .BR U , the only legal attribute .IR attr , is present. The initial value of a variable is taken from (in increasing order of precedence) the default values below, .I mk's environment, the .IR mkfiles , and any command line assignment as an argument to .IR mk . A variable assignment argument overrides the first (but not any subsequent) assignment to that variable. The variable .B MKFLAGS contains all the option arguments (arguments starting with .L - or containing .LR = ) and .B MKARGS contains all the targets in the call to .IR mk . .PP Dynamic information may be included in the mkfile by using a line of the form .I \fR<| \fIcommand\fR \fIargs\fR .br This runs the command .I command with the given arguments .I args and pipes its standard output to .I mk to be included as part of the mkfile. For instance, the file .B /os/sa1100/mkfile uses this technique to run a shell command with an awk script and a configuration file as arguments in order for the .I awk script to process the file and output a set of variables and their values. .SS Execution .PP During execution, .I mk determines which targets must be updated, and in what order, to build the .I names specified on the command line. It then runs the associated recipes. .PP A target is considered up to date if it has no prerequisites or if all its prerequisites are up to date and it is newer than all its prerequisites. Once the recipe for a target has executed, the target is considered up to date. .PP The date stamp used to determine if a target is up to date is computed differently for different types of targets. If a target is .I virtual (the target of a rule with the .B V attribute), its date stamp is initially zero; when the target is updated the date stamp is set to the most recent date stamp of its prerequisites. Otherwise, if a target does not exist as a file, its date stamp is set to the most recent date stamp of its prerequisites, or zero if it has no prerequisites. Otherwise, the target is the name of a file and the target's date stamp is always that file's modification date. The date stamp is computed when the target is needed in the execution of a rule; it is not a static value. .PP Nonexistent targets that have prerequisites and are themselves prerequisites are treated specially. Such a target .I t is given the date stamp of its most recent prerequisite and if this causes all the targets which have .I t as a prerequisite to be up to date, .I t is considered up to date. Otherwise, .I t is made in the normal fashion. The .B -i flag overrides this special treatment. .PP Files may be made in any order that respects the preceding restrictions. .PP A recipe is executed by supplying the recipe as standard input to the command .B $SHELL -e -I .br where the .I SHELL variable is the appropriate shell on the current platform - typically .B /dis/sh . The appropriate value is automatically supplied in the Inferno build environment. The .B -e is omitted if the .B E attribute is set. The environment is augmented by the following variables: .TP 14 .B $alltarget all the targets of this rule. .TP .B $newprereq the prerequisites that caused this rule to execute. .TP .B $nproc the process slot for this recipe. It satisfies .RB 0≤ $nproc < $NPROC . .TP .B $pid the process id for the .I mk executing the recipe. .TP .B $prereq all the prerequisites for this rule. .TP .B $stem if this is a meta-rule, .B $stem is the string that matched .B % or .BR & . Otherwise, it is empty. For regular expression meta-rules (see below), the variables .LR stem0 ", ...," .L stem9 are set to the corresponding subexpressions. .TP .B $target the targets for this rule that need to be remade. .PP These variables are available only during the execution of a recipe, not while evaluating the .IR mkfile . .PP Unless the rule has the .B Q attribute, the recipe is printed prior to execution with recognizable environment variables expanded. Commands returning error status cause .I mk to terminate. .PP Recipes and backquoted .B sh commands in places such as assignments execute in a copy of .I mk's environment; changes they make to environment variables are not visible from .IR mk . .PP Variable substitution in a rule is done when the rule is read; variable substitution in the recipe is done when the recipe is executed. For example: .IP .EX bar=a.b foo: $bar limbo -o foo $bar bar=b.b .EE .PP will compile .B b.b into .BR foo , if .B a.b is newer than .BR foo . .SS Aggregates Names of the form .IR a ( b ) refer to member .I b of the aggregate .IR a . Currently, there are no aggregates supported under Inferno. .SS Attributes The colon separating the target from the prerequisites may be immediately followed by .I attributes and another colon. The attributes are: .TP .B < The standard output of the recipe is read by .I mk as an additional .IR mkfile . .PD 0 .TP .B D If the recipe exits with a non-null status, the target is deleted. .TP .B E Continue execution if the recipe draws errors. .TP .B N If there is no recipe, the target has its time updated. .TP .B n The rule is a meta-rule that cannot be a target of a virtual rule.