omake

omake is a ClearCase utility for building software. It includes many of the configuration management facilities provided by the clearmake utility. It also features emulation modes, which enable you to use omake with makefiles that were constructed for use with other popular make variants, including Microsoft® NMAKE, Borland Make, and the PVCS Configuration Builder (Polymake).

omake features a number of ClearCase extensions:

• Configuration lookup. A build-avoidance scheme that is more sophisticated than the standard scheme based on the time-modified stamps of built objects. For example, this scheme guarantees correct build behavior as C-language header files change, even if the header files are not listed as dependencies in the makefile.
• Derived object sharing. Developers who work in different views can share the files created by omake builds.
• Creation of configuration records. Software bill-of-materials records that fully document a build and support rebuildability; also includes automatic dependency detection.

omake supports the options below. In general, standard make options are lowercase characters; omake extensions are uppercase. Options that do not take arguments can be grouped on the command line (for example, –rOi).

–f makefile

Use makefile as the input file. If you omit this option, omake looks for input files named makefile and Makefile (in that order) in the current working directory. You can use more than one –f makefile argument pair. Multiple input files are effectively concatenated.

–b file

Specify an initialization (built-ins) file to be read instead of the default. If file is the empty string, omake does not read an initialization file. Valid empty strings are "–b  " (one space), –b" ", or –b "".

Note: If you do not include the –b option, omake uses the file named by the OMAKECFG environment variable. If this environment variable is not set, omake looks for a file called make.ini in (in order) the current directory, ccase-home-dir\bin, and in directories specified by the INIT environment variable.

–a

Rebuild all goal targets specified on the command line, along with the recursive closure of their dependencies, regardless of whether they need to be rebuilt.

–k

Abandon work on the current entry if it fails, but continue on other targets that do not depend on that entry.

–i

Ignore error codes returned by commands.

–n

(no-execute) List command lines from the makefile for targets that need to be rebuilt, but do not execute them. Lines that begin with an at-sign (@) character are included in this list.

To override this option for a recursive make, use the .MAKE target attribute. For example:

nt .MAKE :
  cd nt.dir & $(MAKE) $(MFLAGS)

Typing the command

omake –n nt

does a cd nt.dir then a recursive make with omake –n. Without the .MAKE attribute, omake displays, but does not execute, the cd nt.dir & $(MAKE) $(MFLAGS) line.

–s

(Silent) Do not list command lines before executing them.

–e

Environment variables override macro assignments within the makefile. (But macro=value assignments on the command line override environment variables.)

–r

Do not use the built-in rules.

–v

(Verbose) Slightly more verbose than the default output mode. Some particularly useful features of verbose mode:

• List of messages when omake does not reuse a DO that already appears in your view (for example, because its CR does not match your build configuration, or because your view does not have a DO at that path name)
• List of names of DOs being created

–d

(Debug) Quite verbose; appropriate only for debugging makefiles.

–p

Lists all target descriptions and all macro definitions, including target-specific macro definitions and implicit rules.

–h

Displays the command-line syntax.

–x file

Redirects error messages into file. If file is “-”, the error messages are redirected to standard output.

–z

Ignore the MFLAGS macro.

–A

Use automatic dependencies. This option is enabled only if you are not using configuration lookup (because you are processing non-MVFS files or using the –W option).

–C

(Check out DOs) Before building or winking in a target, omake determines whether the target is a checked-in DO that is visible in the view at the path named in the makefile. If such a DO is found, omake -C checks it out before rebuilding it or winking it in.

–D

Keep-directory mode. The first access of a directory to look for a file results in the directory being read into memory.

–G

Restricts dependency checking to makefile dependencies only (those dependencies declared explicitly in the makefile or inferred from an inference rule). All detected dependencies are ignored. For safety, this option disables winkin of DOs from other views; it is quite likely that other views select different versions of detected dependencies.

For example, a derived object in your view may be reused even if it was built with a different version of a header file than is currently selected by your view. This option is mutually exclusive with –W.

–M

Makes the makefile before reading it.

–EN

Emulates Microsoft NMAKE utility.

–EP

Emulates PVCS Configuration Builder (PolyMake) utility.

–EO

Default emulation mode (that is, no emulation).

For details on emulation features, see the IBM Rational ClearCase OMAKE Guide.

–O –L (mutually exclusive)

–O compares only the names and versions of objects listed in the targets' CRs; it does not compare build scripts or build options. This option is useful when this extra level of checking would force a rebuild that you do not want. Examples:

• The only change from the previous build is the setting or canceling of a “compile-for-debugging” option.
• A target was built using a makefile in the current working directory. Now, you want to reuse it in a build to be performed in the parent directory, where a different makefile builds the target (with a different script, which typically references the target using a different path name).

–L makes rebuild decisions using the standard algorithm, based on time-modified stamps; configuration lookup is disabled. It also suppresses creation of configuration records. All MVFS files created during the build are view-private files, not derived objects.

–W

Restricts configuration lookup to the current view only. Winkin of DOs from other views is disabled.

–T

Examines sibling derived objects (objects created by the same build rule that created the target) when determining whether a target object in a VOB can be reused (is up to date). By default, when determining whether a target can be reused, omake ignores modifications to sibling derived objects. –T directs omake to consider a target out of date if its siblings have been modified or deleted.

–#1

Read-time debugging mode. Displays omake reading makefiles and interpreting conditional directives.

–#2

Displays a warning when omake tries to expand the value of an undefined macro.

–#4

Displays a warning when omake reads a makefile line that it can't understand.

–#8

Do not delete generated response files and batch files.

-directOutput logfile

Redirects standard output to the specified file.

String-valued variables called make macros can be used anywhere in a makefile: in target lists, in dependency lists, and/or in build scripts. For example, the value of make macro CFLAGS can be incorporated into a build script as follows:

omake takes into account the fact that software builds are not instantaneous. As your build progresses, other developers can continue to work on their files, and may check in new versions of elements that your build uses. If your build takes an hour to complete, you do not want build scripts executed early in the build to use version 6 of a header file, and scripts executed later to use version 7 or 8. To prevent such inconsistencies, omake locks out any version that meets both these conditions:

• The version is selected by a config spec rule that includes the LATEST version label.
• The version was checked in after the time the build began (the build reference time).

This reference-time facility applies to checked-in versions of elements only; it does not lock out changes to checked-out versions, other view-private files, and non-MVFS objects. omake automatically adjusts for the fact that the system clocks on different hosts in a network may be somewhat out of sync (clock skew).

For more information, see the IBM Rational ClearCase Guide to Building Software.

omake returns a zero exit status if all goal targets are successfully processed. It returns various nonzero exit status values when the build is not successful. See the IBM Rational ClearCase OMAKE Guide.

• Build target hello.exe without checking build scripts or build options during configuration lookup. Be moderately verbose in generating status messages.

  > omake –v –O hello.exe

• Build the default target in the default makefile, with a particular value of make macro INCL_DIR.

  > omake INCL_DIR=c:\src\include_test

• Build target bgrs.exe, restricting configuration lookup to the current view only. Have environment variables override makefile macro assignments.

  > omake –e –W bgrs.exe

• Unconditionally build the default target in a particular makefile, along with all its dependent targets.

  > omake –a –f project.mk

• ccase-home-dir\bin\builtins.cb
• ccase-home-dir\bin\builtins.nm
• ccase-home-dir\bin\make.ini

catcr, clearmake, clearaudit, cleartool, config_spec, diffcr, lsdo, promote_server, rmdo, scrubber, IBM Rational ClearCase Guide to Building Software, IBM Rational ClearCase OMAKE Guide