Clearmake
Clearmake主要适用于使用UNIX型的makefile的用户,它本身兼容GNU make。 在执行建立脚本期间，clearmake在ClearCase的多版本文件系统下执行一个建立追踪，它会记录每个派生对象被构建时的信息。
使用Clearmake的优势：
1). 它可以和clearcase配合，将生成的目标文件,库文件和二进制文件(DO)共享;
2). 支持并行构建和分布式构建，并行构建能够同时执行多重编译，分布式构建允许用户使用多台机器完整构建步骤;
3). 可以生成配置记录(config record)，作审计用。
clearmake provides partial compatibility with GNU make. This section provides the details.
Supported GNU make Command Options
clearmake –C gnu supports most of the single-character and long-form spellings of GNU make command options, as follows:
–b
Disables GNU's built-in rules (equivalent to gnumake –R).
– –directory=dir
Change to the specified directory before reading the makefiles.
–d – –debug
Prints debugging information in addition to normal processing messages.
–e – –environment-override
Gives variables taken from the environment precedence over variables from makefiles.
–f file – –file=file – –makefile=file
Reads file as a makefile.
–I dir
Specifies a directory dir to search for included makefiles.
–i – –ignore-errors
Ignores all errors in commands executed to remake files.
– –include-dir=dir
Specifies a directory in which to search for included makefiles.
–k – –keep-going
Continues as much as possible after an error.
– –no-builtin-variables
Eliminate use of built-in, rule-specific variables.
– –-no-print-directory
Disables printing of the working directory under –w.
–n – –just-print – –dry-run – –-recon
Prints the commands that would be executed, but does not execute them.
–p – –print-data-base
Prints the database (rules and variable values) that results from reading the makefiles, then executes as usual or as otherwise specified.
–q – –question
Question mode. Does not run any commands or print anything. Returns an exit status of 0 if the specified targets are already up to date, or 1 if any remaking is required.
–r – –no-builtin-rules
Eliminates use of the built-in implicit rules.
–s – –silent – –quiet
Silent operation. Does not print the commands as they are executed.
– –warn-undefined-variables
Issues a warning whenever a reference to an undefined variable is found. Null warnings for VPATH and SHELLare suppressed by default; null warnings for these can be displayed using the clearmake options –v or –d.
–w – –print-directory
Prints a message containing the working directory both before and after executing the makefile.
Unsupported GNU make Command-Line Options
The following options are not supported:
- -m
- -C dir
- -h --help
- -I dir
- -j [jobs] --jobs[=jobs]
- -l [load] --load-average[=load] --max-load[=load]
- -o file --old-file=file --assume-old=file
- -R (this is supported as –b)
- -S --no-keep-going --stop
- -t --touch
- -v --version
- -W file --what-if=file --new-file=file --assume-new=file
Supported GNU make Features
The following features are enabled with –C gnu (see the GNU make documentation):
- Conditional makefile interpretation. For example:
ifeq ($(CC),gcc)
$(CC) -o foo $(objects) $(libs_for_gcc)
else
$(CC) -o foo $(objects) $(normal_libs)
endif
- Simply expanded variables in which the RHS is expanded once when the assignment is first scanned. For example:
y := $(x) bar
- The += syntax to append to the value of a variable.
- The ?= macro operator.
- The use of $$ in target names as an equivalent to a literal $.
- Special characters ()<>;!=&|$#:”{}/ (UNIX) or ()<>;!=&|$#:” (Windows) within macro names
- Escaping special characters in target names by preceding them with a /. Note that the escaping must be consistent within the makefile. For example,
test: test#footest/#foo:
echo $@test: test#footest/#foo:
echo $@
generates a Don't know how to make error.
- Stripping leading sequences of ./ (UNIX) or ./ (Windows) from file names, so that (for example) ./file and file are considered the same target
- Variable references using pattern substitution:
${VAR:PATTERN_1=PATTERN_2}
- Text-manipulation functions:
$(subst FROM,TO,TEXT)
$(patsubst PATTERN,REPLACEMENT,TEXT)
$(strip STRING)
$(findstring FIND,IN)
$(filter PATTERN...,TEXT)
$(filter-out PATTERN...,TEXT)
$(sort LIST)
$(dir NAMES...)
$(notdir NAMES...)
$(suffix NAMES...)
$(basename NAMES...)
$(addsuffix SUFFIX,NAMES...)
$(addprefix PREFIX,NAMES...)
$(join LIST1,LIST2)
$(word N,TEXT)
$(words TEXT)
$(wordlist START, END, TEXT)
$(firstword NAMES...)
$(wildcard PATTERN)
$(foreach VAR,LIST,TEXT)
$(origin VARIABLE)
$(shell COMMAND)
- The VPATH variable for specifying a search path for every dependency.
Note: clearmake searches only in the current view. For more information, see the makefile_ccase reference page.
- The MAKECMDGOALS variable for specifying the targets given on the command line.
- The vpath statement for specifying a search path for a specified class of names.
- The export statement.
- The unexport directive.
- The .PHONY target declaration.
- All of GNU make's built-in implicit rules.
- Pattern rules. For example:
%.o : %.c
COMMANDS
...
- Static pattern rules:
TARGETS ...: TARGET-PATTERN: DEP-PATTERNS ...
COMMANDS
...
- The automatic variables:
$@ $* $< $% $? $^ $+
Also, their file-name and directory-name variants. For example:
$(@F) $(@D) ...
- Multiline variable definition:
define VAR
TEXT
...
endef
- Target-specific variable values:
target ... : variable-assignment
or
target ... : override variable-assignment
Unsupported GNU make Features
The following features are not supported:
- Automatic remaking of any makefiles that are declared as targets (you must explicitly rebuild them).
- The declarations .DELETE_ON_ERROR, .INTERMEDIATE, .SECONDARY.
- Automatic makefile regeneration and restart if the makefile and included makefile fragments are targets in the makefile itself.
- Automatic deletion of intermediate results of a chain of implicit-rules.
- Special search method for library dependencies written in the form -lNAME. For each directory on theVPATH/vpath list, GNU make searches in DIR/lib .
- When MAKEFILES is defined, GNU make considers its value as a list of names of additional makefiles to be read before the others, as though they were implicitly included.
- The following functions:
- $(error ...)
- $(warning ...)
- $(call ...)
- $(if ...)