There can be as many else conditional-directive clauses as necessary. Once a given condition is true, text-if-true is used and no other clause is used if no condition is true then text-if-false is used.Conditionals affect which lines of the makefile make uses. I just wanna let my makefile recognize the CPU type then automatically choose the bootloader address. I wrote: MCU name MCU atmega1281.ifneq ("", (or (findstring atmega128, (MCU)), (findstring atmega1281, (MCU)))) LDSECTION --section-start.text0x1E000 else LDSECTION I need to write an else-if condition in a makefile, and though the format is posted on several websites, nothing seem to be working, andI get an error everytime.Yes, at least one syntax was broken in make (GNU Make 3.81). The conditional ifeq (et al) seems to work OK Part of GNU Emacs and XEmacs. Here are things extending makefile-mode(defconst makefile-nmake-font-lock-keywords (makefile-make-font-lock-keywords. makefile-var-use-regex. With GNU make 3.81 on Linux, the list of .FEATURES is target-specific order-only second-expansion else-if archives jobserver check-symlink.This last part is subtle. If the makefile that included help-system.mak was simply called Makefile (or makefile or GNUmakefile), then GNU make would look Im creating a Makefile, and in one of my targets, i need an IF statement to determine if two things are equal but, I cant get it to run.python somefile.py. else.
1GNU Make - how to add timestamp output (with minimal makefile modification). 1 Make cannot match the target. 1Makefile: nested dependency. 1Using makefile check if symlink exists and create if it doesnt. 1get makefile parameter from folder name. This chapter describes conventions for writing the Makefiles for GNU programs.
Makefile Basics.else true fi. uninstall. Delete all the installed files that the install target would create (but not the noninstalled files such as make all would create). 5.13. Makefile Options. Prev. Chapter 5. Configuring the Makefile.5.13. Makefile Options. Many applications can be built with optional or differing configurations.When using a GNU configure script, keep an eye on which optional features are activated by auto-detection. Conditionals control what make actually "sees" in the makefile, so they cannot be used to control shell commands at the time of execution.This conditional uses three directives: one ifeq, one else and one endif. The ifeq directive begins the conditional, and specifies the condition. I am trying to get if else syntax working in Makefile TYPEsrc RTLsrc program: ifeq ( (TYPE),(RTL) ) echo.
Tags : bash if-statement gnu-make. However, if you are running make without a specific makefile, a makefile in MAKEFILES can do useful things to help the built-in implicit rules work better, such as defining search paths (see section 4.5 SearchingThis is a very bad idea, because such makefiles will fail to work if run by anyone else. Suppose I have a (GNU) Makefile like this: OBJS : foo.o bar.o . link proggie: (OBJS) gcc (OBJS) -o proggie .and this wont work because nothing else in the Makefile refers to bar.o. To work around this (arguably a bug in gcc), one more sed command is needed in the block that builds the The first name checked, GNUmakefile, is not recom-mended for most makefiles. You should use this name if you have a makefile that is specific to GNU make, and will not be understood by otherSee Section 9.7 [Sum-mary of Options], page 85. else-if Supports else if non-nested conditionals. This is a very bad idea, because such makefiles will fail to work if run by anyone else. It is much better to write explicit include directives in the makefiles .Published under the terms of the GNU General Public License. This is a GNU make specific file, showing GNU make semantics. This wont make any difference: .POSIXThis is evaluated only once, here: VAR2 : (shell if [ ! -f count2 ] then echo 0 > count2 else expr cat count2 2 > count2 fi cat count2 ) . Conditionals control what make actually "sees" in the makefile, so they cannot be used to control shell commands at the time of execution.This conditional uses three directives: one ifeq, one else and one endif. The ifeq directive begins the conditional, and specifies the condition. More "makefile else if" pdf. Advertisement.The C Preprocessor - gcc.gnu.org. 4.2.4 Else::::: 42 4.2.5 Elif The C preprocessor is intended to be used only with C, and the Makefile will not work. It does not appear to be possible to call Windows system commands (e.g. del, move, etc) using GNU Make. Im trying to create a makefile that doesnt rely on the user having extra tools (e.g. rm.exe from Cygwin) installed. This is an example of a quite generic GNU Makefile. CXX (shell wx-config --cxx) PROGRAM yourproject OBJECTS (PROGRAM).o implementation .SUFFIXES: .o .cpp .cpp.o : (CXX) -c wx-config --cxxflags -o < all: (PROGRAM) (PROGRAM): (OBJECTS) (CXX) -o (PROGRAM) Search path. External variables. The GNU make utility and Makefiles.else int n atoi(argv) int prime isPrime(n) printf("isPrime(d) dn", n, prime) return 0 Here is the result of running the program on a small selection of input values GNU make supports these directives.Variable substitution is performed on both arguments and then they are compared. The lines of the makefile following the ifneq are obeyed if the two arguments do not match otherwise they are ignored. Makefile preprocessing expressions can use operators that act on constant values, exit codes from commands, strings, macros, and file-system paths.DEFINED in combination with !IF or !ELSE IF is equivalent to !IFDEF or ! ELSE IFDEF. Can I express this concept in the makefile and have dependent targets only run if the content actually changed? To specific, I have a file date.h which has the current date, hour and minute (but not seconds), which is generated by a rule like thiselse . gnu Make and gnu Remake work like many other interpreters. First Makefiles are read in and parsed and then they are executed which in gnu Make means that dependency checks are done and actions are performed based on those checks.rm -rf remake else rm -Rf remake.htp remake.html fi The very same is true for GNU Make so a cc65-based project coming with a GNU Make Makefile can easily be built by any cc65 developer no matter what host system is used. 12.3.3. Passing CFLAGS to GNU configure scripts. 12.3.4. Handling possibly empty variables. Pkgsrc consists of many Makefile fragments, each of which forms a12.1. Caveats. When you are creating a file as a target of a rule, always write the data to a temporary file first and finally rename that file. Creating GNU Makefiles. For me, makefiles are a love-hate relationship.You cannot substitute spaces for TABs, they must be real tabs or else the makefile will not work. So a makefile is made up of targets and dependencies, and commands Makefile variables (, <) By ench0 On 14 February 2013 3 Comments. Ever wondered what the funny-looking vars in the GNU Makefiles are? These two are the most common ones: and < there are some other are special vars as well. "Context of makefile" means that if sees only global make variables. Special variables like are available in the rule context only. Complex rules. Complex rules are possible by. Define complexruleA echo "complexruleA" echo "done" endef. Can someone give me an example of how to do if/then/else in a makefile? I followed the example in the make info page, but it doesnt seem to work for me. Heres what I tried (for mpg123, if that matters). ARCH(shell dpkg --print- gnu-build-architecture). build: ifeq ((ARCH),i486) make linux else make GNUmakefile Makefile GNUmakefile GNU make.if else. Makefile directives control the makefile lines Make reads at read time. Here is our example extended with conditional directives (if, elif, else and endif) to support both Borland and Microsoft compilers. In our example, we use (CC) to specify the compiler, so we could set it to something else if we wanted to without having to change the whole makefile. Heres another trick that GNU make can let you do. In the above makefile, we had to include the rule for compiling sources into objects twice - once for The first name checked, GNUmakefile, is not recommended for most makefiles. You should use this name if you have a makefile that is specific to GNU make, and will notChange to directory dir before reading the makefiles or doing anything else. If multiple C options are specified, each is interpreted I tried commenting out the references to makeinfo in the configure file and the makefile.Not the answer youre looking for? Browse other questions tagged makefile gnu or ask your own question. Matthias009 when I test GNU Make v4.2.1, using ifdef or ifndef (as in the accepted answer) only works if the variable being evaluated is immediately setAs a bonus, the output (such as program version) might be useful in other parts of your Makefile. Dont add tabs to the ifdef, else, endif lines. The first name checked, GNUmakefile, is not recommended for most makefiles. You should use this name if you have a makefile that is specific to GNU make, and will not be understood by other versions of make.This is a very bad idea, because such makefiles will fail to work if run by anyone else. GNU make - Conditional Parts of 18/03/2010 I need to write an else-if condition in a makefile, and though the format is posted on several websites, nothing seem to be working, andI get an error. The default makefile names GNUmakefile, makefile and Makefile are not checked automatically if you specify -f or -- file.(if condition,then-part [,else-part ]) The if function provides support for conditional expansion in a functional context (as opposed to the GNU make makefile conditionals did you try to search for gnu make conditional in google? Does something like this work?makefile help. how best to check a value? (if/else or try/except?) send command to other users within access. 7. Can someone explain how to use if-then statements and for loops in Makefiles? I cant seem to find any good documentation with examples.Have you tried the GNU make documentation? It has a whole section about conditionals with examples. The first name checked, GNUmakefile, is not recommended for most makefiles. You should use this name if you have a makefile that is specific to GNU make, and will not be understood by other versions of make.This is a very bad idea, because such makefiles will fail to work if run by anyone else. 1. Im trying to setup a Makefile that will search and copy some files ( if-else condition) and I cant figure out what exactly is wrong with it? (thou Im pretty sure its because a combination of spaces/tabsRelated. 563. What is the difference between the GNU Makefile variable assignments , ?, : and ? GNU Makefile, detect architecture. I want to autodetect system architecture, when i compile my program under freebsd and i want 2 includes for x64 and x32 but dont work, i triedWhen i compile on i386 with code below the makefile see x64 dir. Soo bassicaly that else dont have any effect ? This is a very bad idea, because such makefiles will fail to work if run by anyone else. It is much better to write explicit include directives in the makefiles .The if function provides support for conditional expansion in a functional context (as opposed to the GNU make makefile conditionals such as ifeq dash-f : (if (filter-out Makefile makefile GNUmakefile, (parent- makefile)), -f (parent-makefile)). dash-f looks at the value of a variable called-e command line option, 2, 4, 34 else, non-nested, 3031 else-if feature, in GNU make 3.81, 14 empty file, opening, 42 emptyset variable, 213 empty string. GNU Make provides a rich set of conditional directives, with which you can annotate parts of the Makefile to be used conditionally (or ignored).Example 5.27: Format of a Make conditional directive. The else keyword, and the following false text can be omitted entirely if necessary. Relatedgnu make - makefile compile multiple source files in one call.If all the members exist, then the output of the shell command will be empty, else it will contain one word for each missing file. You can test for emptiness If Makefile provides a rule for updating bar, make will apply the rule. And likewise for any other target that GNUmakefile does not say how to make.make: Entering directory /u/gnu/make. before doing anything else, and a line of the form