1152_ Makefile learning_ Pattern matching rules

    All learning summary ： https://github.com/GreyZhang/g_makefile

    I looked at a static pattern matching rule , This time look at the pattern matching rules .

    here , Take a paragraph from a tutorial written by someone else . The interpretation of these two rules is actually very simple , The first is to be able to .o And .c Automatic derivation of dependencies between , Then execute the compiled command . And when compiling , Two built-in variables are used ,$< Used to refer to a file that is dependent on [email protected] Used to refer to the target file . The second one was used in the previous example , Used to create missing empty files .

    Next , See the explanation of some documents .

    First, we give an introduction to the pattern rules , Then a typical grammar format is given . Actually , If you have a certain coding foundation, you may take a look at the general working mechanism of the marked format . The whole expression is a relatively direct content replacement .

    About stem What is it? , Here is another explanation . And rely on files , It must already exist or be created next . Some dependent files may not be accompanied by %, Under such a rule, all target The general processing rules are used , Such rules are sometimes useful , But I really didn't think about the use of my current demands . One target Can be hit by multiple rules , In this case make Will choose the best rule . The choice of the best rule , Later, I'll go and sort it out . In turn, , A rule may hit more than one target, In this case make The explicit rule execution command will be responsible for the creation of all targets and will only be created once .

    The above part is about Makefile Simple sorting of matching rules in , So many items make me doubt ： Now the script automation function is also very powerful ,Makefile Functions of python Is it also possible to write such scripts ？ Is there a big deviation in efficiency ？！