健哥的数据花园

摘要： 继续翻译`ifdef VARIABLE-NAME' The `ifdef' form takes the _name_ of a variable as its argument, not a reference to a variable. The value of that variable has a non-empty value, the TEXT-IF-TRUE is effective; otherwise, the TEXT-IF-FALSE, if any, is effective. Variables that have never ... 阅读全文

摘要： 继续翻译 The syntax of the CONDITIONAL-DIRECTIVE is the same whether theconditional is simple or complex; after an `else' or not. There arefour different directives that test different conditions. Here is atable of them:`ifeq (ARG1, ARG2)'`ifeq 'ARG1' 'ARG2''`ifeq "ARG1& 阅读全文

摘要： 继续翻译7.2 Syntax of Conditionals==========================The syntax of a simple conditional with no `else' is as follows: CONDITIONAL-DIRECTIVE TEXT-IF-TRUE endifThe TEXT-IF-TRUE may be any lines of text, to be considered as part ofthe makefile if the condition is true. If the condition ... 阅读全文

摘要： 继续翻译 As this example illustrates, conditionals work at the textual level:the lines of the conditional are treated as part of the makefile, orignored, according to the condition. This is why the larger syntacticunits of the makefile, such as rules, may cross the beginning or theend of the conditio... 阅读全文