继续翻译
`MAKE_RESTARTS' This variable is set only if this instance of `make' has restarted (*note How Makefiles Are Remade: Remaking Makefiles.): it will contain the number of times this instance has restarted. Note this is not the same as recursion (counted by the `MAKELEVEL' variable). You should not set, modify, or export this variable. `.RECIPEPREFIX' The first character of the value of this variable is used as the character make assumes is introducing a recipe line. If the variable is empty (as it is by default) that character is the standard tab character. For example, this is a valid makefile: .RECIPEPREFIX = > all: > @echo Hello, world The value of `.RECIPEPREFIX' can be changed multiple times; once set it stays in effect for all rules parsed until it is modified. `.VARIABLES' Expands to a list of the _names_ of all global variables defined so far. This includes variables which have empty values, as well as built-in variables (*note Variables Used by Implicit Rules: Implicit Variables.), but does not include any variables which are only defined in a target-specific context. Note that any value you assign to this variable will be ignored; it will always return its special value.
`MAKE_RESTARTS'
只有当 make 的实例重新启动后才会被设置(*note How Makefiles Are Remade: Remaking Makefiles.): 它会包含此实例重新启动的次数。请注意这个和递归(recursion)(由MAKELEVEL来计数)不同。你无法设定，更改或者导出此变量。
`.RECIPEPREFIX'这个变量的第一个字符被用作引入一个片段行。如果此变量的值为空(缺省值)，那么这个引入片段行的字符将是标准tab键。例如下面是一个有效的makefile。
.RECIPEPREFIX = >
all:
> @echo Hello, world
`.RECIPEPREFIX' 的值可以被改变很多次; 一旦被设置就开始对所有规则有效，直到被再次改变为止。
`.VARIABLES'
扩展为一个所有全局变量的列表。其中包括拥有空值的，也包口内建的变量(*note Variables Used by Implicit Rules: Implicit Variables.)，但是不包括那些仅仅在目的特定的上下文中定义的变量。请注意任何你所设的值会被忽略，它总是返回其特殊值。
后文待续