Question

我一直在努力使用John Graham-Cumming关于GNU Make＆＃34;＆＃34; Atomic Rules in GNU Make＆＃34; 在http://www.cmcrossroads.com/article/atomic-rules-gnu-make?page=0%2C0

但是，我有时必须使用单独的规则指定两个文件之间的依赖关系看似简单的食谱：

a : b

这对我来说总是如预期的那样，但是在指定依赖时它会失败两个原子规则之间。这是一个包含3个测试用例的简单Makefile：

atomic = $(eval $1: $(firstword $1).sentinel ; @:) \
         $(firstword $1).sentinel : $2 ; touch $$@ \
         $(foreach _, $1, $(if $(wildcard $_), , $(shell rm -f $(firstword $1).sentinel)))

d1 d2 d3:
    touch $@

## Test case 1 using sentinel and dependency (u1 u2 : t1 t2) specified in call to atomic
$(call atomic, t1 t2, d1)
    touch t1 t2

$(call atomic, u1 u2, t1 t2)
    touch u1 u2

## Test case 2 using sentinel and dependency (w1 w2 : v1 v2) specified as another rule does not work
$(call atomic, v1 v2, d2)
    touch v1 v2

$(call atomic, w1 w2, )
    touch w1 w2

w1 w2 : v1 v2

## Test case 3 showing that specifying a dependency (y1 : x1) with another rule does work
x1 : d3
    touch x1

y1 :
    touch y1

y1 : x1

##

clean :
    rm -f {d,t,u,v,w,x,y}{1,2,3}{,.sentinel} test{1,2,3}

test1 : u1
    touch test1

test2 : w1
    touch test2

test3 : y1
    touch test3

第一个测试用例做正确的事情并按预期顺序构建所有内容

> make test1
touch d1
touch t1.sentinel      
touch t1 t2
touch u1.sentinel      
touch u1 u2
touch test1

第二个测试用例通过以错误的顺序构建事物来惨败原子规则

> make test2
touch w1.sentinel      
touch w1 w2
touch d2
touch v1.sentinel      
touch v1 v2
touch test2

第三个简单的测试用例证明使用单独的规则来指定依赖项确实有效

> make test3
touch d3
touch x1
touch y1
touch test3

任何人都可以解释为什么会这样吗？更好的是，任何人都可以提出解决方案，以便test2与test1的工作方式相同吗？我真的卡住了。

谢谢， - 汤姆

Answer 1

您在错误的目标上手动添加了依赖项。

回想原子构造正在做什么。它将原始目标集合折叠为单个标记目标，并将其用作排序点。

您正在将先决条件添加到各个原始目标（原始解决方法首先设计为允许/修复的确切事项）。

您需要将先决条件添加到sentinel文件：w1.sentinel : v1 v2

（或者更好的是，使用原始帖子中的哨兵功能并使用$(call sentinel,w1 w2): v1 v2。

顺便说一下，在make函数调用中添加，周围的空格要小心。它可能对事物产生非常具有破坏性和奇怪的影响。

atomic.mk：

atomic = $(eval $1: $(firstword $1).sentinel ; @:) \
         $(firstword $1).sentinel : $2 ; touch $$@ \
         $(foreach _,$1,$(if $(wildcard $_),,$(shell rm -f $(firstword $1).sentinel)))

d1 d2 d3 d4:
>-------touch $@

## Test case 1 using sentinel and dependency (u1 u2 : t1 t2) specified in call to atomic
$(call atomic, t1 t2, d1)
>-------touch t1 t2

$(call atomic, u1 u2, t1 t2)
>-------touch u1 u2

## Test case 2 using sentinel and dependency (w1 w2 : v1 v2) specified as another rule does not work
$(call atomic, v1 v2, d2)
>-------touch v1 v2

$(call atomic, w1 w2, )
>-------touch w1 w2

w1 w2 : v1 v2

## Test case 4 using manual dependencies added to sentinel explicitly.
$(call atomic, z1 z2, d4)
>-------touch z1 z2

$(call atomic, a1 a2, )
>-------touch a1 a2

a1.sentinel : z1 z2

##

clean :
>-------rm -f {d,t,u,v,w,x,y,z,a}{1,2,3,4}{,.sentinel} test{1,2,3,4}

test1 : u1
>-------touch test1

test2 : w1
>-------touch test2

test4: a1
>-------touch test4

make -f ../atomic.mk -drR test1的输出：

Reading makefiles...
Reading makefile `../atomic.mk'...
Updating makefiles....
 ....
Updating goal targets....
Considering target file `test1'.
 File `test1' does not exist.
  Considering target file `u1'.
   File `u1' does not exist.
    Considering target file `u1.sentinel'.
     File `u1.sentinel' does not exist.
      Considering target file `t1'.
       File `t1' does not exist.
        Considering target file `t1.sentinel'.
         File `t1.sentinel' does not exist.
          Considering target file `d1'.
           File `d1' does not exist.
           Finished prerequisites of target file `d1'.
          Must remake target `d1'.
touch d1
....
          Successfully remade target file `d1'.
         Finished prerequisites of target file `t1.sentinel'.
        Must remake target `t1.sentinel'.
touch t1.sentinel
....
touch t1 t2
....
        Successfully remade target file `t1.sentinel'.
       Finished prerequisites of target file `t1'.
      Must remake target `t1'.
      Successfully remade target file `t1'.
      Considering target file `t2'.
        Pruning file `t1.sentinel'.
       Finished prerequisites of target file `t2'.
       Prerequisite `t1.sentinel' is older than target `t2'.
      No need to remake target `t2'.
     Finished prerequisites of target file `u1.sentinel'.
    Must remake target `u1.sentinel'.
touch u1.sentinel
....
touch u1 u2
....
    Successfully remade target file `u1.sentinel'.
   Finished prerequisites of target file `u1'.
  Must remake target `u1'.
  Successfully remade target file `u1'.
 Finished prerequisites of target file `test1'.
Must remake target `test1'.
touch test1
....
Successfully remade target file `test1'.

make -f ../atomic.mk -drR test2的输出：

Reading makefiles...
Reading makefile `../atomic.mk'...
Updating makefiles....
 ....
Updating goal targets....
Considering target file `test2'.
 File `test2' does not exist.
  Considering target file `w1'.
   File `w1' does not exist.
    Considering target file `w1.sentinel'.
     File `w1.sentinel' does not exist.
     Finished prerequisites of target file `w1.sentinel'.
    Must remake target `w1.sentinel'.
touch w1.sentinel
....
touch w1 w2
....
    Successfully remade target file `w1.sentinel'.
    Considering target file `v1'.
     File `v1' does not exist.
      Considering target file `v1.sentinel'.
       File `v1.sentinel' does not exist.
        Considering target file `d2'.
         File `d2' does not exist.
         Finished prerequisites of target file `d2'.
        Must remake target `d2'.
touch d2
....
        Successfully remade target file `d2'.
       Finished prerequisites of target file `v1.sentinel'.
      Must remake target `v1.sentinel'.
touch v1.sentinel
....
touch v1 v2
....
      Successfully remade target file `v1.sentinel'.
     Finished prerequisites of target file `v1'.
    Must remake target `v1'.
    Successfully remade target file `v1'.
    Considering target file `v2'.
      Pruning file `v1.sentinel'.
     Finished prerequisites of target file `v2'.
     Prerequisite `v1.sentinel' is older than target `v2'.
    No need to remake target `v2'.
   Finished prerequisites of target file `w1'.
  Must remake target `w1'.
  Successfully remade target file `w1'.
 Finished prerequisites of target file `test2'.
Must remake target `test2'.
touch test2
....
Successfully remade target file `test2'.

make -f ../atomic.mk -drR test4的输出：

Reading makefiles...
Reading makefile `../atomic.mk'...
Updating makefiles....
 ....
Updating goal targets....
Considering target file `test4'.
 File `test4' does not exist.
  Considering target file `a1'.
   File `a1' does not exist.
    Considering target file `a1.sentinel'.
     File `a1.sentinel' does not exist.
      Considering target file `z1'.
       File `z1' does not exist.
        Considering target file `z1.sentinel'.
         File `z1.sentinel' does not exist.
          Considering target file `d4'.
           File `d4' does not exist.
           Finished prerequisites of target file `d4'.
          Must remake target `d4'.
touch d4
....
          Successfully remade target file `d4'.
         Finished prerequisites of target file `z1.sentinel'.
        Must remake target `z1.sentinel'.
touch z1.sentinel
....
touch z1 z2
....
        Successfully remade target file `z1.sentinel'.
       Finished prerequisites of target file `z1'.
      Must remake target `z1'.
      Successfully remade target file `z1'.
      Considering target file `z2'.
        Pruning file `z1.sentinel'.
       Finished prerequisites of target file `z2'.
       Prerequisite `z1.sentinel' is older than target `z2'.
      No need to remake target `z2'.
     Finished prerequisites of target file `a1.sentinel'.
    Must remake target `a1.sentinel'.
touch a1.sentinel
....
touch a1 a2
....
    Successfully remade target file `a1.sentinel'.
   Finished prerequisites of target file `a1'.
  Must remake target `a1'.
  Successfully remade target file `a1'.
 Finished prerequisites of target file `test4'.
Must remake target `test4'.
touch test4
....
Successfully remade target file `test4'.

请参阅this graph以查看相关的必备树（由于我不知道有任何好的工具可以通过make输出来创建，但是我已经想要一段时间了，所以请道歉我有点不对劲。）

使用sentinel文件失败的Gnumake原子规则

1 个答案: