Error in processing of :: targets

[reid . madsen]

Gnumake maintainers,

 

I've run into a functional difference between the standard unix make and GNUmake (3.80) involving how the :: rules are processed.

 

In the standard unix make (Solaris), the :: targets ( i.e., all::) are process in the order they are found in the Makefile serially, regardless of whether parallelism is used (i.e., -jN, where N is > 1).

 

In GNUmake (3.80), the when -j1 is used, the "::" targets are executed serially.  When -jN is used the "::" targets are executed in parallel.

 

Consider the following -- from an IMAKE generated Makefile:

 

all:: all.prologue

all:: all.serial all.parallel

all:: ; @echo $@; sleep 1; echo address@hidden

all:: all.epilogue

 

all.epilogue all.prologue:: ; @echo $@; sleep 2; echo address@hidden

all.serial:: ; @echo address@hidden; sleep 1; echo address@hidden

all.serial:: ; @echo address@hidden; sleep 1; echo address@hidden

all.parallel: aaa bbb ccc

aaa bbb ccc: ; @echo $@; sleep 1; echo address@hidden

 

In a non-parallel make (i.e. -j1) in both Unix and Gnu make, the following is the result:

 

all.prologue

all.prologue-done

all.serial-1

all.serial-1-done

all.serial-2

all.serial-2-done

aaa

aaa-done

bbb

bbb-done

ccc

ccc-done

all

all-done

all.epilogue

all.epilogue-done

 

When run in parallel using Unix make (i.e., -j12), the following occurs:

 

all.prologue

all.prologue-done

all.serial-1

aaa

bbb

ccc

all.serial-1-done

aaa-done

bbb-done

ccc-done

all.serial-2

all.serial-2-done

all

all-done

all-epilogue

all-epilogue-done

 

When run in parallel using GNUmake (i.e., -j12), the following occurs:

 

all.prologue

all.serial-1

aaa

bbb

ccc

all.epilogue

all.prologue-done

all.serial-1-done

aaa-done

all.serial-2

all.epilogue-done

bbb-done

ccc-done

all.serial-2-done

all

all-done

 

It appears that all the :: targets that exist in the file are started at the same time and not executed sequentially as is done for standard Unix make.  The only exception to this is the all.serial target which has multiple command, which are executed in order... As a result of this I cannot port our IMAKE based make utility to use GNUmake.

 

The intent of the above targets is as follows:

 

+ all.prologue -- things which should be performed before any other all* targets are made

                        For example, creating, or removing a directory.

+ all.epilogue -- things which should occur after all* targets have completed -- for example sending email.

+ a.serial -- rules that MUST execute serially

+ a.parallel -- rules that may execute in parallel

 

The following defines the order of execution:

 

all: all.prologue                   

all: all.serial all.parallel

[ multiple all, all-serial, and all.parallel targets]

all: all.epilogue

 

I'm interested in your views on this problem.  I think it's a bug because GNUmake is clearly out of sync with standard make on the order in which :: targets are evaluated in a parallel build environment.

 

Reid Madsen

Principal Engineer - Architecture Group

Tektronix, Inc.

214-912-5152