How to write multiple conditions in Makefile.am with "else if"

Question

I want to compile my project with autoconf/automake. There are 2 conditions defined in my configure.ac

AM_CONDITIONAL(HAVE_CLIENT, test $enable-client -eq 1)
AM_CONDITIONAL(HAVE_SERVER, test $enable-server -eq 1)

I want to separate _LIBS from these 2 conditions in Makefile.am

if HAVE_CLIENT

libtest_LIBS = \

    $(top_builddir)/libclient.la

else if HAVE_SERVER

libtest_LIBS = \

    $(top_builddir)/libserver.la

else

libtest_LIBS = 

endif

but else if HAVE_SERVER does NOT work.

How to write 'else if' in makefile.am?

score 168 · Answer 1 · edited Mar 16 '15 at 01:33

168

ptomato's code can also be written in a cleaner manner like:

ifeq ($(TARGET_CPU),x86)
  TARGET_CPU_IS_X86 := 1
else ifeq ($(TARGET_CPU),x86_64)
  TARGET_CPU_IS_X86 := 1
else
  TARGET_CPU_IS_X86 := 0
endif

This doesn't answer OP's question but as it's the top result on google, I'm adding it here in case it's useful to anyone else.

edited Mar 16 '15 at 01:33

blueyed

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answered Jul 25 '12 at 22:20

R.D.

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but here you need to put two `endif` together at the same level of indentation, which altogether wouldn't look good either – Dec 27 '12 at 08:34
1

@amc in the example above a single `endif` is enough, which I've just added. The problem with the indentation is given in all cases (when using a bigger/nested `else` block). – blueyed Mar 16 '15 at 01:34
2

Continuing in the spirit of “as it’s the top result on google” :) if you’re trying to replicate this, make sure you don’t forget the space before the parenthesis in `else ifeq (…)`. `make` gets confused if it’s missing and will end the conditional early. – Lucas Werkmeister Jun 21 '18 at 10:42
2

You cannot use this syntax in Makefile.am – Łukasz Daniluk Jul 30 '18 at 07:33
2

This fails with GNU Make 3.80. Error messages are, *`Extraneous text after 'else' directive.`*. – jww Jul 17 '19 at 06:18
It is useful, even ten years on. Thank you. – Bathsheba Mar 29 '23 at 09:27

ptomato · Answer 2 · 2013-10-22T02:45:26.370

17

I would accept ldav1s' answer if I were you, but I just want to point out that 'else if' can be written in terms of 'else's and 'if's in any language:

if HAVE_CLIENT
  libtest_LIBS = $(top_builddir)/libclient.la
else
  if HAVE_SERVER
    libtest_LIBS = $(top_builddir)/libserver.la
  else
    libtest_LIBS = 
  endif
endif

(The indentation is for clarity. Don't indent the lines, they won't work.)

edited Oct 22 '13 at 02:45

answered Nov 09 '11 at 08:28

ptomato

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I have tried this one, but failed. Is it possible Makefile.am doesn't support recursive if conditions. – Wind Nov 13 '11 at 13:59
4

Did you remove the indentation? All those statements are supposed to start in column 1. – ptomato Nov 13 '11 at 14:05
Sorry, I didn't remove the indentation, I'll try it. – Wind Nov 14 '11 at 02:17
1

I have just tried that, and it works great. Thanks a lot for your help. – Wind Nov 14 '11 at 02:28
2

You can use indentation in line 2, 5 and 7. (only with tabs not with spaces) Only the if, else and endif statements do not allow indentation. – ndreisg Dec 19 '17 at 13:21

score 16 · Answer 3 · edited Sep 06 '12 at 10:44

16

ifeq ($(CHIPSET),8960)
   BLD_ENV_BUILD_ID="8960"
else ifeq ($(CHIPSET),8930)
   BLD_ENV_BUILD_ID="8930"
else ifeq ($(CHIPSET),8064)
   BLD_ENV_BUILD_ID="8064"
else ifeq ($(CHIPSET), 9x15)
   BLD_ENV_BUILD_ID="9615"
else
   BLD_ENV_BUILD_ID=
endif

edited Sep 06 '12 at 10:44

j0k

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answered Sep 06 '12 at 09:39

don

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This fails with GNU Make 3.80. Error messages are, *`Extraneous text after 'else' directive`*. – jww Jul 17 '19 at 06:19
I like this style and this syntax works as written in the version of gnu make I am using. Question: Can this syntax work if the conditional test is for something different on each 'else ifeq' ??? For example could I do this: ifeq ($chipset),1860) BLD_ENV_BUILD_ID="8960" else ifeq ($hostname, "JohnsLaptop") BLD_ENV_BUILD_ID="9615" else BILD_ENV_BUILD_ID= endif – LivingDust Apr 20 '21 at 17:21

score 7 · Answer 4 · answered Oct 11 '13 at 21:27

7

ifdef $(HAVE_CLIENT)
libtest_LIBS = \
    $(top_builddir)/libclient.la
else
ifdef $(HAVE_SERVER)
libtest_LIBS = \
    $(top_builddir)/libserver.la
else
libtest_LIBS = 
endif
endif

NOTE: DO NOT indent the if then it don't work!

answered Oct 11 '13 at 21:27

dkjkj

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score 6 · Answer 5 · answered Nov 09 '11 at 05:18

6

As you've discovered, you can't do that. You can do:

libtest_LIBS =

...

if HAVE_CLIENT
libtest_LIBS += libclient.la
endif

if HAVE_SERVER
libtest_LIBS += libserver.la
endif

answered Nov 09 '11 at 05:18

ldav1s

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Yes, this is good. Thanks for your reply, but actually I have 3 conditions. CLIENT, SERVER, non-CLIENT-non-SERVER. I don't know how to add the 3rd condition in my code. – Wind Nov 13 '11 at 14:03
There's actually 4 conditions wrt AM_CONDITIONAL: !CLIENT && !SERVER, !CLIENT && SERVER, CLIENT && SERVER, CLIENT && !SERVER. This answer will work with all these conditions. For the "3rd condition" (!CLIENT && !SERVER) libtest_LIBS is set to the value you wanted in the 'else if'. – ldav1s Nov 14 '11 at 18:05

How to write multiple conditions in Makefile.am with "else if"

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