[PATCH] amhello: help compilers not supporting -c and -o together

[Peter Rosin]

Hi!

Ok for maint, or should the example be as simple as it can possible get
even if portability is sacrificed?

Cheers,
Peter

>From 782f44dd4d3d42beb9d43ee0dd7cf46accc44731 Mon Sep 17 00:00:00 2001
From: Peter Rosin <address@hidden>
Date: Thu, 5 Jan 2012 01:43:11 +0100
Subject: [PATCH] amhello: help compilers not supporting -c and -o together

doc/amhello/configure.ac: Add AM_PROG_CC_C_O.
doc/automake.texi (Hello World): Likewise.  Also update the expected
output from autoreconf and configure.  Describe what AM_PROG_CC_C_O
does in brief terms.
doc/Makefile.am (amhello_configury): Add compile.
---
 doc/Makefile.am          |    1 +
 doc/amhello/configure.ac |    1 +
 doc/automake.texi        |   18 +++++++++++++-----
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/doc/Makefile.am b/doc/Makefile.am
index f4f76c6..0839d5f 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -55,6 +55,7 @@ amhello_configury = \
   aclocal.m4 \
   autom4te.cache \
   Makefile.in \
+  compile \
   config.h.in \
   configure \
   depcomp \
diff --git a/doc/amhello/configure.ac b/doc/amhello/configure.ac
index cd378cb..5fef25f 100644
--- a/doc/amhello/configure.ac
+++ b/doc/amhello/configure.ac
@@ -5,6 +5,7 @@
 AC_INIT([amhello], [1.0], address@hidden)
 AM_INIT_AUTOMAKE([-Wall -Werror foreign])
 AC_PROG_CC
+AM_PROG_CC_C_O
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([
  Makefile
diff --git a/doc/automake.texi b/doc/automake.texi
index 0c4dc01..3a08ee2 100644
--- a/doc/automake.texi
+++ b/doc/automake.texi
@@ -1470,6 +1470,7 @@ create the @command{configure} script.
 AC_INIT([amhello], [1.0], address@hidden)
 AM_INIT_AUTOMAKE([-Wall -Werror foreign])
 AC_PROG_CC
+AM_PROG_CC_C_O
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([
  Makefile
@@ -1487,14 +1488,15 @@ command as follows:
 
 @example
 ~/amhello % @kbd{autoreconf --install}
-configure.ac: installing `./install-sh'
-configure.ac: installing `./missing'
+configure.ac:4: installing `./compile'
+configure.ac:2: installing `./install-sh'
+configure.ac:2: installing `./missing'
 src/Makefile.am: installing `./depcomp'
 @end example
 
 At this point the build system is complete.
 
-In addition to the three scripts mentioned in its output, you can see
+In addition to the four scripts mentioned in its output, you can see
 that @command{autoreconf} created four other files: @file{configure},
 @file{config.h.in}, @file{Makefile.in}, and @file{src/Makefile.in}.
 The latter three files are templates that will be adapted to the
@@ -1509,16 +1511,17 @@ checking for gawk... no
 checking for mawk... mawk
 checking whether make sets $(MAKE)... yes
 checking for gcc... gcc
-checking for C compiler default output file name... a.out
 checking whether the C compiler works... yes
-checking whether we are cross compiling... no
+checking for C compiler default output file name... a.out
 checking for suffix of executables...
+checking whether we are cross compiling... no
 checking for suffix of object files... o
 checking whether we are using the GNU C compiler... yes
 checking whether gcc accepts -g... yes
 checking for gcc option to accept ISO C89... none needed
 checking for style of include used by make... GNU
 checking dependency style of gcc... gcc3
+checking whether gcc and cc understand -c and -o together... yes
 configure: creating ./config.status
 config.status: creating Makefile
 config.status: creating src/Makefile
@@ -1577,6 +1580,7 @@ Let us begin with the contents of @file{configure.ac}.
 AC_INIT([amhello], [1.0], address@hidden)
 AM_INIT_AUTOMAKE([-Wall -Werror foreign])
 AC_PROG_CC
+AM_PROG_CC_C_O
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([
  Makefile
@@ -1635,6 +1639,10 @@ creates @file{src/Makefile} from @file{src/Makefile.in}, 
it will define
 a @file{Makefile.in} that uses @code{CC} but @file{configure.ac} does
 not define it, it will suggest you add a call to @code{AC_PROG_CC}.
 
+The @code{AM_PROG_CC_C_O} line triggers the help from the @command{compile}
+script when the C compiler does not support the @option{-c} and
address@hidden options together.
+
 The @code{AC_CONFIG_HEADERS([config.h])} invocation causes the
 @command{configure} script to create a @file{config.h} file gathering
 @samp{#define}s defined by other macros in @file{configure.ac}.  In our
-- 
1.7.5.1