-By default, configure will use the "gcc" compiler if found. You can use a
-different compiler, or add unusual options for compiling or linking that
-the "configure" script does not know about, by either editing the user
-configuration section of the top level Makefile (after running configure)
-or giving "configure" initial values for these variables by setting them
-in the environment. Using a Bourne-compatible shell (such as sh,ksh,zsh),
-
-you can do that on the command line like this:
- CC=c89 CFLAGS=-O2 LIBS=-lposix ./configure
-
-Or on systems that have the "env" program, you can do it like this:
- env CPPFLAGS=-I/usr/local/include LDFLAGS=-s ./configure
+
+By default, configure will use the "gcc" compiler if found. You can
+use a different compiler, or add unusual options for compiling or
+linking that the "configure" script does not know about, by giving
+"configure" initial values for these on its command line or in its
+environment. For example,
+
+ ./configure CC=c89 CFLAGS=-O2 LIBS=-lposix
+
+If you wish to add options that are only used at compile time instead of
+link time, you can use the CPPFLAGS variable:
+ ./configure CPPFLAGS='-Wextra -Wno-sign-compare'
+
+If you want to add to both compile and link flags at build time
+without putting them in the configuration, you can use an otherwise
+unused Makefile macro, like this:
+ make AM_CFLAGS=--coverage
+
+That does not include that setting in the configuration, so you will
+have to repeat it if you re-run "make". One example would be if you
+build the test suite as a separate step:
+ make test AM_CFLAGS=--coverage
+
+Note that the Makefile test target depends on the default target, so
+both be can built in one step with "make test".