X-Git-Url: https://git.notmuchmail.org/git?p=notmuch;a=blobdiff_plain;f=configure;h=c6e0c09a8f8014c9458c9461ae59094c49e56e05;hp=70a3c3d881da5c5c9b0244fd63f3a70adbec6b48;hb=9f99a301b158dc1ed1c8c6754db1d57e3b0becf4;hpb=2c2b31d536545189e426b382fad5b5ae0b6cc4de

diff --git a/configure b/configure
index 70a3c3d8..c6e0c09a 100755
--- a/configure
+++ b/configure
@@ -1,14 +1,63 @@
 #! /bin/sh
 
+# Set several defaults (optionally specified by the user in
+# environemnt variables)
 CC=${CC:-gcc}
 CXX=${CXX:-g++}
+CFLAGS=${CFLAGS:--O2}
+CXXFLAGS=${CXXFLAGS:-\$(CFLAGS)}
 
-# defaults
+# Set the defaults for values the user can specify with command-line
+# options.
 PREFIX=/usr/local
 
-# option parsing
+usage ()
+{
+    cat <<EOF
+Usage: ./configure [options]...
+
+This script configures notmuch to build on your system.
+
+It verifies that dependencies are available, determines flags needed
+to compile and link against various required libraries, and identifies
+whether various system functions can be used or if locally-provided
+replacements will be built instead.
+
+Finally, it allows you to control various aspects of the build and
+installation process.
+
+First, some common variables can specified via environment variables:
+
+	CC		The C compiler to use
+	CFLAGS		Flags to pass to the C compiler
+	CXX		The C++ compiler to use
+	CXXFLAGS	Flags to pass to the C compiler
+	LDFLAGS		Flags to pass when linking
+
+Each of these values can further be controlled by specifying them
+later on the "make" command line.
+
+Additionally, various options can be specified on the configure
+command line.
+
+	--prefix=PREFIX	Install files in PREFIX [$PREFIX]
+
+By default, "make install" will install the resulting program to
+$PREFIX/bin, documentation to $PREFIX/share, etc. You can
+specify an installation prefix other than $PREFIX using
+--prefix, for instance:
+
+	./configure --prefix=\$HOME
+
+EOF
+}
+
+# Parse command-line options
 for option; do
-    if [ "${option%=*}" = '--prefix' ] ; then
+    if [ "${option}" = '--help' ] ; then
+	usage
+	exit 0
+    elif [ "${option%%=*}" = '--prefix' ] ; then
 	PREFIX="${option#*=}"
     fi
 done
@@ -195,6 +244,12 @@ CC = ${CC}
 # The C++ compiler to use
 CXX = ${CXX}
 
+# Default FLAGS for C compiler (can be overridden by user such as "make CFLAGS=-g")
+CFLAGS = ${CFLAGS}
+
+# Default FLAGS for C++ compiler (can be overridden by user such as "make CXXFLAGS=-g")
+CXXFLAGS = ${CXXFLAGS}
+
 # The prefix to which notmuch should be installed
 prefix = ${PREFIX}
 
@@ -224,11 +279,11 @@ HAVE_VALGRIND = ${have_valgrind}
 VALGRIND_CFLAGS = ${valgrind_cflags}
 
 # Combined flags for compiling and linking against all of the above
-override CFLAGS += -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS)      \\
+CONFIGURE_CFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS)      \\
 		   \$(TALLOC_CFLAGS) -DHAVE_VALGRIND=\$(HAVE_VALGRIND)   \\
 		   \$(VALGRIND_CFLAGS)
-override CXXFLAGS += -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS)    \\
+CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS)    \\
 		     \$(TALLOC_CFLAGS) -DHAVE_VALGRIND=\$(HAVE_VALGRIND) \\
 		     \$(VALGRIND_CFLAGS) \$(XAPIAN_CXXFLAGS)
-override LDFLAGS += \$(GMIME_LDFLAGS) \$(TALLOC_LDFLAGS) \$(XAPIAN_LDFLAGS)
+CONFIGURE_LDFLAGS =  \$(GMIME_LDFLAGS) \$(TALLOC_LDFLAGS) \$(XAPIAN_LDFLAGS)
 EOF