build: clean up AC_PACKAGE_WANT_GDBM
authorJeff Mahoney <jeffm@suse.com>
Thu, 15 Mar 2018 21:54:54 +0000 (17:54 -0400)
committerEryu Guan <guaneryu@gmail.com>
Fri, 23 Mar 2018 03:25:50 +0000 (11:25 +0800)
The AC_PACKAGE_WANT_GDBM macro is not easily read. It's not doing
anything particularly complex other than working through a set of
alternatives for headers and libraries.

This patch cleans it up to be more readable.  We also only attempt
to check in libgdbm_compat if the checks in libgdbm fail.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
m4/package_gdbmdev.m4

index 3e5f33d..922cbcb 100644 (file)
@@ -1,43 +1,66 @@
 AC_DEFUN([AC_PACKAGE_WANT_GDBM],
-  [ AC_CHECK_HEADER(gdbm-ndbm.h, [ gdbm_ndbm=true; have_db=true ], [ gdbm_ndbm=false; have_db=false ])
+  [
+    have_db=
+    AC_CHECK_HEADER(gdbm-ndbm.h,
+      [
+       have_db=true
+        AC_DEFINE(HAVE_GDBM_NDBM_H, [1],
+                 [Define to 1 if you have the <gdbm-ndbm.h> header file.])
+      ])
 
-    if test $gdbm_ndbm = true; then
-        AC_DEFINE(HAVE_GDBM_NDBM_H, [1], [Define to 1 if you have the <gdbm-ndbm.h> header file.])
-    else
-        AS_UNSET([ac_cv_header_gdbm_ndbm_h])
-        AC_CHECK_HEADER(gdbm/ndbm.h, [ gdbm_ndbm_=true; have_db=true ], [ gdbm_ndbm_=false; have_db=false ])
-        if test $gdbm_ndbm_ = true; then
-            AC_DEFINE(HAVE_GDBM_NDBM_H_, [1], [Define to 1 if you have the <gdbm/ndbm.h> header file.])
-        else
-            AC_CHECK_HEADER(gdbm.h, [ gdbm_ndbm_=true; have_db=true ], [ gdbm_ndbm_=false; have_db=false ])
-            AC_CHECK_HEADER(ndbm.h, [ ndbm_=true ], [ ndbm_=false ])
-                if test $gdbm_ndbm_ = true; then
-                    if test $ndbm_ = true; then
-                        AC_DEFINE(HAVE_GDBM_H, [1], [Define to 1 if you have both <gdbm.h> and <ndbm.h> header files.])
-                    fi
-                fi
-        fi
+    if test -z "$have_db"; then
+      dnl gdbm-ndbm.h and gdbm/ndbm.h map to the same autoconf internal
+      dnl variable.  We need to clear it or this test will be skipped
+      dnl and the cached result from first test will be used.
+      AS_UNSET([ac_cv_header_gdbm_ndbm_h])
+      AC_CHECK_HEADER(gdbm/ndbm.h,
+       [
+         have_db=true
+         AC_DEFINE(HAVE_GDBM_NDBM_H_, [1],
+                   [Define to 1 if you have the <gdbm/ndbm.h> header file.])
+       ])
     fi
 
-    found=false
-    libgdbm=""
+    if test -z "$have_db"; then
+      AC_CHECK_HEADER(gdbm.h,
+       [
+         have_db=true
+         gdbm_ndbm_=true
+       ], [
+         have_db=false
+         gdbm_ndbm_=false
+       ])
+      AC_CHECK_HEADER(ndbm.h,
+       [
+         ndbm_=true
+       ], [
+         ndbm_=false
+       ])
+       if test $gdbm_ndbm_ = true; then
+         if test $ndbm_ = true; then
+           AC_DEFINE(HAVE_GDBM_H, [1],
+                     [Define to 1 if you have both <gdbm.h> and <ndbm.h> header files.])
+         fi
+       fi
+    fi
 
-    if test $have_db = true; then
-      AC_CHECK_LIB(gdbm,dbm_open,found=true,found=false)
-      AC_CHECK_LIB(gdbm,dbm_fetch,,found=false)
-      AC_CHECK_LIB(gdbm,dbm_store,,found=false)
-      AC_CHECK_LIB(gdbm,dbm_close,,found=false)
+    if test "$have_db" = true; then
+      found=false
+      AC_CHECK_LIB(gdbm, dbm_open, found=true, found=false)
+      AC_CHECK_LIB(gdbm, dbm_fetch,, found=false)
+      AC_CHECK_LIB(gdbm, dbm_store,, found=false)
+      AC_CHECK_LIB(gdbm, dbm_close,, found=false)
 
-      if test $found = true; then
-        libgdbm="${libgdbm} -lgdbm"
+      if test "$found" = true; then
+        libgdbm="-lgdbm"
       else
-       AC_CHECK_LIB(gdbm_compat,dbm_open,found=true,found=false,-lgdbm)
-       AC_CHECK_LIB(gdbm_compat,dbm_fetch,,found=false,-lgdbm)
-       AC_CHECK_LIB(gdbm_compat,dbm_store,,found=false,-lgdbm)
-       AC_CHECK_LIB(gdbm_compat,dbm_close,,found="false",-lgdbm)
+       AC_CHECK_LIB(gdbm_compat, dbm_open, found=true, found=false, -lgdbm)
+       AC_CHECK_LIB(gdbm_compat, dbm_fetch,, found=false, -lgdbm)
+       AC_CHECK_LIB(gdbm_compat, dbm_store,, found=false, -lgdbm)
+       AC_CHECK_LIB(gdbm_compat, dbm_close,, found="no", -lgdbm)
 
-       if test $found = true ; then
-         libgdbm="${libgdbm} -lgdbm_compat -lgdbm"
+       if test "$found" = "true"; then
+         libgdbm="-lgdbm_compat -lgdbm"
        fi
       fi
     fi