protoc: log when compiler is missing

In the case where we do have the required headers
but don't have the compiler, this makes it more clear
that we're missing the latter.

diff --git a/configure.ac b/configure.ac
index 606c4effa4e3d60351883066e97018d156d7435d..1f347759035931da623ddaaf4d267dac5d161ab8 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -57,12 +57,17 @@ AC_PROG_YACC
 PKG_PROG_PKG_CONFIG
 
 AC_CHECK_PROG([have_protoc_c], [protoc-c], [yes], [no])
-AC_CHECK_HEADERS([google/protobuf-c/protobuf-c.h],
-                 [have_protobuf_c_h="yes"],
-                 [have_protobuf_c_h="no"])
-if test "x$have_protoc_c" = "xyes" && test "x$have_protobuf_c_h" != "xyes"
+if test "x$have_protoc_c" = "xno"
 then
-       have_protoc_c="no (unable to find <google/protobuf-c/protobuf-c.h>)"
+       have_protoc_c="no (protoc-c compiler not found)"
+else
+       AC_CHECK_HEADERS([google/protobuf-c/protobuf-c.h],
+                        [have_protobuf_c_h="yes"],
+                        [have_protobuf_c_h="no"])
+       if test "x$have_protobuf_c_h" = "xno"
+       then
+               have_protoc_c="no (<google/protobuf-c/protobuf-c.h> not found)"
+       fi
 fi
 AM_CONDITIONAL(HAVE_PROTOC_C, test "x$have_protoc_c" = "xyes")