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 606c4ef..1f34775 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")