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 f6b9f5e21835f153985449d25eacf14937f8f89f..d5b8c798af9acdba9a3acde184988fbcfdc2838e 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")