configure.ac: Only check for things we actually use.

Drop checks where we don't use the result (yet). We might bring back
some of those once we start actually using the result in the code.

configure.ac

@@ -271,7 +271,7 @@ SR_PKGLIBS=""
 # libm (the standard math library) is always needed.
 AC_SEARCH_LIBS([pow], [m])
 
-# RPC is only needed for VXI support
+# RPC is only needed for VXI support.
 AC_MSG_CHECKING([for RPC support])
 AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <rpc/rpc.h>],
                                 [CLIENT *rpc_test(void)],
@@ -279,9 +279,9 @@ AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <rpc/rpc.h>],
                [AC_MSG_RESULT([yes]); have_rpc=1],
                [AC_MSG_RESULT([no]);  have_rpc=0])
 # Define HAVE_RPC in config.h if we found RPC support.
-AC_DEFINE_UNQUOTED(HAVE_RPC, [$have_rpc],[Specifies whether we have RPC support.])
+AC_DEFINE_UNQUOTED(HAVE_RPC, [$have_rpc], [Specifies whether we have RPC support.])
 # VXI support is only compiled if RPC support was found.
-AM_CONDITIONAL(NEED_RPC, test "x$have_rpc" != x0)
+AM_CONDITIONAL(NEED_RPC, test "x$have_rpc" != "x0")
 
 # libglib-2.0 is always needed. Abort if it's not found.
 # Note: glib-2.0 is part of the libsigrok API (hard pkg-config requirement).
@@ -557,23 +557,9 @@ fi
 
 # Checks for header files.
 # These are already checked: inttypes.h stdint.h stdlib.h string.h unistd.h.
-AC_CHECK_HEADERS([fcntl.h sys/time.h termios.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_BIGENDIAN
-AC_C_INLINE
-AC_TYPE_INT8_T
-AC_TYPE_INT16_T
-AC_TYPE_INT32_T
-AC_TYPE_INT64_T
-AC_TYPE_UINT8_T
-AC_TYPE_UINT16_T
-AC_TYPE_UINT32_T
-AC_TYPE_UINT64_T
-AC_TYPE_SIZE_T
-
-# Checks for library functions.
-AC_CHECK_FUNCS([gettimeofday memset strchr strcspn strdup strerror strncasecmp strstr strtol strtoul strtoull])
 
 AC_SUBST(FIRMWARE_DIR, "$datadir/sigrok-firmware")
 AC_SUBST(MAKEFLAGS, '--no-print-directory')