Drop obsolete AM_PROG_CC_C_O (#2342)

From automake manual:

"
 This is an obsolescent macro that checks that the C compiler
 supports the -c and -o options together. Note that, since
 Automake 1.14, the AC_PROG_CC is rewritten to implement such
 checks itself, and thus the explicit use of AM_PROG_CC_C_O
 should no longer be required.
"

This also changes an implicit build requirement of automake 1.5
to an explicit 1.14 or later requirement.

diff --git a/configure.ac b/configure.ac
index 27d35e5df0fba681d12837010155e53e67dc69c8..605cea996f92e25f1fa65e3ac1ac5f09051d34f8 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -16,7 +16,7 @@ AC_COPYRIGHT([Copyright (C) 1996-2026 The Squid Software Foundation and contribu
  contributions from numerous individuals and organizations.
  Please see the COPYING and CONTRIBUTORS files for details.
 ])
-AM_INIT_AUTOMAKE([tar-ustar nostdinc subdir-objects dist-xz])
+AM_INIT_AUTOMAKE([1.14 tar-ustar nostdinc subdir-objects dist-xz])
 AC_PREFIX_DEFAULT(/usr/local/squid)
 AM_MAINTAINER_MODE
 
@@ -65,7 +65,6 @@ AS_IF([test -e /etc/os-release],[
 ])
 
 AC_PROG_CC
-AM_PROG_CC_C_O
 AC_PROG_CXX
 
 # AC_USE_SYSTEM_EXTENSIONS should be called before any macros that run the C compiler.