diff --git a/acinclude.m4 b/acinclude.m4
index ab1231713..bf39601ef 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -51,12 +51,12 @@ AC_DEFUN([TOR_TRY_COMPILE_WITH_CFLAGS], [
   AC_CACHE_CHECK([whether the compiler accepts $1], VAR, [
     tor_saved_CFLAGS="$CFLAGS"
     CFLAGS="$CFLAGS -pedantic -Werror $1"
-    AC_TRY_COMPILE([], [return 0;],
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
                    [AS_VAR_SET(VAR,yes)],
                    [AS_VAR_SET(VAR,no)])
     if test x$2 != x; then
       AS_VAR_PUSHDEF([can_link],[tor_can_link_$1])
-      AC_TRY_LINK([], [return 0;],
+      AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
                   [AS_VAR_SET(can_link,yes)],
                   [AS_VAR_SET(can_link,no)])
       AS_VAR_POPDEF([can_link])
@@ -93,7 +93,7 @@ AC_DEFUN([TOR_CHECK_LDFLAGS], [
     AC_RUN_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>], [fputs("", stdout)])],
                   [AS_VAR_SET(VAR,yes)],
                   [AS_VAR_SET(VAR,no)],
-	          [AC_TRY_LINK([], [return 0;],
+                  [AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
                                    [AS_VAR_SET(VAR,yes)],
                                    [AS_VAR_SET(VAR,no)])])
     CFLAGS="$tor_saved_CFLAGS"
@@ -113,21 +113,21 @@ if test x$2 = xdevpkg; then
   h=" headers for"
 fi
 if test -f /etc/debian_version && test x"$tor_$1_$2_debian" != x; then
-  AC_WARN([On Debian, you can install$h $1 using "apt-get install $tor_$1_$2_debian"])
+  AC_MSG_WARN([On Debian, you can install$h $1 using "apt-get install $tor_$1_$2_debian"])
   if test x"$tor_$1_$2_debian" != x"$tor_$1_devpkg_debian"; then 
-    AC_WARN([   You will probably need $tor_$1_devpkg_debian too.])
+    AC_MSG_WARN([   You will probably need $tor_$1_devpkg_debian too.])
   fi 
 fi
 if test -f /etc/fedora-release && test x"$tor_$1_$2_redhat" != x; then
-  AC_WARN([On Fedora, you can install$h $1 using "dnf install $tor_$1_$2_redhat"])
+  AC_MSG_WARN([On Fedora, you can install$h $1 using "dnf install $tor_$1_$2_redhat"])
   if test x"$tor_$1_$2_redhat" != x"$tor_$1_devpkg_redhat"; then 
-    AC_WARN([   You will probably need to install $tor_$1_devpkg_redhat too.])
+    AC_MSG_WARN([   You will probably need to install $tor_$1_devpkg_redhat too.])
   fi 
 else
   if test -f /etc/redhat-release && test x"$tor_$1_$2_redhat" != x; then
-    AC_WARN([On most Redhat-based systems, you can get$h $1 by installing the $tor_$1_$2_redhat RPM package])
+    AC_MSG_WARN([On most Redhat-based systems, you can get$h $1 by installing the $tor_$1_$2_redhat RPM package])
     if test x"$tor_$1_$2_redhat" != x"$tor_$1_devpkg_redhat"; then 
-      AC_WARN([   You will probably need to install $tor_$1_devpkg_redhat too.])
+      AC_MSG_WARN([   You will probably need to install $tor_$1_devpkg_redhat too.])
     fi 
   fi
 fi
diff --git a/configure.ac b/configure.ac
index 721f5cd8c..b0fd73ef2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -429,7 +429,7 @@ AC_CHECK_FUNCS(
 # checks. So we should only probe for those functions if we are sure that we
 # are not targetting OSX 10.11 or earlier.
 AC_MSG_CHECKING([for a pre-Sierra OSX build target])
-AC_TRY_COMPILE([
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #ifdef __APPLE__
 #  include <AvailabilityMacros.h>
 #  ifndef MAC_OS_X_VERSION_10_12
@@ -441,7 +441,7 @@ AC_TRY_COMPILE([
 #    endif
 #  endif
 #endif
-], [],
+]], [[]])],
    [on_macos_pre_10_12=no ; AC_MSG_RESULT([no])],
    [on_macos_pre_10_12=yes; AC_MSG_RESULT([yes])])
 
@@ -640,16 +640,16 @@ LIBS="$TOR_OPENSSL_LIBS $LIBS"
 LDFLAGS="$TOR_LDFLAGS_openssl $LDFLAGS"
 CPPFLAGS="$TOR_CPPFLAGS_openssl $CPPFLAGS"
 
-AC_TRY_COMPILE([
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <openssl/opensslv.h>
 #if !defined(LIBRESSL_VERSION_NUMBER) && OPENSSL_VERSION_NUMBER < 0x1000100fL
 #error "too old"
 #endif
-   ], [],
+   ]], [[]])],
    [ : ],
-   [ AC_ERROR([OpenSSL is too old. We require 1.0.1 or later. You can specify a path to a newer one with --with-openssl-dir.]) ])
+   [ AC_MSG_ERROR([OpenSSL is too old. We require 1.0.1 or later. You can specify a path to a newer one with --with-openssl-dir.]) ])
 
-AC_TRY_COMPILE([
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <openssl/opensslv.h>
 #include <openssl/evp.h>
 #if defined(OPENSSL_NO_EC) || defined(OPENSSL_NO_ECDH) || defined(OPENSSL_NO_ECDSA)
@@ -658,9 +658,9 @@ AC_TRY_COMPILE([
 #if !defined(NID_X9_62_prime256v1) || !defined(NID_secp224r1)
 #error "curves unavailable"
 #endif
-   ], [],
+   ]], [[]])],
    [ : ],
-   [ AC_ERROR([OpenSSL is built without full ECC support, including curves P256 and P224. You can specify a path to one with ECC support with --with-openssl-dir.]) ])
+   [ AC_MSG_ERROR([OpenSSL is built without full ECC support, including curves P256 and P224. You can specify a path to one with ECC support with --with-openssl-dir.]) ])
 
 AC_CHECK_MEMBERS([struct ssl_method_st.get_cipher_by_char], , ,
 [#include <openssl/ssl.h>
@@ -1465,9 +1465,9 @@ AC_CHECK_FUNC(gethostbyname_r, [
   AC_MSG_CHECKING([how many arguments gethostbyname_r() wants])
   OLD_CFLAGS=$CFLAGS
   CFLAGS="$CFLAGS $MY_CPPFLAGS $MY_THREAD_CPPFLAGS $MY_CFLAGS"
-  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([
+  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <netdb.h>
-  ], [[
+  ]], [[
     char *cp1, *cp2;
     struct hostent *h1, *h2;
     int i1, i2;
@@ -1478,27 +1478,27 @@ AC_CHECK_FUNC(gethostbyname_r, [
      [Define this if gethostbyname_r takes 6 arguments])
     AC_MSG_RESULT(6)
   ], [
-    AC_TRY_COMPILE([
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <netdb.h>
-    ], [
+    ]], [[
       char *cp1, *cp2;
       struct hostent *h1;
       int i1, i2;
       (void)gethostbyname_r(cp1,h1,cp2,i1,&i2);
-    ], [
+    ]])], [
       AC_DEFINE(HAVE_GETHOSTBYNAME_R)
       AC_DEFINE(HAVE_GETHOSTBYNAME_R_5_ARG, 1,
         [Define this if gethostbyname_r takes 5 arguments])
       AC_MSG_RESULT(5)
    ], [
-      AC_TRY_COMPILE([
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #include <netdb.h>
-     ], [
+     ]], [[
        char *cp1;
        struct hostent *h1;
        struct hostent_data hd;
        (void) gethostbyname_r(cp1,h1,&hd);
-     ], [
+     ]])], [
        AC_DEFINE(HAVE_GETHOSTBYNAME_R)
        AC_DEFINE(HAVE_GETHOSTBYNAME_R_3_ARG, 1,
          [Define this if gethostbyname_r takes 3 arguments])
diff --git a/m4/ax_check_sign.m4 b/m4/ax_check_sign.m4
index 104b17014..d67e114db 100644
--- a/m4/ax_check_sign.m4
+++ b/m4/ax_check_sign.m4
@@ -41,8 +41,8 @@ AU_ALIAS([VL_CHECK_SIGN], [AX_CHECK_SIGN])
 AC_DEFUN([AX_CHECK_SIGN], [
  typename=`echo $1 | sed "s/@<:@^a-zA-Z0-9_@:>@/_/g"`
  AC_CACHE_CHECK([whether $1 is signed], ax_cv_decl_${typename}_signed, [
-   AC_TRY_COMPILE([$4],
-     [ int foo @<:@ 1 - 2 * !((($1) -1) < 0) @:>@ ],
+   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[$4]],
+     [[ int foo @<:@ 1 - 2 * !((($1) -1) < 0) @:>@ ]])],
      [ eval "ax_cv_decl_${typename}_signed=\"yes\"" ],
      [ eval "ax_cv_decl_${typename}_signed=\"no\"" ])])
  symbolname=`echo $1 | sed "s/@<:@^a-zA-Z0-9_@:>@/_/g" | tr "a-z" "A-Z"`
diff --git a/m4/pc_from_ucontext.m4 b/m4/pc_from_ucontext.m4
index 8a9dc459e..9b66bf752 100644
--- a/m4/pc_from_ucontext.m4
+++ b/m4/pc_from_ucontext.m4
@@ -79,29 +79,29 @@ AC_DEFUN([AC_PC_FROM_UCONTEXT],
      if ! $pc_field_found; then
        # Prefer sys/ucontext.h to ucontext.h, for OS X's sake.
        if test "x$ac_cv_header_cygwin_signal_h" = xyes; then
-         AC_TRY_COMPILE([#include <cygwin/signal.h>],
-                        [ucontext_t u; return u.$pc_field == 0;],
+         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <cygwin/signal.h>]],
+                        [[ucontext_t u; return u.$pc_field == 0;]])],
                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
                                            How to access the PC from a struct ucontext)
                         AC_MSG_RESULT([$pc_field])
                         pc_field_found=true)
        elif test "x$ac_cv_header_sys_ucontext_h" = xyes; then
-         AC_TRY_COMPILE([#include <sys/ucontext.h>],
-                        [ucontext_t u; return u.$pc_field == 0;],
+         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/ucontext.h>]],
+                        [[ucontext_t u; return u.$pc_field == 0;]])],
                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
                                            How to access the PC from a struct ucontext)
                         AC_MSG_RESULT([$pc_field])
                         pc_field_found=true)
        elif test "x$ac_cv_header_ucontext_h" = xyes; then
-         AC_TRY_COMPILE([#include <ucontext.h>],
-                        [ucontext_t u; return u.$pc_field == 0;],
+         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <ucontext.h>]],
+                        [[ucontext_t u; return u.$pc_field == 0;]])],
                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
                                            How to access the PC from a struct ucontext)
                         AC_MSG_RESULT([$pc_field])
                         pc_field_found=true)
        else     # hope some standard header gives it to us
-         AC_TRY_COMPILE([],
-                        [ucontext_t u; return u.$pc_field == 0;],
+         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],
+                        [[ucontext_t u; return u.$pc_field == 0;]])],
                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
                                            How to access the PC from a struct ucontext)
                         AC_MSG_RESULT([$pc_field])
@@ -114,8 +114,8 @@ AC_DEFUN([AC_PC_FROM_UCONTEXT],
      pc_fields="$pc_fields sc_rip"  # OpenBSD (x86_64)
      for pc_field in $pc_fields; do
        if ! $pc_field_found; then
-         AC_TRY_COMPILE([#include <signal.h>],
-                        [ucontext_t u; return u.$pc_field == 0;],
+         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <signal.h>]],
+                        [[ucontext_t u; return u.$pc_field == 0;]])],
                         AC_DEFINE_UNQUOTED(PC_FROM_UCONTEXT, $pc_field,
                                            How to access the PC from a struct ucontext)
                         AC_MSG_RESULT([$pc_field])