From ffa28f3914ff402b3915f75e4fed86ac6fb1449d Mon Sep 17 00:00:00 2001
From: Paul Smith <psmith@gnu.org>
Date: Sun, 5 Feb 2023 10:22:13 -0500
Subject: [PATCH] [SV 63668] Use autoconf to detect the default C++ compiler
* configure.ac: Add AC_PROG_CXX to search for a C++ compiler.
(MAKE_CXX): Add the discovered compiler to config.h.
* src/default.c (default_variables): Use MAKE_CXX as the C++ compiler.
---
configure.ac | 2 ++
src/default.c | 20 +++++++++++++-------
2 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/configure.ac b/configure.ac
index 67793e6e..8326c010 100644
--- a/configure.ac
+++ b/configure.ac
@@ -37,6 +37,8 @@ AM_INIT_AUTOMAKE([1.16.1 foreign -Werror -Wall])
# Checks for programs.
AC_USE_SYSTEM_EXTENSIONS
AC_PROG_CC
+AC_PROG_CXX
+AC_DEFINE_UNQUOTED(MAKE_CXX, ["$CXX"], [Default C++ compiler.])
# Configure gnulib
gl_EARLY
diff --git a/src/default.c b/src/default.c
index 1082b41d..ffb5f98c 100644
--- a/src/default.c
+++ b/src/default.c
@@ -527,18 +527,24 @@ static const char *default_variables[] =
"AS", "as",
#ifdef GCC_IS_NATIVE
"CC", "gcc",
-# ifdef __MSDOS__
- "CXX", "gpp", /* g++ is an invalid name on MSDOS */
-# else
- "CXX", "gcc",
-# endif /* __MSDOS__ */
"OBJC", "gcc",
#else
"CC", "cc",
- "CXX", "g++",
"OBJC", "cc",
#endif
-
+#ifdef MAKE_CXX
+ "CXX", MAKE_CXX,
+#else
+# ifdef GCC_IS_NATIVE
+# ifdef __MSDOS__
+ "CXX", "gpp", /* g++ is an invalid name on MSDOS */
+# else
+ "CXX", "gcc",
+# endif /* __MSDOS__ */
+# else
+ "CXX", "g++",
+# endif
+#endif
/* This expands to $(CO) $(COFLAGS) $< $@ if $@ does not exist,
and to the empty string if $@ does exist. */
"CHECKOUT,v", "+$(if $(wildcard $@),,$(CO) $(COFLAGS) $< $@)",