--- a/Makefile.in	Fri Feb 25 15:34:54 2022 -0500
+++ b/Makefile.in	Sun Feb 27 12:38:47 2022 +0100
@@ -987,6 +987,10 @@
 	rm -rf native-tools cross-tools octave gnuplot
 	rm -f Makefile cmake-toolchain-file.stamp cmake-native-toolchain-file.stamp
 	rm -f tools/set-mxe-env.sh
+	rm -f installer-files/octave-launch.exe \
+	  installer-files/octave-launch-firsttime.exe \
+	  installer-files/octave-launch.res \
+	  installer-files/.dirstamp
 
 .PHONY: realclean
 realclean: clean

--- a/src/native-gcc-1-canadian-cross.patch	Fri Feb 25 15:34:54 2022 -0500
+++ b/src/native-gcc-1-canadian-cross.patch	Sun Feb 27 12:38:47 2022 +0100
@@ -1,42 +1,81 @@
-See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100017#c12
+From 01a70ccd723eb9a479186fe37c972b0d0f8676cf Mon Sep 17 00:00:00 2001
+From: Jonathan Wakely <jwakely@redhat.com>
+Date: Fri, 7 Jan 2022 15:21:03 +0000
+Subject: [PATCH 1/1] libstdc++: Add -nostdinc++ for c++17 sources [PR100017]
+
+When building a build!=host compiler, the just-built gcc can't be used
+to build the target libstdc++ (because it is built for the host triplet,
+not the build triplet). The top-level configure.ac sets up the build
+flags for libstdc++ (and other "raw_cxx" libs) like this:
+
+GCC_TARGET_TOOL(c++ for libstdc++, RAW_CXX_FOR_TARGET, CXX,
+		[gcc/xgcc -shared-libgcc -B$$r/$(HOST_SUBDIR)/gcc -nostdinc++ -L$$r/$(TARGET_SUBDIR)/libstdc++-v3/src -L$$r/$(TARGET_SUBDIR)/libstdc++-v3/src/.libs -L$$r/$(TARGET_SUBDIR)/libstdc++-v3/libsupc++/.libs],
+		c++)
+
+The -nostdinc++ flag is only used for the IN-TREE-TOOL, i.e. when using
+the just-built gcc/xgcc compiler. This means that the cross-compiler
+used to build libstdc++ will add its own libstdc++ headers to the
+include path. That results in the #include <cfenv> in
+src/c++17/floating_to_chars.cc and src/c++17/floating_from_chars.cc
+doing #include_next <fenv.h> and finding the libstdc++ fenv.h wrapper
+from the host compiler. Because that has the same include guard as the
+<fenv.h> in the libstdc++ we're trying to build, we never reach the
+underlying <fenv.h> from libc. That results in several errors of the
+form:
+
+error: 'fenv_t' has not been declared in '::'
+
+The most correct fix would be to add -nostdinc++ to the
+RAW_CXX_FOR_TARGET variable in configure.ac, or the
+RAW_CXX_TARGET_EXPORTS variable in Makefile.tpl.
+
+Another solution would be to make the libstdc++ <fenv.h> wrapper use
+_GLIBCXX_INCLUDE_NEXT_C_HEADERS like our <stdlib.h> and other C header
+wrappers.
+
+For now though, the simplest and safest solution is to just add
+-nostdinc++ to the CXXFLAGS used for src/c++17/*.cc, which is what this
+does.
+
+libstdc++-v3/ChangeLog:
 
-diff --git a/libstdc++-v3/include/c_compatibility/fenv.h b/libstdc++-v3/include/c_compatibility/fenv.h
-index 0413e3b7c25..56cabaa3635 100644
---- a/libstdc++-v3/include/c_compatibility/fenv.h
-+++ b/libstdc++-v3/include/c_compatibility/fenv.h
-@@ -26,6 +26,10 @@
-  *  This is a Standard C++ Library header.
-  */
- 
-+#if !defined __cplusplus || defined _GLIBCXX_INCLUDE_NEXT_C_HEADERS
-+# include_next <fenv.h>
-+#else
-+
- #ifndef _GLIBCXX_FENV_H
- #define _GLIBCXX_FENV_H 1
- 
-@@ -83,3 +83,5 @@ namespace std
- #endif // C++11
- 
- #endif // _GLIBCXX_FENV_H
-+
-+#endif // include_next
+	PR libstdc++/100017
+	* src/c++17/Makefile.am (AM_CXXFLAGS): Add -nostdinc++.
+	* src/c++17/Makefile.in: Regenerate.
+
+(cherry picked from commit 4fde88e5dd152fe866a97b12e0f8229970d15cb3)
+---
+ libstdc++-v3/src/c++17/Makefile.am | 2 +-
+ libstdc++-v3/src/c++17/Makefile.in | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
 
-diff --git a/libstdc++-v3/include/c_global/cfenv b/libstdc++-v3/include/c_global/cfenv
-index 0b0ec35a837..d24cb1a3c81 100644
---- a/libstdc++-v3/include/c_global/cfenv
-+++ b/libstdc++-v3/include/c_global/cfenv
-@@ -37,9 +37,11 @@
- 
- #include <bits/c++config.h>
- 
--#if _GLIBCXX_HAVE_FENV_H
--# include <fenv.h>
--#endif
-+// Need to ensure this finds the C library's <fenv.h> not a libstdc++
-+// wrapper that might already be installed later in the include search path.
-+#define _GLIBCXX_INCLUDE_NEXT_C_HEADERS
-+#include_next <fenv.h>
-+#undef _GLIBCXX_INCLUDE_NEXT_C_HEADERS
- 
- #ifdef _GLIBCXX_USE_C99_FENV_TR1
+diff --git a/libstdc++-v3/src/c++17/Makefile.am b/libstdc++-v3/src/c++17/Makefile.am
+index cb94aff5f1a..2aebc6d5251 100644
+--- a/libstdc++-v3/src/c++17/Makefile.am
++++ b/libstdc++-v3/src/c++17/Makefile.am
+@@ -79,7 +79,7 @@ endif
+ # OPTIMIZE_CXXFLAGS on the compile line so that -O2 can be overridden
+ # as the occasion calls for it.
+ AM_CXXFLAGS = \
+-	-std=gnu++17 \
++	-std=gnu++17 -nostdinc++ \
+ 	$(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
+ 	$(XTEMPLATE_FLAGS) $(VTV_CXXFLAGS) \
+ 	$(WARN_CXXFLAGS) $(OPTIMIZE_CXXFLAGS) $(CONFIG_CXXFLAGS) \
+diff --git a/libstdc++-v3/src/c++17/Makefile.in b/libstdc++-v3/src/c++17/Makefile.in
+index 63984ecd52a..8c02be6514f 100644
+--- a/libstdc++-v3/src/c++17/Makefile.in
++++ b/libstdc++-v3/src/c++17/Makefile.in
+@@ -455,7 +455,7 @@ libc__17convenience_la_SOURCES = $(sources)  $(inst_sources)
+ # OPTIMIZE_CXXFLAGS on the compile line so that -O2 can be overridden
+ # as the occasion calls for it.
+ AM_CXXFLAGS = \
+-	-std=gnu++17 \
++	-std=gnu++17 -nostdinc++ \
+ 	$(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
+ 	$(XTEMPLATE_FLAGS) $(VTV_CXXFLAGS) \
+ 	$(WARN_CXXFLAGS) $(OPTIMIZE_CXXFLAGS) $(CONFIG_CXXFLAGS) \
+-- 
+2.27.0
+
+