gcc-10-ipxe-fixes.patch

The first hunk originally comes from the ipxe-devel mailing
list: https://lists.ipxe.org/pipermail/ipxe-devel/2020-May/007047.html

The second hunk is a modified version of Gentoo's patch (modified to
drop -fcommon which is already handled by the first hunk in a more
targeted manner)::
https://github.com/hydrapolic/gentoo-dist/blob/master/xen/xen-gentoo-patches-21.tar.xz
(file: xen-tools-4.13.0-ipxe-gcc10.patch)

diff --git a/src/Makefile b/src/Makefile
index d74565d..2ad5b39 100644
--- a/src/Makefile.housekeeping
+++ b/src/Makefile.housekeeping
@@ -170,6 +170,16 @@ CFI_FLAGS := $(shell $(CFI_TEST) && \
 WORKAROUND_CFLAGS += $(CFI_FLAGS)
 endif
 
+# gcc 10 switched default behavior from -fcommon to -fno-common. Since
+# "__shared" relies on the legacy behavior, explicitly specify it.
+#
+ifeq ($(CCTYPE),gcc)
+FCOMMON_TEST = $(CC) -fcommon -x c -c /dev/null \
+		   -o /dev/null >/dev/null 2>&1
+FCOMMON_FLAGS := $(shell $(FCOMMON_TEST) && $(ECHO) '-fcommon')
+WORKAROUND_CFLAGS += $(FCOMMON_FLAGS)
+endif
+
 # gcc 4.6 generates spurious warnings if -Waddress is in force.
 # Inhibit this.
 #
--- a/src/Makefile
+++ b/src/Makefile
@@ -4,7 +4,7 @@
 #
 
 CLEANUP		:=
-CFLAGS		:=
+CFLAGS		:= -Wno-enum-conversion -Wno-array-bounds
 ASFLAGS		:=
 LDFLAGS		:=
 HOST_CFLAGS	:=