dev-util/xdp-tools: Don't call readelf directly

Allow to override it.

Closes: https://bugs.gentoo.org/785214
Package-Manager: Portage-3.0.17, Repoman-3.0.2
Signed-off-by: Kurt Kanzenbach <kurt@kmk-computers.de>

dev-util/xdp-tools/files/xdp-tools-1.1.0-readelf.patch

@@ -0,0 +1,52 @@
+From: Kurt Kanzenbach <kurt@kmk-computers.de>
+Subject: make: Fix hardcoded readelf
+
+Don't hardcode readelf. Allow to reuse something else.
+
+Signed-off-by: Kurt Kanzenbach <kurt@kmk-computers.de>
+
+---
+ lib/libxdp/Makefile |   10 +++++-----
+ 1 file changed, 5 insertions(+), 5 deletions(-)
+
+--- a/lib/libxdp/Makefile
++++ b/lib/libxdp/Makefile
+@@ -26,7 +26,7 @@ TEMPLATED_SOURCES := xdp-dispatcher.c
+ 
+ CFLAGS += -I$(HEADER_DIR) -I$(LIB_DIR)/util
+ BPF_CFLAGS += -I$(HEADER_DIR)
+-
++READELF ?= readelf
+ 
+ ifndef BUILD_STATIC_ONLY
+ 	SHARED_LIBS := $(OBJDIR)/libxdp.so \
+@@ -88,12 +88,12 @@ $(SHARED_OBJDIR)/%.o: %.c $(EXTRA_LIB_DE
+ 
+ XDP_IN_SHARED	:= $(SHARED_OBJDIR)/libxdp.o
+ 
+-GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(XDP_IN_SHARED) | \
++GLOBAL_SYM_COUNT = $(shell $(READELF) -s --wide $(XDP_IN_SHARED) | \
+ 			   cut -d "@" -f1 | sed 's/_v[0-9]_[0-9]_[0-9].*//' | \
+ 			   sed 's/\[.*\]//' | \
+ 			   awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \
+ 			   sort -u | wc -l)
+-VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OBJDIR)/libxdp.so | \
++VERSIONED_SYM_COUNT = $(shell $(READELF) --dyn-syms --wide $(OBJDIR)/libxdp.so | \
+ 			      grep -Eo '[^ ]+@LIBXDP_' | cut -d@ -f1 | sort -u | wc -l)
+ 
+ check: check_abi
+@@ -105,12 +105,12 @@ check_abi: $(OBJDIR)/libxdp.so
+ 		     "versioned symbols in $^ ($(VERSIONED_SYM_COUNT))." \
+ 		     "Please make sure all symbols are"	 \
+ 		     "versioned in $(VERSION_SCRIPT)." >&2;		 \
+-		readelf -s --wide $(XDP_IN_SHARED) |			 \
++		$(READELF) -s --wide $(XDP_IN_SHARED) |			 \
+ 		    cut -d "@" -f1 | sed 's/_v[0-9]_[0-9]_[0-9].*//' |	 \
+ 		    sed 's/\[.*\]//' |					 \
+ 		    awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'|  \
+ 		    sort -u > $(OUTPUT)libxdp_global_syms.tmp;		 \
+-		readelf --dyn-syms --wide $(OUTPUT)libxdp.so |		 \
++		$(READELF) --dyn-syms --wide $(OUTPUT)libxdp.so |		 \
+ 		    grep -Eo '[^ ]+@LIBXDP_' | cut -d@ -f1 |		 \
+ 		    sort -u > $(OUTPUT)libxdp_versioned_syms.tmp; 	 \
+ 		diff -u $(OUTPUT)libxdp_global_syms.tmp			 \

dev-util/xdp-tools/xdp-tools-1.1.0.ebuild

@@ -40,7 +40,10 @@ DEPEND="${RDEPEND}
 	sys-devel/llvm:10
 "
 
-PATCHES=( "${FILESDIR}/${P}-install.patch" )
+PATCHES=(
+	"${FILESDIR}/${P}-install.patch"
+	"${FILESDIR}/${P}-readelf.patch"
+)
 
 pkg_setup() {
 	llvm_pkg_setup
@@ -54,6 +57,7 @@ src_compile() {
 	emake \
 		CC="$(tc-getCC)" \
 		AR="$(tc-getAR)" \
+		READELF=$(tc-getREADELF) \
 		PRODUCTION=1 \
 		DYNAMIC_LIBXDP=1 \
 		FORCE_SYSTEM_LIBBPF=1 \