[PATCH v3 4/4] objtool: Add explicitly sequenced -lzstd to libopcodes fallback

[Ian Rogers <irogers@google.com>]

Distributions like Fedora ship a statically compiled binutils libbfd (an
intrinsic dependency of libopcodes) that uses zstd to decompress
sections.

Because objtool resolves host dependencies sequentially via a manual
HOSTCC shell loop, linking against static binutils fails with undefined
references to 'ZSTD_decompress' unless the loop probes for -lzstd.

Add the '-lopcodes -lbfd -liberty -lz -lzstd' combination to the
LIBOPCODES_LIBS fallback chain.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/objtool/Makefile | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index db99c4759b2c..238da6fd277f 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -81,14 +81,15 @@ HOST_OVERRIDES := CC="$(HOSTCC)" LD="$(HOSTLD)" AR="$(HOSTAR)"
 #
 # When using shared libraries, -lopcodes is sufficient as dependencies are
 # resolved automatically. With static libraries, we must explicitly link
-# against libopcodes' dependencies: libbfd, libiberty, and sometimes libz.
-# Try each combination and use the first one that succeeds.
+# against libopcodes' dependencies: libbfd, libiberty, and sometimes libz
+# and libzstd. Try each combination and use the first one that succeeds.
 #
 LIBOPCODES_LIBS := $(shell \
 	for libs in "-lopcodes" \
 		    "-lopcodes -lbfd" \
 		    "-lopcodes -lbfd -liberty" \
-		    "-lopcodes -lbfd -liberty -lz"; do \
+		    "-lopcodes -lbfd -liberty -lz" \
+		    "-lopcodes -lbfd -liberty -lz -lzstd"; do \
 		printf '%s\n' \
 		       '$(pound)include <bfd.h>' \
 		       '$(pound)include <dis-asm.h>' \
-- 
2.56.0.385.gac671c819a-goog