From ff95e2aaa649ec035e8f0fddb3fd8877401506c6 Mon Sep 17 00:00:00 2001
From: Christian Machacek <39452430+machacekch@users.noreply.github.com>
Date: Sat, 8 May 2021 20:39:48 +0200
Subject: [PATCH] Add a make target to run the readelf utility on a compiled
 program

The readelf utility (already shipped with the solana tools) shows meta-information about ELF files, such as symbol tables. It is useful for investigating "unresolved symbol" errors that crop up at runtime.

This commit also fixes the objdump flags (two dashes are required and there is no "color" option) as well as a few typos.
---
 sdk/bpf/c/bpf.mk | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/sdk/bpf/c/bpf.mk b/sdk/bpf/c/bpf.mk
index 31584e2943..dd3584d161 100644
--- a/sdk/bpf/c/bpf.mk
+++ b/sdk/bpf/c/bpf.mk
@@ -22,6 +22,7 @@ CC := $(LLVM_DIR)/bin/clang
 CXX := $(LLVM_DIR)/bin/clang++
 LLD := $(LLVM_DIR)/bin/ld.lld
 OBJ_DUMP := $(LLVM_DIR)/bin/llvm-objdump
+READ_ELF := $(LLVM_DIR)/bin/llvm-readelf
 endif
 
 SYSTEM_INC_DIRS := \
@@ -64,9 +65,11 @@ BPF_LLD_FLAGS := \
   --entry entrypoint \
 
 OBJ_DUMP_FLAGS := \
-  -color \
-  -source \
-  -disassemble \
+  --source \
+  --disassemble \
+
+READ_ELF_FLAGS := \
+  --all \
 
 TESTFRAMEWORK_RPATH := $(abspath $(LOCAL_PATH)../dependencies/criterion/lib)
 TESTFRAMEWORK_FLAGS := \
@@ -122,7 +125,8 @@ help:
 	@echo '  - make all - Build all the programs and tests, run the tests'
 	@echo '  - make programs - Build all the programs'
 	@echo '  - make tests - Build and run all tests'
-	@echo '  - make dump_<program name> - Dumps the contents of the program to stdout'
+	@echo '  - make dump_<program name> - Dump the contents of the program to stdout'
+	@echo '  - make readelf_<program name> - Display information about the ELF binary'
 	@echo '  - make <program name> - Build a single program by name'
 	@echo '  - make <test name> - Build and run a single test by name'
 	@echo ''
@@ -133,7 +137,7 @@ help:
 	$(foreach name, $(TEST_NAMES), @echo '  - $(name)'$(\n))
 	@echo ''
 	@echo 'Example:'
-	@echo '  - Assuming a programed named foo (src/foo/foo.c)'
+	@echo '  - Assuming a program named foo (src/foo/foo.c)'
 	@echo '    - make foo'
 	@echo '    - make dump_foo'
 	@echo ''
@@ -247,5 +251,8 @@ tests: $(TEST_NAMES)
 dump_%: %
 	$(_@)$(OBJ_DUMP) $(OBJ_DUMP_FLAGS) $(addprefix $(OUT_DIR)/, $(addsuffix .so, $<))
 
+readelf_%: %
+	$(_@)$(READ_ELF) $(READ_ELF_FLAGS) $(addprefix $(OUT_DIR)/, $(addsuffix .so, $<))
+
 clean:
 	rm -rf $(OUT_DIR)