--- /dev/null
+BUILD_ID_PREFIX=cd
+BUILD_ID_SUFFIX=d98cdd87f7fe64c13b6daad553987eafd40cbb
+BUILD_ID=$(BUILD_ID_PREFIX)$(BUILD_ID_SUFFIX)
+
+BUILD_DIR ?= build
+
+OBJS=$(BUILD_DIR)/dwarf_full/libhello_so \
+ $(BUILD_DIR)/elf_only/libhello_so \
+ $(BUILD_DIR)/build_id/libhello_so \
+ $(BUILD_DIR)/debug_link/libhello_so
+
+all: $(OBJS)
+
+%.o: %.c
+ $(CC) -gdwarf -fdebug-prefix-map=$(CURDIR)=. -fPIC -c -I. -o $@ $<
+
+# Master copy: ELF with DWARF and build-id
+$(BUILD_DIR)/dwarf_full/libhello_so: tp.o libhello.o
+ mkdir -p $(@D)
+ $(CC) -shared -gdwarf -llttng-ust -ldl -Wl,-soname,libhello.so -Wl,--build-id=0x$(BUILD_ID) -o $@ $^
+
+# ELF only, no debug symbols, no build-d
+$(BUILD_DIR)/elf_only/libhello_so: $(BUILD_DIR)/dwarf_full/libhello_so
+ mkdir -p $(@D)
+ objcopy -g $< $@.tmp
+ objcopy --remove-section=.note.gnu.build-id $@.tmp
+ mv $@.tmp $@
+
+# ELF with external build-id DWARF
+$(BUILD_DIR)/build_id/libhello_so: $(BUILD_DIR)/dwarf_full/libhello_so
+ mkdir -p $(@D)/.build-id/$(BUILD_ID_PREFIX)
+ objcopy --only-keep-debug $< $(@D)/.build-id/$(BUILD_ID_PREFIX)/$(BUILD_ID_SUFFIX).debug
+ objcopy -g $< $@
+
+# ELF with external debug link DWARF
+$(BUILD_DIR)/debug_link/libhello_so: $(BUILD_DIR)/dwarf_full/libhello_so
+ mkdir -p $(@D)
+ objcopy --remove-section=.note.gnu.build-id $< $@.tmp
+ objcopy --only-keep-debug $@.tmp $(@D)/libhello_so.debug
+ objcopy -g $@.tmp
+ cd $(@D) && objcopy --add-gnu-debuglink=libhello_so.debug $(@F).tmp
+ mv $@.tmp $@
+
+clean:
+ rm -f *.o
+
+dist-clean: clean
+ rm -rf $(BUILD_DIR)
+
+.PHONY: all clean dist-clean
The generated files are:
-* `libhello_so` (ELF and DWARF)
-* `libhello_elf_so` (ELF only)
-* `libhello_build_id_so` (ELF with separate DWARF via build ID)
-* `libhello_debug_link_so` (ELF with separate DWARF via debug link)
-* `libhello_debug_link_so.debug` (DWARF for debug link)
-* `.build-id/cd/d98cdd87f7fe64c13b6daad553987eafd40cbb.debug` (DWARF for build ID)
+* `ARCH/dwarf_full/libhello_so` (ELF and DWARF)
+* `ARCH/elf_only/libhello_so` (ELF only)
+* `ARCH/build_id/libhello_so` (ELF with separate DWARF via build ID)
+* `ARCH/build_id/.build-id/cd/d98cdd87f7fe64c13b6daad553987eafd40cbb.debug` (DWARF for build ID)
+* `ARCH/debug_link/libhello_so` (ELF with separate DWARF via debug link)
+* `ARCH/debug_link/libhello_so.debug` (DWARF for debug link)
We use a suffix of "_so" instead of ".so" since some distributions
build systems will consider ".so" files as artifacts from a previous
* tp.c
* tp.h
-The generated executables were built using a GNU toolchain on an
-x86_64 machine.
+The generated executables were built using a native GNU toolchain on either
+Ubuntu 16.04 or 18.04 depending on the architecture.
-To regenerate them, you can use follow these steps:
+To regenerate them, you can use the included Makefile or follow these steps:
-## ELF and DWARF
+## Generate the object files
- $ gcc -g -fPIC -c -I. tp.c libhello.c
- $ gcc -shared -g -llttng-ust -ldl -Wl,-soname,libhello.so -o libhello_so tp.o libhello.o
+ $ gcc -gdwarf -fdebug-prefix-map=$(pwd)=. -fPIC -c -I. tp.c libhello.c
+
+## Combined ELF and DWARF
+
+ $ build_id_prefix=cd
+ $ build_id_suffix=d98cdd87f7fe64c13b6daad553987eafd40cbb
+ $ build_id="$build_id_prefix$build_id_suffix"
+ $ mkdir dwarf_full
+ $ gcc -shared -g -llttng-ust -ldl -Wl,-soname,libhello.so -Wl,--build-id=0x$build_id -o dwarf_full/libhello_so tp.o libhello.o
## ELF only
- $ gcc -fPIC -c -I. tp.c libhello.c
- $ gcc -shared -llttng-ust -ldl -Wl,-soname,libhello_elf.so -o libhello_elf_so tp.o libhello.o
+ $ mkdir elf_only
+ $ objcopy -g dwarf_full/libhello_so elf_only/libhello_so
+ $ objcopy --remove-section=.note.gnu.build-id elf_only/libhello_so
## ELF and DWARF with Build ID
- $ gcc -g -fPIC -c -I. tp.c libhello.c
- $ gcc -shared -g -llttng-ust -ldl -Wl,-soname,libhello_build_id.so -Wl,--build-id=sha1 -o libhello_build_id_so tp.o libhello.o
- $ mkdir -p .build-id/cd/
- $ objcopy --only-keep-debug libhello_build_id_so .build-id/cd/d98cdd87f7fe64c13b6daad553987eafd40cbb.debug
- $ strip -g libhello_build_id_so
-
-The build ID might not be the same once the executable is regenerated
-on your system, so adjust the values in the directory and file names
-accordingly. Refer to the GDB documentation for more information:
-https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
+ $ mkdir -p build_id/.build-id/$build_id_prefix
+ $ objcopy --only-keep-debug dwarf_full/libhello_so build_id/.build-id/$build_id_prefix/$build_id_suffix.debug
+ $ objcopy -g dwarf_full/libhello_so build_id/libhello_so
## ELF and DWARF with Debug Link
- $ gcc -g -fPIC -c -I. tp.c libhello.c
- $ gcc -shared -g -llttng-ust -ldl -Wl,-soname,libhello_debug_link.so -o libhello_debug_link_so tp.o libhello.o
-
- $ objcopy --only-keep-debug libhello_debug_link_so libhello_debug_link_so.debug
- $ strip -g libhello_debug_link_so
- $ objcopy --add-gnu-debuglink=libhello_debug_link_so.debug libhello_debug_link_so
+ $ mkdir debug_link
+ $ objcopy --remove-section=.note.gnu.build-id dwarf_full/libhello_so debug_link/libhello_so
+ $ objcopy --only-keep-debug debug_link/libhello_so debug_link/libhello_so.debug
+ $ objcopy -g debug_link/libhello_so
+ $ cd debug_link && objcopy --add-gnu-debuglink=libhello_so.debug libhello_so && cd ..
Test program