[Crash-utility] [PATCH 02/11] build: make debug information optional, off by default

A debug build takes noticeably longer to produce and is much larger, and it is not needed for a production crash binary: gdb is configured with "-g -O2" and crash compiles its own files with -g. Add a global DEBUG=1 switch which builds both crash and the embedded gdb with -g. Without it no -g is used anywhere. gdb compiles its .c sources as C++, using $(CXX) -x c++ with CXXFLAGS, so CXXFLAGS has to be filtered as well as CFLAGS. The build-time CFLAGS_FOR_BUILD and CXXFLAGS_FOR_BUILD are filtered too. The two gdb Makefile.in files are added to the list of files which are restored from the tarball before the patch is re-applied, as required for any gdb file whose hunks are modified. Assisted-by: LLM Signed-off-by: Dave Young <yangrr.2009(a)tsinghua.org.cn&gt; --- Makefile | 13 ++++++++++++- README | 10 ++++++++++ gdb-16.2.patch | 22 +++++++++++++++++++--- 3 files changed, 41 insertions(+), 4 deletions(-) diff --git a/Makefile b/Makefile index c392c23b7327..ae29ea5b5737 100644 --- a/Makefile +++ b/Makefile @@ -258,7 +258,18 @@ GDB_FLAGS= # TARGET_CFLAGS will be configured automatically by configure TARGET_CFLAGS= -CRASH_CFLAGS=-g -D${TARGET} ${TARGET_CFLAGS} ${GDB_FLAGS} ${CFLAGS} +# +# Debug information (-g) is not built by default. Use "make DEBUG=1" to +# build both crash and the embedded gdb module with debug information. +# +ifeq ($(DEBUG),1) +DEBUG_CFLAGS=-g +else +DEBUG_CFLAGS= +endif +export DEBUG + +CRASH_CFLAGS=$(DEBUG_CFLAGS) -D${TARGET} ${TARGET_CFLAGS} ${GDB_FLAGS} ${CFLAGS} GPL_FILES= TAR_FILES=${SOURCE_FILES} Makefile ${GPL_FILES} README crash-release crash.8 \ diff --git a/README b/README index 69232eb4861b..a4e22d95093a 100644 --- a/README +++ b/README @@ -84,6 +84,16 @@ $ cd crash-9.0.x $ make + By default, debug information (-g) is not built into either crash or the + embedded gdb module. To build both with debug information: + + $ make DEBUG=1 + + Changing the target ("make target=...") or toggling DEBUG on an existing + build tree does not recompile objects that are already up to date. Run + "make clean" before rebuilding, and also remove the gdb-16.2 directory if + the embedded gdb was configured for a different target. + To cross compile the crash utility for aarch64 on x86_64: $ make CROSS_COMPILE=aarch64-linux-gnu- -j`nproc` diff --git a/gdb-16.2.patch b/gdb-16.2.patch index 78cf605a83bb..1317959d768f 100644 --- a/gdb-16.2.patch +++ b/gdb-16.2.patch @@ -9,6 +9,8 @@ # to all subsequent patch applications. tar xvzmf gdb-16.2.tar.gz \ + gdb-16.2/Makefile.in \ + gdb-16.2/gdb/Makefile.in \ gdb-16.2/gdb/symfile.c \ gdb-16.2/gdb/symtab.c @@ -17,25 +19,33 @@ exit 0 --- gdb-16.2/Makefile.in.orig +++ gdb-16.2/Makefile.in @@ -369,6 +369,9 @@ CC_FOR_BUILD = @CC_FOR_BUILD@ - CFLAGS_FOR_BUILD = @CFLAGS_FOR_BUILD@ +-CFLAGS_FOR_BUILD = @CFLAGS_FOR_BUILD@ ++CFLAGS_FOR_BUILD = $(filter-out -g,@CFLAGS_FOR_BUILD@) $(if $(filter 1,$(DEBUG)),-g) CPP_FOR_BUILD = @CPP_FOR_BUILD@ CPPFLAGS_FOR_BUILD = @CPPFLAGS_FOR_BUILD@ +ifeq (${CRASH_TARGET}, PPC64) +CFLAGS_FOR_BUILD += -m64 -fPIC +endif - CXXFLAGS_FOR_BUILD = @CXXFLAGS_FOR_BUILD@ +-CXXFLAGS_FOR_BUILD = @CXXFLAGS_FOR_BUILD@ ++CXXFLAGS_FOR_BUILD = $(filter-out -g,@CXXFLAGS_FOR_BUILD@) $(if $(filter 1,$(DEBUG)),-g) CXX_FOR_BUILD = @CXX_FOR_BUILD@ DLLTOOL_FOR_BUILD = @DLLTOOL_FOR_BUILD@ @@ -441,6 +444,9 @@ GNATBIND = @GNATBIND@ GNATMAKE = @GNATMAKE@ - CFLAGS = @CFLAGS@ +-CFLAGS = @CFLAGS@ ++CFLAGS = $(filter-out -g,@CFLAGS@) $(if $(filter 1,$(DEBUG)),-g) +ifeq (${CRASH_TARGET}, PPC64) +CFLAGS += -m64 -fPIC +endif LDFLAGS = @LDFLAGS@ LIBCFLAGS = $(CFLAGS) CXXFLAGS = @CXXFLAGS@ +@@ -446,3 +452,3 @@ +-CXXFLAGS = @CXXFLAGS@ ++CXXFLAGS = $(filter-out -g,@CXXFLAGS@) $(if $(filter 1,$(DEBUG)),-g) + LIBCXXFLAGS = $(CXXFLAGS) -fno-implicit-templates + GOCFLAGS = $(CFLAGS) --- gdb-16.2/gdb/Makefile.in.orig +++ gdb-16.2/gdb/Makefile.in @@ -603,7 +603,7 @@ CONFIG_DEP_SUBDIR = $(addsuffix /$(DEPDIR),$(CONFIG_SRC_SUBDIR)) @@ -47,6 +57,12 @@ exit 0 GDB_INCLUDED_HEADER = -include $(srcdir)/defs.h GDB_CFLAGS = \ -I. \ +@@ -623,3 +623,3 @@ +-CFLAGS = @CFLAGS@ ++CFLAGS = $(filter-out -g,@CFLAGS@) $(if $(filter 1,$(DEBUG)),-g) +-CXXFLAGS = @CXXFLAGS@ ++CXXFLAGS = $(filter-out -g,@CXXFLAGS@) $(if $(filter 1,$(DEBUG)),-g) + CPPFLAGS = @CPPFLAGS@ @@ -1220,6 +1220,7 @@ COMMON_SFILES = \ symmisc.c \ symtab.c \ -- 2.51.1