| Message ID | 20210115210616.404156-3-ndesaulniers@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Kbuild: DWARF v5 support | expand |
On Fri, Jan 15, 2021 at 10:06 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice. Adds an > explicit CONFIG_DEBUG_INFO_DWARF2, which is the default. Does so in a > way that's forward compatible with existing configs, and makes adding > future versions more straightforward. > > Suggested-by: Arvind Sankar <nivedita@alum.mit.edu> > Suggested-by: Fangrui Song <maskray@google.com> > Suggested-by: Masahiro Yamada <masahiroy@kernel.org> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> > --- > Makefile | 13 ++++++------- > lib/Kconfig.debug | 21 ++++++++++++++++----- > 2 files changed, 22 insertions(+), 12 deletions(-) > > diff --git a/Makefile b/Makefile > index d49c3f39ceb4..4eb3bf7ee974 100644 > --- a/Makefile > +++ b/Makefile > @@ -826,13 +826,12 @@ else > DEBUG_CFLAGS += -g > endif > > -ifneq ($(LLVM_IAS),1) > -KBUILD_AFLAGS += -Wa,-gdwarf-2 > -endif > - > -ifdef CONFIG_DEBUG_INFO_DWARF4 > -DEBUG_CFLAGS += -gdwarf-4 > -endif > +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF2) := 2 > +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4 > +DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) > +# Binutils 2.35+ required for -gdwarf-4+ support. > +dwarf-aflag := $(call as-option,-Wa$(comma)-gdwarf-$(dwarf-version-y)) > +KBUILD_AFLAGS += $(dwarf-aflag) > > ifdef CONFIG_DEBUG_INFO_REDUCED > DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \ > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index dd7d8d35b2a5..e80770fac4f0 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -256,13 +256,24 @@ config DEBUG_INFO_SPLIT > to know about the .dwo files and include them. > Incompatible with older versions of ccache. > > +choice > + prompt "DWARF version" Here you use "DWARF version" so keep this for v2 and v4. > + help > + Which version of DWARF debug info to emit. > + > +config DEBUG_INFO_DWARF2 > + bool "Generate DWARF Version 2 debuginfo" s/DWARF Version/DWARF version > + help > + Generate DWARF v2 debug info. > + > config DEBUG_INFO_DWARF4 > - bool "Generate dwarf4 debuginfo" > + bool "Generate DWARF Version 4 debuginfo" Same here: s/DWARF Version/DWARF version - Sedat - > help > - Generate dwarf4 debug info. This requires recent versions > - of gcc and gdb. It makes the debug information larger. > - But it significantly improves the success of resolving > - variables in gdb on optimized code. > + Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+. > + It makes the debug information larger, but it significantly > + improves the success of resolving variables in gdb on optimized code. > + > +endchoice # "DWARF version" > > config DEBUG_INFO_BTF > bool "Generate BTF typeinfo" > -- > 2.30.0.284.gd98b1dd5eaa7-goog >
On 2021-01-15, Sedat Dilek wrote: >On Fri, Jan 15, 2021 at 10:06 PM Nick Desaulniers ><ndesaulniers@google.com> wrote: >> >> Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice. Adds an >> explicit CONFIG_DEBUG_INFO_DWARF2, which is the default. Does so in a >> way that's forward compatible with existing configs, and makes adding >> future versions more straightforward. >> >> Suggested-by: Arvind Sankar <nivedita@alum.mit.edu> >> Suggested-by: Fangrui Song <maskray@google.com> >> Suggested-by: Masahiro Yamada <masahiroy@kernel.org> >> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> >> --- >> Makefile | 13 ++++++------- >> lib/Kconfig.debug | 21 ++++++++++++++++----- >> 2 files changed, 22 insertions(+), 12 deletions(-) >> >> diff --git a/Makefile b/Makefile >> index d49c3f39ceb4..4eb3bf7ee974 100644 >> --- a/Makefile >> +++ b/Makefile >> @@ -826,13 +826,12 @@ else >> DEBUG_CFLAGS += -g >> endif >> >> -ifneq ($(LLVM_IAS),1) >> -KBUILD_AFLAGS += -Wa,-gdwarf-2 >> -endif >> - >> -ifdef CONFIG_DEBUG_INFO_DWARF4 >> -DEBUG_CFLAGS += -gdwarf-4 >> -endif >> +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF2) := 2 >> +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4 >> +DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) >> +# Binutils 2.35+ required for -gdwarf-4+ support. >> +dwarf-aflag := $(call as-option,-Wa$(comma)-gdwarf-$(dwarf-version-y)) >> +KBUILD_AFLAGS += $(dwarf-aflag) >> >> ifdef CONFIG_DEBUG_INFO_REDUCED >> DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \ >> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug >> index dd7d8d35b2a5..e80770fac4f0 100644 >> --- a/lib/Kconfig.debug >> +++ b/lib/Kconfig.debug >> @@ -256,13 +256,24 @@ config DEBUG_INFO_SPLIT >> to know about the .dwo files and include them. >> Incompatible with older versions of ccache. >> >> +choice >> + prompt "DWARF version" > >Here you use "DWARF version" so keep this for v2 and v4. > >> + help >> + Which version of DWARF debug info to emit. >> + >> +config DEBUG_INFO_DWARF2 >> + bool "Generate DWARF Version 2 debuginfo" > >s/DWARF Version/DWARF version > >> + help >> + Generate DWARF v2 debug info. >> + >> config DEBUG_INFO_DWARF4 >> - bool "Generate dwarf4 debuginfo" >> + bool "Generate DWARF Version 4 debuginfo" > >Same here: s/DWARF Version/DWARF version DWARF Version 2 is fine and preferable. I have checked DWARF Version 2/3/4/5 specifications. "DWARF Version 2" is the official way that version is referred to... > >- Sedat - > >> help >> - Generate dwarf4 debug info. This requires recent versions >> - of gcc and gdb. It makes the debug information larger. >> - But it significantly improves the success of resolving >> - variables in gdb on optimized code. >> + Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+. >> + It makes the debug information larger, but it significantly >> + improves the success of resolving variables in gdb on optimized code. >> + >> +endchoice # "DWARF version" >> >> config DEBUG_INFO_BTF >> bool "Generate BTF typeinfo" >> -- >> 2.30.0.284.gd98b1dd5eaa7-goog >>
On Fri, Jan 15, 2021 at 01:06:15PM -0800, Nick Desaulniers wrote: > Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice. Adds an > explicit CONFIG_DEBUG_INFO_DWARF2, which is the default. Does so in a > way that's forward compatible with existing configs, and makes adding > future versions more straightforward. > > Suggested-by: Arvind Sankar <nivedita@alum.mit.edu> > Suggested-by: Fangrui Song <maskray@google.com> > Suggested-by: Masahiro Yamada <masahiroy@kernel.org> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> > --- > Makefile | 13 ++++++------- > lib/Kconfig.debug | 21 ++++++++++++++++----- > 2 files changed, 22 insertions(+), 12 deletions(-) > > diff --git a/Makefile b/Makefile > index d49c3f39ceb4..4eb3bf7ee974 100644 > --- a/Makefile > +++ b/Makefile > @@ -826,13 +826,12 @@ else > DEBUG_CFLAGS += -g > endif > > -ifneq ($(LLVM_IAS),1) > -KBUILD_AFLAGS += -Wa,-gdwarf-2 > -endif Aren't you regressing this with this patch? Why is the hunk from 3/3 that adds ifdef CONFIG_CC_IS_CLANG ifneq ($(LLVM_IAS),1) not in this patch? > -ifdef CONFIG_DEBUG_INFO_DWARF4 > -DEBUG_CFLAGS += -gdwarf-4 > -endif > +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF2) := 2 > +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4 > +DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) > +# Binutils 2.35+ required for -gdwarf-4+ support. > +dwarf-aflag := $(call as-option,-Wa$(comma)-gdwarf-$(dwarf-version-y)) > +KBUILD_AFLAGS += $(dwarf-aflag) > > ifdef CONFIG_DEBUG_INFO_REDUCED > DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \ > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index dd7d8d35b2a5..e80770fac4f0 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -256,13 +256,24 @@ config DEBUG_INFO_SPLIT > to know about the .dwo files and include them. > Incompatible with older versions of ccache. > > +choice > + prompt "DWARF version" > + help > + Which version of DWARF debug info to emit. > + > +config DEBUG_INFO_DWARF2 > + bool "Generate DWARF Version 2 debuginfo" > + help > + Generate DWARF v2 debug info. > + > config DEBUG_INFO_DWARF4 > - bool "Generate dwarf4 debuginfo" > + bool "Generate DWARF Version 4 debuginfo" > help > - Generate dwarf4 debug info. This requires recent versions > - of gcc and gdb. It makes the debug information larger. > - But it significantly improves the success of resolving > - variables in gdb on optimized code. > + Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+. > + It makes the debug information larger, but it significantly > + improves the success of resolving variables in gdb on optimized code. > + > +endchoice # "DWARF version" > > config DEBUG_INFO_BTF > bool "Generate BTF typeinfo" > -- > 2.30.0.284.gd98b1dd5eaa7-goog >
On Wed, Jan 20, 2021 at 9:40 PM Nathan Chancellor <natechancellor@gmail.com> wrote: > > On Fri, Jan 15, 2021 at 01:06:15PM -0800, Nick Desaulniers wrote: > > Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice. Adds an > > explicit CONFIG_DEBUG_INFO_DWARF2, which is the default. Does so in a > > way that's forward compatible with existing configs, and makes adding > > future versions more straightforward. > > > > Suggested-by: Arvind Sankar <nivedita@alum.mit.edu> > > Suggested-by: Fangrui Song <maskray@google.com> > > Suggested-by: Masahiro Yamada <masahiroy@kernel.org> > > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> > > --- > > Makefile | 13 ++++++------- > > lib/Kconfig.debug | 21 ++++++++++++++++----- > > 2 files changed, 22 insertions(+), 12 deletions(-) > > > > diff --git a/Makefile b/Makefile > > index d49c3f39ceb4..4eb3bf7ee974 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -826,13 +826,12 @@ else > > DEBUG_CFLAGS += -g > > endif > > > > -ifneq ($(LLVM_IAS),1) > > -KBUILD_AFLAGS += -Wa,-gdwarf-2 > > -endif > > Aren't you regressing this with this patch? Why is the hunk from 3/3 > that adds > > ifdef CONFIG_CC_IS_CLANG > ifneq ($(LLVM_IAS),1) > > not in this patch? > Nice catch Nathan. Just FYI: The patch... "kbuild: Remove $(cc-option,-gdwarf-4) dependency from DEBUG_INFO_DWARF4" ... has now entered kbuild-next. ( This patch is included in this patch-series. ) So should we point to this one and add a comment? Thinking of a next version of this DWARF5 support patch-series. - Sedat - [1] https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git/commit/?h=kbuild&id=3f4d8ce271c7082be75bacbcbd2048aa78ce2b44 > > -ifdef CONFIG_DEBUG_INFO_DWARF4 > > -DEBUG_CFLAGS += -gdwarf-4 > > -endif > > +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF2) := 2 > > +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4 > > +DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) > > +# Binutils 2.35+ required for -gdwarf-4+ support. > > +dwarf-aflag := $(call as-option,-Wa$(comma)-gdwarf-$(dwarf-version-y)) > > +KBUILD_AFLAGS += $(dwarf-aflag) > > > > ifdef CONFIG_DEBUG_INFO_REDUCED > > DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \ > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > > index dd7d8d35b2a5..e80770fac4f0 100644 > > --- a/lib/Kconfig.debug > > +++ b/lib/Kconfig.debug > > @@ -256,13 +256,24 @@ config DEBUG_INFO_SPLIT > > to know about the .dwo files and include them. > > Incompatible with older versions of ccache. > > > > +choice > > + prompt "DWARF version" > > + help > > + Which version of DWARF debug info to emit. > > + > > +config DEBUG_INFO_DWARF2 > > + bool "Generate DWARF Version 2 debuginfo" > > + help > > + Generate DWARF v2 debug info. > > + > > config DEBUG_INFO_DWARF4 > > - bool "Generate dwarf4 debuginfo" > > + bool "Generate DWARF Version 4 debuginfo" > > help > > - Generate dwarf4 debug info. This requires recent versions > > - of gcc and gdb. It makes the debug information larger. > > - But it significantly improves the success of resolving > > - variables in gdb on optimized code. > > + Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+. > > + It makes the debug information larger, but it significantly > > + improves the success of resolving variables in gdb on optimized code. > > + > > +endchoice # "DWARF version" > > > > config DEBUG_INFO_BTF > > bool "Generate BTF typeinfo" > > -- > > 2.30.0.284.gd98b1dd5eaa7-goog > >
diff --git a/Makefile b/Makefile index d49c3f39ceb4..4eb3bf7ee974 100644 --- a/Makefile +++ b/Makefile @@ -826,13 +826,12 @@ else DEBUG_CFLAGS += -g endif -ifneq ($(LLVM_IAS),1) -KBUILD_AFLAGS += -Wa,-gdwarf-2 -endif - -ifdef CONFIG_DEBUG_INFO_DWARF4 -DEBUG_CFLAGS += -gdwarf-4 -endif +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF2) := 2 +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4 +DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) +# Binutils 2.35+ required for -gdwarf-4+ support. +dwarf-aflag := $(call as-option,-Wa$(comma)-gdwarf-$(dwarf-version-y)) +KBUILD_AFLAGS += $(dwarf-aflag) ifdef CONFIG_DEBUG_INFO_REDUCED DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index dd7d8d35b2a5..e80770fac4f0 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -256,13 +256,24 @@ config DEBUG_INFO_SPLIT to know about the .dwo files and include them. Incompatible with older versions of ccache. +choice + prompt "DWARF version" + help + Which version of DWARF debug info to emit. + +config DEBUG_INFO_DWARF2 + bool "Generate DWARF Version 2 debuginfo" + help + Generate DWARF v2 debug info. + config DEBUG_INFO_DWARF4 - bool "Generate dwarf4 debuginfo" + bool "Generate DWARF Version 4 debuginfo" help - Generate dwarf4 debug info. This requires recent versions - of gcc and gdb. It makes the debug information larger. - But it significantly improves the success of resolving - variables in gdb on optimized code. + Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+. + It makes the debug information larger, but it significantly + improves the success of resolving variables in gdb on optimized code. + +endchoice # "DWARF version" config DEBUG_INFO_BTF bool "Generate BTF typeinfo"
Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice. Adds an explicit CONFIG_DEBUG_INFO_DWARF2, which is the default. Does so in a way that's forward compatible with existing configs, and makes adding future versions more straightforward. Suggested-by: Arvind Sankar <nivedita@alum.mit.edu> Suggested-by: Fangrui Song <maskray@google.com> Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> --- Makefile | 13 ++++++------- lib/Kconfig.debug | 21 ++++++++++++++++----- 2 files changed, 22 insertions(+), 12 deletions(-)