| Message ID | 20190724173538.22913-5-joseph.kogut@gmail.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Add Buildroot toolchain support for LLD | expand |
On Wed, Jul 24, 2019 at 2:35 PM Joseph Kogut <joseph.kogut@gmail.com> wrote: > > Signed-off-by: Joseph Kogut <joseph.kogut@gmail.com> [...] > > +ifeq ($(BR2_LINKER_LLD),y) > +TOOLCHAIN_WRAPPER_ARGS += -DBR_LINKER='"lld"' Sorry for the nitpicking but Buildroot normally uses the "BR2_" prefix fo perhaps this should be "BR2_LINKER"
Hi Carlos, On Fri, Jul 26, 2019 at 7:25 PM Carlos Santos <unixmania@gmail.com> wrote: > > On Wed, Jul 24, 2019 at 2:35 PM Joseph Kogut <joseph.kogut@gmail.com> wrote: > > > > Signed-off-by: Joseph Kogut <joseph.kogut@gmail.com> > [...] > > > > +ifeq ($(BR2_LINKER_LLD),y) > > +TOOLCHAIN_WRAPPER_ARGS += -DBR_LINKER='"lld"' > > Sorry for the nitpicking but Buildroot normally uses the "BR2_" prefix > fo perhaps this should be "BR2_LINKER" > Correct, most constants are prefixed with BR2_*, with the exception of definitions in the toolchain wrapper. I chose BR_LINKER to remain consistent with the other code in the wrapper. Best, Joseph
On 24/07/2019 19:35, Joseph Kogut wrote: > Signed-off-by: Joseph Kogut <joseph.kogut@gmail.com> Please make the commit message a bit more extensive. Actually, almost all of the cover text could be put here. > --- > Config.in | 27 +++++++++++++++++++++++++++ > package/gcc/gcc.mk | 3 ++- > package/glibc/glibc.mk | 3 +++ > toolchain/toolchain-wrapper.mk | 4 ++++ > 4 files changed, 36 insertions(+), 1 deletion(-) > > diff --git a/Config.in b/Config.in > index 757ad1ca40..576d95305d 100644 > --- a/Config.in > +++ b/Config.in > @@ -318,6 +318,33 @@ config BR2_JLEVEL > Number of jobs to run simultaneously. If 0, determine > automatically according to number of CPUs on the host system. > > +choice > + prompt "Default linker" > + default BR2_LINKER_BFD I think this option belongs in the toolchain menu, under the toolchain generic options. > + help > + Choose the default linker > + Individual packages may override this choice Please end sentences with a period, and if it's intended as two paragraphs, add an empty line between them. > + > +config BR2_LINKER_BFD > + bool "GNU ld" > + help > + GNU GCC linker > + > +config BR2_LINKER_LLD > + bool "LLVM LLD" > + select BR2_PACKAGE_HOST_LLD If this requires gcc 9+, you should add depends on BR2_TOOLCHAIN_GCC_AT_LEAST_9 > + help > + Clang/LLVM linker > + > + Offers a faster link times compared to GNU linkers such as ld.bfd and > + ld.gold. > + > + NOTE: This option requires building LLVM, which is time consuming itself. > + > + https://lld.llvm.org/ > + > +endchoice > + > config BR2_CCACHE > bool "Enable compiler cache" > help > diff --git a/package/gcc/gcc.mk b/package/gcc/gcc.mk > index 46ad16df13..aef0038639 100644 > --- a/package/gcc/gcc.mk > +++ b/package/gcc/gcc.mk > @@ -85,7 +85,8 @@ HOST_GCC_COMMON_DEPENDENCIES = \ > host-gmp \ > host-mpc \ > host-mpfr \ > - $(if $(BR2_BINFMT_FLAT),host-elf2flt) > + $(if $(BR2_BINFMT_FLAT),host-elf2flt) \ > + $(if $(BR2_LINKER_LLD),host-lld) I think it's not really needed by gcc itself, but only by the packages that will add the -fuse-ld flag, right? Then I think it's more appropriate to add the dependency to the toolchain (virtual) package. That way, we also support external toolchains. > > HOST_GCC_COMMON_CONF_OPTS = \ > --target=$(GNU_TARGET_NAME) \ > diff --git a/package/glibc/glibc.mk b/package/glibc/glibc.mk > index f8d8c1bd87..1c06028241 100644 > --- a/package/glibc/glibc.mk > +++ b/package/glibc/glibc.mk > @@ -32,6 +32,9 @@ GLIBC_LICENSE_FILES = COPYING COPYING.LIB LICENSES > # glibc is part of the toolchain so disable the toolchain dependency > GLIBC_ADD_TOOLCHAIN_DEPENDENCY = NO > > +# Glibc requires ld.bfd > +GLIBC_MAKE_ENV += BR2_NO_LINKER_OVERRIDE=1 > + > # Before glibc is configured, we must have the first stage > # cross-compiler and the kernel headers > GLIBC_DEPENDENCIES = host-gcc-initial linux-headers host-bison host-gawk \ > diff --git a/toolchain/toolchain-wrapper.mk b/toolchain/toolchain-wrapper.mk > index ca66fa7ba4..ff7a7ab448 100644 > --- a/toolchain/toolchain-wrapper.mk > +++ b/toolchain/toolchain-wrapper.mk > @@ -16,6 +16,10 @@ endif > TOOLCHAIN_WRAPPER_ARGS = $($(PKG)_TOOLCHAIN_WRAPPER_ARGS) > TOOLCHAIN_WRAPPER_ARGS += -DBR_SYSROOT='"$(STAGING_SUBDIR)"' > > +ifeq ($(BR2_LINKER_LLD),y) > +TOOLCHAIN_WRAPPER_ARGS += -DBR_LINKER='"lld"' > +endif > + > TOOLCHAIN_WRAPPER_OPTS = \ > $(call qstrip,$(BR2_SSP_OPTION)) \ > $(call qstrip,$(BR2_TARGET_OPTIMIZATION)) I think two additional patches will be needed: 1. An update to the manual that explains how to disable lld in the adding-packages section. 2. An update to genrandconfig that makes sure the LLD option gets tested in the autobuilders. Regards, Arnout
diff --git a/Config.in b/Config.in index 757ad1ca40..576d95305d 100644 --- a/Config.in +++ b/Config.in @@ -318,6 +318,33 @@ config BR2_JLEVEL Number of jobs to run simultaneously. If 0, determine automatically according to number of CPUs on the host system. +choice + prompt "Default linker" + default BR2_LINKER_BFD + help + Choose the default linker + Individual packages may override this choice + +config BR2_LINKER_BFD + bool "GNU ld" + help + GNU GCC linker + +config BR2_LINKER_LLD + bool "LLVM LLD" + select BR2_PACKAGE_HOST_LLD + help + Clang/LLVM linker + + Offers a faster link times compared to GNU linkers such as ld.bfd and + ld.gold. + + NOTE: This option requires building LLVM, which is time consuming itself. + + https://lld.llvm.org/ + +endchoice + config BR2_CCACHE bool "Enable compiler cache" help diff --git a/package/gcc/gcc.mk b/package/gcc/gcc.mk index 46ad16df13..aef0038639 100644 --- a/package/gcc/gcc.mk +++ b/package/gcc/gcc.mk @@ -85,7 +85,8 @@ HOST_GCC_COMMON_DEPENDENCIES = \ host-gmp \ host-mpc \ host-mpfr \ - $(if $(BR2_BINFMT_FLAT),host-elf2flt) + $(if $(BR2_BINFMT_FLAT),host-elf2flt) \ + $(if $(BR2_LINKER_LLD),host-lld) HOST_GCC_COMMON_CONF_OPTS = \ --target=$(GNU_TARGET_NAME) \ diff --git a/package/glibc/glibc.mk b/package/glibc/glibc.mk index f8d8c1bd87..1c06028241 100644 --- a/package/glibc/glibc.mk +++ b/package/glibc/glibc.mk @@ -32,6 +32,9 @@ GLIBC_LICENSE_FILES = COPYING COPYING.LIB LICENSES # glibc is part of the toolchain so disable the toolchain dependency GLIBC_ADD_TOOLCHAIN_DEPENDENCY = NO +# Glibc requires ld.bfd +GLIBC_MAKE_ENV += BR2_NO_LINKER_OVERRIDE=1 + # Before glibc is configured, we must have the first stage # cross-compiler and the kernel headers GLIBC_DEPENDENCIES = host-gcc-initial linux-headers host-bison host-gawk \ diff --git a/toolchain/toolchain-wrapper.mk b/toolchain/toolchain-wrapper.mk index ca66fa7ba4..ff7a7ab448 100644 --- a/toolchain/toolchain-wrapper.mk +++ b/toolchain/toolchain-wrapper.mk @@ -16,6 +16,10 @@ endif TOOLCHAIN_WRAPPER_ARGS = $($(PKG)_TOOLCHAIN_WRAPPER_ARGS) TOOLCHAIN_WRAPPER_ARGS += -DBR_SYSROOT='"$(STAGING_SUBDIR)"' +ifeq ($(BR2_LINKER_LLD),y) +TOOLCHAIN_WRAPPER_ARGS += -DBR_LINKER='"lld"' +endif + TOOLCHAIN_WRAPPER_OPTS = \ $(call qstrip,$(BR2_SSP_OPTION)) \ $(call qstrip,$(BR2_TARGET_OPTIMIZATION))
Signed-off-by: Joseph Kogut <joseph.kogut@gmail.com> --- Config.in | 27 +++++++++++++++++++++++++++ package/gcc/gcc.mk | 3 ++- package/glibc/glibc.mk | 3 +++ toolchain/toolchain-wrapper.mk | 4 ++++ 4 files changed, 36 insertions(+), 1 deletion(-)