[Buildroot] [PATCH 0/3] Misc gcc fixes/improvements

[Buildroot] [PATCH 0/3] Misc gcc fixes/improvements

[Thomas Petazzoni]

Hello,

The first patch fixes the build of no-thread toolchains: the
libcilkrts cannot build without threads. This was not noticed until
now, because we don't regularly build no-thread toolchain, except for
ARM, and libcilkrts was only enabled for ARM in gcc 7.x. This patch
was made as minimal as possible so that it can be backported to the
LTS branch.

The second patch reworks a bit the licilkrts handling so that we know
we can drop it at some point in the future (libcilkrts was removed
starting from gcc 8.x).

The third patch drops an unneeded option.

Best regards,

Thomas

Thomas Petazzoni (3):
  package/gcc: disable libcilkrts when there is no thread support
  package/gcc: introduce BR2_GCC_SUPPORTS_LIBCILKRTS
  package/gcc: remove BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE

 package/gcc/Config.in.host             |  6 ++++--
 package/gcc/gcc-final/gcc-final.mk     | 17 +++++++++++++++--
 package/gcc/gcc-initial/gcc-initial.mk |  9 ++-------
 package/gcc/gcc.mk                     |  5 +----
 4 files changed, 22 insertions(+), 15 deletions(-)

-- 
2.14.4

[Buildroot] [PATCH 1/3] package/gcc: disable libcilkrts when there is no thread support

[Thomas Petazzoni]

The libcilkrts configure script errors out with "Pthreads are required
to build libcilkrts" if the C library doesn't have thread support. To
fix that, we disable libcilkrts when thread support is not available.

This issue was not noticed until now, because we only regularly build
a no-thread toolchain for ARM, and libcilkrts was enabled on ARM only
starting in gcc 7.x.

This fixes the build of no-thread toolchains on architectures where
libcilkrts is supported, i.e x86/x86-64, ARM and Sparc.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 package/gcc/gcc-final/gcc-final.mk | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/package/gcc/gcc-final/gcc-final.mk b/package/gcc/gcc-final/gcc-final.mk
index 9897d18682..1be0b9bfc9 100644
--- a/package/gcc/gcc-final/gcc-final.mk
+++ b/package/gcc/gcc-final/gcc-final.mk
@@ -81,6 +81,11 @@ ifeq ($(BR2_sparc),y)
 HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
 endif
 
+# Pthreads are required to build libcilkrts
+ifeq ($(BR2_PTHREADS_NONE),y)
+HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
+endif
+
 # Disable shared libs like libstdc++ if we do static since it confuses linking
 # In that case also disable libcilkrts as there is no static version
 ifeq ($(BR2_STATIC_LIBS),y)
-- 
2.14.4

[Buildroot] [PATCH 1/3] package/gcc: disable libcilkrts when there is no thread support

[Romain Naour]

Hi Thomas,

Le 21/10/2018 ? 13:54, Thomas Petazzoni a ?crit?:
> The libcilkrts configure script errors out with "Pthreads are required
> to build libcilkrts" if the C library doesn't have thread support. To
> fix that, we disable libcilkrts when thread support is not available.
> 
> This issue was not noticed until now, because we only regularly build
> a no-thread toolchain for ARM, and libcilkrts was enabled on ARM only
> starting in gcc 7.x.
> 
> This fixes the build of no-thread toolchains on architectures where
> libcilkrts is supported, i.e x86/x86-64, ARM and Sparc.
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Reviewed-by: Romain Naour <romain.naour@gmail.com>

Best regards,
Romain


> ---
>  package/gcc/gcc-final/gcc-final.mk | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/package/gcc/gcc-final/gcc-final.mk b/package/gcc/gcc-final/gcc-final.mk
> index 9897d18682..1be0b9bfc9 100644
> --- a/package/gcc/gcc-final/gcc-final.mk
> +++ b/package/gcc/gcc-final/gcc-final.mk
> @@ -81,6 +81,11 @@ ifeq ($(BR2_sparc),y)
>  HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
>  endif
>  
> +# Pthreads are required to build libcilkrts
> +ifeq ($(BR2_PTHREADS_NONE),y)
> +HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
> +endif
> +
>  # Disable shared libs like libstdc++ if we do static since it confuses linking
>  # In that case also disable libcilkrts as there is no static version
>  ifeq ($(BR2_STATIC_LIBS),y)
> 

[Buildroot] [PATCH 1/3] package/gcc: disable libcilkrts when there is no thread support

[Peter Korsgaard]

>>>>> "Thomas" == Thomas Petazzoni <thomas.petazzoni@bootlin.com> writes:

 > The libcilkrts configure script errors out with "Pthreads are required
 > to build libcilkrts" if the C library doesn't have thread support. To
 > fix that, we disable libcilkrts when thread support is not available.

 > This issue was not noticed until now, because we only regularly build
 > a no-thread toolchain for ARM, and libcilkrts was enabled on ARM only
 > starting in gcc 7.x.

 > This fixes the build of no-thread toolchains on architectures where
 > libcilkrts is supported, i.e x86/x86-64, ARM and Sparc.

 > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Committed to 2018.02.x and 2018.08.x, thanks.

-- 
Bye, Peter Korsgaard

[Buildroot] [PATCH 2/3] package/gcc: introduce BR2_GCC_SUPPORTS_LIBCILKRTS

[Thomas Petazzoni]

libcilkrts was introduced in gcc 4.9, and removed in gcc
8.x. Therefore, it does not make sense to pass --disable-libcilkrts in
gcc 8.x and higher. This commit introduces BR2_GCC_SUPPORTS_LIBCILKRTS
that allows the makefile code to know if the selected gcc version
supports libcilkrts or not.

This new option mainly allows to annotate the fact that libcilkrts
exists in gcc [4.9, 7] and that once we have dropped support for those
gcc versions, the libcilkrts related logic can be removed.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 package/gcc/Config.in.host         |  6 ++++++
 package/gcc/gcc-final/gcc-final.mk | 12 ++++++++++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/package/gcc/Config.in.host b/package/gcc/Config.in.host
index 5a8f684a4c..3bf87fe597 100644
--- a/package/gcc/Config.in.host
+++ b/package/gcc/Config.in.host
@@ -76,6 +76,12 @@ config BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE
 	bool
 	default y
 
+# libcilkrts was introduced in gcc 4.9 (oldest gcc version we
+# support), and removed in gcc 8.x
+config BR2_GCC_SUPPORTS_LIBCILKRTS
+	bool
+	default y if !BR2_TOOLCHAIN_GCC_AT_LEAST_8
+
 config BR2_GCC_VERSION
 	string
 	default "4.9.4"     if BR2_GCC_VERSION_4_9_X
diff --git a/package/gcc/gcc-final/gcc-final.mk b/package/gcc/gcc-final/gcc-final.mk
index 1be0b9bfc9..cbde56ce1c 100644
--- a/package/gcc/gcc-final/gcc-final.mk
+++ b/package/gcc/gcc-final/gcc-final.mk
@@ -76,6 +76,8 @@ HOST_GCC_FINAL_CONF_OPTS += "--with-multilib-list=m4a,m4a-nofpu"
 HOST_GCC_FINAL_GCC_LIB_DIR = $(HOST_DIR)/$(GNU_TARGET_NAME)/lib/!m4*
 endif
 
+ifeq ($(BR2_GCC_SUPPORTS_LIBCILKRTS),y)
+
 # libcilkrts does not support v8
 ifeq ($(BR2_sparc),y)
 HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
@@ -86,10 +88,16 @@ ifeq ($(BR2_PTHREADS_NONE),y)
 HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
 endif
 
+ifeq ($(BR2_STATIC_LIBS),y)
+# disable libcilkrts as there is no static version
+HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
+endif
+
+endif # BR2_GCC_SUPPORTS_LIBCILKRTS
+
 # Disable shared libs like libstdc++ if we do static since it confuses linking
-# In that case also disable libcilkrts as there is no static version
 ifeq ($(BR2_STATIC_LIBS),y)
-HOST_GCC_FINAL_CONF_OPTS += --disable-shared --disable-libcilkrts
+HOST_GCC_FINAL_CONF_OPTS += --disable-shared
 else
 HOST_GCC_FINAL_CONF_OPTS += --enable-shared
 endif
-- 
2.14.4

[Buildroot] [PATCH 2/3] package/gcc: introduce BR2_GCC_SUPPORTS_LIBCILKRTS

[Romain Naour]

Hi Thomas,

Le 21/10/2018 ? 13:54, Thomas Petazzoni a ?crit?:
> libcilkrts was introduced in gcc 4.9, and removed in gcc
> 8.x. Therefore, it does not make sense to pass --disable-libcilkrts in
> gcc 8.x and higher. This commit introduces BR2_GCC_SUPPORTS_LIBCILKRTS
> that allows the makefile code to know if the selected gcc version
> supports libcilkrts or not.
> 
> This new option mainly allows to annotate the fact that libcilkrts
> exists in gcc [4.9, 7] and that once we have dropped support for those
> gcc versions, the libcilkrts related logic can be removed.
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Reviewed-by: Romain Naour <romain.naour@gmail.com>

Best regards,
Romain

> ---
>  package/gcc/Config.in.host         |  6 ++++++
>  package/gcc/gcc-final/gcc-final.mk | 12 ++++++++++--
>  2 files changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/package/gcc/Config.in.host b/package/gcc/Config.in.host
> index 5a8f684a4c..3bf87fe597 100644
> --- a/package/gcc/Config.in.host
> +++ b/package/gcc/Config.in.host
> @@ -76,6 +76,12 @@ config BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE
>  	bool
>  	default y
>  
> +# libcilkrts was introduced in gcc 4.9 (oldest gcc version we
> +# support), and removed in gcc 8.x
> +config BR2_GCC_SUPPORTS_LIBCILKRTS
> +	bool
> +	default y if !BR2_TOOLCHAIN_GCC_AT_LEAST_8
> +
>  config BR2_GCC_VERSION
>  	string
>  	default "4.9.4"     if BR2_GCC_VERSION_4_9_X
> diff --git a/package/gcc/gcc-final/gcc-final.mk b/package/gcc/gcc-final/gcc-final.mk
> index 1be0b9bfc9..cbde56ce1c 100644
> --- a/package/gcc/gcc-final/gcc-final.mk
> +++ b/package/gcc/gcc-final/gcc-final.mk
> @@ -76,6 +76,8 @@ HOST_GCC_FINAL_CONF_OPTS += "--with-multilib-list=m4a,m4a-nofpu"
>  HOST_GCC_FINAL_GCC_LIB_DIR = $(HOST_DIR)/$(GNU_TARGET_NAME)/lib/!m4*
>  endif
>  
> +ifeq ($(BR2_GCC_SUPPORTS_LIBCILKRTS),y)
> +
>  # libcilkrts does not support v8
>  ifeq ($(BR2_sparc),y)
>  HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
> @@ -86,10 +88,16 @@ ifeq ($(BR2_PTHREADS_NONE),y)
>  HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
>  endif
>  
> +ifeq ($(BR2_STATIC_LIBS),y)
> +# disable libcilkrts as there is no static version
> +HOST_GCC_FINAL_CONF_OPTS += --disable-libcilkrts
> +endif
> +
> +endif # BR2_GCC_SUPPORTS_LIBCILKRTS
> +
>  # Disable shared libs like libstdc++ if we do static since it confuses linking
> -# In that case also disable libcilkrts as there is no static version
>  ifeq ($(BR2_STATIC_LIBS),y)
> -HOST_GCC_FINAL_CONF_OPTS += --disable-shared --disable-libcilkrts
> +HOST_GCC_FINAL_CONF_OPTS += --disable-shared
>  else
>  HOST_GCC_FINAL_CONF_OPTS += --enable-shared
>  endif
> 

[Buildroot] [PATCH 3/3] package/gcc: remove BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE

[Thomas Petazzoni]

Since commit 8f8e9162fae5fdc1788dcf33f02b20ddaa5e6846 ("package/gcc:
do not mourn avr32 for too long..."), in which we dropped AVR32
support, the BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE is always
'y'. Therefore, it is totally useless to keep this option around, and
this commit removes it, making the corresponding code unconditional
along the way.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 package/gcc/Config.in.host             | 4 ----
 package/gcc/gcc-initial/gcc-initial.mk | 9 ++-------
 package/gcc/gcc.mk                     | 5 +----
 3 files changed, 3 insertions(+), 15 deletions(-)

diff --git a/package/gcc/Config.in.host b/package/gcc/Config.in.host
index 3bf87fe597..1d4e946f55 100644
--- a/package/gcc/Config.in.host
+++ b/package/gcc/Config.in.host
@@ -72,10 +72,6 @@ config BR2_GCC_VERSION_8_X
 
 endchoice
 
-config BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE
-	bool
-	default y
-
 # libcilkrts was introduced in gcc 4.9 (oldest gcc version we
 # support), and removed in gcc 8.x
 config BR2_GCC_SUPPORTS_LIBCILKRTS
diff --git a/package/gcc/gcc-initial/gcc-initial.mk b/package/gcc/gcc-initial/gcc-initial.mk
index 9b20eb18f9..d5d925a3d9 100644
--- a/package/gcc/gcc-initial/gcc-initial.mk
+++ b/package/gcc/gcc-initial/gcc-initial.mk
@@ -45,13 +45,8 @@ HOST_GCC_INITIAL_CONF_OPTS = \
 HOST_GCC_INITIAL_CONF_ENV = \
 	$(HOST_GCC_COMMON_CONF_ENV)
 
-HOST_GCC_INITIAL_MAKE_OPTS = $(HOST_GCC_COMMON_MAKE_OPTS) all-gcc
-HOST_GCC_INITIAL_INSTALL_OPTS = install-gcc
-
-ifeq ($(BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE),y)
-HOST_GCC_INITIAL_MAKE_OPTS += all-target-libgcc
-HOST_GCC_INITIAL_INSTALL_OPTS += install-target-libgcc
-endif
+HOST_GCC_INITIAL_MAKE_OPTS = $(HOST_GCC_COMMON_MAKE_OPTS) all-gcc all-target-libgcc
+HOST_GCC_INITIAL_INSTALL_OPTS = install-gcc install-target-libgcc
 
 HOST_GCC_INITIAL_TOOLCHAIN_WRAPPER_ARGS += $(HOST_GCC_COMMON_TOOLCHAIN_WRAPPER_ARGS)
 HOST_GCC_INITIAL_POST_BUILD_HOOKS += TOOLCHAIN_WRAPPER_BUILD
diff --git a/package/gcc/gcc.mk b/package/gcc/gcc.mk
index 9e9069ce0e..8b0fec74f1 100644
--- a/package/gcc/gcc.mk
+++ b/package/gcc/gcc.mk
@@ -98,6 +98,7 @@ HOST_GCC_COMMON_CONF_OPTS = \
 	--with-gnu-ld \
 	--disable-libssp \
 	--disable-multilib \
+	--disable-decimal-float \
 	--with-gmp=$(HOST_DIR) \
 	--with-mpc=$(HOST_DIR) \
 	--with-mpfr=$(HOST_DIR) \
@@ -195,10 +196,6 @@ HOST_GCC_COMMON_CONF_OPTS += --with-float=soft
 endif
 endif
 
-ifeq ($(BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE),y)
-HOST_GCC_COMMON_CONF_OPTS += --disable-decimal-float
-endif
-
 # Determine arch/tune/abi/cpu options
 ifneq ($(GCC_TARGET_ARCH),)
 HOST_GCC_COMMON_CONF_OPTS += --with-arch="$(GCC_TARGET_ARCH)"
-- 
2.14.4

[Buildroot] [PATCH 3/3] package/gcc: remove BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE

[Romain Naour]

Hi Thomas,

Le 21/10/2018 ? 13:54, Thomas Petazzoni a ?crit?:
> Since commit 8f8e9162fae5fdc1788dcf33f02b20ddaa5e6846 ("package/gcc:
> do not mourn avr32 for too long..."), in which we dropped AVR32
> support, the BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE is always
> 'y'. Therefore, it is totally useless to keep this option around, and
> this commit removes it, making the corresponding code unconditional
> along the way.
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Reviewed-by: Romain Naour <romain.naour@gmail.com>

Best regards,
Romain

> ---
>  package/gcc/Config.in.host             | 4 ----
>  package/gcc/gcc-initial/gcc-initial.mk | 9 ++-------
>  package/gcc/gcc.mk                     | 5 +----
>  3 files changed, 3 insertions(+), 15 deletions(-)
> 
> diff --git a/package/gcc/Config.in.host b/package/gcc/Config.in.host
> index 3bf87fe597..1d4e946f55 100644
> --- a/package/gcc/Config.in.host
> +++ b/package/gcc/Config.in.host
> @@ -72,10 +72,6 @@ config BR2_GCC_VERSION_8_X
>  
>  endchoice
>  
> -config BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE
> -	bool
> -	default y
> -
>  # libcilkrts was introduced in gcc 4.9 (oldest gcc version we
>  # support), and removed in gcc 8.x
>  config BR2_GCC_SUPPORTS_LIBCILKRTS
> diff --git a/package/gcc/gcc-initial/gcc-initial.mk b/package/gcc/gcc-initial/gcc-initial.mk
> index 9b20eb18f9..d5d925a3d9 100644
> --- a/package/gcc/gcc-initial/gcc-initial.mk
> +++ b/package/gcc/gcc-initial/gcc-initial.mk
> @@ -45,13 +45,8 @@ HOST_GCC_INITIAL_CONF_OPTS = \
>  HOST_GCC_INITIAL_CONF_ENV = \
>  	$(HOST_GCC_COMMON_CONF_ENV)
>  
> -HOST_GCC_INITIAL_MAKE_OPTS = $(HOST_GCC_COMMON_MAKE_OPTS) all-gcc
> -HOST_GCC_INITIAL_INSTALL_OPTS = install-gcc
> -
> -ifeq ($(BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE),y)
> -HOST_GCC_INITIAL_MAKE_OPTS += all-target-libgcc
> -HOST_GCC_INITIAL_INSTALL_OPTS += install-target-libgcc
> -endif
> +HOST_GCC_INITIAL_MAKE_OPTS = $(HOST_GCC_COMMON_MAKE_OPTS) all-gcc all-target-libgcc
> +HOST_GCC_INITIAL_INSTALL_OPTS = install-gcc install-target-libgcc
>  
>  HOST_GCC_INITIAL_TOOLCHAIN_WRAPPER_ARGS += $(HOST_GCC_COMMON_TOOLCHAIN_WRAPPER_ARGS)
>  HOST_GCC_INITIAL_POST_BUILD_HOOKS += TOOLCHAIN_WRAPPER_BUILD
> diff --git a/package/gcc/gcc.mk b/package/gcc/gcc.mk
> index 9e9069ce0e..8b0fec74f1 100644
> --- a/package/gcc/gcc.mk
> +++ b/package/gcc/gcc.mk
> @@ -98,6 +98,7 @@ HOST_GCC_COMMON_CONF_OPTS = \
>  	--with-gnu-ld \
>  	--disable-libssp \
>  	--disable-multilib \
> +	--disable-decimal-float \
>  	--with-gmp=$(HOST_DIR) \
>  	--with-mpc=$(HOST_DIR) \
>  	--with-mpfr=$(HOST_DIR) \
> @@ -195,10 +196,6 @@ HOST_GCC_COMMON_CONF_OPTS += --with-float=soft
>  endif
>  endif
>  
> -ifeq ($(BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE),y)
> -HOST_GCC_COMMON_CONF_OPTS += --disable-decimal-float
> -endif
> -
>  # Determine arch/tune/abi/cpu options
>  ifneq ($(GCC_TARGET_ARCH),)
>  HOST_GCC_COMMON_CONF_OPTS += --with-arch="$(GCC_TARGET_ARCH)"
> 

[Buildroot] [PATCH 0/3] Misc gcc fixes/improvements

[Thomas Petazzoni]

Hello,

On Sun, 21 Oct 2018 13:54:12 +0200, Thomas Petazzoni wrote:

> Thomas Petazzoni (3):
>   package/gcc: disable libcilkrts when there is no thread support
>   package/gcc: introduce BR2_GCC_SUPPORTS_LIBCILKRTS
>   package/gcc: remove BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE

Series applied. Thanks Romain for the review!

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com