packages/gcc/12.2.0: Add picolibc patches

These patches allow picolibc to act as the system C library within gcc.

Signed-off-by: Keith Packard <keithp@keithp.com>

5 files changed, 427 insertions, 0 deletions

diff --git a/packages/gcc/12.2.0/0005-Allow-default-libc-to-be-specified-to-configure.patch b/packages/gcc/12.2.0/0005-Allow-default-libc-to-be-specified-to-configure.patch
new file mode 100644
index 00000000..4f155f61
--- /dev/null
+++ b/packages/gcc/12.2.0/0005-Allow-default-libc-to-be-specified-to-configure.patch
@@ -0,0 +1,141 @@
+From e55524baedbf2dc94b5159373c2b71049bdde1a8 Mon Sep 17 00:00:00 2001
+From: Keith Packard <keithp@keithp.com>
+Date: Fri, 2 Sep 2022 23:07:05 -0700
+Subject: [PATCH 5/9] Allow default libc to be specified to configure
+
+The default C library is normally computed based on the target
+triplet. However, for embedded systems, it can be useful to leave the
+triplet alone while changing which C library is used by default. Other
+C libraries may still be available on the system so the compiler and
+can be used by specifying suitable include and library paths at build
+time.
+
+If an unknown --with-default-libc= value is provided, emit an error
+and stop.
+
+Signed-off-by: Keith Packard <keithp@keithp.com>
+---
+ gcc/config.gcc   | 48 ++++++++++++++++++++++++++++++++++++++++--------
+ gcc/configure.ac |  4 ++++
+ 2 files changed, 44 insertions(+), 8 deletions(-)
+
+diff --git a/gcc/config.gcc b/gcc/config.gcc
+index c5064dd3766..ddab68fbf8f 100644
+--- a/gcc/config.gcc
++++ b/gcc/config.gcc
+@@ -648,6 +648,8 @@ esac
+ # Common C libraries.
+ tm_defines="$tm_defines LIBC_GLIBC=1 LIBC_UCLIBC=2 LIBC_BIONIC=3 LIBC_MUSL=4"
+ 
++default_libc=""
++
+ # 32-bit x86 processors supported by --with-arch=.  Each processor
+ # MUST be separated by exactly one space.
+ x86_archs="athlon athlon-4 athlon-fx athlon-mp athlon-tbird \
+@@ -854,16 +856,16 @@ case ${target} in
+   esac
+   case $target in
+     *-*-*android*)
+-      tm_defines="$tm_defines DEFAULT_LIBC=LIBC_BIONIC"
++      default_libc=LIBC_BIONIC
+       ;;
+     *-*-*uclibc* | *-*-uclinuxfdpiceabi)
+-      tm_defines="$tm_defines DEFAULT_LIBC=LIBC_UCLIBC"
++      default_libc=LIBC_UCLIBC
+       ;;
+     *-*-*musl*)
+-      tm_defines="$tm_defines DEFAULT_LIBC=LIBC_MUSL"
++      default_libc=LIBC_MUSL
+       ;;
+     *)
+-      tm_defines="$tm_defines DEFAULT_LIBC=LIBC_GLIBC"
++      default_libc=LIBC_GLIBC
+       ;;
+   esac
+   # Assume that glibc or uClibc or Bionic are being used and so __cxa_atexit
+@@ -956,7 +958,8 @@ case ${target} in
+   case ${enable_threads} in
+     "" | yes | posix) thread_file='posix' ;;
+   esac
+-  tm_defines="$tm_defines DEFAULT_LIBC=LIBC_UCLIBC SINGLE_LIBC"
++  tm_defines="$tm_defines SINGLE_LIBC"
++  default_libc=LIBC_UCLIBC
+   ;;
+ *-*-rdos*)
+   use_gcc_stdint=wrap
+@@ -1606,13 +1609,13 @@ csky-*-*)
+ 
+ 		case ${target} in
+ 		    csky-*-linux-gnu*)
+-			tm_defines="$tm_defines DEFAULT_LIBC=LIBC_GLIBC"
++			default_libc=LIBC_GLIBC
+ 			# Force .init_array support.  The configure script cannot always
+ 			# automatically detect that GAS supports it, yet we require it.
+ 			gcc_cv_initfini_array=yes
+ 			;;
+ 		    csky-*-linux-uclibc*)
+-			tm_defines="$tm_defines DEFAULT_LIBC=LIBC_UCLIBC"
++			default_libc=LIBC_UCLIBC
+ 			default_use_cxa_atexit=no
+ 			;;
+ 		    *)
+@@ -3065,7 +3068,7 @@ powerpc*-wrs-vxworks7r*)
+ 	tmake_file="${tmake_file} t-linux rs6000/t-linux64 rs6000/t-fprules rs6000/t-ppccomm"
+ 	tmake_file="${tmake_file} rs6000/t-vxworks"
+ 
+-	tm_defines="$tm_defines DEFAULT_LIBC=LIBC_GLIBC"
++	default_libc=LIBC_GLIBC
+ 	extra_objs="$extra_objs linux.o rs6000-linux.o"
+ 	;;
+ powerpc-wrs-vxworks*)
+@@ -5915,3 +5918,32 @@ i[34567]86-*-* | x86_64-*-*)
+ 	fi
+ 	;;
+ esac
++
++case "${with_default_libc}" in
++glibc)
++    default_libc=LIBC_GLIBC
++    ;;
++uclibc)
++    default_libc=LIBC_UCLIBC
++    ;;
++bionic)
++    default_libc=LIBC_BIONIC
++    ;;
++musl)
++    default_libc=LIBC_MUSL
++    ;;
++"")
++    ;;
++*)
++    echo "Unknown libc in --with-default-libc=$with_default_libc" 1>&2
++    exit 1
++    ;;
++esac
++
++case "$default_libc" in
++"")
++        ;;
++*)
++	tm_defines="$tm_defines DEFAULT_LIBC=$default_libc"
++	;;
++esac
+diff --git a/gcc/configure.ac b/gcc/configure.ac
+index 23bee7010a3..4fd41993b58 100644
+--- a/gcc/configure.ac
++++ b/gcc/configure.ac
+@@ -2481,6 +2481,10 @@ if { { test x$host != x$target && test "x$with_sysroot" = x ; } ||
+ fi
+ AC_SUBST(inhibit_libc)
+ 
++AC_ARG_WITH(default-libc,
++	[AS_HELP_STRING([--with-default-libc],
++			[Use specified default C library])])
++
+ # When building gcc with a cross-compiler, we need to adjust things so
+ # that the generator programs are still built with the native compiler.
+ # Also, we cannot run fixincludes.
+-- 
+2.39.0
+
diff --git a/packages/gcc/12.2.0/0006-Add-newlib-and-picolibc-as-default-C-library-choices.patch b/packages/gcc/12.2.0/0006-Add-newlib-and-picolibc-as-default-C-library-choices.patch
new file mode 100644
index 00000000..e4805ae8
--- /dev/null
+++ b/packages/gcc/12.2.0/0006-Add-newlib-and-picolibc-as-default-C-library-choices.patch
@@ -0,0 +1,42 @@
+From 2e3918a283c1c9fb3b4775fe96a56e430748579a Mon Sep 17 00:00:00 2001
+From: Keith Packard <keithp@keithp.com>
+Date: Tue, 23 Aug 2022 22:12:06 -0700
+Subject: [PATCH 6/9] Add newlib and picolibc as default C library choices
+
+Signed-off-by: Keith Packard <keithp@keithp.com>
+---
+ gcc/config.gcc | 11 ++++++++++-
+ 1 file changed, 10 insertions(+), 1 deletion(-)
+
+diff --git a/gcc/config.gcc b/gcc/config.gcc
+index ddab68fbf8f..e294ff8fbc8 100644
+--- a/gcc/config.gcc
++++ b/gcc/config.gcc
+@@ -646,7 +646,7 @@ case ${target} in
+ esac
+ 
+ # Common C libraries.
+-tm_defines="$tm_defines LIBC_GLIBC=1 LIBC_UCLIBC=2 LIBC_BIONIC=3 LIBC_MUSL=4"
++tm_defines="$tm_defines LIBC_GLIBC=1 LIBC_UCLIBC=2 LIBC_BIONIC=3 LIBC_MUSL=4 LIBC_NEWLIB=5 LIBC_PICOLIBC=6"
+ 
+ default_libc=""
+ 
+@@ -5932,6 +5932,15 @@ bionic)
+ musl)
+     default_libc=LIBC_MUSL
+     ;;
++newlib)
++    # Newlib configurations don't set the DEFAULT_LIBC variable, so
++    # avoid changing those by allowing --with-default-libc=newlib but
++    # not actually setting the DEFAULT_LIBC variable.
++    default_libc=
++    ;;
++picolibc)
++    default_libc=LIBC_PICOLIBC
++    ;;
+ "")
+     ;;
+ *)
+-- 
+2.39.0
+
diff --git a/packages/gcc/12.2.0/0007-Support-picolibc-targets.patch b/packages/gcc/12.2.0/0007-Support-picolibc-targets.patch
new file mode 100644
index 00000000..01dbba87
--- /dev/null
+++ b/packages/gcc/12.2.0/0007-Support-picolibc-targets.patch
@@ -0,0 +1,38 @@
+From 41b20e994970f0ae63fb3f49c6f89a0b2f06aecb Mon Sep 17 00:00:00 2001
+From: Keith Packard <keithp@keithp.com>
+Date: Sun, 12 Feb 2023 14:23:32 -0800
+Subject: [PATCH 7/9] Support picolibc targets
+
+Match *-picolibc-* and select picolibc as the default C library, plus continuing to use
+the newlib-based logic for other configuration items.
+
+Signed-off-by: Keith Packard <keithp@keithp.com>
+---
+ gcc/config.gcc | 11 +++++++++++
+ 1 file changed, 11 insertions(+)
+
+diff --git a/gcc/config.gcc b/gcc/config.gcc
+index e294ff8fbc8..06af4057079 100644
+--- a/gcc/config.gcc
++++ b/gcc/config.gcc
+@@ -1082,6 +1082,17 @@ case ${target} in
+       ;;
+   esac
+   ;;
++*-picolibc-*)
++  # __cxa_atexit is provided.
++  default_use_cxa_atexit=yes
++  use_gcc_stdint=wrap
++  default_libc=LIBC_PICOLIBC
++  case "${with_newlib}-${with_headers}" in
++  no-no) use_gcc_stdint=provide ;;
++  *) ;;
++  esac
++  ;;
++
+ *-*-elf|arc*-*-elf*)
+   # Assume that newlib is being used and so __cxa_atexit is provided.
+   default_use_cxa_atexit=yes
+-- 
+2.39.0
+
diff --git a/packages/gcc/12.2.0/0008-gcc-Allow-g-to-work-differently-from-gcc.patch b/packages/gcc/12.2.0/0008-gcc-Allow-g-to-work-differently-from-gcc.patch
new file mode 100644
index 00000000..d84e52f3
--- /dev/null
+++ b/packages/gcc/12.2.0/0008-gcc-Allow-g-to-work-differently-from-gcc.patch
@@ -0,0 +1,68 @@
+From e426a20988185695675a2c456e0c24dcea515baf Mon Sep 17 00:00:00 2001
+From: Keith Packard <keithp@keithp.com>
+Date: Sat, 11 Feb 2023 23:07:08 -0800
+Subject: [PATCH 8/9] gcc: Allow g++ to work differently from gcc
+
+Compile gcc.cc with -DIN_GPP defined when building g++ so that the
+code can respond appropriately for the default target language. This
+allows the driver to customize the specs used, selecting different
+linker scripts, adjusting the use of crtbegin.o/crtend.o etc.
+
+By default, this change has no effect; targets need to explicitly
+check for IN_GPP to have alternate behavior.
+
+Signed-off-by: Keith Packard <keithp@keithp.com>
+---
+ gcc/cp/Make-lang.in |  7 ++++++-
+ gcc/gpp.cc          | 21 +++++++++++++++++++++
+ 2 files changed, 27 insertions(+), 1 deletion(-)
+ create mode 100644 gcc/gpp.cc
+
+diff --git a/gcc/cp/Make-lang.in b/gcc/cp/Make-lang.in
+index 2de4e47c659..39c659b9537 100644
+--- a/gcc/cp/Make-lang.in
++++ b/gcc/cp/Make-lang.in
+@@ -68,7 +68,12 @@ CFLAGS-cp/module.o += -DMODULE_VERSION='($(subst -,,$(MODULE_VERSION))U)'
+ endif
+ 
+ # Create the compiler driver for g++.
+-GXX_OBJS = $(GCC_OBJS) cp/g++spec.o
++GXX_OBJS = $(GCC_OBJS:gcc.o=gpp.o) cp/g++spec.o
++
++CFLAGS-gpp.o = $(CFLAGS-gcc.o)
++gpp.o: $(BASEVER)
++gpp.o: gcc.o
++
+ xg++$(exeext): $(GXX_OBJS) $(EXTRA_GCC_OBJS) libcommon-target.a $(LIBDEPS)
+ 	+$(LINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
+ 	  $(GXX_OBJS) $(EXTRA_GCC_OBJS) libcommon-target.a \
+diff --git a/gcc/gpp.cc b/gcc/gpp.cc
+new file mode 100644
+index 00000000000..3cd7b45e808
+--- /dev/null
++++ b/gcc/gpp.cc
+@@ -0,0 +1,21 @@
++/* Compiler driver program that can handle many languages.
++   Copyright (C) 1987-2022 Free Software Foundation, Inc.
++
++This file is part of GCC.
++
++GCC is free software; you can redistribute it and/or modify it under
++the terms of the GNU General Public License as published by the Free
++Software Foundation; either version 3, or (at your option) any later
++version.
++
++GCC is distributed in the hope that it will be useful, but WITHOUT ANY
++WARRANTY; without even the implied warranty of MERCHANTABILITY or
++FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
++for more details.
++
++You should have received a copy of the GNU General Public License
++along with GCC; see the file COPYING3.  If not see
++<http://www.gnu.org/licenses/>.  */
++
++#define IN_GPP
++#include "gcc.cc"
+-- 
+2.39.0
+
diff --git a/packages/gcc/12.2.0/0009-picolibc-Add-custom-spec-file-fragments-for-using-pi.patch b/packages/gcc/12.2.0/0009-picolibc-Add-custom-spec-file-fragments-for-using-pi.patch
new file mode 100644
index 00000000..0c4b90b5
--- /dev/null
+++ b/packages/gcc/12.2.0/0009-picolibc-Add-custom-spec-file-fragments-for-using-pi.patch
@@ -0,0 +1,138 @@
+From ad485aba918ea651987c6d153c2202a3efb5a75f Mon Sep 17 00:00:00 2001
+From: Keith Packard <keithp@keithp.com>
+Date: Tue, 23 Aug 2022 22:13:08 -0700
+Subject: [PATCH 9/9] picolibc: Add custom spec file fragments for using
+ picolibc
+
+The '--oslib=' option allows targets to insert an OS library after the
+C library in the LIB_PATH spec file fragment. This library maps a few
+POSIX APIs used by picolibc to underlying system capabilities.
+
+The '--crt0=' option allows targets to use an alternate crt0 in place
+of the usual one as provided by Picolibc.
+
+For example, picolibc provides 'libsemihost' and 'crt0-semihost.o' on
+various targets which maps some POSIX APIs to semihosting capabilities
+and signals the semihosting environment when 'main' returns. These
+would be used by specifying --oslib=semihost --crt0=semihost.
+
+This patch also takes advantage of the IN_GPP conditional when
+building g++ to elide exception handling contents from the executable
+when not linking with the g++ driver.
+
+Signed-off-by: Keith Packard <keithp@keithp.com>
+---
+ gcc/config.gcc          |  7 +++++++
+ gcc/config/picolibc.h   | 44 +++++++++++++++++++++++++++++++++++++++++
+ gcc/config/picolibc.opt | 33 +++++++++++++++++++++++++++++++
+ 3 files changed, 84 insertions(+)
+ create mode 100644 gcc/config/picolibc.h
+ create mode 100644 gcc/config/picolibc.opt
+
+diff --git a/gcc/config.gcc b/gcc/config.gcc
+index 06af4057079..94d53970ceb 100644
+--- a/gcc/config.gcc
++++ b/gcc/config.gcc
+@@ -5967,3 +5967,10 @@ case "$default_libc" in
+ 	tm_defines="$tm_defines DEFAULT_LIBC=$default_libc"
+ 	;;
+ esac
++
++case "$default_libc" in
++    LIBC_PICOLIBC)
++	extra_options="${extra_options} picolibc.opt"
++	tm_file="${tm_file} picolibc.h"
++	;;
++esac
+diff --git a/gcc/config/picolibc.h b/gcc/config/picolibc.h
+new file mode 100644
+index 00000000000..d1d3fc44477
+--- /dev/null
++++ b/gcc/config/picolibc.h
+@@ -0,0 +1,44 @@
++/* Configuration common to all targets running Picolibc.
++   Copyright (C) 2023 Free Software Foundation, Inc.
++
++   This file is part of GCC.
++
++   GCC is free software; you can redistribute it and/or modify it
++   under the terms of the GNU General Public License as published
++   by the Free Software Foundation; either version 3, or (at your
++   option) any later version.
++
++   GCC is distributed in the hope that it will be useful, but WITHOUT
++   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
++   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
++   License for more details.
++
++   Under Section 7 of GPL version 3, you are granted additional
++   permissions described in the GCC Runtime Library Exception, version
++   3.1, as published by the Free Software Foundation.
++
++   You should have received a copy of the GNU General Public License and
++   a copy of the GCC Runtime Library Exception along with this program;
++   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
++   <http://www.gnu.org/licenses/>.  */
++
++#ifdef IN_GPP
++#define PICOLIBC_LD "picolibcpp.ld"
++#define PICOLIBC_BEGIN " crtbegin%O%s"
++#define PICOLIBC_END   "crtend%O%s"
++#else
++#define PICOLIBC_LD "picolibc.ld"
++#define PICOLIBC_BEGIN ""
++#define PICOLIBC_END   ""
++#endif
++
++#undef  LIB_SPEC
++#define LIB_SPEC "%{!T:-T" PICOLIBC_LD "} --start-group -lc %{-oslib=*:-l%*} %(libgcc) --end-group"
++
++#undef  STARTFILE_SPEC
++#define STARTFILE_SPEC "%{-crt0=*:crt0-%*%O%s; :crt0%O%s}" PICOLIBC_BEGIN
++
++#undef  ENDFILE_SPEC
++#define ENDFILE_SPEC PICOLIBC_END
++
++#define EH_TABLES_CAN_BE_READ_ONLY 1
+diff --git a/gcc/config/picolibc.opt b/gcc/config/picolibc.opt
+new file mode 100644
+index 00000000000..39f81c446bb
+--- /dev/null
++++ b/gcc/config/picolibc.opt
+@@ -0,0 +1,33 @@
++; Processor-independent options for picolibc.
++;
++; Copyright (C) 2022 Free Software Foundation, Inc.
++;
++; This file is part of GCC.
++;
++; GCC is free software; you can redistribute it and/or modify it under
++; the terms of the GNU General Public License as published by the Free
++; Software Foundation; either version 3, or (at your option) any later
++; version.
++;
++; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
++; WARRANTY; without even the implied warranty of MERCHANTABILITY or
++; FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
++; for more details.
++;
++; You should have received a copy of the GNU General Public License
++; along with GCC; see the file COPYING3.  If not see
++; <http://www.gnu.org/licenses/>.
++
++-oslib
++Driver Separate Alias(-oslib=)
++
++-oslib=
++Driver Joined
++Specify an OS support library to load after libc.
++
++-crt0
++Driver Separate Alias(-crt0=)
++
++-crt0=
++Driver Joined
++Specify an alternate startup file.
+-- 
+2.39.0
+