From 43f50793826918f78b79d2e8197da4e58bdf6748 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Thu, 7 Jan 2021 17:25:32 -0800 Subject: [PATCH] gcc: Add support for building libstdc++ with alternate libc This adds another mode to do_gcc_core_backend that builds libstdc++ against an alternate libc implementation. Signed-off-by: Keith Packard --- config/cc/gcc.in | 2 +- .../10.2.0/0019-libstdcxx-pure-stdio.patch | 275 ++++++++++++++++++ scripts/build/cc/gcc.sh | 84 +++++- 3 files changed, 353 insertions(+), 8 deletions(-) create mode 100644 packages/gcc/10.2.0/0019-libstdcxx-pure-stdio.patch diff --git a/config/cc/gcc.in b/config/cc/gcc.in index 849b1ad0..9d9b6921 100644 --- a/config/cc/gcc.in +++ b/config/cc/gcc.in @@ -1,6 +1,6 @@ # GCC options -## select CC_SUPPORT_CXX if !LIBC_NONE +## select CC_SUPPORT_CXX ## select CC_SUPPORT_FORTRAN ## select CC_SUPPORT_JAVA if !GCC_7_or_later && OBSOLETE ## select CC_SUPPORT_ADA diff --git a/packages/gcc/10.2.0/0019-libstdcxx-pure-stdio.patch b/packages/gcc/10.2.0/0019-libstdcxx-pure-stdio.patch new file mode 100644 index 00000000..da92ba3f --- /dev/null +++ b/packages/gcc/10.2.0/0019-libstdcxx-pure-stdio.patch @@ -0,0 +1,275 @@ +From ce06ad6901b1d24abb90d6baba5fe01c750ffb4e Mon Sep 17 00:00:00 2001 +From: Keith Packard +Date: Tue, 15 Dec 2020 17:39:24 +0000 +Subject: [PATCH] libstdc++: Support libc with stdio-only I/O in libstdc++ + +The current libstdc++ basic_file_stdio.cc code assumes a POSIX API +underneath the stdio implementation provided by the host libc. This +means that the host must provide a fairly broad POSIX file API, +including read, write, open, close, lseek and ioctl. + +This patch changes basic_file_stdio.cc to only use basic ANSI-C stdio +functions, allowing it to be used with libc implementations like +picolibc which may not have a POSIX operating system underneath. + +This is enabled by a new --enable-cstdio=stdio_pure configure option. + +Aided-by: Jonathan Wakely +Signed-off-by: Keith Packard + +libstdc++-v3/ChangeLog: + + * acinclude.m4 (GLIBCXX_ENABLE_CSTDIO): Allow "stdio_pure" + option and define _GLIBCXX_USE_PURE_STDIO when it is used. Also + add "stdio_posix" option as an alias for "stdio". + * config/io/basic_file_stdio.cc [_GLIBCXX_USE_PURE_STDIO]: Only + use defined stdio entry points for all I/O operations, without + direct calls to underlying POSIX functions. + * config.h.in: Regenerate. + * configure: Regenerate. +--- + libstdc++-v3/acinclude.m4 | 20 ++++++---- + libstdc++-v3/config.h.in | 3 ++ + libstdc++-v3/config/io/basic_file_stdio.cc | 46 +++++++++++++++++++--- + libstdc++-v3/configure | 17 +++++--- + 4 files changed, 69 insertions(+), 17 deletions(-) + +diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4 +index ee5e0336f2c..9604533c306 100644 +--- a/libstdc++-v3/acinclude.m4 ++++ b/libstdc++-v3/acinclude.m4 +@@ -2826,24 +2826,30 @@ AC_DEFUN([GLIBCXX_ENABLE_PARALLEL], [ + + + dnl +-dnl Check for which I/O library to use: stdio, or something specific. ++dnl Check for which I/O library to use: stdio and POSIX, or pure stdio. + dnl +-dnl Default is stdio. ++dnl Default is stdio_posix. + dnl + AC_DEFUN([GLIBCXX_ENABLE_CSTDIO], [ + AC_MSG_CHECKING([for underlying I/O to use]) + GLIBCXX_ENABLE(cstdio,stdio,[[[=PACKAGE]]], +- [use target-specific I/O package], [permit stdio]) ++ [use target-specific I/O package], [permit stdio|stdio_posix|stdio_pure]) + +- # Now that libio has been removed, you can have any color you want as long +- # as it's black. This is one big no-op until other packages are added, but +- # showing the framework never hurts. ++ # The only available I/O model is based on stdio, via basic_file_stdio. ++ # The default "stdio" is actually "stdio + POSIX" because it uses fdopen(3) ++ # to get a file descriptor and then uses read(3) and write(3) with it. ++ # The "stdio_pure" model doesn't use fdopen and only uses FILE* for I/O. + case ${enable_cstdio} in +- stdio) ++ stdio*) + CSTDIO_H=config/io/c_io_stdio.h + BASIC_FILE_H=config/io/basic_file_stdio.h + BASIC_FILE_CC=config/io/basic_file_stdio.cc + AC_MSG_RESULT(stdio) ++ ++ if test "x$enable_cstdio" = "xstdio_pure" ; then ++ AC_DEFINE(_GLIBCXX_USE_STDIO_PURE, 1, ++ [Define to restrict std::__basic_file<> to stdio APIs.]) ++ fi + ;; + esac + +diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in +index 8940e0c7acd..eabcf18b52b 100644 +--- a/libstdc++-v3/config.h.in ++++ b/libstdc++-v3/config.h.in +@@ -1031,6 +1031,9 @@ + /* Define if sendfile is available in . */ + #undef _GLIBCXX_USE_SENDFILE + ++/* Define to restrict std::__basic_file<> to stdio APIs. */ ++#undef _GLIBCXX_USE_STDIO_PURE ++ + /* Define if struct stat has timespec members. */ + #undef _GLIBCXX_USE_ST_MTIM + +diff --git a/libstdc++-v3/config/io/basic_file_stdio.cc b/libstdc++-v3/config/io/basic_file_stdio.cc +index ba830fb9e97..eedffb017b6 100644 +--- a/libstdc++-v3/config/io/basic_file_stdio.cc ++++ b/libstdc++-v3/config/io/basic_file_stdio.cc +@@ -111,13 +111,21 @@ namespace + + // Wrapper handling partial write. + static std::streamsize ++#ifdef _GLIBCXX_USE_STDIO_PURE ++ xwrite(FILE *__file, const char* __s, std::streamsize __n) ++#else + xwrite(int __fd, const char* __s, std::streamsize __n) ++#endif + { + std::streamsize __nleft = __n; + + for (;;) + { ++#ifdef _GLIBCXX_USE_STDIO_PURE ++ const std::streamsize __ret = fwrite(__file, 1, __nleft, __file); ++#else + const std::streamsize __ret = write(__fd, __s, __nleft); ++#endif + if (__ret == -1L && errno == EINTR) + continue; + if (__ret == -1L) +@@ -133,7 +141,7 @@ namespace + return __n - __nleft; + } + +-#ifdef _GLIBCXX_HAVE_WRITEV ++#if defined(_GLIBCXX_HAVE_WRITEV) && !defined(_GLIBCXX_USE_STDIO_PURE) + // Wrapper handling partial writev. + static std::streamsize + xwritev(int __fd, const char* __s1, std::streamsize __n1, +@@ -286,9 +294,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION + __basic_file::is_open() const throw () + { return _M_cfile != 0; } + ++#ifndef _GLIBCCXX_USE_STDIO_PURE + int + __basic_file::fd() throw () + { return fileno(_M_cfile); } ++#endif + + __c_file* + __basic_file::file() throw () +@@ -315,28 +325,46 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION + { + streamsize __ret; + do ++#ifdef _GLIBCXX_USE_STDIO_PURE ++ __ret = fread(__s, 1, __n, this->file()); ++#else + __ret = read(this->fd(), __s, __n); ++#endif + while (__ret == -1L && errno == EINTR); + return __ret; + } + + streamsize + __basic_file::xsputn(const char* __s, streamsize __n) +- { return xwrite(this->fd(), __s, __n); } ++ { ++#ifdef _GLIBCXX_USE_STDIO_PURE ++ return xwrite(this->file(), __s, __n); ++#else ++ return xwrite(this->fd(), __s, __n); ++#endif ++ } + + streamsize + __basic_file::xsputn_2(const char* __s1, streamsize __n1, + const char* __s2, streamsize __n2) + { + streamsize __ret = 0; +-#ifdef _GLIBCXX_HAVE_WRITEV ++#if defined(_GLIBCXX_HAVE_WRITEV) && !defined(_GLIBCXX_USE_STDIO_PURE) + __ret = xwritev(this->fd(), __s1, __n1, __s2, __n2); + #else + if (__n1) ++#ifdef _GLIBCXX_USE_STDIO_PURE ++ __ret = xwrite(this->file(), __s1, __n1); ++#else + __ret = xwrite(this->fd(), __s1, __n1); ++#endif + + if (__ret == __n1) ++#ifdef _GLIBCXX_USE_STDIO_PURE ++ __ret += xwrite(this->file(), __s2, __n2); ++#else + __ret += xwrite(this->fd(), __s2, __n2); ++#endif + #endif + return __ret; + } +@@ -350,7 +378,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION + if (__off > numeric_limits::max() + || __off < numeric_limits::min()) + return -1L; ++#ifdef _GLIBCXX_USE_STDIO_PURE ++ return fseek(this->file(), __off, __way); ++#else + return lseek(this->fd(), __off, __way); ++#endif + #endif + } + +@@ -361,7 +393,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION + streamsize + __basic_file::showmanyc() + { +-#ifndef _GLIBCXX_NO_IOCTL ++#if !defined(_GLIBCXX_NO_IOCTL) && !defined(_GLIBCXX_USE_STDIO_PURE) + #ifdef FIONREAD + // Pipes and sockets. + int __num = 0; +@@ -371,7 +403,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION + #endif + #endif + +-#ifdef _GLIBCXX_HAVE_POLL ++#if defined(_GLIBCXX_HAVE_POLL) && !defined(_GLIBCXX_USE_STDIO_PURE) + // Cheap test. + struct pollfd __pfd[1]; + __pfd[0].fd = this->fd(); +@@ -395,8 +427,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION + struct stat __buffer; + const int __err = fstat(this->fd(), &__buffer); + if (!__err && _GLIBCXX_ISREG(__buffer.st_mode)) ++#ifdef _GLIBCXX_USE_STDIO_PURE ++ return __buffer.st_size - fseek(this->file(), 0, ios_base::cur); ++#else + return __buffer.st_size - lseek(this->fd(), 0, ios_base::cur); + #endif ++#endif + #endif + return 0; + } +diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure +index 9f9c5a2419a..50c8f00a41c 100755 +--- a/libstdc++-v3/configure ++++ b/libstdc++-v3/configure +@@ -16299,7 +16299,7 @@ $as_echo_n "checking for underlying I/O to use... " >&6; } + if test "${enable_cstdio+set}" = set; then : + enableval=$enable_cstdio; + case "$enableval" in +- stdio) ;; ++ stdio|stdio_posix|stdio_pure) ;; + *) as_fn_error $? "Unknown argument to enable/disable cstdio" "$LINENO" 5 ;; + esac + +@@ -16309,16 +16309,23 @@ fi + + + +- # Now that libio has been removed, you can have any color you want as long +- # as it's black. This is one big no-op until other packages are added, but +- # showing the framework never hurts. ++ # The only available I/O model is based on stdio, via basic_file_stdio. ++ # The default "stdio" is actually "stdio + POSIX" because it uses fdopen(3) ++ # to get a file descriptor and then uses read(3) and write(3) with it. ++ # The "stdio_pure" model doesn't use fdopen and only uses FILE* for I/O. + case ${enable_cstdio} in +- stdio) ++ stdio*) + CSTDIO_H=config/io/c_io_stdio.h + BASIC_FILE_H=config/io/basic_file_stdio.h + BASIC_FILE_CC=config/io/basic_file_stdio.cc + { $as_echo "$as_me:${as_lineno-$LINENO}: result: stdio" >&5 + $as_echo "stdio" >&6; } ++ ++ if test "x$enable_cstdio" = "xstdio_pure" ; then ++ ++$as_echo "#define _GLIBCXX_USE_STDIO_PURE 1" >>confdefs.h ++ ++ fi + ;; + esac + +-- +2.29.2 + diff --git a/scripts/build/cc/gcc.sh b/scripts/build/cc/gcc.sh index 3d4db35b..1ad1db5e 100644 --- a/scripts/build/cc/gcc.sh +++ b/scripts/build/cc/gcc.sh @@ -279,7 +279,8 @@ do_cc_core_pass_2() { # build_manuals : whether to build manuals or not : bool : no # cflags : cflags to use : string : (empty) # ldflags : ldflags to use : string : (empty) -# build_step : build step 'core1', 'core2', 'gcc_build' +# build_step : build step 'core1', 'core2', 'gcc_build', +# 'libstdcxx' # or 'gcc_host' : string : (none) # Usage: do_gcc_core_backend mode=[static|shared|baremetal] build_libgcc=[yes|no] build_staticlinked=[yes|no] do_gcc_core_backend() { @@ -291,6 +292,7 @@ do_gcc_core_backend() { local build_manuals=no local host local prefix + local enable_optspace local complibs local lang_list local cflags cflags_for_build cflags_for_target @@ -298,6 +300,9 @@ do_gcc_core_backend() { local build_step local log_txt local tmp + local exec_prefix + local header_dir + local libstdcxx_name local -a host_libstdcxx_flags local -a extra_config local -a core_LDFLAGS @@ -327,11 +332,30 @@ do_gcc_core_backend() { # to inhibit the libiberty and libgcc tricks later on build_libgcc=no ;; + libstdcxx) + CT_DoLog EXTRA "Configuring libstdc++ for ${libstdcxx_name}" + if [ "${header_dir}" = "" ]; then + header_dir="${CT_PREFIX_DIR}/${libstdcxx_name}/include" + fi + if [ "${exec_prefix}" = "" ]; then + exec_prefix="${CT_PREFIX_DIR}/${libstdcxx_name}" + fi + extra_config+=( "${CT_CC_SYSROOT_ARG[@]}" ) + extra_config+=( "--with-headers=${header_dir}" ) + extra_user_config=( "${CT_CC_GCC_EXTRA_CONFIG_ARRAY[@]}" ) + log_txt="libstdc++ ${libstdcxx_name} library" + # to inhibit the libiberty and libgcc tricks later on + build_libgcc=no + ;; *) - CT_Abort "Internal Error: 'build_step' must be one of: 'core1', 'core2', 'gcc_build' or 'gcc_host', not '${build_step:-(empty)}'" + CT_Abort "Internal Error: 'build_step' must be one of: 'core1', 'core2', 'gcc_build', 'gcc_host' or 'libstdcxx', not '${build_step:-(empty)}'" ;; esac + if [ "${exec_prefix}" = "" ]; then + exec_prefix="${prefix}" + fi + case "${mode}" in static) extra_config+=("--with-newlib") @@ -389,6 +413,10 @@ do_gcc_core_backend() { extra_config+=(--disable-libquadmath-support) fi + if [ "${build_libstdcxx}" = "no" ]; then + extra_config+=(--disable-libstdcxx) + fi + core_LDFLAGS+=("${ldflags}") # *** WARNING ! *** @@ -447,7 +475,8 @@ do_gcc_core_backend() { extra_config+=("--with-host-libstdcxx=${host_libstdcxx_flags[*]}") fi - if [ "${CT_CC_GCC_ENABLE_TARGET_OPTSPACE}" = "y" ]; then + if [ "${CT_CC_GCC_ENABLE_TARGET_OPTSPACE}" = "y" ] || \ + [ "${enable_optspace}" = "yes" ]; then extra_config+=("--enable-target-optspace") fi if [ "${CT_CC_GCC_DISABLE_PCH}" = "y" ]; then @@ -595,6 +624,7 @@ do_gcc_core_backend() { --host=${host} \ --target=${CT_TARGET} \ --prefix="${prefix}" \ + --exec_prefix="${exec_prefix}" \ --with-local-prefix="${CT_SYSROOT_DIR}" \ "${extra_config[@]}" \ --enable-languages="${lang_list}" \ @@ -678,6 +708,11 @@ do_gcc_core_backend() { core_targets_all=all core_targets_install=install ;; + libstdcxx) + core_targets=( target-libstdc++-v3 ) + core_targets_all="${core_targets[@]/#/all-}" + core_targets_install="${core_targets[@]/#/install-}" + ;; esac CT_DoLog EXTRA "Building ${log_txt}" @@ -754,7 +789,9 @@ do_cc_for_build() { # lack of such a compiler, but better safe than sorry... build_final_opts+=( "mode=baremetal" ) build_final_opts+=( "build_libgcc=yes" ) - build_final_opts+=( "build_libstdcxx=yes" ) + if [ "${CT_LIBC_NONE}" != "y" ]; then + build_final_opts+=( "build_libstdcxx=yes" ) + fi build_final_opts+=( "build_libgfortran=yes" ) if [ "${CT_STATIC_TOOLCHAIN}" = "y" ]; then build_final_opts+=( "build_staticlinked=yes" ) @@ -843,7 +880,9 @@ do_cc_for_host() { if [ "${CT_BARE_METAL}" = "y" ]; then final_opts+=( "mode=baremetal" ) final_opts+=( "build_libgcc=yes" ) - final_opts+=( "build_libstdcxx=yes" ) + if [ "${CT_LIBC_NONE}" != "y" ]; then + final_opts+=( "build_libstdcxx=yes" ) + fi final_opts+=( "build_libgfortran=yes" ) if [ "${CT_STATIC_TOOLCHAIN}" = "y" ]; then final_opts+=( "build_staticlinked=yes" ) @@ -876,20 +915,27 @@ do_cc_for_host() { # Parameter : Definition : Type : Default # host : the host we run onto : tuple : (none) # prefix : the runtime prefix : dir : (none) +# exec_prefix : prefix for executables : dir : (none) # complibs : the companion libraries prefix : dir : (none) # cflags : cflags to use : string : (empty) # ldflags : ldflags to use : string : (empty) # lang_list : the list of languages to build : string : (empty) # build_manuals : whether to build manuals or not : bool : no +# build_step : build step 'gcc_build', 'gcc_host' +# or 'libstdcxx' : string : (none) do_gcc_backend() { local host local prefix + local exec_prefix local complibs local lang_list local cflags local cflags_for_build local ldflags local build_manuals + local exec_prefix + local header_dir + local libstdcxx_name local -a host_libstdcxx_flags local -a extra_config local -a final_LDFLAGS @@ -900,7 +946,24 @@ do_gcc_backend() { eval "${arg// /\\ }" done - CT_DoLog EXTRA "Configuring final gcc compiler" + if [ "${exec_prefix}" = "" ]; then + exec_prefix="${prefix}" + fi + + # This function gets called for final gcc and libstdcxx. + case "${build_step}" in + gcc_build|gcc_host) + log_txt="final gcc compiler" + ;; + libstdcxx) + log_txt="libstdc++ library for ${libstdcxx_name}" + ;; + *) + CT_Abort "Internal Error: 'build_step' must be one of: 'gcc_build', 'gcc_host' or 'libstdcxx', not '${build_step:-(empty)}'" + ;; + esac + + CT_DoLog EXTRA "Configuring ${log_txt}" # Enable selected languages extra_config+=("--enable-languages=${lang_list}") @@ -974,6 +1037,10 @@ do_gcc_backend() { fi fi + if [ "${build_libstdcxx}" = "no" ]; then + extra_config+=(--disable-libstdcxx) + fi + final_LDFLAGS+=("${ldflags}") # *** WARNING ! *** @@ -1043,9 +1110,11 @@ do_gcc_backend() { fi fi - if [ "${CT_CC_GCC_ENABLE_TARGET_OPTSPACE}" = "y" ]; then + if [ "${CT_CC_GCC_ENABLE_TARGET_OPTSPACE}" = "y" ] || \ + [ "${enable_optspace}" = "yes" ]; then extra_config+=("--enable-target-optspace") fi + if [ "${CT_CC_GCC_DISABLE_PCH}" = "y" ]; then extra_config+=("--disable-libstdcxx-pch") fi @@ -1161,6 +1230,7 @@ do_gcc_backend() { --host=${host} \ --target=${CT_TARGET} \ --prefix="${prefix}" \ + --exec_prefix="${exec_prefix}" \ ${CT_CC_SYSROOT_ARG} \ "${extra_config[@]}" \ --with-local-prefix="${CT_SYSROOT_DIR}" \