[PATCH v7] Check global symbols in static library against shared library
H.J. Lu
hjl.tools@gmail.com
Fri May 24 23:35:15 GMT 2024
Here is the v7 patch to check global symbols in static library against
shared library. The test results may not be clean due to:
https://sourceware.org/bugzilla/show_bug.cgi?id=31776
H.J.
--
Changes in v7:
1. Remove --just-symbols since it was added only in binutils 2.37.
2. Fold archive-function.awk into check-static-abi.sh.
Changes in v6:
1. Drop __nldbl__IO_vfscanf libc-shared-only-symbols.
Changes in v5:
1. Move libc-shared-only-symbols referenced from libnldbl_nonshared.a to
sysdeps/ieee754/ldbl-opt/Makefile.
Changes in v4:
1. Use a per library shared-only-symbols.
2. Report extra functions with filenames in an archive.
Changes in v3:
1. Update the shared-only-symbols order in sysdeps/sparc/sparc32/Makefile.
Changes in v2:
1. Add export LC_ALL for nm.
2. Pass $* to check-static-abi.sh.
3. Don't pass $(static-only-symbols) to check-static-abi.sh.
4. Get installed static libraries from $(extra-libs).
5. Add shared-only-symbols for powerpc and sparc32.
---
The shared library ABIs are checked against the abilist files. Extract
global symbol definitions from static libraries and check them against
exported global symbol definitions in shared libraries. Special cases
are handled:
1. Some global symbols are available only in libc.so.
2. Some math functions are in libc.a, but not in libc.so.
3. The libgcc symbols are in libc.so only on some targets.
4. Internal symbols have global visibility only in the static library.
This check is enabled only if nm displays symbol versions for dynamic
symbols.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
---
Makerules | 71 ++++++++++++++++++
configure | 42 +++++++++++
configure.ac | 31 ++++++++
elf/Makefile | 15 ++++
math/Makefile | 4 +
scripts/check-static-abi.sh | 133 +++++++++++++++++++++++++++++++++
sysdeps/generic/Makefile | 11 +++
sysdeps/sparc/sparc32/Makefile | 12 +++
8 files changed, 319 insertions(+)
create mode 100644 scripts/check-static-abi.sh
diff --git a/Makerules b/Makerules
index 275110dda8..84046dbffc 100644
--- a/Makerules
+++ b/Makerules
@@ -1238,6 +1238,23 @@ ifeq ($(build-shared),yes)
LC_ALL=C $(OBJDUMP) --dynamic-syms $< > $@T
mv -f $@T $@
+# Extract global symbol definitions from shared and static libraries.
+NM-FLAGS=--extern-only --defined-only
+
+%.dynamicsymlist: %.so
+ LC_ALL=C; export LC_ALL; $(NM) --dynamic $(NM-FLAGS) $< \
+ | $(AWK) 'NF == 3 { print $$3 }' \
+ | grep -v "^_.*GLIBC_PRIVATE" | grep @@ | sed -e "s/@@.*//" \
+ | sort > $@T
+ mv -f $@T $@
+
+%.staticsymlist: %.a
+ LC_ALL=C; export LC_ALL; $(NM) $(NM-FLAGS) $< \
+ | $(AWK) 'NF == 3 { print $$3 }' \
+ | grep -v DW.ref.__gcc_personality_v0 \
+ | sort > $@T
+ mv -f $@T $@
+
vpath %.abilist $(+sysdep_dirs)
# The .PRECIOUS rule prevents the files built by an implicit rule whose
@@ -1246,6 +1263,16 @@ vpath %.abilist $(+sysdep_dirs)
# 'make clean', which is handled by the 'generated' variable.
.PRECIOUS: %.symlist
generated += $(extra-libs:=.symlist)
+ifeq (yes,$(nm-has-symbol-version))
+.PRECIOUS: %.dynamicsymlist %.staticsymlist
+# Only check global symbols in static libraries in $(extra-libs).
+static-libs := $(foreach lib, $(extra-libs), \
+ $(if $($(lib)-inhibit-o),,$(lib)))
+generated += \
+ $(static-libs:=.dynamicsymlist) \
+ $(static-libs:=.staticsymlist) \
+# generated
+endif
$(objpfx)check-abi-%.out: $(common-objpfx)config.make %.abilist \
$(objpfx)%.symlist
@@ -1259,6 +1286,24 @@ define check-abi
diff -p -U 0 $(filter %.abilist,$^) $(filter %.symlist,$^) > $@
endef
+$(objpfx)check-static-abi-%.out: $(common-objpfx)config.make \
+ $(objpfx)%.dynamicsymlist \
+ $(objpfx)%.staticsymlist
+ $(check-static-abi); \
+ $(evaluate-test)
+$(objpfx)check-static-abi-%.out: $(common-objpfx)config.make \
+ $(common-objpfx)%.dynamicsymlist \
+ $(common-objpfx)%.staticsymlist
+ $(check-static-abi); \
+ $(evaluate-test)
+define check-static-abi
+ $(SHELL) $(..)scripts/check-static-abi.sh $* \
+ $(subst elf/libc.a,libc.a,$(objpfx)$*.a) $(NM) $(AWK) \
+ $(filter %.dynamicsymlist,$^) \
+ $(filter %.staticsymlist,$^) \
+ "$($*-shared-only-symbols)" > $@
+endef
+
update-abi-%: $(objpfx)%.symlist %.abilist
$(update-abi)
update-abi-%: $(common-objpfx)%.symlist %.abilist
@@ -1290,6 +1335,11 @@ update-all-abi: $(patsubst %.so,update-all-abi-%,$(install-lib.so-versioned))
check-abi-list = $(patsubst %.so,$(objpfx)check-abi-%.out, \
$(install-lib.so-versioned))
check-abi: $(check-abi-list)
+ifeq (yes,$(nm-has-symbol-version))
+check-static-abi-list = $(patsubst %.a,$(objpfx)check-static-abi-%.out, \
+ $(static-libs:=.a))
+check-abi: $(check-static-abi-list)
+endif
ifdef subdir
subdir_check-abi: check-abi
subdir_update-abi: update-abi
@@ -1298,6 +1348,10 @@ else
check-abi: subdir_check-abi
if grep -q '^FAIL:' $(objpfx)*/check-abi*.test-result; then \
cat $(objpfx)*/check-abi*.out && exit 1; fi
+ifeq (yes,$(nm-has-symbol-version))
+ if grep -q '^FAIL:' $(objpfx)*/check-static-abi*.test-result; \
+ then cat $(objpfx)*/check-static-abi*.out && exit 1; fi
+endif
update-abi: subdir_update-abi
update-all-abi: subdir_update-all-abi
endif
@@ -1308,11 +1362,28 @@ tests-special += $(objpfx)check-abi-libc.out
update-abi: update-abi-libc
update-all-abi: update-all-abi-libc
common-generated += libc.symlist
+ifeq (yes,$(nm-has-symbol-version))
+check-abi: $(objpfx)check-static-abi-libc.out
+tests-special += $(objpfx)check-static-abi-libc.out
+common-generated += \
+ libc.dynamicsymlist \
+ libc.staticsymlist \
+ libc_nonshared.staticsymlist \
+ # common-generated
+# check-static-abi.sh needs libc_nonshared.staticsymlist and
+# libm.dynamicsymlist to check the global symbol list in libc.a.
+$(objpfx)check-static-abi-libc.out: \
+ $(common-objpfx)libc_nonshared.staticsymlist \
+ $(common-objpfx)math/libm.dynamicsymlist
+endif
endif
ifeq ($(build-shared),yes)
ifdef subdir
tests-special += $(check-abi-list)
+ifeq (yes,$(nm-has-symbol-version))
+tests-special += $(check-static-abi-list)
+endif
endif
endif
diff --git a/configure b/configure
index 432e40a592..11ac7c094a 100755
--- a/configure
+++ b/configure
@@ -7566,6 +7566,48 @@ if test "$libc_cv_symver_needs_alias" = yes; then
fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether nm displays symbol versions for dynamic symbols" >&5
+printf %s "checking whether nm displays symbol versions for dynamic symbols... " >&6; }
+if test ${libc_cv_nm_has_symbol_version+y}
+then :
+ printf %s "(cached) " >&6
+else $as_nop
+ cat > conftest.s <<EOF
+ .text
+ .globl new_foo
+ .type new_foo, %function
+new_foo:
+ .byte 0
+ .symver new_foo,foo@@VERS_2.0
+EOF
+ cat > conftest.t <<EOF
+VERS_2.0 {
+global:
+ foo;
+local:
+ *;
+};
+EOF
+ libc_cv_nm_has_symbol_version=no
+ if { ac_try='${CC-cc} -nostdlib -nostartfiles -fPIC -shared conftest.s -Wl,-version-script=conftest.t -o conftest.so'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; }; then
+ if $NM --dynamic --extern-only --defined-only conftest.so 2>&1 \
+ | grep -q foo@@VERS_2.0; then
+ libc_cv_nm_has_symbol_version=yes
+ fi
+ fi
+ rm conftest.*
+
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_nm_has_symbol_version" >&5
+printf "%s\n" "$libc_cv_nm_has_symbol_version" >&6; }
+config_vars="$config_vars
+nm-has-symbol-version = $libc_cv_nm_has_symbol_version"
+
{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for __builtin_trap with no external dependencies" >&5
printf %s "checking for __builtin_trap with no external dependencies... " >&6; }
if test ${libc_cv_builtin_trap+y}
diff --git a/configure.ac b/configure.ac
index bdc385d03c..e0ad986ae0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1554,6 +1554,37 @@ if test "$libc_cv_symver_needs_alias" = yes; then
AC_DEFINE(SYMVER_NEEDS_ALIAS)
fi
+dnl Starting with binutils 2.35, NM displays symbol versions for dynamic
+dnl symbols (PR 25708).
+AC_CACHE_CHECK(whether nm displays symbol versions for dynamic symbols,
+ libc_cv_nm_has_symbol_version, [dnl
+ cat > conftest.s <<EOF
+ .text
+ .globl new_foo
+ .type new_foo, %function
+new_foo:
+ .byte 0
+ .symver new_foo,foo@@VERS_2.0
+EOF
+ cat > conftest.t <<EOF
+VERS_2.0 {
+global:
+ foo;
+local:
+ *;
+};
+EOF
+ libc_cv_nm_has_symbol_version=no
+ if AC_TRY_COMMAND([${CC-cc} -nostdlib -nostartfiles -fPIC -shared conftest.s -Wl,-version-script=conftest.t -o conftest.so]); then
+ if $NM --dynamic --extern-only --defined-only conftest.so 2>&1 \
+ | grep -q foo@@VERS_2.0; then
+ libc_cv_nm_has_symbol_version=yes
+ fi
+ fi
+ rm conftest.*
+])
+LIBC_CONFIG_VAR([nm-has-symbol-version], [$libc_cv_nm_has_symbol_version])
+
AC_CACHE_CHECK(for __builtin_trap with no external dependencies,
libc_cv_builtin_trap, [dnl
libc_cv_builtin_trap=no
diff --git a/elf/Makefile b/elf/Makefile
index 280e777c19..eb4357a0dc 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -182,6 +182,21 @@ CFLAGS-rtld.os += $(rtld-early-cflags)
ifeq ($(unwind-find-fde),yes)
routines += unwind-dw2-fde-glibc
shared-only-routines += unwind-dw2-fde-glibc
+
+# These global symbols are only in libc.so.
+libc-shared-only-symbols += \
+ _Unwind_Find_FDE \
+ __deregister_frame \
+ __deregister_frame_info \
+ __deregister_frame_info_bases \
+ __register_frame \
+ __register_frame_info \
+ __register_frame_info_bases \
+ __register_frame_info_bases \
+ __register_frame_info_table \
+ __register_frame_info_table_bases \
+ __register_frame_table \
+# libc-shared-only-symbols
endif
before-compile += $(objpfx)trusted-dirs.h
diff --git a/math/Makefile b/math/Makefile
index 58e5c070cf..ae268e0088 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -1674,3 +1674,7 @@ object-suffixes-left := $(libmvec-tests)
include $(o-iterator)
$(objpfx)test-fenv-tls: $(shared-thread-library)
+
+# check-static-abi.sh needs libc.staticsymlist to check the global symbol
+# list in libm.a.
+$(objpfx)check-static-abi-libm.out: $(common-objpfx)libc.staticsymlist
diff --git a/scripts/check-static-abi.sh b/scripts/check-static-abi.sh
new file mode 100644
index 0000000000..72a198d481
--- /dev/null
+++ b/scripts/check-static-abi.sh
@@ -0,0 +1,133 @@
+#!/bin/sh
+# Check global symbols in static library against global symbols in shared
+# library.
+# Copyright (C) 2024 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <https://www.gnu.org/licenses/>.
+
+export LC_ALL=C
+
+lib="$1"
+shift
+archive="$1"
+shift
+nm="$1"
+shift
+awk="$1"
+shift
+dynamicsymlist="$1"
+shift
+if test $lib = libc; then
+ libm_dynamicsymlist="$1"
+ shift
+fi
+staticsymlist="$1"
+shift
+if test $lib = libc; then
+ libc_nonshared_staticsymlist="$1"
+ shift
+elif test $lib = libm; then
+ libc_staticsymlist="$1"
+ shift
+fi
+shared_only_functions="$1"
+
+staticdiff="$(mktemp)"
+staticlist="$(mktemp)"
+
+cleanup () {
+ rm -f -- "$staticdiff" "$staticlist"
+}
+
+trap cleanup 0
+
+status=0
+
+diff -up $dynamicsymlist $staticsymlist > $staticdiff
+
+# Check missing global symbols, including symbols with a leading
+# underscore, in static library.
+shared_only="$(grep '^-[^-]' $staticdiff | sed -e 's/^-//')"
+if test -n "$shared_only"; then
+ # Exclude shared only functions.
+ for f in $shared_only; do
+ case " $shared_only_functions " in
+ *" $f "*)
+ ;;
+ *)
+ # Skip the missing function, $f, in libm.a if $f is in libc.a.
+ if test $lib = libm \
+ && grep -q "^$f$" $libc_staticsymlist; then
+ continue
+ fi
+ missing="$missing $f"
+ ;;
+ esac
+ done
+ if test -n "$missing"; then
+ status=1
+ echo Missing functions in ${lib}.a:
+ echo "$missing"
+ fi
+fi
+
+# Check extra global symbols, excluding symbols with a leading underscore
+# which can be internal symbols, in static library.
+static_only="$(grep '^+[^_^\+]' $staticdiff | sed -e 's/^+//')"
+if test -n "$static_only"; then
+ # Exclude static only functions.
+ for f in $static_only; do
+ # Skip the extra function, $f, in libc.a if $f is in libc_nonshared.a
+ # or libm.so.
+ if test $lib = libc; then
+ if grep -q "^$f$" $libc_nonshared_staticsymlist \
+ || grep -q "^$f$" $libm_dynamicsymlist; then
+ continue
+ fi
+ fi
+ extra="$extra $f"
+ done
+ if test -n "$extra"; then
+ status=1
+ echo Extra functions in ${lib}.a:
+ $nm --extern-only --defined-only $archive > $staticlist 2>&1
+ $awk -v functions="$extra" \
+ ' \
+NF == 1 { \
+ thisfile = $1; \
+ filenames[$1] = 1; \
+ next; \
+} \
+NF == 3 { \
+ allsymbols[thisfile, $3] = 1; \
+ next; \
+} \
+END { \
+ split (functions, symbols, " "); \
+ for (s in symbols) { \
+ for (f in filenames) { \
+ if (allsymbols[f, symbols[s]] == 1) { \
+ print f, symbols[s];
+ } \
+ } \
+ } \
+} \
+ ' \
+ $staticlist
+ fi
+fi
+
+exit $status
diff --git a/sysdeps/generic/Makefile b/sysdeps/generic/Makefile
index 72522d1f0e..f24c517bbd 100644
--- a/sysdeps/generic/Makefile
+++ b/sysdeps/generic/Makefile
@@ -25,7 +25,18 @@ ifeq (yes:yes,$(build-shared):$(unwind-find-fde))
# This is needed to support g++ v2 and v3.
sysdep_routines += framestate unwind-pe
shared-only-routines += framestate unwind-pe
+
+# These global symbols are only in libc.so.
+libc-shared-only-symbols += __frame_state_for
endif
+
+# These global symbols are only in libc.so.
+libc-shared-only-symbols += \
+ __xmknod \
+ __xmknodat \
+ _dl_mcount_wrapper_check \
+ re_max_failures \
+# libc-shared-only-symbols
endif
ifeq ($(subdir),malloc)
diff --git a/sysdeps/sparc/sparc32/Makefile b/sysdeps/sparc/sparc32/Makefile
index 4ba8794aa0..154af1b8e1 100644
--- a/sysdeps/sparc/sparc32/Makefile
+++ b/sysdeps/sparc/sparc32/Makefile
@@ -15,6 +15,18 @@
# License along with the GNU C Library; if not, see
# <https://www.gnu.org/licenses/>.
+ifeq ($(subdir),elf)
+# These global symbols are only in libc.so. Filter out the
+# $(shared-only-routines) routines.
+libc-shared-only-symbols += \
+ .div \
+ .rem \
+ .udiv \
+ .umul \
+ .urem \
+ # libc-shared-only-symbols
+endif
+
ifeq ($(subdir),gnulib)
sysdep_routines = dotmul umul $(divrem) alloca
shared-only-routines += umul $(divrem)
--
2.45.1
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