diff options
| -rw-r--r-- | libc/Android.mk | 1 | ||||
| -rw-r--r-- | libc/arch-arm/bionic/libgcc_compat.c | 152 |
2 files changed, 153 insertions, 0 deletions
diff --git a/libc/Android.mk b/libc/Android.mk index 12d5c92..5718d18 100644 --- a/libc/Android.mk +++ b/libc/Android.mk @@ -288,6 +288,7 @@ libc_common_src_files += \ arch-arm/bionic/clone.S \ arch-arm/bionic/ffs.S \ arch-arm/bionic/kill.S \ + arch-arm/bionic/libgcc_compat.c \ arch-arm/bionic/tkill.S \ arch-arm/bionic/memcmp.S \ arch-arm/bionic/memcmp16.S \ diff --git a/libc/arch-arm/bionic/libgcc_compat.c b/libc/arch-arm/bionic/libgcc_compat.c new file mode 100644 index 0000000..886d025 --- /dev/null +++ b/libc/arch-arm/bionic/libgcc_compat.c @@ -0,0 +1,152 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* This file contains dummy references to libgcc.a functions to force the + * dynamic linker to copy their definition into the final libc.so binary. + * + * They are required to ensure backwards binary compatibility with + * Android 1.5 and Android 1.6 system images. Some applications built + * using the NDK require them to be here. + * + * Now, for a more elaborate description of the issue: + * + * libgcc.a is a compiler-specific library containing various helper + * functions used to implement certain operations that are not necessarily + * supported by the target CPU. For example, integer division doesn't have a + * corresponding CPU instruction on ARMv5, and is instead implemented in the + * compiler-generated machine code as a call to an __idiv helper function. + * + * Normally, one has to place libgcc.a in the link command used to generate + * target binaries (shared libraries and executables) after all objects and + * static libraries, but before dependent shared libraries, i.e. something + * like: + * gcc <options> -o libfoo.so foo.a libgcc.a -lc -lm + * + * This ensures that any helper function needed by the code in foo.a is copied + * into the final libfoo.so. Unfortunately, the Android build system has been + * using this instead: + * + * gcc <options> -o libfoo.so foo.a -lc -lm libgcc.a + * + * The problem with this is that if one helper function needed by foo.a has + * already been copied into libc.so or libm.so, then nothing will be copied + * into libfoo.so. Instead, a symbol import definition will be added to it + * so libfoo.so can directly call the one in libc.so at runtime. + * + * When changing toolchains for 2.0, the set of helper functions copied to + * libc.so changed, which resulted in some native shared libraries generated + * with the NDK to fail to load properly. + * + * The NDK has been fixed after 1.6_r1 to use the correct link command, so + * any native shared library generated with it should now be safe from that + * problem. On the other hand, existing shared libraries distributed with + * applications that were generated with a previous version of the NDK + * still need all 1.5/1.6 helper functions in libc.so and libn.so + * + * Final note: some of the functions below should really be in libm.so to + * completely reflect the state of 1.5/1.6 system images. However, + * since libm.so depends on libc.so, it's easier to put all of + * these in libc.so instead, since the dynamic linker will always + * search in libc.so before libm.so for dependencies. + */ + +#define COMPAT_FUNCTIONS_LIST \ + XX(__adddf3) \ + XX(__addsf3) \ + XX(__aeabi_cdcmpeq) \ + XX(__aeabi_cdcmple) \ + XX(__aeabi_cdrcmple) \ + XX(__aeabi_d2f) \ + XX(__aeabi_d2iz) \ + XX(__aeabi_dadd) \ + XX(__aeabi_dcmpeq) \ + XX(__aeabi_dcmpge) \ + XX(__aeabi_dcmpgt) \ + XX(__aeabi_dcmple) \ + XX(__aeabi_dcmplt) \ + XX(__aeabi_dcmpun) \ + XX(__aeabi_ddiv) \ + XX(__aeabi_dmul) \ + XX(__aeabi_drsub) \ + XX(__aeabi_dsub) \ + XX(__aeabi_f2d) \ + XX(__aeabi_f2iz) \ + XX(__aeabi_fadd) \ + XX(__aeabi_fcmpun) \ + XX(__aeabi_fdiv) \ + XX(__aeabi_fmul) \ + XX(__aeabi_frsub) \ + XX(__aeabi_fsub) \ + XX(__aeabi_i2d) \ + XX(__aeabi_i2f) \ + XX(__aeabi_l2d) \ + XX(__aeabi_l2f) \ + XX(__aeabi_lmul) \ + XX(__aeabi_ui2d) \ + XX(__aeabi_ui2f) \ + XX(__aeabi_ul2d) \ + XX(__aeabi_ul2f) \ + XX(__cmpdf2) \ + XX(__divdf3) \ + XX(__divsf3) \ + XX(__eqdf2) \ + XX(__extendsfdf2) \ + XX(__fixdfsi) \ + XX(__fixsfsi) \ + XX(__floatdidf) \ + XX(__floatdisf) \ + XX(__floatsidf) \ + XX(__floatsisf) \ + XX(__floatundidf) \ + XX(__floatundisf) \ + XX(__floatunsidf) \ + XX(__floatunsisf) \ + XX(__gedf2) \ + XX(__gtdf2) \ + XX(__ledf2) \ + XX(__ltdf2) \ + XX(__muldf3) \ + XX(__muldi3) \ + XX(__mulsf3) \ + XX(__nedf2) \ + XX(__subdf3) \ + XX(__subsf3) \ + XX(__truncdfsf2) \ + XX(__unorddf2) \ + XX(__unordsf2) \ + +#define XX(f) extern void f(void); +COMPAT_FUNCTIONS_LIST +#undef XX + +void __bionic_libgcc_compat_hooks(void) +{ +#define XX(f) f(); +COMPAT_FUNCTIONS_LIST +#undef XX +} |