Steven Bosscher <stevenb....@gmail.com> writes: > Therefore, an RFA for the attached patch. Bootstrapped&tested on > powerpc64-unknown-linux-gnu. OK?
Unfortunately, this patch completely broke libjava testing on i386-pc-solaris2* and x86_64-unknown-linux-gnu: all execution tests fail with a SEGV: Program received signal SIGSEGV, Segmentation fault. 0xfd0ddf7d in _Jv_Linker::verify_class (klass=klass@entry=0xfe945d80) at /vol/gcc/src/hg/trunk/local/libjava/link.cc:1904 1904 klass->engine->verify(klass); klass->engine is NULL at this point. Checking the generated .jcr sections, I found that a large number of them have sh_addralign 0x20 instead of 0x4 before your patch. This caused a massive reduction in the number of _Jv_RegisterClassHookDefault calls: With the following DTrace one-liner pid$target::_Jv_RegisterClassHookDefault:entry{ @[ustack()] = count(); } to investigate ArrayStore.exe execution, I find for the unpatched jc1: libgcj.so.13.0.0`_Jv_RegisterClassHookDefault libgcj.so.13.0.0`_Jv_RegisterClasses+0x44 libgcj.so.13.0.0`_ZN4java4lang9Cloneable6class$E 0xe0ec 7213 With your patch, I get libgcj.so.13.0.0`_Jv_RegisterClassHookDefault libgcj.so.13.0.0`_Jv_RegisterNewClasses+0xb7 ArrayStore.exe`_Utf18 1 libgcj.so.13.0.0`_Jv_RegisterClassHookDefault libgcj.so.13.0.0`_Jv_RegisterClasses+0x44 libgcj.so.13.0.0`_ZN4java4lang9Cloneable6class$E 0xe0ec 12 instead. The alignment change happens because LOCAL_ALIGNMENT overrides DECL_ALIGN. This can be avoided by setting DECL_USER_ALIGN (which unfortunately is undocumented). The result looks better, but still fails in a different way: Exception in thread "main" java.lang.NoClassDefFoundError: ArrayStore at java.lang.Class.initializeClass(libgcj.so.13.0.0) Caused by: java.lang.NullPointerException at java.lang.Class.initializeClass(libgcj.so.13.0.0) But the _Jv_RegisterClassHookDefault are almost back to normal: libgcj.so.13.0.0`_Jv_RegisterClassHookDefault libgcj.so.13.0.0`_Jv_RegisterClasses+0x44 libgcj.so.13.0.0`_ZN4java4lang9Cloneable6class$E 0xe0ec 7212 I could trace this to a change in .jcr section flags: in ArrayStore.exe, I find Section Header[18]: sh_name: .jcr sh_addr: 0x8052058 sh_flags: [ SHF_ALLOC ] sh_size: 0x4 sh_type: [ SHT_PROGBITS ] sh_offset: 0x2058 sh_entsize: 0 sh_link: 0 sh_info: 0 sh_addralign: 0x4 Section Header[26]: sh_name: .jcr sh_addr: 0x80625e4 sh_flags: [ SHF_WRITE SHF_ALLOC ] sh_size: 0x4 sh_type: [ SHT_PROGBITS ] sh_offset: 0x25e4 sh_entsize: 0 sh_link: 0 sh_info: 0 sh_addralign: 0x4 The first (without SHF_WRITE set) is from jc1, the second from crtbegin.o. The Solaris linker (and probably other ELF linkers which don't special-case .jcr) merges sections not just by name, but only if name and attributs (flags, type) match. Not marking .jcr read-only fixes that part of the failure and restores libjava testsuite results on Solaris 11/x86 back to normal (no failures). Bootstrapped without regressions on i386-pc-solaris2.11. Ok for mainline? Rainer 2012-03-31 Rainer Orth <r...@cebitec.uni-bielefeld.de> * class.c (emit_register_classes_in_jcr_section): Set DECL_USER_ALIGN. Clear TREE_READONLY.
# HG changeset patch # Parent ae1fe58e699b5ec26f0ad31675d3915eef63d963 Fix .jcr alignment diff --git a/gcc/java/class.c b/gcc/java/class.c --- a/gcc/java/class.c +++ b/gcc/java/class.c @@ -2815,10 +2815,11 @@ emit_register_classes_in_jcr_section (vo DECL_SECTION_NAME (cdecl) = build_string (strlen (JCR_SECTION_NAME), JCR_SECTION_NAME); DECL_ALIGN (cdecl) = POINTER_SIZE; + DECL_USER_ALIGN (cdecl) = 1; DECL_INITIAL (cdecl) = build_constructor (class_array_type, init); TREE_CONSTANT (DECL_INITIAL (cdecl)) = 1; TREE_STATIC (cdecl) = 1; - TREE_READONLY (cdecl) = 1; + TREE_READONLY (cdecl) = 0; TREE_CONSTANT (cdecl) = 1; DECL_ARTIFICIAL (cdecl) = 1; DECL_IGNORED_P (cdecl) = 1;
-- ----------------------------------------------------------------------------- Rainer Orth, Center for Biotechnology, Bielefeld University