From 0e6a3f07f50723d1831291492b96fdf74bcbdc11 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 22 Jul 2020 03:49:07 -0700 Subject: [PATCH] ld: Properly override the IR definition We change the previous definition in the IR object to undefweak only after all LTO symbols have been read. include/ PR ld/26262 PR ld/26267 * bfdlink.h (bfd_link_info): Add lto_all_symbols_read. ld/ PR ld/26262 PR ld/26267 * ldlang.c (lang_process): Set lto_all_symbols_read after all LTO IR symbols have been read. * plugin.c (plugin_notice): Override the IR definition only if all LTO IR symbols have been read or the new definition is non-weak and the the IR definition is weak * testsuite/ld-plugin/lto.exp: Run PR ld/26262 and ld/26267 tests. * testsuite/ld-plugin/pr26262a.c: New file. * testsuite/ld-plugin/pr26262b.c: Likewise. * testsuite/ld-plugin/pr26262c.c: Likewise. * testsuite/ld-plugin/pr26267.err: Likewise. * testsuite/ld-plugin/pr26267a.c: Likewise. * testsuite/ld-plugin/pr26267b.c: Likewise. * testsuite/ld-plugin/pr26267c.c: Likewise. --- include/ChangeLog | 6 +++++ include/bfdlink.h | 3 +++ ld/ChangeLog | 19 ++++++++++++++ ld/ldlang.c | 1 + ld/plugin.c | 16 +++++++----- ld/testsuite/ld-plugin/lto.exp | 40 ++++++++++++++++++++++++++++++ ld/testsuite/ld-plugin/pr26262a.c | 21 ++++++++++++++++ ld/testsuite/ld-plugin/pr26262b.c | 16 ++++++++++++ ld/testsuite/ld-plugin/pr26262c.c | 6 +++++ ld/testsuite/ld-plugin/pr26267.err | 3 +++ ld/testsuite/ld-plugin/pr26267a.c | 21 ++++++++++++++++ ld/testsuite/ld-plugin/pr26267b.c | 15 +++++++++++ ld/testsuite/ld-plugin/pr26267c.c | 6 +++++ 13 files changed, 167 insertions(+), 6 deletions(-) create mode 100644 ld/testsuite/ld-plugin/pr26262a.c create mode 100644 ld/testsuite/ld-plugin/pr26262b.c create mode 100644 ld/testsuite/ld-plugin/pr26262c.c create mode 100644 ld/testsuite/ld-plugin/pr26267.err create mode 100644 ld/testsuite/ld-plugin/pr26267a.c create mode 100644 ld/testsuite/ld-plugin/pr26267b.c create mode 100644 ld/testsuite/ld-plugin/pr26267c.c diff --git a/include/ChangeLog b/include/ChangeLog index 6a69a74b6f4..211d54530e0 100644 --- a/include/ChangeLog +++ b/include/ChangeLog @@ -1,3 +1,9 @@ +2020-07-22 H.J. Lu + + PR ld/26262 + PR ld/26267 + * bfdlink.h (bfd_link_info): Add lto_all_symbols_read. + 2020-07-11 H.J. Lu * elf/common.h (GNU_PROPERTY_X86_FEATURE_2_TMM): New. diff --git a/include/bfdlink.h b/include/bfdlink.h index 71634333830..3badfbdb19f 100644 --- a/include/bfdlink.h +++ b/include/bfdlink.h @@ -361,6 +361,9 @@ struct bfd_link_info /* TRUE if the LTO plugin is active. */ unsigned int lto_plugin_active: 1; + /* TRUE if all LTO IR symbols have been read. */ + unsigned int lto_all_symbols_read : 1; + /* TRUE if global symbols in discarded sections should be stripped. */ unsigned int strip_discarded: 1; diff --git a/ld/ChangeLog b/ld/ChangeLog index c4951288590..aef3d97f87f 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,22 @@ +2020-07-22 H.J. Lu + + PR ld/26262 + PR ld/26267 + * ldlang.c (lang_process): Set lto_all_symbols_read after all + LTO IR symbols have been read. + * plugin.c (plugin_notice): Override the IR definition only if + all LTO IR symbols have been read or the new definition is + non-weak and the the IR definition is weak + * testsuite/ld-plugin/lto.exp: Run PR ld/26262 and ld/26267 + tests. + * testsuite/ld-plugin/pr26262a.c: New file. + * testsuite/ld-plugin/pr26262b.c: Likewise. + * testsuite/ld-plugin/pr26262c.c: Likewise. + * testsuite/ld-plugin/pr26267.err: Likewise. + * testsuite/ld-plugin/pr26267a.c: Likewise. + * testsuite/ld-plugin/pr26267b.c: Likewise. + * testsuite/ld-plugin/pr26267c.c: Likewise. + 2020-07-20 Nick Clifton * testsuite/ld-powerpc/powerpc.exp (ppcelftests): Use section name diff --git a/ld/ldlang.c b/ld/ldlang.c index 2b3a5f9069c..d3ed5d461e3 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -7886,6 +7886,7 @@ lang_process (void) if (plugin_call_all_symbols_read ()) einfo (_("%F%P: %s: plugin reported error after all symbols read\n"), plugin_error_plugin ()); + link_info.lto_all_symbols_read = TRUE; /* Open any newly added files, updating the file chains. */ plugin_undefs = link_info.hash->undefs_tail; open_input_bfds (*added.tail, OPEN_BFD_NORMAL); diff --git a/ld/plugin.c b/ld/plugin.c index b455af6d676..d709ee10fe7 100644 --- a/ld/plugin.c +++ b/ld/plugin.c @@ -1433,12 +1433,16 @@ plugin_notice (struct bfd_link_info *info, new value from a real BFD. Weak symbols are not normally overridden by a new weak definition, and strong symbols will normally cause multiple definition errors. Avoid - this by making the symbol appear to be undefined. */ - else if (((h->type == bfd_link_hash_defweak - || h->type == bfd_link_hash_defined) - && is_ir_dummy_bfd (sym_bfd = h->u.def.section->owner)) - || (h->type == bfd_link_hash_common - && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner))) + this by making the symbol appear to be undefined. + + NB: We change the previous definition in the IR object to + undefweak only after all LTO symbols have been read. */ + else if (info->lto_all_symbols_read + && (((h->type == bfd_link_hash_defweak + || h->type == bfd_link_hash_defined) + && is_ir_dummy_bfd (sym_bfd = h->u.def.section->owner)) + || (h->type == bfd_link_hash_common + && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner)))) { h->type = bfd_link_hash_undefweak; h->u.undef.abfd = sym_bfd; diff --git a/ld/testsuite/ld-plugin/lto.exp b/ld/testsuite/ld-plugin/lto.exp index 2d6ca6888b4..a44b6cf4b0d 100644 --- a/ld/testsuite/ld-plugin/lto.exp +++ b/ld/testsuite/ld-plugin/lto.exp @@ -210,6 +210,36 @@ set lto_link_tests [list \ [list "Build pr26163a.o" \ "" "-O2 -fno-lto" \ {pr26163a.c}] \ + [list "Build pr26262b.o" \ + "" "-O2" \ + {pr26262b.c} {} "" "c"] \ + [list "Build pr26262c.o" \ + "" "-O2" \ + {pr26262c.c} {} "" "c"] \ + [list "Build pr26267a.o" \ + "" "-O2 -flto $lto_no_fat" \ + {pr26267a.c} {} "" "c"] \ + [list "Build pr26267b.o" \ + "" "-O2" \ + {pr26267b.c} {} "" "c"] \ + [list "Build pr26267c.o" \ + "" "-O2" \ + {pr26267c.c} {} "" "c"] \ + [list "Build pr26267a" \ + "" "-O2" \ + {pr26267a.c} {} "" "c"] \ + [list "Build pr26267a" \ + "-flto tmpdir/pr26267a.o tmpdir/pr26267b.o tmpdir/pr26267c.o" \ + "-flto $lto_no_fat" \ + {dummy.c} \ + {{error_output "pr26267.err"}} \ + "pr26267a"] \ + [list "Build pr26267b" \ + "-flto tmpdir/pr26267b.o tmpdir/pr26267c.o tmpdir/pr26267a.o" \ + "-flto $lto_no_fat" \ + {dummy.c} \ + {{error_output "pr26267.err"}} \ + "pr26267b"] \ ] if { [at_least_gcc_version 10 0] } { @@ -510,6 +540,16 @@ set lto_run_tests [list \ {pr26163b.c} "pr24406-2" "pass.out" \ "-flto -O2" "c" "" \ "tmpdir/pr26163a.o -Wl,--defsym,g=real_g"] \ + [list "Run pr26262a" \ + "-O2 -flto" "" \ + {pr26262a.c} "pr26262a" "pass.out" \ + "-flto -O2" "c" "" \ + "tmpdir/pr26262b.o tmpdir/pr26262c.o"] \ + [list "Run pr26262b" \ + "-flto -O2 tmpdir/pr26262b.o tmpdir/pr26262c.o" "" \ + {pr26262a.c} "pr26262b" "pass.out" \ + "-flto -O2" "c" "" \ + ""] \ ] if { [at_least_gcc_version 4 7] } { diff --git a/ld/testsuite/ld-plugin/pr26262a.c b/ld/testsuite/ld-plugin/pr26262a.c new file mode 100644 index 00000000000..488470f4dd0 --- /dev/null +++ b/ld/testsuite/ld-plugin/pr26262a.c @@ -0,0 +1,21 @@ +#include + +int counter; +extern void foo (void); +extern void xxx (void); + +void +bar (void) +{ +} + +int +main(void) +{ + bar (); + foo (); + xxx (); + if (counter == 1) + printf ("PASS\n"); + return 0; +} diff --git a/ld/testsuite/ld-plugin/pr26262b.c b/ld/testsuite/ld-plugin/pr26262b.c new file mode 100644 index 00000000000..91ec492ac76 --- /dev/null +++ b/ld/testsuite/ld-plugin/pr26262b.c @@ -0,0 +1,16 @@ +#include + +extern int counter; + +void +foo (void) +{ + counter++; +} + +__attribute__((weak)) +void +bar (void) +{ + abort (); +} diff --git a/ld/testsuite/ld-plugin/pr26262c.c b/ld/testsuite/ld-plugin/pr26262c.c new file mode 100644 index 00000000000..fcc49411254 --- /dev/null +++ b/ld/testsuite/ld-plugin/pr26262c.c @@ -0,0 +1,6 @@ +extern void bar (void); +void +xxx (void) +{ + bar (); +} diff --git a/ld/testsuite/ld-plugin/pr26267.err b/ld/testsuite/ld-plugin/pr26267.err new file mode 100644 index 00000000000..b1b1c3a47dd --- /dev/null +++ b/ld/testsuite/ld-plugin/pr26267.err @@ -0,0 +1,3 @@ +#... +.*: multiple definition of `bar'; .* +#... diff --git a/ld/testsuite/ld-plugin/pr26267a.c b/ld/testsuite/ld-plugin/pr26267a.c new file mode 100644 index 00000000000..488470f4dd0 --- /dev/null +++ b/ld/testsuite/ld-plugin/pr26267a.c @@ -0,0 +1,21 @@ +#include + +int counter; +extern void foo (void); +extern void xxx (void); + +void +bar (void) +{ +} + +int +main(void) +{ + bar (); + foo (); + xxx (); + if (counter == 1) + printf ("PASS\n"); + return 0; +} diff --git a/ld/testsuite/ld-plugin/pr26267b.c b/ld/testsuite/ld-plugin/pr26267b.c new file mode 100644 index 00000000000..f1e32e25e3b --- /dev/null +++ b/ld/testsuite/ld-plugin/pr26267b.c @@ -0,0 +1,15 @@ +#include + +extern int counter; + +void +foo (void) +{ + counter++; +} + +void +bar (void) +{ + abort (); +} diff --git a/ld/testsuite/ld-plugin/pr26267c.c b/ld/testsuite/ld-plugin/pr26267c.c new file mode 100644 index 00000000000..fcc49411254 --- /dev/null +++ b/ld/testsuite/ld-plugin/pr26267c.c @@ -0,0 +1,6 @@ +extern void bar (void); +void +xxx (void) +{ + bar (); +} -- 2.30.2