// relocation will be created, pass the control to relocateAlloc() or
// relocateNonAlloc() to resolve it.
//
- // The behavior of an undefined weak reference is implementation defined. If
- // the relocation is to a weak undef, and we are producing an executable, let
- // relocate{,Non}Alloc() resolve it.
+ // The behavior of an undefined weak reference is implementation defined. For
+ // non-link-time constants, we resolve relocations statically (let
+ // relocate{,Non}Alloc() resolve them) for -no-pie and try producing dynamic
+ // relocations for -pie and -shared.
+ //
+ // The general expectation of -no-pie static linking is that there is no
+ // dynamic relocation (except IRELATIVE). Emitting dynamic relocations for
+ // -shared matches the spirit of its -z undefs default. -pie has freedom on
+ // choices, and we choose dynamic relocations to be consistent with the
+ // handling of GOT-generating relocations.
if (isStaticLinkTimeConstant(expr, type, sym, sec, offset) ||
- (!config->shared && sym.isUndefWeak())) {
+ (!config->isPic && sym.isUndefWeak())) {
sec.relocations.push_back({expr, type, offset, addend, &sym});
return;
}
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
# RUN: ld.lld %t.o -o %t --export-dynamic
-# RUN: llvm-readelf -r %t | FileCheck %s
+# RUN: llvm-readelf -r %t | FileCheck %s --check-prefix=NOPIC
+# RUN: ld.lld %t.o -o %t.pie -pie
+# RUN: llvm-readobj -r %t.pie | FileCheck %s --check-prefix=PIC
+# RUN: ld.lld %t.o -o %t.so -shared
+# RUN: llvm-readobj -r %t.so | FileCheck %s --check-prefix=PIC
## gABI leaves the behavior of weak undefined references implementation defined.
-## We choose to resolve it statically and not create a dynamic relocation for
-## implementation simplicity. This also matches ld.bfd and gold.
+## We choose to resolve them statically for -no-pie and produce dynamic relocations
+## for -pie and -shared.
+##
+## Note: Some ports of GNU ld support -z nodynamic-undefined-weak that we don't
+## implement.
-# CHECK: no relocations
+# NOPIC: no relocations
+
+# PIC: .rela.dyn {
+# PIC-NEXT: R_X86_64_64 foobar 0x0
+# PIC-NEXT: }
.global _start
_start: