[lld-macho] Unreferenced weak dylib symbols shouldn't fetch archive symbols
We were fetching archive symbols too eagerly, bloating binary size as well as
just screwing up binaries that expected to look up certain symbols only at
runtime.
Reviewed By: #lld-macho, oontvoo
Differential Revision: https://reviews.llvm.org/D115092
GitOrigin-RevId: 1b44364714981017302f182583a43fda4d28e0eb
diff --git a/MachO/SymbolTable.cpp b/MachO/SymbolTable.cpp
index c212516..cec717e 100644
--- a/MachO/SymbolTable.cpp
+++ b/MachO/SymbolTable.cpp
@@ -184,10 +184,18 @@
bool wasInserted;
std::tie(s, wasInserted) = insert(name, file);
- if (wasInserted)
+ if (wasInserted) {
replaceSymbol<LazySymbol>(s, file, sym);
- else if (isa<Undefined>(s) || (isa<DylibSymbol>(s) && s->isWeakDef()))
+ } else if (isa<Undefined>(s)) {
file->fetch(sym);
+ } else if (auto *dysym = dyn_cast<DylibSymbol>(s)) {
+ if (dysym->isWeakDef()) {
+ if (dysym->getRefState() != RefState::Unreferenced)
+ file->fetch(sym);
+ else
+ replaceSymbol<LazySymbol>(s, file, sym);
+ }
+ }
return s;
}
diff --git a/test/MachO/weak-definition-direct-fetch.s b/test/MachO/weak-definition-direct-fetch.s
index 48f101a..8c90be5 100644
--- a/test/MachO/weak-definition-direct-fetch.s
+++ b/test/MachO/weak-definition-direct-fetch.s
@@ -4,7 +4,8 @@
## This test exercises the various possible combinations of weak and non-weak
## symbols that get referenced directly by a relocation in an object file.
-# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/test.s -o %t/test.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/refs-foo.s -o %t/refs-foo.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/weak-refs-foo.s -o %t/weak-refs-foo.o
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/foo.s -o %t/foo.o
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/weakfoo.s -o %t/weakfoo.o
@@ -33,6 +34,7 @@
# PREFER-NONWEAK-DYLIB: __DATA __la_symbol_ptr 0x{{[0-9a-f]+}} libfoo _foo
# PREFER-WEAK-OBJECT: O __TEXT,weak _foo
# PREFER-NONWEAK-OBJECT: O __TEXT,nonweak _foo
+# NO-SYM-NOT: _foo
## First, we test the cases where the symbols are of the same type (both from a
## dylib, or both from an archive, etc.)
@@ -40,53 +42,66 @@
## For dylibs and object files, the non-weak symbol always wins. But the weak
## flag has no effect when we are dealing with two archive symbols.
-# RUN: %lld -lSystem -o %t/weak-nonweak-dylibs -L%t -lweakfoo -lfoo %t/test.o
+# RUN: %lld -lSystem -o %t/weak-nonweak-dylibs -L%t -lweakfoo -lfoo %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-nonweak-dylibs | FileCheck %s --check-prefix=PREFER-NONWEAK-DYLIB
-# RUN: %lld -lSystem -o %t/nonweak-weak-dylibs -L%t -lfoo -lweakfoo %t/test.o
+# RUN: %lld -lSystem -o %t/nonweak-weak-dylibs -L%t -lfoo -lweakfoo %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/nonweak-weak-dylibs | FileCheck %s --check-prefix=PREFER-NONWEAK-DYLIB
-# RUN: %lld -lSystem -o %t/weak-nonweak-objs %t/weakfoo.o %t/foo.o %t/test.o
+# RUN: %lld -lSystem -o %t/weak-nonweak-objs %t/weakfoo.o %t/foo.o %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-nonweak-objs | FileCheck %s --check-prefix=PREFER-NONWEAK-OBJECT
-# RUN: %lld -lSystem -o %t/nonweak-weak-objs %t/foo.o %t/weakfoo.o %t/test.o
+# RUN: %lld -lSystem -o %t/nonweak-weak-objs %t/foo.o %t/weakfoo.o %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/nonweak-weak-objs | FileCheck %s --check-prefix=PREFER-NONWEAK-OBJECT
-# RUN: %lld -lSystem -o %t/weak-nonweak-archives %t/weakfoo.a %t/foo.a %t/test.o
+# RUN: %lld -lSystem -o %t/weak-nonweak-archives %t/weakfoo.a %t/foo.a %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-nonweak-archives | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
-# RUN: %lld -lSystem -o %t/nonweak-weak-archives %t/foo.a %t/weakfoo.a %t/test.o
+# RUN: %lld -lSystem -o %t/nonweak-weak-archives %t/foo.a %t/weakfoo.a %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/nonweak-weak-archives | FileCheck %s --check-prefix=PREFER-NONWEAK-OBJECT
-## The remaining lines test symbol pairs of different types.
+## The next 5 chunks refs-foo.symbol pairs of different types.
## (Weak) archive symbols take precedence over weak dylib symbols.
-# RUN: %lld -lSystem -o %t/weak-dylib-weak-ar -L%t -lweakfoo %t/weakfoo.a %t/test.o
+# RUN: %lld -lSystem -o %t/weak-dylib-weak-ar -L%t -lweakfoo %t/weakfoo.a %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-dylib-weak-ar | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
-# RUN: %lld -lSystem -o %t/weak-ar-weak-dylib -L%t %t/weakfoo.a -lweakfoo %t/test.o
+# RUN: %lld -lSystem -o %t/weak-ar-weak-dylib -L%t %t/weakfoo.a -lweakfoo %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-ar-weak-dylib | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
## (Weak) archive symbols have the same precedence as dylib symbols.
-# RUN: %lld -lSystem -o %t/weak-ar-nonweak-dylib -L%t %t/weakfoo.a -lfoo %t/test.o
+# RUN: %lld -lSystem -o %t/weak-ar-nonweak-dylib -L%t %t/weakfoo.a -lfoo %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-ar-nonweak-dylib | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
-# RUN: %lld -lSystem -o %t/nonweak-dylib-weak-ar -L%t -lfoo %t/weakfoo.a %t/test.o
+# RUN: %lld -lSystem -o %t/nonweak-dylib-weak-ar -L%t -lfoo %t/weakfoo.a %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/nonweak-dylib-weak-ar | FileCheck %s --check-prefix=PREFER-NONWEAK-DYLIB
## Weak defined symbols take precedence over weak dylib symbols.
-# RUN: %lld -lSystem -o %t/weak-dylib-weak-obj -L%t -lweakfoo %t/weakfoo.o %t/test.o
+# RUN: %lld -lSystem -o %t/weak-dylib-weak-obj -L%t -lweakfoo %t/weakfoo.o %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-dylib-weak-obj | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
-# RUN: %lld -lSystem -o %t/weak-obj-weak-dylib -L%t %t/weakfoo.o -lweakfoo %t/test.o
+# RUN: %lld -lSystem -o %t/weak-obj-weak-dylib -L%t %t/weakfoo.o -lweakfoo %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-obj-weak-dylib | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
## Weak defined symbols take precedence over dylib symbols.
-# RUN: %lld -lSystem -o %t/weak-obj-nonweak-dylib -L%t %t/weakfoo.o -lfoo %t/test.o
+# RUN: %lld -lSystem -o %t/weak-obj-nonweak-dylib -L%t %t/weakfoo.o -lfoo %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-obj-nonweak-dylib | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
-# RUN: %lld -lSystem -o %t/nonweak-dylib-weak-obj -L%t -lfoo %t/weakfoo.o %t/test.o
+# RUN: %lld -lSystem -o %t/nonweak-dylib-weak-obj -L%t -lfoo %t/weakfoo.o %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/nonweak-dylib-weak-obj | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
## Weak defined symbols take precedence over archive symbols.
-# RUN: %lld -lSystem -o %t/weak-obj-nonweak-ar %t/weakfoo.o %t/foo.a %t/test.o
+# RUN: %lld -lSystem -o %t/weak-obj-nonweak-ar %t/weakfoo.o %t/foo.a %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-obj-nonweak-ar | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
-# RUN: %lld -lSystem -o %t/nonweak-ar-weak-obj %t/foo.a %t/weakfoo.o %t/test.o
+# RUN: %lld -lSystem -o %t/nonweak-ar-weak-obj %t/foo.a %t/weakfoo.o %t/refs-foo.o
# RUN: llvm-objdump --macho --lazy-bind --syms %t/nonweak-ar-weak-obj | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
+## Regression test: A weak dylib symbol that isn't referenced by an undefined
+## symbol should not cause an archive symbol to get loaded.
+# RUN: %lld -dylib -lSystem -o %t/weak-ar-weak-unref-dylib -L%t %t/weakfoo.a -lweakfoo
+# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-ar-weak-unref-dylib | FileCheck %s --check-prefix=NO-SYM
+# RUN: %lld -dylib -lSystem -o %t/weak-unref-dylib-weak-ar -L%t -lweakfoo %t/weakfoo.a
+# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-unref-dylib-weak-ar | FileCheck %s --check-prefix=NO-SYM
+
+## However, weak references are sufficient to cause the archive to be loaded.
+# RUN: %lld -dylib -lSystem -o %t/weak-ar-weak-ref-weak-dylib -L%t %t/weakfoo.a -lweakfoo %t/weak-refs-foo.o
+# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-ar-weak-ref-weak-dylib | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
+# RUN: %lld -dylib -lSystem -o %t/weak-ref-weak-dylib-weak-ar -L%t -lweakfoo %t/weakfoo.a %t/weak-refs-foo.o
+# RUN: llvm-objdump --macho --lazy-bind --syms %t/weak-ref-weak-dylib-weak-ar | FileCheck %s --check-prefix=PREFER-WEAK-OBJECT
+
#--- foo.s
.globl _foo
.section __TEXT,nonweak
@@ -98,8 +113,15 @@
.section __TEXT,weak
_foo:
-#--- test.s
+#--- refs-foo.s
.globl _main
_main:
callq _foo
ret
+
+#--- weak-refs-foo.s
+.globl _main
+.weak_reference _foo
+_main:
+ callq _foo
+ ret
