[PATCH] D114397: [lld-macho] Mark dylib symbols coming from -weak_framework as weak-def.

[Vy Nguyen via Phabricator via llvm-commits]

oontvoo updated this revision to Diff 390347.
oontvoo marked 2 inline comments as done.
oontvoo added a comment.

added comment on weakref


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D114397/new/

https://reviews.llvm.org/D114397

Files:
  lld/MachO/Symbols.h
  lld/test/MachO/weak-import.s


Index: lld/test/MachO/weak-import.s
===================================================================
--- lld/test/MachO/weak-import.s
+++ lld/test/MachO/weak-import.s
@@ -9,12 +9,12 @@
 # RUN: %lld -lSystem -dylib %t/bar.o -o %t/libbar.dylib
 # RUN: %lld -lSystem -dylib %t/foo.o %t/libbar.dylib -sub_library libbar -o %t/libfoo.dylib
 
-# RUN: %lld -weak-lSystem %t/test.o -weak_framework CoreFoundation -weak_library %t/libfoo.dylib -o %t/test
-# RUN: llvm-objdump --macho --all-headers %t/test | FileCheck %s -DDIR=%t --check-prefixes=WEAK-SYS,WEAK-FOO
+# RUN: %lld -weak-lSystem %t/test.o -weak_framework CoreFoundation -weak_library %t/libfoo.dylib -o %t/basic
+# RUN: llvm-objdump --macho --all-headers %t/basic | FileCheck %s -DDIR=%t --check-prefixes=WEAK-SYS,WEAK-FOO
 # RUN: %lld -weak-lSystem %t/test.o \
 # RUN:   -framework CoreFoundation -weak_framework CoreFoundation -framework CoreFoundation \
-# RUN:   %t/libfoo.dylib -weak_library %t/libfoo.dylib %t/libfoo.dylib -o %t/test
-# RUN: llvm-objdump --macho --all-headers %t/test | FileCheck %s -DDIR=%t --check-prefixes=WEAK-SYS,WEAK-FOO
+# RUN:   %t/libfoo.dylib -weak_library %t/libfoo.dylib %t/libfoo.dylib -o %t/basic-weak-strong
+# RUN: llvm-objdump --macho --all-headers %t/basic-weak-strong | FileCheck %s -DDIR=%t --check-prefixes=WEAK-SYS,WEAK-FOO
 # RUN: %lld -lSystem -dylib %t/libfoo.dylib %t/weak-ref-only.o -o %t/weak-ref-only
 # RUN: llvm-objdump --macho --all-headers %t/weak-ref-only | FileCheck %s -DDIR=%t --check-prefixes=SYS,WEAK-FOO
 # RUN: %lld -lSystem -dylib %t/libfoo.dylib %t/weak-ref-sub-library.o -o %t/weak-ref-sub-library
@@ -22,6 +22,10 @@
 # RUN: %lld -lSystem -dylib %t/libfoo.dylib %t/mixed-ref.o -o %t/mixed-ref
 # RUN: llvm-objdump --macho --all-headers %t/mixed-ref | FileCheck %s -DDIR=%t --check-prefixes=SYS,FOO
 
+# RUN: %lld -framework CoreFoundation %t/test.o -weak_framework CoreFoundation -o %t/strong-weak-import.out
+# RUN: llvm-objdump --macho --bind %t/strong-weak-import.out | FileCheck %s --check-prefix=WEAK-IMP
+# RUN: llvm-objdump --macho --bind %t/basic-weak-strong | FileCheck %s --check-prefix=WEAK-IMP
+
 # WEAK-SYS:          cmd LC_LOAD_WEAK_DYLIB
 # WEAK-SYS-NEXT: cmdsize
 # WEAK-SYS-NEXT:    name /usr/lib/libSystem.dylib
@@ -42,6 +46,7 @@
 # FOO-NEXT:      cmdsize
 # FOO-NEXT:         name [[DIR]]/libfoo.dylib
 
+# WEAK-IMP: {{.+}} pointer         0 CoreFoundation   __CFBigNumGetInt128 (weak_import)
 #--- foo.s
 .globl _foo
 _foo:
@@ -69,4 +74,5 @@
 #--- test.s
 .globl _main
 _main:
+  movq __CFBigNumGetInt128 at GOTPCREL(%rip), %rax        
   ret
Index: lld/MachO/Symbols.h
===================================================================
--- lld/MachO/Symbols.h
+++ lld/MachO/Symbols.h
@@ -235,8 +235,19 @@
   }
 
   uint64_t getVA() const override;
-  bool isWeakDef() const override { return weakDef; }
-  bool isWeakRef() const override { return refState == RefState::Weak; }
+
+  // Libraries and framework can be loaded multiple times with different
+  // forceWeakImport (eg., first loaded as strong then as weak)
+  // When that happens we must ensure the weak-property sticks.
+  // Do not cache the result of this expression because `file` could change
+  // as we loaded more libraries/frameworks.
+  bool isWeakDef() const override {
+    return weakDef || (file && getFile()->umbrella->forceWeakImport);
+  }
+  bool isWeakRef() const override {
+    return refState == RefState::Weak ||
+           (file && getFile()->umbrella->forceWeakImport);
+  }
   bool isReferenced() const { return refState != RefState::Unreferenced; }
   bool isTlv() const override { return tlv; }
   bool isDynamicLookup() const { return file == nullptr; }


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