[PATCH] D124143: [lld-macho] Allow dead_strip to work with autohide symbols that cannot be exported

[Vincent Lee via Phabricator via llvm-commits]

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thevinster retitled this revision from "[lld-macho] Allow dead_strip on autohide symbols" to "[lld-macho] Allow dead_strip to work with autohide symbols that cannot be exported".
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It seems like we are overly asserting when running `-dead_strip` with 
exported symbols. ld64 links successfully (or at least no-ops) with 
`-dead_strip`  when a symbol cannot be exported. Loosen the assert 
to match ld64's behavior.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D124143

Files:
  lld/MachO/MarkLive.cpp
  lld/test/MachO/export-options.s


Index: lld/test/MachO/export-options.s
===================================================================
--- lld/test/MachO/export-options.s
+++ lld/test/MachO/export-options.s
@@ -133,7 +133,7 @@
 # RUN: llvm-nm -g %t/exp-autohide.dylib | FileCheck %s --check-prefix=EXP-AUTOHIDE
 
 # RUN: not %lld -dylib -exported_symbol "_foo" %t/autohide-private-extern.o \
-# RUN: -o /dev/null  2>&1 | FileCheck %s --check-prefix=AUTOHIDE-PRIVATE
+# RUN:   -o /dev/null  2>&1 | FileCheck %s --check-prefix=AUTOHIDE-PRIVATE
 
 # RUN: not %lld -dylib -exported_symbol "_foo" %t/autohide.o \
 # RUN:   %t/glob-private-extern.o -o /dev/null 2>&1 | \
@@ -143,8 +143,22 @@
 # RUN:   %t/weak-private-extern.o -o /dev/null 2>&1 | \
 # RUN:   FileCheck %s --check-prefix=AUTOHIDE-PRIVATE
 
+## Test that dead_strip does not crash when we cannot export the autohide symbol
+# RUN: %no-fatal-warnings-lld -dylib -exported_symbol "_foo" %t/autohide-private-extern.o \
+# RUN:   -dead_strip -o %t/no_crash
+# RUN: llvm-nm -m %t/no_crash | FileCheck %s --check-prefix=NO-CRASH
+
+# RUN: %no-fatal-warnings-lld -dylib -exported_symbol "_foo" %t/autohide.o \
+# RUN:   -dead_strip %t/glob-private-extern.o -o %t/no_crash
+# RUN: llvm-nm -m %t/no_crash | FileCheck %s --check-prefix=NO-CRASH
+
+# RUN: %no-fatal-warnings-lld -dylib -exported_symbol "_foo" %t/autohide.o \
+# RUN:   -dead_strip %t/weak-private-extern.o -o %t/no_crash
+# RUN: llvm-nm -m %t/no_crash | FileCheck %s --check-prefix=NO-CRASH
+
 # EXP-AUTOHIDE: T _foo
 # AUTOHIDE-PRIVATE: error: cannot export hidden symbol _foo
+# NO-CRASH: (__TEXT,__text) non-external (was a private external) _foo
 
 #--- default.s
 
Index: lld/MachO/MarkLive.cpp
===================================================================
--- lld/MachO/MarkLive.cpp
+++ lld/MachO/MarkLive.cpp
@@ -231,8 +231,6 @@
         // FIXME: Instead of doing this here, maybe the Driver code doing
         // the matching should add them to explicitUndefineds? Then the
         // explicitUndefineds code below would handle this automatically.
-        assert(!defined->privateExtern &&
-               "should have been rejected by driver");
         marker->addSym(defined);
         continue;
       }


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