[PATCH] D89444: [dsymutil] Fix handling of aliases to private external symbols

[Jonas Devlieghere via Phabricator via llvm-commits]

JDevlieghere created this revision.
JDevlieghere added reviewers: friss, aprantl.
Herald added a project: LLVM.
JDevlieghere requested review of this revision.

dsymutil was incorrectly ignoring aliases to private extern symbols in the MachODebugMapParser. This resulted in spurious warnings about not being able to find symbols.

rdar://49652389


https://reviews.llvm.org/D89444

Files:
  llvm/test/tools/dsymutil/ARM/private-extern-alias.test
  llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/main.o
  llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/private_extern.o
  llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/private_extern.out
  llvm/tools/dsymutil/MachODebugMapParser.cpp


Index: llvm/tools/dsymutil/MachODebugMapParser.cpp
===================================================================
--- llvm/tools/dsymutil/MachODebugMapParser.cpp
+++ llvm/tools/dsymutil/MachODebugMapParser.cpp
@@ -562,7 +562,9 @@
       continue;
     }
     Section = *SectionOrErr;
-    if (Section == MainBinary.section_end() || Section->isText())
+    if ((Section == MainBinary.section_end() || Section->isText()) &&
+        !(SymType &
+          MachO::N_PEXT)) // Alias to non-external (was a private external)
       continue;
     uint64_t Addr = cantFail(Sym.getValue());
     Expected<StringRef> NameOrErr = Sym.getName();
Index: llvm/test/tools/dsymutil/ARM/private-extern-alias.test
===================================================================
--- /dev/null
+++ llvm/test/tools/dsymutil/ARM/private-extern-alias.test
@@ -0,0 +1,29 @@
+$ cat private_extern.c
+__attribute__((visibility("hidden")))
+int* foo() {
+  int i = 10;
+  volatile int* j = &i;
+  return j;
+}
+
+int* bar() {
+  return foo();
+}
+
+$ cat main.c
+int* bar();
+int main() {
+  return *bar();
+}
+
+$ cat alias_list
+_foo _baz
+
+$ xcrun --sdk iphoneos clang -g private_extern.c -c -o private_extern.o -target arm64-apple-ios14.0
+$ xcrun --sdk iphoneos clang -g main.c -c -o main.o -target arm64-apple-ios14.0
+$ xcrun --sdk iphoneos clang private_extern.o main.o -target arm64-apple-ios14.0 -o private_extern.out -Xlinker -alias_list -Xlinker alias_list
+
+RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/private_extern/private_extern.out -o %t.dSYM --verbose 2>&1 | FileCheck %s
+CHECK-NOT: could not find object file symbol for symbol _baz
+CHECK: { sym: _foo, objAddr: 0x0000000000000000, binAddr: 0x0000000100007F58, size: 0x00000020 }
+CHECK: { sym: _baz, objAddr: 0x0000000000000000, binAddr: 0x0000000100007F58, size: 0x00000000 }


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