From: Jonas Devlieghere <jonas@devlieghere.com>
Date: Thu, 15 Oct 2020 03:10:55 +0000 (-0700)
Subject: [dsymutil] Fix handling of aliases to private external symbols
X-Git-Tag: llvmorg-13-init~9227
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f9fb9da36c34d2745b74dc30e6c26f7d3f48466c;p=platform%2Fupstream%2Fllvm.git

[dsymutil] Fix handling of aliases to private external symbols

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

Differential revision: https://reviews.llvm.org/D89444
---

diff --git a/llvm/test/tools/dsymutil/ARM/private-extern-alias.test b/llvm/test/tools/dsymutil/ARM/private-extern-alias.test
new file mode 100644
index 0000000..99301fe
--- /dev/null
+++ b/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 }
diff --git a/llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/main.o b/llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/main.o
new file mode 100644
index 0000000..d9cf74e
Binary files /dev/null and b/llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/main.o differ
diff --git a/llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/private_extern.o b/llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/private_extern.o
new file mode 100644
index 0000000..b7f1a6a
Binary files /dev/null and b/llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/private_extern.o differ
diff --git a/llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/private_extern.out b/llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/private_extern.out
new file mode 100755
index 0000000..fff5df1
Binary files /dev/null and b/llvm/test/tools/dsymutil/Inputs/private/tmp/private_extern/private_extern.out differ
diff --git a/llvm/tools/dsymutil/MachODebugMapParser.cpp b/llvm/tools/dsymutil/MachODebugMapParser.cpp
index 617b708..3323a05 100644
--- a/llvm/tools/dsymutil/MachODebugMapParser.cpp
+++ b/llvm/tools/dsymutil/MachODebugMapParser.cpp
@@ -562,7 +562,9 @@ void MachODebugMapParser::loadMainBinarySymbols(
       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();