[lld] r292594 - [ELF] - Do not crash when assign common symbol's values in script

[George Rimar via llvm-commits]

Author: grimar
Date: Fri Jan 20 03:45:36 2017
New Revision: 292594

URL: http://llvm.org/viewvc/llvm-project?rev=292594&view=rev
Log:
[ELF] - Do not crash when assign common symbol's values in script

Found that during attempts of linking linux kernel,
previously we partially duplicated code from getOutputSection(),
and it missed commons symbol case.

Differential revision: https://reviews.llvm.org/D28903

Added:
    lld/trunk/test/ELF/linkerscript/common-assign.s
Modified:
    lld/trunk/ELF/LinkerScript.cpp
    lld/trunk/ELF/SyntheticSections.h

Modified: lld/trunk/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=292594&r1=292593&r2=292594&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.cpp (original)
+++ lld/trunk/ELF/LinkerScript.cpp Fri Jan 20 03:45:36 2017
@@ -918,12 +918,7 @@ const OutputSectionBase *LinkerScript<EL
     return CurOutSec ? CurOutSec : (*OutputSections)[0];
   }
 
-  if (auto *DR = dyn_cast_or_null<DefinedRegular<ELFT>>(Sym))
-    return DR->Section ? DR->Section->OutSec : nullptr;
-  if (auto *DS = dyn_cast_or_null<DefinedSynthetic>(Sym))
-    return DS->Section;
-
-  return nullptr;
+  return SymbolTableSection<ELFT>::getOutputSection(Sym);
 }
 
 // Returns indices of ELF headers containing specific section, identified

Modified: lld/trunk/ELF/SyntheticSections.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SyntheticSections.h?rev=292594&r1=292593&r2=292594&view=diff
==============================================================================
--- lld/trunk/ELF/SyntheticSections.h (original)
+++ lld/trunk/ELF/SyntheticSections.h Fri Jan 20 03:45:36 2017
@@ -372,6 +372,8 @@ public:
 
   ArrayRef<SymbolTableEntry> getSymbols() const { return Symbols; }
 
+  static const OutputSectionBase *getOutputSection(SymbolBody *Sym);
+
   unsigned NumLocals = 0;
   StringTableSection<ELFT> &StrTabSec;
 
@@ -379,8 +381,6 @@ private:
   void writeLocalSymbols(uint8_t *&Buf);
   void writeGlobalSymbols(uint8_t *Buf);
 
-  const OutputSectionBase *getOutputSection(SymbolBody *Sym);
-
   // A vector of symbols and their string table offsets.
   std::vector<SymbolTableEntry> Symbols;
 };

Added: lld/trunk/test/ELF/linkerscript/common-assign.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/common-assign.s?rev=292594&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/common-assign.s (added)
+++ lld/trunk/test/ELF/linkerscript/common-assign.s Fri Jan 20 03:45:36 2017
@@ -0,0 +1,48 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: echo "SECTIONS { . = SIZEOF_HEADERS; pfoo = foo; pbar = bar; }" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t
+# RUN: llvm-readobj -symbols %t1 | FileCheck %s
+
+# CHECK:       Symbol {
+# CHECK:         Name: bar
+# CHECK-NEXT:     Value: 0x134
+# CHECK-NEXT:     Size: 4
+# CHECK-NEXT:     Binding: Global
+# CHECK-NEXT:     Type: Object
+# CHECK-NEXT:     Other: 0
+# CHECK-NEXT:     Section: .bss
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: foo
+# CHECK-NEXT:     Value: 0x138
+# CHECK-NEXT:     Size: 4
+# CHECK-NEXT:     Binding: Global
+# CHECK-NEXT:     Type: Object
+# CHECK-NEXT:     Other: 0
+# CHECK-NEXT:     Section: .bss
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: pfoo
+# CHECK-NEXT:     Value: 0x138
+# CHECK-NEXT:     Size: 0
+# CHECK-NEXT:     Binding: Global
+# CHECK-NEXT:     Type: None
+# CHECK-NEXT:     Other: 0
+# CHECK-NEXT:     Section: .bss
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: pbar
+# CHECK-NEXT:     Value: 0x134
+# CHECK-NEXT:     Size: 0
+# CHECK-NEXT:     Binding: Global
+# CHECK-NEXT:     Type: None
+# CHECK-NEXT:     Other: 0
+# CHECK-NEXT:     Section: .bss
+# CHECK-NEXT:   }
+# CHECK-NEXT: ]
+
+.comm	foo,4,4
+.comm	bar,4,4
+movl	$1, foo(%rip)
+movl	$2, bar(%rip)