[PATCH] D22300: [ELF] Allow overriding reserved symbols in linker script

[Eugene Leviant via llvm-commits]

evgeny777 created this revision.
evgeny777 added a reviewer: ruiu.
evgeny777 added subscribers: grimar, ikudrin, llvm-commits.
evgeny777 set the repository for this revision to rL LLVM.
evgeny777 added a project: lld.

This is a small bugfix for http://reviews.llvm.org/D21965

Resverved symbols are added in addReservedSymbols(), which is called before createSections()
Therefore if you define some reserved symbol in linker script then lld will report error because of name conflict

Repository:
  rL LLVM

http://reviews.llvm.org/D22300

Files:
  ELF/LinkerScript.cpp
  test/ELF/linkerscript-symbols.s

Index: test/ELF/linkerscript-symbols.s
===================================================================
--- test/ELF/linkerscript-symbols.s
+++ test/ELF/linkerscript-symbols.s
@@ -1,10 +1,10 @@
 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
 
-# RUN: echo "SECTIONS {.text : {*(.text.*)} text_end = .;}" > %t.script
+# RUN: echo "SECTIONS {.text : {*(.text.*)} end = .;}" > %t.script
 # RUN: ld.lld -o %t1 --script %t.script %t
 # RUN: llvm-objdump -t %t1 | FileCheck %s
-# CHECK: 0000000000000121         *ABS*    00000000 text_end
+# CHECK: 0000000000000121         *ABS*    00000000 end
 
 .global _start
 _start:
Index: ELF/LinkerScript.cpp
===================================================================
--- ELF/LinkerScript.cpp
+++ ELF/LinkerScript.cpp
@@ -309,10 +309,10 @@
   return I < J ? -1 : 1;
 }
 
-template <class ELFT>
-void LinkerScript<ELFT>::addScriptedSymbols() {
+template <class ELFT> void LinkerScript<ELFT>::addScriptedSymbols() {
   for (SectionsCommand &Cmd : Opt.Commands)
-    if (Cmd.Kind == SymbolAssignmentKind)
+    if (Cmd.Kind == SymbolAssignmentKind &&
+        Symtab<ELFT>::X->find(Cmd.Name) == nullptr)
       Symtab<ELFT>::X->addAbsolute(Cmd.Name, STV_DEFAULT);
 }
 


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