[lld] r296085 - [ELF] Make __ehdr_start point to ELF file headers

[Petr Hosek via llvm-commits]

Author: phosek
Date: Thu Feb 23 22:11:02 2017
New Revision: 296085

URL: http://llvm.org/viewvc/llvm-project?rev=296085&view=rev
Log:
[ELF] Make __ehdr_start point to ELF file headers

__ehdr_start should be pointing to ELF file headers, not program
headers.

This is a reland of D30319.

Differential Revision: https://reviews.llvm.org/D30323

Modified:
    lld/trunk/ELF/Writer.cpp
    lld/trunk/test/ELF/ehdr_start.s

Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=296085&r1=296084&r2=296085&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Thu Feb 23 22:11:02 2017
@@ -844,9 +844,9 @@ template <class ELFT> void Writer<ELFT>:
   if (ScriptConfig->HasSections)
     return;
 
-  // __ehdr_start is the location of program headers.
+  // __ehdr_start is the location of ELF file headers.
   ElfSym<ELFT>::EhdrStart =
-      addOptionalSynthetic<ELFT>("__ehdr_start", Out<ELFT>::ProgramHeaders, 0);
+      addOptionalSynthetic<ELFT>("__ehdr_start", Out<ELFT>::ElfHeader, 0);
 
   auto Define = [](StringRef S, DefinedSynthetic *&Sym1,
                    DefinedSynthetic *&Sym2) {
@@ -1138,7 +1138,7 @@ template <class ELFT> void Writer<ELFT>:
   // This is a bit of a hack. A value of 0 means undef, so we set it
   // to 1 t make __ehdr_start defined. The section number is not
   // particularly relevant.
-  Out<ELFT>::ProgramHeaders->SectionIndex = 1;
+  Out<ELFT>::ElfHeader->SectionIndex = 1;
 
   unsigned I = 1;
   for (OutputSectionBase *Sec : OutputSections) {

Modified: lld/trunk/test/ELF/ehdr_start.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/ehdr_start.s?rev=296085&r1=296084&r2=296085&view=diff
==============================================================================
--- lld/trunk/test/ELF/ehdr_start.s (original)
+++ lld/trunk/test/ELF/ehdr_start.s Thu Feb 23 22:11:02 2017
@@ -2,8 +2,16 @@
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
 # RUN: ld.lld %t.o -o %t
-# RUN: llvm-objdump -t %t | FileCheck %s
-# CHECK: 0000000000200040 .text 00000000 .hidden __ehdr_start
+# RUN: llvm-readobj -symbols %t | FileCheck %s
+# CHECK:    Name: __ehdr_start (1)
+# CHECK-NEXT:    Value: 0x200000
+# CHECK-NEXT:    Size: 0
+# CHECK-NEXT:    Binding: Local (0x0)
+# CHECK-NEXT:    Type: None (0x0)
+# CHECK-NEXT:    Other [ (0x2)
+# CHECK-NEXT:      STV_HIDDEN (0x2)
+# CHECK-NEXT:    ]
+# CHECK-NEXT:    Section: .text (0x1)
 
 .text
 .global _start, __ehdr_start
@@ -11,6 +19,12 @@ _start:
   .quad __ehdr_start
 
 # RUN: ld.lld -r %t.o -o %t.r
-# RUN: llvm-objdump -t %t.r | FileCheck %s --check-prefix=RELOCATABLE
+# RUN: llvm-readobj -symbols %t.r | FileCheck %s --check-prefix=RELOCATABLE
 
-# RELOCATABLE: 0000000000000000 *UND* 00000000 __ehdr_start
+# RELOCATABLE:    Name: __ehdr_start (1)
+# RELOCATABLE-NEXT:    Value: 0x0
+# RELOCATABLE-NEXT:    Size: 0
+# RELOCATABLE-NEXT:    Binding: Global (0x1)
+# RELOCATABLE-NEXT:    Type: None (0x0)
+# RELOCATABLE-NEXT:    Other: 0
+# RELOCATABLE-NEXT:    Section: Undefined (0x0)