[LLD] Order writable executable sections before writable ones

[kettenis]

Summary

I'm working on SPARC support in lld. I've got a working diff against lld 4.0.0, and I'm working on moving the changes over into the current source tree. Here is a first diff that addresses one of the more fundamental issues I ran into.

On SPARC, .plt is both writeable and executable. The current way sections are sorted means that lld puts it after .data/.bss. but it really needs to be close to .test to make sure branches into .plt don't overflow. I'd argue that because .bss is supposed to come last on all architectures, we should change the default sort order such that writable and executable sections come before sections that are just writeable. read-only executable sections should still come after sections that are just read-only of course. This diff makes this change.

With this diff, the following tests fail:

lld :: ELF/amdgpu-globals.s
lld :: ELF/gc-sections.s
lld :: ELF/i386-tls-ie-shared.s
lld :: ELF/relocation-size-shared.s
lld :: ELF/relocation-size.s
lld :: ELF/section-layout.s
lld :: ELF/tls-i686.s

The ELF/section-layout.s test fails because it explicitly tests that writeable and executable sections come after sections that are just writeable. Once adjusted that tests will act as a regression test for this diff.
I think most of the other tests just accidentally include a executable and writeable section. I'm not sure about amdgpu-globals.s though as I'm not really familliar with the requirements of that architecture.

[ruiu]

lld/ELF/Writer.cpp

688–695

Is there any problem if you just return AIsExec?

[kettenis]

lld/ELF/Writer.cpp

688–695

Yes. Then read-only executable sections would be sorted before read-only sections, which is not what we want. Basically the current ordering is:

R
RX
RW <- contains .bss
RWX

I propose we change this to

R
RX
RWX
RW <- contains .bss

[ruiu]

lld/ELF/Writer.cpp

688–695

I believe this code is correct, but this function seems a bit puzzling to me. Each decision-making code block is well-commented and clear about what it does, but as a whole it's not easy to predict what this function returns for some two sections. I want to make this as simple as your example

R
RX
RWX
RW.

Do you think you can improve this function? If you don't have a bandwidth to handle it, I'll try to simplify.

[kettenis]

Updated diff adapted to the changes that have been made to the function that determines the section ordering. Also adjusts the testsuite for the changed ordering,

[ruiu]

LGTM

lld/ELF/Writer.cpp

637

nit: RF_WRITE_EXEC is probably more natural order, as in rwx.

681

Add "(such as SPARC)" after "writable"

693–694

} else if {

[kettenis]

Diff has been committed in r304008.

lld/ELF/Writer.cpp

 // We compute a rank for each section. The rank indicates where the
 // section should be placed in the file.  Instead of using simple
 // numbers (0,1,2...), we use a series of flags. One for each decision
 // point when placing the section.
 // Using flags has two key properties:
 // * It is easy to check if a give branch was taken.
 // * It is easy two see how similar two ranks are (see getRankProximity).
 enum RankFlags {
-  RF_NOT_ADDR_SET = 1 << 15,
-  RF_NOT_INTERP = 1 << 14,
-  RF_NOT_ALLOC = 1 << 13,
-  RF_WRITE = 1 << 12,
+  RF_NOT_ADDR_SET = 1 << 16,
+  RF_NOT_INTERP = 1 << 15,
+  RF_NOT_ALLOC = 1 << 14,
+  RF_WRITE = 1 << 13,
+  RF_EXEC_WRITE = 1 << 12,
   RF_EXEC = 1 << 11,
   RF_NON_TLS_BSS = 1 << 10,
   RF_NON_TLS_BSS_RO = 1 << 9,
   RF_NOT_TLS = 1 << 8,
   RF_BSS = 1 << 7,
   RF_PPC_NOT_TOCBSS = 1 << 6,
   RF_PPC_OPD = 1 << 5,
   RF_PPC_TOCL = 1 << 4,
if (Sec->Name == ".interp")
     return Rank;
   Rank |= RF_NOT_INTERP;
 
   // Allocatable sections go first to reduce the total PT_LOAD size and
   // so debug info doesn't change addresses in actual code.
   if (!(Sec->Flags & SHF_ALLOC))
     return Rank | RF_NOT_ALLOC;
 
-  // We want the read only sections first so that they go in the PT_LOAD
-  // covering the program headers at the start of the file.
-  if (Sec->Flags & SHF_WRITE)
-    Rank |= RF_WRITE;
-
-  if (Sec->Flags & SHF_EXECINSTR) {
-    // For a corresponding reason, put non exec sections first (the program
-    // header PT_LOAD is not executable).
-    // We only do that if we are not using linker scripts, since with linker
-    // scripts ro and rx sections are in the same PT_LOAD, so their relative
-    // order is not important. The same applies for -no-rosegment.
-    if ((Rank & RF_WRITE) || !Config->SingleRoRx)
+  // Sort sections based on their access permission in the following
+  // order: R, RX, RWX, RW.  This order is based on the following
+  // considerations:
+  // * Read-only sections come first such that they go in the
+  //   PT_LOAD covering the program headers at the start of the file.
+  // * Read-only, executable sections come next, unless the
+  //   -no-rosegment option is used.
+  // * Writable, executable sections follow such that .plt on
+  //   architectures where it needs to be writable will be placed
+  //   between .text and .data.
+  // * Writable sections come last, such that .bss lands at the very
+  //   end of the last PT_LOAD.
+  bool IsExec = Sec->Flags & SHF_EXECINSTR;
+  bool IsWrite = Sec->Flags & SHF_WRITE;
+
+  if (IsExec) {
+    if (IsWrite)
+      Rank |= RF_EXEC_WRITE;
+    else if (!Config->SingleRoRx)
       Rank |= RF_EXEC;
+  } else {
+    if (IsWrite)
+      Rank |= RF_WRITE;
   }
 
   // If we got here we know that both A and B are in the same PT_LOAD.
 
   bool IsTls = Sec->Flags & SHF_TLS;
   bool IsNoBits = Sec->Type == SHT_NOBITS;
 
   // The first requirement we have is to put (non-TLS) nobits sections last. The

lld/test/ELF/amdgpu-globals.s

module_global_readonly:
 
   .amdgpu_hsa_program_global program_global_readonly
   .size program_global_readonly, 4
   .hsatext
 program_global_readonly:
   .long 0                       ; 0x0
 
 # CHECK: Section {
+# CHECK: Name: .hsatext
+# CHECK: Type: SHT_PROGBITS
+# CHECK: Flags [ (0xC00007)
+# CHECK: SHF_ALLOC (0x2)
+# CHECK: SHF_AMDGPU_HSA_AGENT (0x800000)
+# CHECK: SHF_AMDGPU_HSA_CODE (0x400000)
+# CHECK: SHF_EXECINSTR (0x4)
+# CHECK: SHF_WRITE (0x1)
+# CHECK: ]
+# CHECK: Address: [[HSATEXT_ADDR:[0-9xa-f]+]]
+# CHECK: }
+
+# CHECK: Section {
 # CHECK: Name: .hsadata_global_program
 # CHECK: Type: SHT_PROGBITS (0x1)
 # CHECK: Flags [ (0x100003)
 # CHECK: SHF_ALLOC (0x2)
 # CHECK: SHF_AMDGPU_HSA_GLOBAL (0x100000)
 # CHECK: SHF_WRITE (0x1)
 # CHECK: ]
 # CHECK: Address: [[HSADATA_GLOBAL_PROGRAM_ADDR:[0-9xa-f]+]]
 # CHECK: }
 
 # CHECK: Section {
 # CHECK: Name: .hsadata_global_agent
 # CHECK: Type: SHT_PROGBITS (0x1)
 # CHECK: Flags [ (0x900003)
 # CHECK: SHF_ALLOC (0x2)
 # CHECK: SHF_AMDGPU_HSA_AGENT (0x800000)
 # CHECK: SHF_AMDGPU_HSA_GLOBAL (0x100000)
 # CHECK: SHF_WRITE (0x1)
 # CHECK: ]
 # CHECK: }
 
-# CHECK: Section {
-# CHECK: Name: .hsatext
-# CHECK: Type: SHT_PROGBITS
-# CHECK: Flags [ (0xC00007)
-# CHECK: SHF_ALLOC (0x2)
-# CHECK: SHF_AMDGPU_HSA_AGENT (0x800000)
-# CHECK: SHF_AMDGPU_HSA_CODE (0x400000)
-# CHECK: SHF_EXECINSTR (0x4)
-# CHECK: SHF_WRITE (0x1)
-# CHECK: ]
-# CHECK: Address: [[HSATEXT_ADDR:[0-9xa-f]+]]
-# CHECK: }
-
 # CHECK: Symbol {
 # CHECK: Name: module_global_agent
 # CHECK: Value:
 # CHECK: Size: 4
 # CHECK: Binding: Local
 # CHECK: Section: .hsadata_global_agent
 # CHECK: }
 

lld/test/ELF/gc-sections.s

 # REQUIRES: x86
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
 # RUN: ld.lld %t -o %t2
 # RUN: llvm-readobj -sections -symbols %t2 | FileCheck -check-prefix=NOGC %s
 # RUN: ld.lld --gc-sections %t -o %t2
 # RUN: llvm-readobj -sections -symbols %t2 | FileCheck -check-prefix=GC1 %s
 # RUN: ld.lld --export-dynamic --gc-sections %t -o %t2
 # RUN: llvm-readobj -sections -symbols %t2 | FileCheck -check-prefix=GC2 %s
 
 # NOGC: Name: .eh_frame
 # NOGC: Name: .text
-# NOGC: Name: .ctors
-# NOGC: Name: .dtors
 # NOGC: Name: .init
 # NOGC: Name: .fini
+# NOGC: Name: .ctors
+# NOGC: Name: .dtors
 # NOGC: Name: .debug_pubtypes
 # NOGC: Name: .comment
 # NOGC: Name: a
 # NOGC: Name: b
 # NOGC: Name: c
 # NOGC: Name: x
 # NOGC: Name: y
 # NOGC: Name: d
 
 # GC1:     Name: .eh_frame
 # GC1:     Name: .text
-# GC1:     Name: .ctors
-# GC1:     Name: .dtors
 # GC1:     Name: .init
 # GC1:     Name: .fini
+# GC1:     Name: .ctors
+# GC1:     Name: .dtors
 # GC1:     Name: .debug_pubtypes
 # GC1:     Name: .comment
 # GC1:     Name: a
 # GC1:     Name: b
 # GC1:     Name: c
 # GC1-NOT: Name: x
 # GC1-NOT: Name: y
 # GC1-NOT: Name: d
 
 # GC2:     Name: .eh_frame
 # GC2:     Name: .text
-# GC2:     Name: .ctors
-# GC2:     Name: .dtors
 # GC2:     Name: .init
 # GC2:     Name: .fini
+# GC2:     Name: .ctors
+# GC2:     Name: .dtors
 # GC2:     Name: .debug_pubtypes
 # GC2:     Name: .comment
 # GC2:     Name: a
 # GC2:     Name: b
 # GC2:     Name: c
 # GC2-NOT: Name: x
 # GC2-NOT: Name: y
 # GC2:     Name: d

lld/test/ELF/i386-tls-ie-shared.s

 // RUN: llvm-mc -filetype=obj -triple=i686-pc-linux %s -o %t.o
 // RUN: llvm-mc -filetype=obj -triple=i686-pc-linux %p/Inputs/tls-opt-iele-i686-nopic.s -o %tso.o
 // RUN: ld.lld -shared %tso.o -o %tso
 // RUN: ld.lld -shared %t.o %tso -o %t1
 // RUN: llvm-readobj -s -r -d %t1 | FileCheck --check-prefix=GOTRELSHARED %s
 // RUN: llvm-objdump -d %t1 | FileCheck --check-prefix=DISASMSHARED %s
 
 // GOTRELSHARED:     Section {
 // GOTRELSHARED:      Index: 8
 // GOTRELSHARED:      Name: .got
 // GOTRELSHARED-NEXT:   Type: SHT_PROGBITS
 // GOTRELSHARED-NEXT:   Flags [
 // GOTRELSHARED-NEXT:     SHF_ALLOC
 // GOTRELSHARED-NEXT:     SHF_WRITE
 // GOTRELSHARED-NEXT:   ]
-// GOTRELSHARED-NEXT:   Address: 0x1058
-// GOTRELSHARED-NEXT:   Offset: 0x1058
+// GOTRELSHARED-NEXT:   Address: 0x2058
+// GOTRELSHARED-NEXT:   Offset: 0x2058
 // GOTRELSHARED-NEXT:   Size: 16
 // GOTRELSHARED-NEXT:   Link: 0
 // GOTRELSHARED-NEXT:   Info: 0
 // GOTRELSHARED-NEXT:   AddressAlignment: 4
 // GOTRELSHARED-NEXT:   EntrySize: 0
 // GOTRELSHARED-NEXT: }
 // GOTRELSHARED:      Relocations [
 // GOTRELSHARED-NEXT:   Section ({{.*}}) .rel.dyn {
-// GOTRELSHARED-NEXT:     0x2002 R_386_RELATIVE - 0x0
-// GOTRELSHARED-NEXT:     0x200A R_386_RELATIVE - 0x0
-// GOTRELSHARED-NEXT:     0x2013 R_386_RELATIVE - 0x0
-// GOTRELSHARED-NEXT:     0x201C R_386_RELATIVE - 0x0
-// GOTRELSHARED-NEXT:     0x2024 R_386_RELATIVE - 0x0
-// GOTRELSHARED-NEXT:     0x202D R_386_RELATIVE - 0x0
-// GOTRELSHARED-NEXT:     0x2036 R_386_RELATIVE - 0x0
-// GOTRELSHARED-NEXT:     0x203F R_386_RELATIVE - 0x0
-// GOTRELSHARED-NEXT:     0x1058 R_386_TLS_TPOFF tlslocal0 0x0
-// GOTRELSHARED-NEXT:     0x105C R_386_TLS_TPOFF tlslocal1 0x0
-// GOTRELSHARED-NEXT:     0x1060 R_386_TLS_TPOFF tlsshared0 0x0
-// GOTRELSHARED-NEXT:     0x1064 R_386_TLS_TPOFF tlsshared1 0x0
+// GOTRELSHARED-NEXT:     0x1002 R_386_RELATIVE - 0x0
+// GOTRELSHARED-NEXT:     0x100A R_386_RELATIVE - 0x0
+// GOTRELSHARED-NEXT:     0x1013 R_386_RELATIVE - 0x0
+// GOTRELSHARED-NEXT:     0x101C R_386_RELATIVE - 0x0
+// GOTRELSHARED-NEXT:     0x1024 R_386_RELATIVE - 0x0
+// GOTRELSHARED-NEXT:     0x102D R_386_RELATIVE - 0x0
+// GOTRELSHARED-NEXT:     0x1036 R_386_RELATIVE - 0x0
+// GOTRELSHARED-NEXT:     0x103F R_386_RELATIVE - 0x0
+// GOTRELSHARED-NEXT:     0x2058 R_386_TLS_TPOFF tlslocal0 0x0
+// GOTRELSHARED-NEXT:     0x205C R_386_TLS_TPOFF tlslocal1 0x0
+// GOTRELSHARED-NEXT:     0x2060 R_386_TLS_TPOFF tlsshared0 0x0
+// GOTRELSHARED-NEXT:     0x2064 R_386_TLS_TPOFF tlsshared1 0x0
 // GOTRELSHARED-NEXT:   }
 // GOTRELSHARED-NEXT: ]
 // GOTRELSHARED:      0x6FFFFFFA RELCOUNT             8
 
 // DISASMSHARED:       Disassembly of section test:
 // DISASMSHARED-NEXT:  _start:
-// (.got)[0] = 0x2050 = 8272
-// (.got)[1] = 0x2054 = 8276
-// (.got)[2] = 0x2058 = 8280
-// (.got)[3] = 0x205C = 8284
-// DISASMSHARED-NEXT:  2000: 8b 0d 58 10 00 00   movl  4184, %ecx
-// DISASMSHARED-NEXT:  2006: 65 8b 01  movl  %gs:(%ecx), %eax
-// DISASMSHARED-NEXT:  2009: a1 58 10 00 00  movl  4184, %eax
-// DISASMSHARED-NEXT:  200e: 65 8b 00  movl  %gs:(%eax), %eax
-// DISASMSHARED-NEXT:  2011: 03 0d 58 10 00 00   addl  4184, %ecx
-// DISASMSHARED-NEXT:  2017: 65 8b 01  movl  %gs:(%ecx), %eax
-// DISASMSHARED-NEXT:  201a: 8b 0d 5c 10 00 00   movl  4188, %ecx
-// DISASMSHARED-NEXT:  2020: 65 8b 01  movl  %gs:(%ecx), %eax
-// DISASMSHARED-NEXT:  2023: a1 5c 10 00 00  movl  4188, %eax
-// DISASMSHARED-NEXT:  2028: 65 8b 00  movl  %gs:(%eax), %eax
-// DISASMSHARED-NEXT:  202b: 03 0d 5c 10 00 00   addl  4188, %ecx
-// DISASMSHARED-NEXT:  2031: 65 8b 01  movl  %gs:(%ecx), %eax
-// DISASMSHARED-NEXT:  2034: 8b 0d 60 10 00 00   movl  4192, %ecx
-// DISASMSHARED-NEXT:  203a: 65 8b 01  movl  %gs:(%ecx), %eax
-// DISASMSHARED-NEXT:  203d: 03 0d 64 10 00 00   addl  4196, %ecx
-// DISASMSHARED-NEXT:  2043: 65 8b 01  movl  %gs:(%ecx), %eax
+// (.got)[0] = 0x2058 = 8280
+// (.got)[1] = 0x205C = 8284
+// (.got)[2] = 0x2060 = 8288
+// (.got)[3] = 0x2064 = 8292
+// DISASMSHARED-NEXT:  1000: 8b 0d 58 20 00 00   movl  8280, %ecx
+// DISASMSHARED-NEXT:  1006: 65 8b 01  movl  %gs:(%ecx), %eax
+// DISASMSHARED-NEXT:  1009: a1 58 20 00 00  movl  8280, %eax
+// DISASMSHARED-NEXT:  100e: 65 8b 00  movl  %gs:(%eax), %eax
+// DISASMSHARED-NEXT:  1011: 03 0d 58 20 00 00   addl  8280, %ecx
+// DISASMSHARED-NEXT:  1017: 65 8b 01  movl  %gs:(%ecx), %eax
+// DISASMSHARED-NEXT:  101a: 8b 0d 5c 20 00 00   movl  8284, %ecx
+// DISASMSHARED-NEXT:  1020: 65 8b 01  movl  %gs:(%ecx), %eax
+// DISASMSHARED-NEXT:  1023: a1 5c 20 00 00  movl  8284, %eax
+// DISASMSHARED-NEXT:  1028: 65 8b 00  movl  %gs:(%eax), %eax
+// DISASMSHARED-NEXT:  102b: 03 0d 5c 20 00 00   addl  8284, %ecx
+// DISASMSHARED-NEXT:  1031: 65 8b 01  movl  %gs:(%ecx), %eax
+// DISASMSHARED-NEXT:  1034: 8b 0d 60 20 00 00   movl  8288, %ecx
+// DISASMSHARED-NEXT:  103a: 65 8b 01  movl  %gs:(%ecx), %eax
+// DISASMSHARED-NEXT:  103d: 03 0d 64 20 00 00   addl  8292, %ecx
+// DISASMSHARED-NEXT:  1043: 65 8b 01  movl  %gs:(%ecx), %eax
 
 .type tlslocal0,@object
 .section .tbss,"awT",@nobits
 .globl tlslocal0
 .align 4
 tlslocal0:
  .long 0
  .size tlslocal0, 4

lld/test/ELF/linkerscript/sections-constraint.s

 # RUN: ld.lld -o %t2 --script %t2.script %t
 # RUN: llvm-objdump -section-headers %t2 | \
 # RUN:   FileCheck -check-prefix=NO1 %s
 # NO1: Sections:
 # NO1-NEXT: Idx Name          Size
 # NO1-NEXT: 0               00000000
 # NO1:  .writable     00000004
 # NO1:  .foo.2        00000004
-# NO1:  .foo.1        00000004
 # NO1:  .readable     00000004
+# NO1:  .foo.1        00000004
 
 .global _start
 _start:
   nop
 
 .section .writable, "aw"
 writable:
  .long 1

lld/test/ELF/relocation-size-shared.s

 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/relocation-size-shared.s -o %tso.o
 // RUN: ld.lld -shared %tso.o -o %tso
 // RUN: ld.lld %t.o %tso -o %t1
 // RUN: llvm-readobj -r %t1 | FileCheck --check-prefix=RELOCSHARED %s
 // RUN: llvm-objdump -d %t1 | FileCheck --check-prefix=DISASM %s
 
 // RELOCSHARED:       Relocations [
 // RELOCSHARED-NEXT:  Section ({{.*}}) .rela.dyn {
-// RELOCSHARED-NEXT:    0x203018 R_X86_64_SIZE64 fooshared 0xFFFFFFFFFFFFFFFF
-// RELOCSHARED-NEXT:    0x203020 R_X86_64_SIZE64 fooshared 0x0
-// RELOCSHARED-NEXT:    0x203028 R_X86_64_SIZE64 fooshared 0x1
-// RELOCSHARED-NEXT:    0x203048 R_X86_64_SIZE32 fooshared 0xFFFFFFFFFFFFFFFF
-// RELOCSHARED-NEXT:    0x20304F R_X86_64_SIZE32 fooshared 0x0
-// RELOCSHARED-NEXT:    0x203056 R_X86_64_SIZE32 fooshared 0x1
+// RELOCSHARED-NEXT:    0x201018 R_X86_64_SIZE64 fooshared 0xFFFFFFFFFFFFFFFF
+// RELOCSHARED-NEXT:    0x201020 R_X86_64_SIZE64 fooshared 0x0
+// RELOCSHARED-NEXT:    0x201028 R_X86_64_SIZE64 fooshared 0x1
+// RELOCSHARED-NEXT:    0x201048 R_X86_64_SIZE32 fooshared 0xFFFFFFFFFFFFFFFF
+// RELOCSHARED-NEXT:    0x20104F R_X86_64_SIZE32 fooshared 0x0
+// RELOCSHARED-NEXT:    0x201056 R_X86_64_SIZE32 fooshared 0x1
 // RELOCSHARED-NEXT:  }
 // RELOCSHARED-NEXT:]
 
 // DISASM:      Disassembly of section test
 // DISASM:      _data:
-// DISASM-NEXT: 203000: 19 00
-// DISASM-NEXT: 203002: 00 00
-// DISASM-NEXT: 203004: 00 00
-// DISASM-NEXT: 203006: 00 00
-// DISASM-NEXT: 203008: 1a 00
-// DISASM-NEXT: 20300a: 00 00
-// DISASM-NEXT: 20300c: 00 00
-// DISASM-NEXT: 20300e: 00 00
-// DISASM-NEXT: 203010: 1b 00
-// DISASM-NEXT: 203012: 00 00
-// DISASM-NEXT: 203014: 00 00
-// DISASM-NEXT: 203016: 00 00
-// DISASM-NEXT: 203018: 00 00
-// DISASM-NEXT: 20301a: 00 00
-// DISASM-NEXT: 20301c: 00 00
-// DISASM-NEXT: 20301e: 00 00
-// DISASM-NEXT: 203020: 00 00
-// DISASM-NEXT: 203022: 00 00
-// DISASM-NEXT: 203024: 00 00
-// DISASM-NEXT: 203026: 00 00
-// DISASM-NEXT: 203028: 00 00
-// DISASM-NEXT: 20302a: 00 00
-// DISASM-NEXT: 20302c: 00 00
-// DISASM-NEXT: 20302e: 00 00
+// DISASM-NEXT: 201000: 19 00
+// DISASM-NEXT: 201002: 00 00
+// DISASM-NEXT: 201004: 00 00
+// DISASM-NEXT: 201006: 00 00
+// DISASM-NEXT: 201008: 1a 00
+// DISASM-NEXT: 20100a: 00 00
+// DISASM-NEXT: 20100c: 00 00
+// DISASM-NEXT: 20100e: 00 00
+// DISASM-NEXT: 201010: 1b 00
+// DISASM-NEXT: 201012: 00 00
+// DISASM-NEXT: 201014: 00 00
+// DISASM-NEXT: 201016: 00 00
+// DISASM-NEXT: 201018: 00 00
+// DISASM-NEXT: 20101a: 00 00
+// DISASM-NEXT: 20101c: 00 00
+// DISASM-NEXT: 20101e: 00 00
+// DISASM-NEXT: 201020: 00 00
+// DISASM-NEXT: 201022: 00 00
+// DISASM-NEXT: 201024: 00 00
+// DISASM-NEXT: 201026: 00 00
+// DISASM-NEXT: 201028: 00 00
+// DISASM-NEXT: 20102a: 00 00
+// DISASM-NEXT: 20102c: 00 00
+// DISASM-NEXT: 20102e: 00 00
 // DISASM:      _start:
-// DISASM-NEXT: 203030: 8b 04 25 19 00 00 00 movl 25, %eax
-// DISASM-NEXT: 203037: 8b 04 25 1a 00 00 00 movl 26, %eax
-// DISASM-NEXT: 20303e: 8b 04 25 1b 00 00 00 movl 27, %eax
-// DISASM-NEXT: 203045: 8b 04 25 00 00 00 00 movl 0, %eax
-// DISASM-NEXT: 20304c: 8b 04 25 00 00 00 00 movl 0, %eax
-// DISASM-NEXT: 203053: 8b 04 25 00 00 00 00 movl 0, %eax
+// DISASM-NEXT: 201030: 8b 04 25 19 00 00 00 movl 25, %eax
+// DISASM-NEXT: 201037: 8b 04 25 1a 00 00 00 movl 26, %eax
+// DISASM-NEXT: 20103e: 8b 04 25 1b 00 00 00 movl 27, %eax
+// DISASM-NEXT: 201045: 8b 04 25 00 00 00 00 movl 0, %eax
+// DISASM-NEXT: 20104c: 8b 04 25 00 00 00 00 movl 0, %eax
+// DISASM-NEXT: 201053: 8b 04 25 00 00 00 00 movl 0, %eax
 
 .data
 .global foo
 .type foo,%object
 .size foo,26
 foo:
 .zero 26
 

lld/test/ELF/relocation-size.s

 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
 // RUN: ld.lld %t.o -o %t1
 // RUN: llvm-readobj -r %t1 | FileCheck --check-prefix=NORELOC %s
 // RUN: llvm-objdump -d %t1 | FileCheck --check-prefix=DISASM %s
 // RUN: ld.lld -shared %t.o -o %t1
 // RUN: llvm-readobj -r %t1 | FileCheck --check-prefix=RELOCSHARED %s
 // RUN: llvm-objdump -d %t1 | FileCheck --check-prefix=DISASMSHARED %s
 
 // NORELOC:      Relocations [
 // NORELOC-NEXT: ]
 
 // DISASM:      Disassembly of section test:
 // DISASM-NEXT: _data:
-// DISASM-NEXT: 202000: 19 00
-// DISASM-NEXT: 202002: 00 00
-// DISASM-NEXT: 202004: 00 00
-// DISASM-NEXT: 202006: 00 00
-// DISASM-NEXT: 202008: 1a 00
-// DISASM-NEXT: 20200a: 00 00
-// DISASM-NEXT: 20200c: 00 00
-// DISASM-NEXT: 20200e: 00 00
-// DISASM-NEXT: 202010: 1b 00
-// DISASM-NEXT: 202012: 00 00
-// DISASM-NEXT: 202014: 00 00
-// DISASM-NEXT: 202016: 00 00
-// DISASM-NEXT: 202018: 19 00
-// DISASM-NEXT: 20201a: 00 00
-// DISASM-NEXT: 20201c: 00 00
-// DISASM-NEXT: 20201e: 00 00
-// DISASM-NEXT: 202020: 1a 00
-// DISASM-NEXT: 202022: 00 00
-// DISASM-NEXT: 202024: 00 00
-// DISASM-NEXT: 202026: 00 00
-// DISASM-NEXT: 202028: 1b 00
-// DISASM-NEXT: 20202a: 00 00
-// DISASM-NEXT: 20202c: 00 00
-// DISASM-NEXT: 20202e: 00 00
+// DISASM-NEXT: 201000: 19 00
+// DISASM-NEXT: 201002: 00 00
+// DISASM-NEXT: 201004: 00 00
+// DISASM-NEXT: 201006: 00 00
+// DISASM-NEXT: 201008: 1a 00
+// DISASM-NEXT: 20100a: 00 00
+// DISASM-NEXT: 20100c: 00 00
+// DISASM-NEXT: 20100e: 00 00
+// DISASM-NEXT: 201010: 1b 00
+// DISASM-NEXT: 201012: 00 00
+// DISASM-NEXT: 201014: 00 00
+// DISASM-NEXT: 201016: 00 00
+// DISASM-NEXT: 201018: 19 00
+// DISASM-NEXT: 20101a: 00 00
+// DISASM-NEXT: 20101c: 00 00
+// DISASM-NEXT: 20101e: 00 00
+// DISASM-NEXT: 201020: 1a 00
+// DISASM-NEXT: 201022: 00 00
+// DISASM-NEXT: 201024: 00 00
+// DISASM-NEXT: 201026: 00 00
+// DISASM-NEXT: 201028: 1b 00
+// DISASM-NEXT: 20102a: 00 00
+// DISASM-NEXT: 20102c: 00 00
+// DISASM-NEXT: 20102e: 00 00
 // DISASM:      _start:
-// DISASM-NEXT: 202030: 8b 04 25 19 00 00 00 movl 25, %eax
-// DISASM-NEXT: 202037: 8b 04 25 1a 00 00 00 movl 26, %eax
-// DISASM-NEXT: 20203e: 8b 04 25 1b 00 00 00 movl 27, %eax
-// DISASM-NEXT: 202045: 8b 04 25 19 00 00 00 movl 25, %eax
-// DISASM-NEXT: 20204c: 8b 04 25 1a 00 00 00 movl 26, %eax
-// DISASM-NEXT: 202053: 8b 04 25 1b 00 00 00 movl 27, %eax
+// DISASM-NEXT: 201030: 8b 04 25 19 00 00 00 movl 25, %eax
+// DISASM-NEXT: 201037: 8b 04 25 1a 00 00 00 movl 26, %eax
+// DISASM-NEXT: 20103e: 8b 04 25 1b 00 00 00 movl 27, %eax
+// DISASM-NEXT: 201045: 8b 04 25 19 00 00 00 movl 25, %eax
+// DISASM-NEXT: 20104c: 8b 04 25 1a 00 00 00 movl 26, %eax
+// DISASM-NEXT: 201053: 8b 04 25 1b 00 00 00 movl 27, %eax
 
 // RELOCSHARED:      Relocations [
 // RELOCSHARED-NEXT: Section ({{.*}}) .rela.dyn {
-// RELOCSHARED-NEXT:    0x3000 R_X86_64_SIZE64 foo 0xFFFFFFFFFFFFFFFF
-// RELOCSHARED-NEXT:    0x3008 R_X86_64_SIZE64 foo 0x0
-// RELOCSHARED-NEXT:    0x3010 R_X86_64_SIZE64 foo 0x1
-// RELOCSHARED-NEXT:    0x3033 R_X86_64_SIZE32 foo 0xFFFFFFFFFFFFFFFF
-// RELOCSHARED-NEXT:    0x303A R_X86_64_SIZE32 foo 0x0
-// RELOCSHARED-NEXT:    0x3041 R_X86_64_SIZE32 foo 0x1
+// RELOCSHARED-NEXT:    0x1000 R_X86_64_SIZE64 foo 0xFFFFFFFFFFFFFFFF
+// RELOCSHARED-NEXT:    0x1008 R_X86_64_SIZE64 foo 0x0
+// RELOCSHARED-NEXT:    0x1010 R_X86_64_SIZE64 foo 0x1
+// RELOCSHARED-NEXT:    0x1033 R_X86_64_SIZE32 foo 0xFFFFFFFFFFFFFFFF
+// RELOCSHARED-NEXT:    0x103A R_X86_64_SIZE32 foo 0x0
+// RELOCSHARED-NEXT:    0x1041 R_X86_64_SIZE32 foo 0x1
 // RELOCSHARED-NEXT:  }
 // RELOCSHARED-NEXT: ]
 
 // DISASMSHARED:      Disassembly of section test:
 // DISASMSHARED-NEXT: _data:
-// DISASMSHARED-NEXT: 3000: 00 00
-// DISASMSHARED-NEXT: 3002: 00 00
-// DISASMSHARED-NEXT: 3004: 00 00
-// DISASMSHARED-NEXT: 3006: 00 00
-// DISASMSHARED-NEXT: 3008: 00 00
-// DISASMSHARED-NEXT: 300a: 00 00
-// DISASMSHARED-NEXT: 300c: 00 00
-// DISASMSHARED-NEXT: 300e: 00 00
-// DISASMSHARED-NEXT: 3010: 00 00
-// DISASMSHARED-NEXT: 3012: 00 00
-// DISASMSHARED-NEXT: 3014: 00 00
-// DISASMSHARED-NEXT: 3016: 00 00
-// DISASMSHARED-NEXT: 3018: 19 00
-// DISASMSHARED-NEXT: 301a: 00 00
-// DISASMSHARED-NEXT: 301c: 00 00
-// DISASMSHARED-NEXT: 301e: 00 00
-// DISASMSHARED-NEXT: 3020: 1a 00
-// DISASMSHARED-NEXT: 3022: 00 00
-// DISASMSHARED-NEXT: 3024: 00 00
-// DISASMSHARED-NEXT: 3026: 00 00
-// DISASMSHARED-NEXT: 3028: 1b 00
-// DISASMSHARED-NEXT: 302a: 00 00
-// DISASMSHARED-NEXT: 302c: 00 00
-// DISASMSHARED-NEXT: 302e: 00 00
+// DISASMSHARED-NEXT: 1000: 00 00
+// DISASMSHARED-NEXT: 1002: 00 00
+// DISASMSHARED-NEXT: 1004: 00 00
+// DISASMSHARED-NEXT: 1006: 00 00
+// DISASMSHARED-NEXT: 1008: 00 00
+// DISASMSHARED-NEXT: 100a: 00 00
+// DISASMSHARED-NEXT: 100c: 00 00
+// DISASMSHARED-NEXT: 100e: 00 00
+// DISASMSHARED-NEXT: 1010: 00 00
+// DISASMSHARED-NEXT: 1012: 00 00
+// DISASMSHARED-NEXT: 1014: 00 00
+// DISASMSHARED-NEXT: 1016: 00 00
+// DISASMSHARED-NEXT: 1018: 19 00
+// DISASMSHARED-NEXT: 101a: 00 00
+// DISASMSHARED-NEXT: 101c: 00 00
+// DISASMSHARED-NEXT: 101e: 00 00
+// DISASMSHARED-NEXT: 1020: 1a 00
+// DISASMSHARED-NEXT: 1022: 00 00
+// DISASMSHARED-NEXT: 1024: 00 00
+// DISASMSHARED-NEXT: 1026: 00 00
+// DISASMSHARED-NEXT: 1028: 1b 00
+// DISASMSHARED-NEXT: 102a: 00 00
+// DISASMSHARED-NEXT: 102c: 00 00
+// DISASMSHARED-NEXT: 102e: 00 00
 // DISASMSHARED:      _start:
-// DISASMSHARED-NEXT: 3030: 8b 04 25 00 00 00 00 movl 0, %eax
-// DISASMSHARED-NEXT: 3037: 8b 04 25 00 00 00 00 movl 0, %eax
-// DISASMSHARED-NEXT: 303e: 8b 04 25 00 00 00 00 movl 0, %eax
-// DISASMSHARED-NEXT: 3045: 8b 04 25 19 00 00 00 movl 25, %eax
-// DISASMSHARED-NEXT: 304c: 8b 04 25 1a 00 00 00 movl 26, %eax
-// DISASMSHARED-NEXT: 3053: 8b 04 25 1b 00 00 00 movl 27, %eax
+// DISASMSHARED-NEXT: 1030: 8b 04 25 00 00 00 00 movl 0, %eax
+// DISASMSHARED-NEXT: 1037: 8b 04 25 00 00 00 00 movl 0, %eax
+// DISASMSHARED-NEXT: 103e: 8b 04 25 00 00 00 00 movl 0, %eax
+// DISASMSHARED-NEXT: 1045: 8b 04 25 19 00 00 00 movl 25, %eax
+// DISASMSHARED-NEXT: 104c: 8b 04 25 1a 00 00 00 movl 26, %eax
+// DISASMSHARED-NEXT: 1053: 8b 04 25 1b 00 00 00 movl 27, %eax
 
 .data
 .global foo
 .type foo,%object
 .size foo,26
 foo:
 .zero 26
 

lld/test/ELF/section-layout.s

 .section b,"a",@nobits
 .section a,"a"
 
 // CHECK: Name: a
 // CHECK: Name: b
 // CHECK: Name: c
 // CHECK: Name: d
 
+// Sections that are both writable and executable appear before
+// sections that are only writable.
+// CHECK: Name: k
+// CHECK: Name: l
+
 // Writable sections appear before TLS and other relro sections.
 // CHECK: Name: i
 
 // TLS sections are only sorted on NOBITS.
 // CHECK: Name: e
 // CHECK: Name: g
 
 // CHECK: Name: j
-// CHECK: Name: k
-// CHECK: Name: l
 
 // Non allocated sections are in input order.
 // CHECK: Name: t
 // CHECK: Name: s
 // CHECK: Name: r
 // CHECK: Name: q
 // CHECK: Name: p
 // CHECK: Name: o
 // CHECK: Name: n
 // CHECK: Name: m

lld/test/ELF/tls-i686.s

 
  movl %gs:0, %ecx
  leal var@ntpoff(%ecx), %eax
  movl %gs:0, %ecx
  leal var1@ntpoff+123(%ecx), %eax
 
 // DIS:      Disassembly of section test:
 // DIS-NEXT: _start:
-// DIS-NEXT: 12000: ba 08 00 00 00       movl $8, %edx
-// DIS-NEXT: 12005: 65 8b 0d 00 00 00 00 movl %gs:0, %ecx
-// DIS-NEXT: 1200c: 29 d0                subl %edx, %eax
-// DIS-NEXT: 1200e: ba 04 00 00 00       movl $4, %edx
-// DIS-NEXT: 12013: 65 8b 0d 00 00 00 00 movl %gs:0, %ecx
-// DIS-NEXT: 1201a: 29 d0                subl %edx, %eax
-// DIS-NEXT: 1201c: 65 8b 0d 00 00 00 00 movl %gs:0, %ecx
-// DIS-NEXT: 12023: 8d 81 f8 ff ff ff    leal -8(%ecx), %eax
-// DIS-NEXT: 12029: 65 8b 0d 00 00 00 00 movl %gs:0, %ecx
-// DIS-NEXT: 12030: 8d 81 77 00 00 00    leal 119(%ecx), %eax
+// DIS-NEXT: 11000: ba 08 00 00 00       movl $8, %edx
+// DIS-NEXT: 11005: 65 8b 0d 00 00 00 00 movl %gs:0, %ecx
+// DIS-NEXT: 1100c: 29 d0                subl %edx, %eax
+// DIS-NEXT: 1100e: ba 04 00 00 00       movl $4, %edx
+// DIS-NEXT: 11013: 65 8b 0d 00 00 00 00 movl %gs:0, %ecx
+// DIS-NEXT: 1101a: 29 d0                subl %edx, %eax
+// DIS-NEXT: 1101c: 65 8b 0d 00 00 00 00 movl %gs:0, %ecx
+// DIS-NEXT: 11023: 8d 81 f8 ff ff ff    leal -8(%ecx), %eax
+// DIS-NEXT: 11029: 65 8b 0d 00 00 00 00 movl %gs:0, %ecx
+// DIS-NEXT: 11030: 8d 81 77 00 00 00    leal 119(%ecx), %eax
 
 // RELOC: Relocations [
 // RELOC-NEXT: ]
 
 // DISSHARED: Disassembly of section test:
 // DISSHARED-NEXT: _start:
-// DISSHARED-NEXT: 2000: ba 00 00 00 00 movl   $0, %edx
-// DISSHARED-NEXT: 2005: 65 8b 0d 00 00 00 00  movl %gs:0, %ecx
-// DISSHARED-NEXT: 200c: 29 d0 subl            %edx, %eax
-// DISSHARED-NEXT: 200e: ba 00 00 00 00        movl $0, %edx
-// DISSHARED-NEXT: 2013: 65 8b 0d 00 00 00 00  movl %gs:0, %ecx
-// DISSHARED-NEXT: 201a: 29 d0 subl            %edx, %eax
-// DISSHARED-NEXT: 201c: 65 8b 0d 00 00 00 00  movl %gs:0, %ecx
-// DISSHARED-NEXT: 2023: 8d 81 00 00 00 00     leal (%ecx), %eax
-// DISSHARED-NEXT: 2029: 65 8b 0d 00 00 00 00  movl %gs:0, %ecx
-// DISSHARED-NEXT: 2030: 8d 81 7b 00 00 00     leal 123(%ecx), %eax
+// DISSHARED-NEXT: 1000: ba 00 00 00 00 movl   $0, %edx
+// DISSHARED-NEXT: 1005: 65 8b 0d 00 00 00 00  movl %gs:0, %ecx
+// DISSHARED-NEXT: 100c: 29 d0 subl            %edx, %eax
+// DISSHARED-NEXT: 100e: ba 00 00 00 00        movl $0, %edx
+// DISSHARED-NEXT: 1013: 65 8b 0d 00 00 00 00  movl %gs:0, %ecx
+// DISSHARED-NEXT: 101a: 29 d0 subl            %edx, %eax
+// DISSHARED-NEXT: 101c: 65 8b 0d 00 00 00 00  movl %gs:0, %ecx
+// DISSHARED-NEXT: 1023: 8d 81 00 00 00 00     leal (%ecx), %eax
+// DISSHARED-NEXT: 1029: 65 8b 0d 00 00 00 00  movl %gs:0, %ecx
+// DISSHARED-NEXT: 1030: 8d 81 7b 00 00 00     leal 123(%ecx), %eax
 
 // RELOCSHARED:      Relocations [
 // RELOCSHARED-NEXT: Section (4) .rel.dyn {
-// RELOCSHARED-NEXT:   0x2001 R_386_TLS_TPOFF32 var 0x0
-// RELOCSHARED-NEXT:   0x2025 R_386_TLS_TPOFF var 0x0
-// RELOCSHARED-NEXT:   0x200F R_386_TLS_TPOFF32 var1 0x0
-// RELOCSHARED-NEXT:   0x2032 R_386_TLS_TPOFF var1 0x0
+// RELOCSHARED-NEXT:   0x1001 R_386_TLS_TPOFF32 var 0x0
+// RELOCSHARED-NEXT:   0x1025 R_386_TLS_TPOFF var 0x0
+// RELOCSHARED-NEXT:   0x100F R_386_TLS_TPOFF32 var1 0x0
+// RELOCSHARED-NEXT:   0x1032 R_386_TLS_TPOFF var1 0x0
 // RELOCSHARED-NEXT:  }
 // RELOCSHARED-NEXT: ]