Change how we handle section symbols on ELF.

On ELF every section can have a corresponding section symbol. When in
an assembly file we have

.quad .text

the '.text' refers to that symbol.

The way we used to handle them is to leave .text an undefined symbol
until the very end when the object writer would map them to the
actual section symbol.

The problem with that is that anything before the end would see an
undefined symbol. This could result in bad diagnostics
(test/MC/AArch64/label-arithmetic-diags-elf.s), or incorrect results
when using the asm streamer (est/MC/Mips/expansion-jal-sym-pic.s).

Fixing this will also allow using the section symbol earlier for
setting sh_link of SHF_METADATA sections.

This patch includes a few hacks to avoid changing our behaviour when
handling conflicts between section symbols and other symbols. I
reported pr31850 to track that.

llvm-svn: 293936

10 files changed, 30 insertions, 35 deletions

diff --git a/llvm/test/DebugInfo/Generic/2010-06-29-InlinedFnLocalVar.ll b/llvm/test/DebugInfo/Generic/2010-06-29-InlinedFnLocalVar.ll
index 31d3487db7a..11c78ef0351 100644
--- a/llvm/test/DebugInfo/Generic/2010-06-29-InlinedFnLocalVar.ll
+++ b/llvm/test/DebugInfo/Generic/2010-06-29-InlinedFnLocalVar.ll
@@ -1,7 +1,7 @@
 ; RUN: %llc_dwarf -O2 %s -o - | FileCheck %s
 ; Check struct X for dead variable xyz from inlined function foo.
 
-; CHECK: section_info
+; CHECK: .section .debug_info,"",@progbits
 ; CHECK:	DW_TAG_structure_type
 ; CHECK-NEXT:	DW_AT_name
 
diff --git a/llvm/test/DebugInfo/Generic/array.ll b/llvm/test/DebugInfo/Generic/array.ll
index 7b4ff7cb805..ed858ee6197 100644
--- a/llvm/test/DebugInfo/Generic/array.ll
+++ b/llvm/test/DebugInfo/Generic/array.ll
@@ -25,7 +25,7 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
 !7 = distinct !DILexicalBlock(line: 3, column: 12, file: !14, scope: !0)
 !8 = !DICompositeType(tag: DW_TAG_array_type, align: 32, file: !14, scope: !2, baseType: !5, elements: !9)
 !9 = !{!10}
-;CHECK: section_info:
+;CHECK: .section .debug_info,"",@progbits
 ;CHECK: DW_TAG_subrange_type
 ;CHECK-NEXT: DW_AT_type
 ;CHECK-NOT: DW_AT_lower_bound
diff --git a/llvm/test/DebugInfo/Mips/InlinedFnLocalVar.ll b/llvm/test/DebugInfo/Mips/InlinedFnLocalVar.ll
index 51b319c3a5b..3ffc6451d8f 100644
--- a/llvm/test/DebugInfo/Mips/InlinedFnLocalVar.ll
+++ b/llvm/test/DebugInfo/Mips/InlinedFnLocalVar.ll
@@ -1,7 +1,7 @@
 ; RUN: llc -mtriple mips-linux-gnu -O2 %s -o - | FileCheck %s
 ; Check struct X for dead variable xyz from inlined function foo.
 
-; CHECK: section_info
+; CHECK: .section .debug_info,"",@progbits
 ; CHECK:	DW_TAG_structure_type
 ; CHECK-NEXT:	info_string
 
diff --git a/llvm/test/DebugInfo/PowerPC/tls-fission.ll b/llvm/test/DebugInfo/PowerPC/tls-fission.ll
index 358fd5b32c4..f456cbcb714 100644
--- a/llvm/test/DebugInfo/PowerPC/tls-fission.ll
+++ b/llvm/test/DebugInfo/PowerPC/tls-fission.ll
@@ -13,8 +13,7 @@
 ; DW_OP_GNU_push_tls_address
 ; CHECK-NEXT: .byte 224
 ; check that the expected TLS address description is the first thing in the debug_addr section
-; CHECK: debug_addr
-; CHECK-NEXT: .Laddr_sec:
+; CHECK: .section .debug_addr,"",@progbits
 ; CHECK-NEXT: .quad tls@DTPREL+32768
 
 source_filename = "test/DebugInfo/PowerPC/tls-fission.ll"
diff --git a/llvm/test/DebugInfo/X86/ref_addr_relocation.ll b/llvm/test/DebugInfo/X86/ref_addr_relocation.ll
index 58fc236e6bb..373ccfd2dea 100644
--- a/llvm/test/DebugInfo/X86/ref_addr_relocation.ll
+++ b/llvm/test/DebugInfo/X86/ref_addr_relocation.ll
@@ -46,7 +46,7 @@
 ; CHECK: DW_TAG_variable
 ; Make sure this is relocatable.
 ; and test that we don't create the labels to emit a correct COFF relocation
-; ELF-ASM: .quad .Lsection_info+[[TYPE]] # DW_AT_type
+; ELF-ASM: .quad .debug_info+[[TYPE]] # DW_AT_type
 ; COFF-ASM: .secrel32 .Lsection_info+[[TYPE]] # DW_AT_type
 ; DARWIN-ASM2: .quad [[TYPE]] ## DW_AT_type
 ; DARWIN-ASM4: .long [[TYPE]] ## DW_AT_type
diff --git a/llvm/test/DebugInfo/X86/tls.ll b/llvm/test/DebugInfo/X86/tls.ll
index 19570d0e0c0..b6ea213dd74 100644
--- a/llvm/test/DebugInfo/X86/tls.ll
+++ b/llvm/test/DebugInfo/X86/tls.ll
@@ -78,7 +78,6 @@
 
 ; check that the expected TLS address description is the first thing in the debug_addr section
 ; FISSION: .section    .debug_addr
-; FISSION: addr_sec:
 ; FISSION-NEXT: .quad  tls@DTPOFF
 ; FISSION-NEXT: .quad  glbl
 ; FISSION-NOT: .quad  glbl
diff --git a/llvm/test/MC/AArch64/label-arithmetic-diags-elf.s b/llvm/test/MC/AArch64/label-arithmetic-diags-elf.s
index 6e928bdf094..e9d92d591fa 100644
--- a/llvm/test/MC/AArch64/label-arithmetic-diags-elf.s
+++ b/llvm/test/MC/AArch64/label-arithmetic-diags-elf.s
@@ -63,9 +63,9 @@ end_across_sec:
 
   add w0, w1, #(sec_y - sec_x)
   cmp w0, #(sec_y - sec_x)
-  // CHECK: error: symbol 'sec_x' can not be undefined in a subtraction expression
+  // CHECK: error: Cannot represent a difference across sections
   // CHECK-NEXT: add w0, w1, #(sec_y - sec_x)
   // CHECK-NEXT: ^
-  // CHECK: error: symbol 'sec_x' can not be undefined in a subtraction expression
+  // CHECK: error: Cannot represent a difference across sections
   // CHECK-NEXT: cmp w0, #(sec_y - sec_x)
   // CHECK-NEXT: ^
diff --git a/llvm/test/MC/ELF/gen-dwarf.s b/llvm/test/MC/ELF/gen-dwarf.s
index 4e773c79af2..7f0c0594ce9 100644
--- a/llvm/test/MC/ELF/gen-dwarf.s
+++ b/llvm/test/MC/ELF/gen-dwarf.s
@@ -34,7 +34,6 @@ foo:
 // ASM: .section .debug_info
 
 // ASM: .section .debug_abbrev
-// ASM-NEXT: .Lsection_abbrev:
 // ASM-NEXT: [[ABBREV_LABEL:.Ltmp[0-9]+]]
 
 // Second instance of the section has the CU
diff --git a/llvm/test/MC/Mips/expansion-j-sym-pic.s b/llvm/test/MC/Mips/expansion-j-sym-pic.s
index b22d60ca4f2..3c0f5ea7c4d 100644
--- a/llvm/test/MC/Mips/expansion-j-sym-pic.s
+++ b/llvm/test/MC/Mips/expansion-j-sym-pic.s
@@ -87,11 +87,11 @@ local_label:
 # MICRO:  b      .text            # encoding: [0x94,0x00,A,A]
 # MICRO:                          #   fixup A - offset: 0, value: .text, kind: fixup_MICROMIPS_PC16_S1
 
-# ELF-O32:      10 00 ff ff     b       0
-# ELF-O32-NEXT:         00000018:  R_MIPS_PC16  .text
+# ELF-O32:      10 00 ff f9 	b	-24 <local_label>
+# ELF-O32-NEXT: 00 00 00 00 	nop
 
-# ELF-NXX:      10 00 00 00     b       4
-# ELF-NXX-NEXT:                 R_MIPS_PC16/R_MIPS_NONE/R_MIPS_NONE  .text
+# ELF-NXX:      10 00 ff f9 	b	-24 <local_label>
+# ELF-NXX-NEXT: 00 00 00 00 	nop
 
   j 1f
   nop
diff --git a/llvm/test/MC/Mips/expansion-jal-sym-pic.s b/llvm/test/MC/Mips/expansion-jal-sym-pic.s
index d188101d66e..116d1eb15b3 100644
--- a/llvm/test/MC/Mips/expansion-jal-sym-pic.s
+++ b/llvm/test/MC/Mips/expansion-jal-sym-pic.s
@@ -151,37 +151,35 @@ local_label:
   jal .text
   nop
 
-# FIXME: The .text section MCSymbol isn't created when printing assembly. However,
-# it is created when generating an ELF object file.
 # Expanding "jal .text":
-# O32-FIXME: lw    $25, %call16(.text)($gp)        # encoding: [0x8f,0x99,A,A]
-# O32-FIXME:                                       #   fixup A - offset: 0, value: %got(.text), kind: fixup_Mips_GOT_CALL
+# O32: lw	$25, %got(.text)($gp)   # encoding: [0x8f,0x99,A,A]
+# O32-NEXT:                                       #   fixup A - offset: 0, value: %got(.text), kind: fixup_Mips_GOT
 
 # ELF-O32:      8f 99 00 00 lw $25, 0($gp)
-# ELF-O32-NEXT:                 R_MIPS_CALL16 .text
+# ELF-O32-NEXT:                 R_MIPS_GOT16 .text
 
-# N32-FIXME: lw  $25, %call16(.text)($gp)          # encoding: [0x8f,0x99,A,A]
-# N32-FIXME:                                       #   fixup A - offset: 0, value: %call16(.text), kind: fixup_Mips_GOT_DISP
+# N32: lw	$25, %got_disp(.text)($gp) # encoding: [0x8f,0x99,A,A]
+# N32-NEXT:                                       #   fixup A - offset: 0, value: %got_disp(.text), kind: fixup_Mips_GOT_DISP
 
 # ELF-N32:      8f 99 00 00 lw $25, 0($gp)
-# ELF-N32-NEXT:                 R_MIPS_CALL16/R_MIPS_NONE/R_MIPS_NONE .text
+# ELF-N32-NEXT:                 R_MIPS_GOT_DISP/R_MIPS_NONE/R_MIPS_NONE	.text
 
-# N64-FIXME: ld  $25, %call16(.text)($gp)          # encoding: [0xdf,0x99,A,A]
-# N64-FIXME:                                       #   fixup A - offset: 0, value: %call16(.text), kind: fixup_Mips_GOT_DISP
+# N64: ld	$25, %got_disp(.text)($gp) # encoding: [0xdf,0x99,A,A]
+# N64-NEXT:                                       #   fixup A - offset: 0, value: %got_disp(.text), kind: fixup_Mips_GOT_DISP
 
 # ELF-N64:      df 99 00 00 ld $25, 0($gp)
-# ELF-N64-NEXT:                 R_MIPS_CALL16/R_MIPS_NONE/R_MIPS_NONE .text
+# ELF-N64-NEXT:                 R_MIPS_GOT_DISP/R_MIPS_NONE/R_MIPS_NONE	.text
 
-# O32-MM-FIXME: lw    $25, %got(.text)($gp)      # encoding: [0xff,0x3c,A,A]
-# O32-MM-FIXME:                                  #   fixup A - offset: 0, value: %got(.text), kind: fixup_MICROMIPS_GOT16
-# O32-MM-FIXME: addiu $25, $25, %lo(.text)       # encoding: [0x33,0x39,A,A]
-# O32-MM-FIXME:                                  #   fixup A - offset: 0, value: %lo(.text), kind: fixup_MICROMIPS_LO16
+# O32-MM: lw    $25, %got(.text)($gp)      # encoding: [0xff,0x3c,A,A]
+# O32-MM-NEXT:                                  #   fixup A - offset: 0, value: %got(.text), kind: fixup_MICROMIPS_GOT16
+# O32-MM-NEXT: addiu $25, $25, %lo(.text)       # encoding: [0x33,0x39,A,A]
+# O32-MM-NEXT:                                  #   fixup A - offset: 0, value: %lo(.text), kind: fixup_MICROMIPS_LO16
 
-# N32-MM-FIXME: lw    $25, %got_disp(.text)($gp) # encoding: [0xff,0x3c,A,A]
-# N32-MM-FIXME:                                  #   fixup A - offset: 0, value: %got_disp(.text), kind: fixup_MICROMIPS_GOT_DISP
+# N32-MM: lw    $25, %got_disp(.text)($gp) # encoding: [0xff,0x3c,A,A]
+# N32-MM-NEXT:                                  #   fixup A - offset: 0, value: %got_disp(.text), kind: fixup_MICROMIPS_GOT_DISP
 
-# N64-MM-FIXME: ld    $25, %got_disp(.text)($gp) # encoding: [0xdf,0x99,A,A]
-# N64-MM-FIXME:                                  #   fixup A - offset: 0, value: %got_disp(.text), kind: fixup_MICROMIPS_GOT_DISP
+# N64-MM: ld    $25, %got_disp(.text)($gp) # encoding: [0xdf,0x99,A,A]
+# N64-MM-NEXT:                                  #   fixup A - offset: 0, value: %got_disp(.text), kind: fixup_MICROMIPS_GOT_DISP
 
 # MIPS: jalr $25      # encoding: [0x03,0x20,0xf8,0x09]
 # MM:   jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
@@ -199,7 +197,7 @@ local_label:
 
 # ELF-O32:      8f 99 00 00 lw $25, 0($gp)
 # ELF-O32-NEXT:                 R_MIPS_GOT16 .text
-# ELF-O32-NEXT: 27 39 00 54 addiu $25, $25, 84
+# ELF-O32-NEXT: 27 39 00 58 	addiu	$25, $25, 88
 # ELF-O32-NEXT:                 R_MIPS_LO16 .text
 
 # N32: lw  $25, %got_disp($tmp0)($gp) # encoding: [0x8f,0x99,A,A]
@@ -241,7 +239,7 @@ local_label:
 
 # ELF-O32:      8f 99 00 00 lw $25, 0($gp)
 # ELF-O32-NEXT:                 R_MIPS_GOT16 .text
-# ELF-O32-NEXT: 27 39 00 60 addiu $25, $25, 96
+# ELF-O32-NEXT: 27 39 00 64 	addiu	$25, $25, 100
 # ELF-O32-NEXT:                 R_MIPS_LO16 .text
 
 # N32-FIXME: lw  $25, %got_disp(forward_local)($gp)            # encoding: [0x8f,0x99,A,A]