[DebugInfo] Fix emitting DWARF64 .debug_loclists sections (14/19).

[ikudrin]

Summary

The size of the offsets in the table depends on the DWARF format.

[dblaikie]

Looks good.

(note to self/anyone: Be nice if this code wasn't loclist specific/was instead shared with the rnglist handling too)

llvm/test/CodeGen/X86/debug-loclists.ll

26

Should this dump the loclist = XXX value with a wider encoding, since it's stored wider? (I think that's generally the idea you've had for dumping, that the dumper should dump the width of the encoded field?)

[ikudrin]

llvm/test/CodeGen/X86/debug-loclists.ll

26

In general, yes, but with some exceptions. In particular, when we show the offset of the information we dump, like the case we have here. The actual encoding of the value in the field is ULEB, and the stored value is 1, while it indirectly points to offset 0x39 in .debug_loclists.

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

static MCSymbol *emitLoclistsTableHeader(AsmPrinter *Asm,
 
   const auto &DebugLocs = DD.getDebugLocs();
 
   Asm->OutStreamer->AddComment("Offset entry count");
   Asm->emitInt32(DebugLocs.getLists().size());
   Asm->OutStreamer->emitLabel(DebugLocs.getSym());
 
   for (const auto &List : DebugLocs.getLists())
-    Asm->emitLabelDifference(List.Label, DebugLocs.getSym(), 4);
+    Asm->emitLabelDifference(List.Label, DebugLocs.getSym(),
+                             Asm->getDwarfOffsetByteSize());
 
   return TableEnd;
 }
 
 template <typename Ranges, typename PayloadEmitter>
 static void emitRangeList(
     DwarfDebug &DD, AsmPrinter *Asm, MCSymbol *Sym, const Ranges &R,
     const DwarfCompileUnit &CU, unsigned BaseAddressx, unsigned OffsetPair,

llvm/test/CodeGen/X86/debug-loclists-lto.ll

-; RUN: llc -mtriple=x86_64-pc-linux -filetype=asm -function-sections < %s | FileCheck --implicit-check-not=loclists_table_base %s
+; RUN: llc -mtriple=x86_64-pc-linux -filetype=asm -function-sections < %s | \
+; RUN:   FileCheck --check-prefixes=CHECK,DWARF32 --implicit-check-not=loclists_table_base %s
+; RUN: llc -dwarf64 -mtriple=x86_64-pc-linux -filetype=asm -function-sections < %s | \
+; RUN:   FileCheck --check-prefixes=CHECK,DWARF64 --implicit-check-not=loclists_table_base %s
 
-; CHECK: {{^}}.Lloclists_table_base0:
-; CHECK-NEXT: .long   .Ldebug_loc0-.Lloclists_table_base0
-; CHECK-NEXT: .long   .Ldebug_loc1-.Lloclists_table_base0
-; CHECK: .long   .Lloclists_table_base0  # DW_AT_loclists_base
-; CHECK: .long   .Lloclists_table_base0  # DW_AT_loclists_base
+; CHECK:        {{^}}.Lloclists_table_base0:
+; DWARF32-NEXT: .long   .Ldebug_loc0-.Lloclists_table_base0
+; DWARF32-NEXT: .long   .Ldebug_loc1-.Lloclists_table_base0
+; DWARF64-NEXT: .quad   .Ldebug_loc0-.Lloclists_table_base0
+; DWARF64-NEXT: .quad   .Ldebug_loc1-.Lloclists_table_base0
+
+; DWARF32:      .long   .Lloclists_table_base0  # DW_AT_loclists_base
+; DWARF32:      .long   .Lloclists_table_base0  # DW_AT_loclists_base
+; DWARF64:      .quad   .Lloclists_table_base0  # DW_AT_loclists_base
+; DWARF64:      .quad   .Lloclists_table_base0  # DW_AT_loclists_base
 
 ; Function Attrs: uwtable
 define dso_local void @_Z2f2v() local_unnamed_addr #0 !dbg !15 {
 entry:
   tail call void @_Z2f1v(), !dbg !19
   call void @llvm.dbg.value(metadata i32 3, metadata !17, metadata !DIExpression()), !dbg !20
   tail call void @_Z2f1v(), !dbg !21
   ret void, !dbg !22

llvm/test/CodeGen/X86/debug-loclists.ll

 ; RUN: llc -mtriple=x86_64-pc-linux -filetype=obj -function-sections -o %t < %s
-; RUN: llvm-dwarfdump -v -debug-info -debug-loclists %t | FileCheck %s
+; RUN: llvm-dwarfdump -v -debug-info -debug-loclists %t | \
+; RUN:   FileCheck %s --check-prefixes=CHECK,DWARF32
+
+; RUN: llc -dwarf64 -mtriple=x86_64-pc-linux -filetype=obj -function-sections -o %t < %s
+; RUN: llvm-dwarfdump -v -debug-info -debug-loclists %t | \
+; RUN:   FileCheck %s --check-prefixes=CHECK,DWARF64
 
 ; RUN: llc -dwarf-version=5 -split-dwarf-file=foo.dwo -mtriple=x86_64-pc-linux -filetype=obj -function-sections -o %t < %s
-; RUN: llvm-dwarfdump -v -debug-info -debug-loclists %t | FileCheck %s --check-prefix=DWO
+; RUN: llvm-dwarfdump -v -debug-info -debug-loclists %t | \
+; RUN:   FileCheck %s --check-prefixes=DWO,DWO32
+
+; RUN: llc -dwarf64 -dwarf-version=5 -split-dwarf-file=foo.dwo -mtriple=x86_64-pc-linux -filetype=obj -function-sections -o %t < %s
+; RUN: llvm-dwarfdump -v -debug-info -debug-loclists %t | \
+; RUN:   FileCheck %s --check-prefixes=DWO,DWO64
 
-; CHECK:      DW_TAG_variable
-; CHECK-NEXT:   DW_AT_location [DW_FORM_loclistx]   (indexed (0x0) loclist = 0x00000018:
-; CHECK-NEXT:     [0x0000000000000000, 0x0000000000000003) ".text._Z2f1ii": DW_OP_consts +3, DW_OP_stack_value
-; CHECK-NEXT:     [0x0000000000000003, 0x0000000000000004) ".text._Z2f1ii": DW_OP_consts +4, DW_OP_stack_value)
-; CHECK-NEXT:   DW_AT_name {{.*}} "y"
+; CHECK:        DW_TAG_variable
+; DWARF32-NEXT:   DW_AT_location [DW_FORM_loclistx]   (indexed (0x0) loclist = 0x00000018:
+; DWARF64-NEXT:   DW_AT_location [DW_FORM_loclistx]   (indexed (0x0) loclist = 0x0000002c:
+; CHECK-NEXT:       [0x0000000000000000, 0x0000000000000003) ".text._Z2f1ii": DW_OP_consts +3, DW_OP_stack_value
+; CHECK-NEXT:       [0x0000000000000003, 0x0000000000000004) ".text._Z2f1ii": DW_OP_consts +4, DW_OP_stack_value)
+; CHECK-NEXT:     DW_AT_name {{.*}} "y"
 
-; CHECK:      DW_TAG_variable
-; CHECK-NEXT:   DW_AT_location [DW_FORM_loclistx]   (indexed (0x1) loclist = 0x00000029:
-; CHECK-NEXT:     [0x0000000000000000, 0x0000000000000003) ".text._Z2f1ii": DW_OP_consts +5, DW_OP_stack_value)
-; CHECK-NEXT:   DW_AT_name {{.*}} "x"
+; CHECK:        DW_TAG_variable
+; DWARF32-NEXT:   DW_AT_location [DW_FORM_loclistx]   (indexed (0x1) loclist = 0x00000029:
+; DWARF64-NEXT:   DW_AT_location [DW_FORM_loclistx]   (indexed (0x1) loclist = 0x0000003d:
+; CHECK-NEXT:       [0x0000000000000000, 0x0000000000000003) ".text._Z2f1ii": DW_OP_consts +5, DW_OP_stack_value)
+; CHECK-NEXT:     DW_AT_name {{.*}} "x"
 
-; CHECK:      DW_TAG_variable
-; CHECK-NEXT:   DW_AT_location [DW_FORM_loclistx]   (indexed (0x2) loclist = 0x00000031:
-; CHECK-NEXT:     [0x0000000000000003, 0x0000000000000004) ".text._Z2f1ii": DW_OP_reg0 RAX)
-; CHECK-NEXT:   DW_AT_name {{.*}} "r"
+; CHECK:        DW_TAG_variable
+; DWARF32-NEXT:   DW_AT_location [DW_FORM_loclistx]   (indexed (0x2) loclist = 0x00000031:
+; DWARF64-NEXT:   DW_AT_location [DW_FORM_loclistx] (indexed (0x2) loclist = 0x00000045:
+; CHECK-NEXT:       [0x0000000000000003, 0x0000000000000004) ".text._Z2f1ii": DW_OP_reg0 RAX)
+; CHECK-NEXT:     DW_AT_name {{.*}} "r"
 
-; CHECK:      .debug_loclists contents:
-; CHECK-NEXT: 0x00000000: locations list header: length = 0x00000035, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000003
+; CHECK:        .debug_loclists contents:
+; DWARF32-NEXT: 0x00000000: locations list header: length = 0x00000035, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000003
+; DWARF64-NEXT: 0x00000000: locations list header: length = 0x0000000000000041, format = DWARF64, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000003
 
 ; DWO:      .debug_loclists.dwo contents:
-; DWO-NEXT: 0x00000000: locations list header: length = 0x00000035, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000003
+; DWO32-NEXT: 0x00000000: locations list header: length = 0x00000035, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000003
+; DWO64-NEXT: 0x00000000: locations list header: length = 0x0000000000000041, format = DWARF64, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000003
 
-; CHECK-NEXT: offsets: [
-; CHECK-NEXT: 0x0000000c => 0x00000018
-; CHECK-NEXT: 0x0000001d => 0x00000029
-; CHECK-NEXT: 0x00000025 => 0x00000031
-; CHECK-NEXT: ]
+; CHECK-NEXT:   offsets: [
+; DWARF32-NEXT: 0x0000000c => 0x00000018
+; DWARF32-NEXT: 0x0000001d => 0x00000029
+; DWARF32-NEXT: 0x00000025 => 0x00000031
+; DWARF64-NEXT: 0x0000000000000018 => 0x0000002c
+; DWARF64-NEXT: 0x0000000000000029 => 0x0000003d
+; DWARF64-NEXT: 0x0000000000000031 => 0x00000045
+; CHECK-NEXT:   ]
 
 ; Don't use startx_length if there's more than one entry, because the shared
 ; base address will be useful for both the range that does start at the start of
 ; the function, and the one that doesn't.
 
-; CHECK-NEXT: 0x00000018:
+; DWARF32-NEXT: 0x00000018:
+; DWARF64-NEXT: 0x0000002c:
 ; CHECK-NEXT:             DW_LLE_base_addressx (0x0000000000000000)
 ; CHECK-NEXT:             DW_LLE_offset_pair   (0x0000000000000000, 0x0000000000000003): DW_OP_consts +3, DW_OP_stack_value
 ; CHECK-NEXT:             DW_LLE_offset_pair   (0x0000000000000003, 0x0000000000000004): DW_OP_consts +4, DW_OP_stack_value
 ; CHECK-NEXT:             DW_LLE_end_of_list   ()
 
 ; Show that startx_length can be used when the address range starts at the start of the function.
 
-; CHECK:      0x00000029:
+; DWARF32:      0x00000029:
+; DWARF64:      0x0000003d:
 ; CHECK-NEXT:             DW_LLE_startx_length (0x0000000000000000, 0x0000000000000003): DW_OP_consts +5, DW_OP_stack_value
 ; CHECK-NEXT:             DW_LLE_end_of_list   ()
 
 ; And use a base address when the range doesn't start at an existing/useful
 ; address in the pool.
 
-; CHECK:      0x00000031:
+; DWARF32:      0x00000031:
+; DWARF64:      0x00000045:
 ; CHECK-NEXT:             DW_LLE_base_addressx (0x0000000000000000)
 ; CHECK-NEXT:             DW_LLE_offset_pair   (0x0000000000000003, 0x0000000000000004): DW_OP_reg0 RAX
 ; CHECK-NEXT:             DW_LLE_end_of_list   ()
 
 ; Built with clang -O3 -ffunction-sections from source:
 ; 
 ; int f1(int i, int j) {
 ;   int x = 5;