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[dwarf] make dwarf fission compatible with RISCV relaxations 2/2 #164813

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[dwarf] make dwarf fission compatible with RISCV relaxations 2/2 #164813

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8 changes: 5 additions & 3 deletions llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -493,10 +493,12 @@ void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
assert(End->isDefined() && "Invalid end label");

addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
if (DD->getDwarfVersion() < 4)
addLabelAddress(D, dwarf::DW_AT_high_pc, End);
else
if (DD->getDwarfVersion() >= 4 &&
(!isDwoUnit() || !llvm::isRangeRelaxable(Begin, End))) {
addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
return;
}
addLabelAddress(D, dwarf::DW_AT_high_pc, End);
}

// Add info for Wasm-global-based relocation.
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44 changes: 30 additions & 14 deletions llvm/test/DebugInfo/RISCV/relax_dwo_ranges.ll
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Original file line number Diff line number Diff line change
@@ -1,12 +1,13 @@
; RUN: llc -dwarf-version=5 -split-dwarf-file=foo.dwo -O0 %s -mtriple=riscv64-unknown-linux-gnu -filetype=obj -o %t
; RUN: llvm-dwarfdump -v %t | FileCheck --check-prefix=DWARF5 %s
; RUN: llvm-dwarfdump --debug-info %t 2> %t.txt
; RUN: FileCheck --input-file=%t.txt %s --check-prefix=RELOCS --implicit-check-not=warning:
; RUN: FileCheck --input-file=%t.txt %s --check-prefix=RELOCS --allow-empty --implicit-check-not=warning:
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Why allow-empty?


; RUN: llc -dwarf-version=4 -split-dwarf-file=foo.dwo -O0 %s -mtriple=riscv64-unknown-linux-gnu -filetype=obj -o %t
; RUN: llvm-dwarfdump -v %t | FileCheck --check-prefix=DWARF4 %s
; RUN: llvm-dwarfdump --debug-info %t 2> %t.txt
; RUN: FileCheck --input-file=%t.txt %s --check-prefix=RELOCS --implicit-check-not=warning:
; RUN: FileCheck --input-file=%t.txt %s --check-prefix=RELOCS --allow-empty --implicit-check-not=warning:
; RUN: llvm-objdump -h %t | FileCheck --check-prefix=HDR %s

; In the RISC-V architecture, the .text section is subject to
; relaxation, meaning the start address of each function can change
Expand Down Expand Up @@ -49,60 +50,75 @@

; clang -g -S -gsplit-dwarf --target=riscv64 -march=rv64gc -O0 relax_dwo_ranges.cpp

; Currently, square() still uses an offset to represent the function's end address,
; which requires a relocation here.
; RELOCS: warning: unexpected relocations for dwo section '.debug_info.dwo'
; RELOCS-NOT: warning: unexpected relocations for dwo section '.debug_info.dwo'
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For -NOT checks I'd try to keep the text matching as vague as possible, so the check is less likely to bit-rot if someone changes the wording and then the thing regresses.

like maybe RELOCS-NOT: warning:?


; Make sure we don't produce any relocations in any .dwo section
; HDR-NOT: .rela.{{.*}}.dwo

; Ensure that 'square()' function uses indexed start and end addresses
; DWARF5: .debug_info.dwo contents:
; DWARF5: DW_TAG_subprogram
; DWARF5-NEXT: DW_AT_low_pc [DW_FORM_addrx] (indexed (00000000) address = 0x0000000000000000 ".text")
; DWARF5-NEXT: DW_AT_high_pc [DW_FORM_data4] (0x00000000)
; DWARF5-NEXT: DW_AT_low_pc [DW_FORM_addrx] (indexed (00000000) address = 0x0000000000000000 ".text")
; DWARF5-NEXT: DW_AT_high_pc [DW_FORM_addrx] (indexed (00000001) address = 0x0000000000000044 ".text")
; DWARF5: DW_AT_name {{.*}} "square")
; DWARF5: DW_TAG_formal_parameter

; HDR-NOT: .rela.{{.*}}.dwo

; Ensure there is no unnecessary addresses in .o file
; DWARF5: .debug_addr contents:
; DWARF5: Addrs: [
; DWARF5-NEXT: 0x0000000000000000
; DWARF5-NEXT: 0x0000000000000044
; DWARF5-NEXT: 0x0000000000000046
; DWARF5-NEXT: 0x000000000000006c
; DWARF5-NEXT: 0x00000000000000b0
; DWARF5-NEXT: ]

; HDR-NOT: .rela.{{.*}}.dwo

; Ensure that 'boo()' and 'main()' use DW_RLE_startx_length and DW_RLE_startx_endx
; entries respectively
; DWARF5: .debug_rnglists.dwo contents:
; DWARF5: ranges:
; DWARF5-NEXT: 0x00000014: [DW_RLE_startx_length]: 0x0000000000000001, 0x0000000000000024 => [0x0000000000000046, 0x000000000000006a)
; DWARF5-NEXT: 0x00000014: [DW_RLE_startx_length]: 0x0000000000000002, 0x0000000000000024 => [0x0000000000000046, 0x000000000000006a)
; DWARF5-NEXT: 0x00000017: [DW_RLE_end_of_list ]
; DWARF5-NEXT: 0x00000018: [DW_RLE_startx_endx ]: 0x0000000000000002, 0x0000000000000003 => [0x000000000000006c, 0x00000000000000b0)
; DWARF5-NEXT: 0x00000018: [DW_RLE_startx_endx ]: 0x0000000000000003, 0x0000000000000004 => [0x000000000000006c, 0x00000000000000b0)
; DWARF5-NEXT: 0x0000001b: [DW_RLE_end_of_list ]
; DWARF5-EMPTY:

; HDR-NOT: .rela.{{.*}}.dwo

; DWARF4: .debug_info.dwo contents:
; DWARF4: DW_TAG_subprogram
; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000000) address = 0x0000000000000000 ".text")
; DWARF4-NEXT: DW_AT_high_pc [DW_FORM_data4] (0x00000000)
; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000000) address = 0x0000000000000000 ".text")
; DWARF4-NEXT: DW_AT_high_pc [DW_FORM_GNU_addr_index] (indexed (00000001) address = 0x0000000000000044 ".text")
; DWARF4: DW_AT_name {{.*}} "square")

; DWARF4: DW_TAG_subprogram
; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000001) address = 0x0000000000000046 ".text")
; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000002) address = 0x0000000000000046 ".text")
; DWARF4-NEXT: DW_AT_high_pc [DW_FORM_data4] (0x00000024)
; DWARF4: DW_AT_name {{.*}} "boo")

; DWARF4: DW_TAG_subprogram
; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000002) address = 0x000000000000006c ".text")
; DWARF4-NEXT: DW_AT_high_pc [DW_FORM_data4] (0x00000000)
; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000003) address = 0x000000000000006c ".text")
; DWARF4-NEXT: DW_AT_high_pc [DW_FORM_GNU_addr_index] (indexed (00000004) address = 0x00000000000000b0 ".text")
; DWARF4: DW_AT_name {{.*}} "main")

; HDR-NOT: .rela.{{.*}}.dwo

; Ensure there is no unnecessary addresses in .o file
; DWARF4: .debug_addr contents:
; DWARF4: Addrs: [
; DWARF4-NEXT: 0x0000000000000000
; DWARF4-NEXT: 0x0000000000000044
; DWARF4-NEXT: 0x0000000000000046
; DWARF4-NEXT: 0x000000000000006c
; DWARF4-NEXT: 0x00000000000000b0
; DWARF4-NEXT: ]

; HDR-NOT: .rela.{{.*}}.dwo

; Function Attrs: mustprogress noinline optnone
define dso_local noundef signext i32 @_Z6squarei(i32 noundef signext %0) #0 !dbg !11 {
%2 = alloca i32, align 4
Expand Down