[llvm] [BOLT][DWARF] Cleanup buffer initialization for DWO range writer (PR #97843)

[Alexander Yermolovich via llvm-commits]

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@@ -0,0 +1,80 @@
+; RUN: rm -rf %t
+; RUN: mkdir %t
+; RUN: cd %t
+; RUN: llvm-mc -dwarf-version=4 -filetype=obj -triple x86_64-unknown-linux %p/Inputs/dwarf4-df-input-lowpc-ranges-main.s \
+; RUN: -split-dwarf-file=main.dwo -o main.o
+; RUN: llvm-mc -dwarf-version=4 -filetype=obj -triple x86_64-unknown-linux %p/Inputs/dwarf4-df-input-lowpc-ranges-cus-other.s \
+; RUN: -split-dwarf-file=mainOther.dwo -o other.o
+; RUN: %clang %cflags -gdwarf-4 -gsplit-dwarf=split main.o other.o -o main.exe
+; RUN: llvm-bolt main.exe -o main.exe.bolt --update-debug-sections
+; RUN: llvm-dwarfdump --show-form --verbose --debug-ranges main.exe.bolt &> %t/foo.txt
+; RUN: llvm-dwarfdump --show-form --verbose --debug-info main.exe.bolt >> %t/foo.txt
+; RUN: cat %t/foo.txt | FileCheck -check-prefix=BOLT %s
+; RUN: not llvm-dwarfdump --show-form --verbose --debug-info main.dwo.dwo mainOther.dwo.dwo &> %t/mainddwodwo.txt
+; RUN: cat %t/mainddwodwo.txt | FileCheck -check-prefix=BOLT-DWO-MAIN %s
+
+;; Tests that BOLT correctly handles mixed input with DW_AT_high_pc/DW_at_low_pc and DW_AT_low_pc/DW_AT_ranges.
+
+; BOLT: .debug_ranges
+; BOLT-NEXT: 00000000 <End of list>
+; BOLT-NEXT: 00000010 [[#%.16x,ADDR1:]] [[#%.16x,ADDRB1:]]
+; BOLT-NEXT: 00000010 [[#%.16x,ADDR2:]] [[#%.16x,ADDRB2:]]
+; BOLT-NEXT: 00000010 [[#%.16x,ADDR3:]] [[#%.16x,ADDRB3:]]
+; BOLT-NEXT: 00000010 [[#%.16x,ADDR4:]] [[#%.16x,ADDRB4:]]
+; BOLT-NEXT: 00000010 [[#%.16x,ADDR5:]] [[#%.16x,ADDRB5:]]
+; BOLT-NEXT: 00000010 [[#%.16x,ADDR6:]] [[#%.16x,ADDRB6:]]
+; BOLT-NEXT: 00000010 [[#%.16x,ADDR7:]] [[#%.16x,ADDRB7:]]
+; BOLT-NEXT: 00000010 <End of list>
+; BOLT-NEXT: 00000090 [[#%.16x,ADDR1:]] [[#%.16x,ADDRB1:]]
+; BOLT-NEXT: 00000090 [[#%.16x,ADDR2:]] [[#%.16x,ADDRB2:]]
+; BOLT-NEXT: 00000090 [[#%.16x,ADDR3:]] [[#%.16x,ADDRB3:]]
+; BOLT-NEXT: 00000090 <End of list>
+; BOLT-NEXT: 000000d0 [[#%.16x,ADDR5:]] [[#%.16x,ADDRB5:]]
+; BOLT-NEXT: 000000d0 [[#%.16x,ADDR6:]] [[#%.16x,ADDRB6:]]
+; BOLT-NEXT: 000000d0 [[#%.16x,ADDR7:]] [[#%.16x,ADDRB7:]]
+; BOLT-NEXT: 000000d0 <End of list>
+; BOLT-NEXT: 00000110 [[#%.16x,ADDR8:]] [[#%.16x,ADDRB8:]]
+; BOLT-NEXT: 00000110 [[#%.16x,ADDR9:]] [[#%.16x,ADDRB9:]]
+; BOLT-NEXT: 00000110 [[#%.16x,ADDR10:]] [[#%.16x,ADDRB10:]]
+; BOLT-NEXT: 00000110 <End of list>
+
+; BOLT: DW_TAG_compile_unit
+; BOLT: DW_AT_GNU_dwo_name [DW_FORM_strp] ( .debug_str[0x{{[0-9a-fA-F]+}}] = "main.dwo.dwo")
+; BOLT-NEXT: DW_AT_GNU_dwo_id
+; BOLT-NEXT: DW_AT_GNU_ranges_base [DW_FORM_sec_offset]  (0x00000090)
+; BOLT-NEXT: DW_AT_low_pc [DW_FORM_addr] (0x0000000000000000)
+; BOLT-NEXT: DW_AT_ranges [DW_FORM_sec_offset] (0x00000010
+; BOLT-NEXT: [0x[[#ADDR1]], 0x[[#ADDRB1]])
+; BOLT-NEXT: [0x[[#ADDR2]], 0x[[#ADDRB2]])
+; BOLT-NEXT: [0x[[#ADDR3]], 0x[[#ADDRB3]])
+; BOLT-NEXT: [0x[[#ADDR4]], 0x[[#ADDRB4]])
+; BOLT-NEXT: [0x[[#ADDR5]], 0x[[#ADDRB5]])
+; BOLT-NEXT: [0x[[#ADDR6]], 0x[[#ADDRB6]])
+; BOLT-NEXT: [0x[[#ADDR7]], 0x[[#ADDRB7]])
+; BOLT-NEXT: DW_AT_GNU_addr_base [DW_FORM_sec_offset]  (0x00000000)
+; BOLT-NEXT: Compile Unit
+
+; BOLT: DW_TAG_compile_unit
+; BOLT: DW_AT_GNU_dwo_name [DW_FORM_strp] ( .debug_str[0x{{[0-9a-fA-F]+}}] = "mainOther.dwo.dwo")
+; BOLT-NEXT: DW_AT_GNU_dwo_id
+; BOLT-NEXT: DW_AT_low_pc [DW_FORM_addr] (0x0000000000000000)
+; BOLT-NEXT: DW_AT_ranges [DW_FORM_sec_offset] (0x00000110
+; BOLT-NEXT: [0x[[#ADDR8]], 0x[[#ADDRB8]])
+; BOLT-NEXT: [0x[[#ADDR9]], 0x[[#ADDRB9]])
+; BOLT-NEXT: [0x[[#ADDR10]], 0x[[#ADDRB10]])
+; BOLT-NEXT: DW_AT_GNU_addr_base [DW_FORM_sec_offset]  (0x00000018)
+; BOLT-NEXT: DW_AT_GNU_ranges_base [DW_FORM_sec_offset]  (0x00000150)
----------------
ayermolo wrote:

A) It shouldn't really exist.
B) if it does exist it should at least point to something valid. In other PR it was at least pointed to an empty list. Offsets should never be invalid.

https://github.com/llvm/llvm-project/pull/97843