[dwarf] make dwarf fission compatible with RISCV relaxations 2/2 (#164813)
This patch makes DWARF fission compatible with RISC-V relaxations by
using indirect addressing for the DW_AT_high_pc attribute. This
eliminates the remaining relocations in .dwo files.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 751d373..2e4a26e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -493,10 +493,12 @@
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.
diff --git a/llvm/test/DebugInfo/RISCV/relax_dwo_ranges.ll b/llvm/test/DebugInfo/RISCV/relax_dwo_ranges.ll
index ab76ce0..3916a20 100644
--- a/llvm/test/DebugInfo/RISCV/relax_dwo_ranges.ll
+++ b/llvm/test/DebugInfo/RISCV/relax_dwo_ranges.ll
@@ -20,68 +20,81 @@
; RUN: llc -dwarf-version=5 -split-dwarf-file=foo.dwo -O0 -mtriple=riscv64-unknown-linux-gnu -filetype=obj relax_dwo_ranges.ll -o %t.o
; RUN: llvm-dwarfdump -v %t.o | FileCheck --check-prefix=DWARF5 %s
-; RUN: llvm-dwarfdump --debug-info %t.o 2> %t.txt
-; RUN: FileCheck --input-file=%t.txt %s --check-prefix=RELOCS --implicit-check-not=warning:
+; RUN: llvm-dwarfdump --debug-info %t.o > /dev/null 2>&1 | count 0
+; RUN: llvm-objdump -h %t.o | FileCheck --check-prefix=HDR %s
; RUN: llc -dwarf-version=4 -split-dwarf-file=foo.dwo -O0 -mtriple=riscv64-unknown-linux-gnu -filetype=obj relax_dwo_ranges.ll -o %t.o
; RUN: llvm-dwarfdump -v %t.o | FileCheck --check-prefix=DWARF4 %s
-; RUN: llvm-dwarfdump --debug-info %t.o 2> %t.txt
-; RUN: FileCheck --input-file=%t.txt %s --check-prefix=RELOCS --implicit-check-not=warning:
+; RUN: llvm-dwarfdump --debug-info %t.o > /dev/null 2>&1 | count 0
+; RUN: llvm-objdump -h %t.o | FileCheck --check-prefix=HDR %s
-; 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'
+; 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: DW_AT_name {{.*}} "square")
+; 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 = 0x000000000000002c ".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: 0x000000000000002c
+; DWARF5-NEXT: 0x000000000000002c
; DWARF5-NEXT: 0x000000000000003e
; DWARF5-NEXT: 0x000000000000006e
; 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, 0x0000000000000012 => [0x000000000000002c, 0x000000000000003e)
+; DWARF5-NEXT: 0x00000014: [DW_RLE_startx_length]: 0x0000000000000002, 0x0000000000000012 => [0x000000000000002c, 0x000000000000003e)
; DWARF5-NEXT: 0x00000017: [DW_RLE_end_of_list ]
-; DWARF5-NEXT: 0x00000018: [DW_RLE_startx_endx ]: 0x0000000000000002, 0x0000000000000003 => [0x000000000000003e, 0x000000000000006e)
+; DWARF5-NEXT: 0x00000018: [DW_RLE_startx_endx ]: 0x0000000000000003, 0x0000000000000004 => [0x000000000000003e, 0x000000000000006e)
; 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: DW_AT_name {{.*}} "square")
+; 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 = 0x000000000000002c ".text")
+; DWARF4: DW_AT_name {{.*}} "square")
; DWARF4: DW_TAG_subprogram
-; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000001) address = 0x000000000000002c ".text")
+; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000002) address = 0x000000000000002c ".text")
; DWARF4-NEXT: DW_AT_high_pc [DW_FORM_data4] (0x00000012)
-; DWARF4: DW_AT_name {{.*}} "boo")
+; DWARF4: DW_AT_name {{.*}} "boo")
; DWARF4: DW_TAG_subprogram
-; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000002) address = 0x000000000000003e ".text")
-; DWARF4-NEXT: DW_AT_high_pc [DW_FORM_data4] (0x00000000)
-; DWARF4: DW_AT_name {{.*}} "main")
+; DWARF4-NEXT: DW_AT_low_pc [DW_FORM_GNU_addr_index] (indexed (00000003) address = 0x000000000000003e ".text")
+; DWARF4-NEXT: DW_AT_high_pc [DW_FORM_GNU_addr_index] (indexed (00000004) address = 0x000000000000006e ".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: 0x000000000000002c
+; DWARF4-NEXT: 0x000000000000002c
; DWARF4-NEXT: 0x000000000000003e
+; DWARF4-NEXT: 0x000000000000006e
; DWARF4-NEXT: ]
+; HDR-NOT: .rela.{{.*}}.dwo
+
#--- relax_dwo_ranges.cpp
__attribute__((noinline)) int boo();
