[llvm] [MC] Add .loc_label instruction (PR #99710)

[via llvm-commits]

================
@@ -0,0 +1,84 @@
+// Verify that the .loc_label instruction resets the line sequence and generates
+// the requested label at the correct position in the line stream
+
+// RUN: llvm-mc -filetype obj -triple x86_64-linux-elf %s -o %t.o
+// RUN: llvm-dwarfdump -v --debug-line %t.o | FileCheck %s --check-prefix=CHECK-LINE-TABLE
+// RUN: llvm-objdump -s -j .offset_02 -j .offset_03 -j .offset_05 %t.o | FileCheck %s --check-prefix=CHECK-SECTIONS
+
+
+
+# CHECK-LINE-TABLE:                  Address            Line   Column File   ISA Discriminator OpIndex Flags
+# CHECK-LINE-TABLE-NEXT:             ------------------ ------ ------ ------ --- ------------- ------- -------------
+# CHECK-LINE-TABLE-NEXT: 0x00000028: 05 DW_LNS_set_column (1)
+# CHECK-LINE-TABLE-NEXT: 0x0000002a: 00 DW_LNE_set_address (0x0000000000000000)
+# CHECK-LINE-TABLE-NEXT: 0x00000035: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT:             0x0000000000000000      1      1      1   0             0       0  is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x00000036: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT:             0x0000000000000000      1      1      1   0             0       0  is_stmt end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x00000039: 05 DW_LNS_set_column (2)
+# CHECK-LINE-TABLE-NEXT: 0x0000003b: 00 DW_LNE_set_address (0x0000000000000008)
+# CHECK-LINE-TABLE-NEXT: 0x00000046: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT:             0x0000000000000008      1      2      1   0             0       0  is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x00000047: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT:             0x0000000000000008      1      2      1   0             0       0  is_stmt end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000004a: 05 DW_LNS_set_column (3)
+# CHECK-LINE-TABLE-NEXT: 0x0000004c: 00 DW_LNE_set_address (0x0000000000000010)
+# CHECK-LINE-TABLE-NEXT: 0x00000057: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT:             0x0000000000000010      1      3      1   0             0       0  is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x00000058: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT:             0x0000000000000010      1      3      1   0             0       0  is_stmt end_sequence
+# CHECK-LINE-TABLE-NEXT: 0x0000005b: 05 DW_LNS_set_column (4)
+# CHECK-LINE-TABLE-NEXT: 0x0000005d: 00 DW_LNE_set_address (0x0000000000000018)
+# CHECK-LINE-TABLE-NEXT: 0x00000068: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT:             0x0000000000000018      1      4      1   0             0       0  is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x00000069: 05 DW_LNS_set_column (5)
+# CHECK-LINE-TABLE-NEXT: 0x0000006b: 01 DW_LNS_copy
+# CHECK-LINE-TABLE-NEXT:             0x0000000000000018      1      5      1   0             0       0  is_stmt
+# CHECK-LINE-TABLE-NEXT: 0x0000006c: 02 DW_LNS_advance_pc (addr += 9, op-index += 0)
+# CHECK-LINE-TABLE-NEXT: 0x0000006e: 00 DW_LNE_end_sequence
+# CHECK-LINE-TABLE-NEXT:             0x0000000000000021      1      5      1   0             0       0  is_stmt end_sequence
+
+# CHECK-SECTIONS: Contents of section .offset_02:
+# CHECK-SECTIONS-NEXT: 0000 39000000
+
+# CHECK-SECTIONS: Contents of section .offset_03:
+# CHECK-SECTIONS-NEXT: 0000 4a000000
+
+# CHECK-SECTIONS: Contents of section .offset_05:
+# CHECK-SECTIONS-NEXT: 0000 5b000000
+	.text
+	.file	"test.c"
+	.globl	foo
+	.align	16, 0x90
+	.type	foo, at function
+foo:
+.Lfunc_begin0:
+	.file	1 "test.c"
+	.cfi_startproc
+	.loc	1 1 1
+	mov     %rax, 0x01
+	.loc_label my_label_02
+	.loc	1 1 2
+	mov     %rax, 0x02
+	.loc	1 1 3
+	.loc_label my_label_03
+	.loc_label my_label_03.1
+	mov     %rax, 0x03
+	.loc	1 1 4
+	.loc_label my_label_04
+	.loc	1 1 5
+	mov     %rax, 0x04
+	ret
+	.cfi_endproc
+
+	.section	.debug_line,"", at progbits
+.Lline_table_start0:
+
+	.section	.offset_02,"", at progbits
----------------
alx32 wrote:

replaced with `.long` into a single section and added `llvm-readelf` check.

https://github.com/llvm/llvm-project/pull/99710