llvm-6502/test/DebugInfo/AArch64/eh_frame.s
Oliver Stannard bb804ee909 Emit DWARF3 call frame information when DWARF3+ debug info is requested
Currently, llvm always emits a DWARF CIE with a version of 1, even when emitting
DWARF 3 or 4, which both support CIE version 3. This patch makes it emit the
newer CIE version when we are emitting DWARF 3 or 4. This will not reduce
compatibility, as we already emit other DWARF3/4 features, and is worth doing as
the DWARF3 spec removed some ambiguities in the interpretation of call frame
information.

It also fixes a minor bug where the "return address" field of the CIE was
encoded as a ULEB128, which is only valid when the CIE version is 3. There are
no test changes for this, because (as far as I can tell) none of the platforms
that we test have a return address register with a DWARF register number >127.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211272 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 15:39:33 +00:00

49 lines
1.5 KiB
ArmAsm

// RUN: llvm-mc -triple aarch64-none-linux-gnu -filetype=obj %s -o %t
// RUN: llvm-objdump -s %t | FileCheck %s
.text
.globl foo
.type foo,@function
foo:
.cfi_startproc
ret
.cfi_endproc
// The really key points we're checking here are:
// * Return register is x30.
// * Pointer format is 0x1b (GNU doesn't appear to understand others).
// The rest is largely incidental, but not expected to change regularly.
// Output is:
// CHECK: Contents of section .eh_frame:
// CHECK-NEXT: 0000 10000000 00000000 037a5200 017c1e01 .........zR..|..
// CHECK-NEXT: 0010 1b0c1f00 10000000 18000000 00000000 ................
// Won't check the rest, it's rather incidental.
// 0020 04000000 00000000 ........
// The first CIE:
// -------------------
// 10000000: length of first CIE = 0x10
// 00000000: This is a CIE
// 03: version = 0x3
// 7a 52 00: augmentation string "zR" -- pointer format is specified
// 01: code alignment factor 1
// 7c: data alignment factor -4
// 1e: return address register 30 (== x30).
// 01: 1 byte of augmentation
// 1b: pointer format 1b: DW_EH_PE_pcrel | DW_EH_PE_sdata4
// 0c 1f 00: initial instructions: "DW_CFA_def_cfa x31 ofs 0" in this case
// Next the FDE:
// -------------
// 10000000: FDE length 0x10
// 18000000: Uses CIE 0x18 backwards (only coincidentally same as above)
// 00000000: PC begin for this FDE is at 00000000 (relocation is applied here)
// 04000000: FDE applies up to PC begin+0x14
// 00: Augmentation string length 0 for this FDE