{"fixup_arm_condbl", 0, 24, MCFixupKindInfo::FKF_IsPCRel},
{"fixup_arm_blx", 0, 24, MCFixupKindInfo::FKF_IsPCRel},
{"fixup_arm_thumb_bl", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
- {"fixup_arm_thumb_blx", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ {"fixup_arm_thumb_blx", 0, 32,
+ MCFixupKindInfo::FKF_IsPCRel |
+ MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
{"fixup_arm_thumb_cb", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
{"fixup_arm_thumb_cp", 0, 8,
MCFixupKindInfo::FKF_IsPCRel |
{"fixup_arm_condbl", 8, 24, MCFixupKindInfo::FKF_IsPCRel},
{"fixup_arm_blx", 8, 24, MCFixupKindInfo::FKF_IsPCRel},
{"fixup_arm_thumb_bl", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
- {"fixup_arm_thumb_blx", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ {"fixup_arm_thumb_blx", 0, 32,
+ MCFixupKindInfo::FKF_IsPCRel |
+ MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
{"fixup_arm_thumb_cb", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
{"fixup_arm_thumb_cp", 8, 8,
MCFixupKindInfo::FKF_IsPCRel |
//
// Note that the halfwords are stored high first, low second; so we need
// to transpose the fixup value here to map properly.
- uint32_t offset = (Value - 2) >> 2;
+ if (Ctx && Value % 4 != 0) {
+ Ctx->reportError(Fixup.getLoc(), "misaligned ARM call destination");
+ return 0;
+ }
+
+ uint32_t offset = (Value - 4) >> 2;
if (const MCSymbolRefExpr *SRE =
dyn_cast<MCSymbolRefExpr>(Fixup.getValue()))
if (SRE->getKind() == MCSymbolRefExpr::VK_TLSCALL)
--- /dev/null
+@ RUN: llvm-mc -triple thumbv7-apple-ios -filetype=obj %s -o %t
+@ RUN: llvm-objdump -macho -d %t | FileCheck %s
+
+ @ Size: 2 bytes
+ .thumb_func _f1
+ .thumb
+ .globl _f1
+_f1:
+ bx lr
+
+ @ A properly aligned ARM function
+ .globl _aligned
+ .p2align 2
+ .arm
+_aligned:
+ bx lr
+
+ @ Align this Thumb function so we can predict the outcome of
+ @ "Align(PC, 4)" during blx operation.
+ .thumb_func _test
+ .thumb
+ .p2align 2
+ .globl _test
+_test:
+ blx _elsewhere
+ blx _aligned @ PC=0 (mod 4)
+ blx _aligned @ PC=0 (mod 4)
+ movs r0, r0
+ blx _aligned @ PC=2 (mod 4)
+
+@ CHECK: blx _elsewhere
+@ CHECK: ff f7 fa ef blx _aligned
+@ CHECK: ff f7 f8 ef blx _aligned
+@ CHECK: ff f7 f6 ef blx _aligned
--- /dev/null
+@ RUN: not llvm-mc -triple thumbv7-apple-ios -filetype=obj %s -o /dev/null 2>&1 | FileCheck %s
+ @ Size: 2 bytes
+ .thumb_func _f1
+ .thumb
+ .globl _f1
+_f1:
+ bx lr
+
+ @ A misalgined ARM destination.
+ .arm
+ .globl _misaligned
+_misaligned:
+ bx lr
+
+ @ And a properly aligned one.
+ .globl _aligned
+ .p2align 2
+ .arm
+_aligned:
+ bx lr
+
+ @ Align this Thumb function so we can predict the outcome of
+ @ "Align(PC, 4)" during blx operation.
+ .thumb_func _test
+ .thumb
+ .p2align 2
+ .globl _test
+_test:
+ blx _misaligned @ PC=0 (mod 4)
+ movs r0, r0
+ blx _misaligned @ PC=2 (mod 4)
+ movs r0, r0
+ blx _aligned @ PC=0 (mod 4)
+ movs r0, r0
+ blx _aligned @ PC=2 (mod 4)
+
+@ CHECK: error: misaligned ARM call destination
+@ CHECK: blx _misaligned
+@ CHECK: error: misaligned ARM call destination
+@ CHECK: blx _misaligned