[AArch64] Avoid crashing on .seh directives in assembly

Differential Revision: https://reviews.llvm.org/D55670

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349549 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/MC/MCWin64EH.cpp b/lib/MC/MCWin64EH.cpp
index 5268d2752d8f467106950df9e21b04f2b34a50b3..0724b109e1a1da6ab89a43e7c4d3561e6470bc7a 100644 (file)
--- a/lib/MC/MCWin64EH.cpp
+++ b/lib/MC/MCWin64EH.cpp
@@ -468,10 +468,10 @@ static void ARM64EmitUnwindInfo(MCStreamer &streamer, WinEH::FrameInfo *info) {
   info->Symbol = Label;
 
   uint32_t FuncLength = 0x0;
-  FuncLength = (uint32_t)GetAbsDifference(streamer, info->FuncletOrFuncEnd,
-                                          info->Begin);
-  if (FuncLength)
-    FuncLength /= 4;
+  if (info->FuncletOrFuncEnd)
+    FuncLength = (uint32_t)GetAbsDifference(streamer, info->FuncletOrFuncEnd,
+                                            info->Begin);
+  FuncLength /= 4;
   uint32_t PrologCodeBytes = ARM64CountOfUnwindCodes(info->Instructions);
   uint32_t TotalCodeBytes = PrologCodeBytes;
 

diff --git a/test/MC/AArch64/seh.s b/test/MC/AArch64/seh.s
new file mode 100644 (file)
index 0000000..ca862cb
--- /dev/null
+++ b/test/MC/AArch64/seh.s
@@ -0,0 +1,84 @@
+// This test checks that the SEH directives emit the correct unwind data.
+
+// RUN: llvm-mc -triple aarch64-pc-win32 -filetype=obj %s | llvm-readobj -s -r | FileCheck %s
+
+// CHECK:      Sections [
+// CHECK:        Section {
+// CHECK:          Name: .text
+// CHECK:          RelocationCount: 0
+// CHECK:          Characteristics [
+// CHECK-NEXT:       ALIGN_4BYTES
+// CHECK-NEXT:       CNT_CODE
+// CHECK-NEXT:       MEM_EXECUTE
+// CHECK-NEXT:       MEM_READ
+// CHECK-NEXT:     ]
+// CHECK-NEXT:   }
+// CHECK:        Section {
+// CHECK:          Name: .xdata
+// CHECK:          RawDataSize: 24
+// CHECK:          RelocationCount: 1
+// CHECK:          Characteristics [
+// CHECK-NEXT:       ALIGN_4BYTES
+// CHECK-NEXT:       CNT_INITIALIZED_DATA
+// CHECK-NEXT:       MEM_READ
+// CHECK-NEXT:     ]
+// CHECK-NEXT:   }
+// CHECK:        Section {
+// CHECK:          Name: .pdata
+// CHECK:          RelocationCount: 6
+// CHECK:          Characteristics [
+// CHECK-NEXT:       ALIGN_4BYTES
+// CHECK-NEXT:       CNT_INITIALIZED_DATA
+// CHECK-NEXT:       MEM_READ
+// CHECK-NEXT:     ]
+// CHECK-NEXT:   }
+// CHECK-NEXT: ]
+
+// CHECK-NEXT: Relocations [
+// CHECK-NEXT:   Section (4) .xdata {
+// CHECK-NEXT:     0x8 IMAGE_REL_ARM64_ADDR32NB __C_specific_handler
+// CHECK-NEXT:   }
+// CHECK-NEXT:   Section (5) .pdata {
+// CHECK-NEXT:     0x0 IMAGE_REL_ARM64_ADDR32NB func
+// CHECK-NEXT:     0x4 IMAGE_REL_ARM64_ADDR32NB .xdata
+// CHECK-NEXT:     0x8 IMAGE_REL_ARM64_ADDR32NB func
+// CHECK-NEXT:     0xC IMAGE_REL_ARM64_ADDR32NB .xdata
+// CHECK-NEXT:     0x10 IMAGE_REL_ARM64_ADDR32NB smallFunc
+// CHECK-NEXT:     0x14 IMAGE_REL_ARM64_ADDR32NB .xdata
+// CHECK-NEXT:   }
+// CHECK-NEXT: ]
+
+
+    .text
+    .globl func
+    .def func
+    .scl 2
+    .type 32
+    .endef
+    .seh_proc func
+func:
+    sub sp, sp, #24
+    .seh_stackalloc 24
+    mov x29, sp
+    .seh_endprologue
+    .seh_handler __C_specific_handler, @except
+    .seh_handlerdata
+    .long 0
+    .text
+    .seh_startchained
+    .seh_endprologue
+    .seh_endchained
+    add sp, sp, #24
+    ret
+    .seh_endproc
+
+// Test emission of small functions.
+    .globl smallFunc
+    .def smallFunc
+    .scl 2
+    .type 32
+    .endef
+    .seh_proc smallFunc
+smallFunc:
+    ret
+    .seh_endproc