[llvm] r349549 - [AArch64] Avoid crashing on .seh directives in assembly

[Martin Storsjo via llvm-commits]

Author: mstorsjo
Date: Tue Dec 18 14:10:17 2018
New Revision: 349549

URL: http://llvm.org/viewvc/llvm-project?rev=349549&view=rev
Log:
[AArch64] Avoid crashing on .seh directives in assembly

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

Added:
    llvm/trunk/test/MC/AArch64/seh.s
Modified:
    llvm/trunk/lib/MC/MCWin64EH.cpp

Modified: llvm/trunk/lib/MC/MCWin64EH.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCWin64EH.cpp?rev=349549&r1=349548&r2=349549&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCWin64EH.cpp (original)
+++ llvm/trunk/lib/MC/MCWin64EH.cpp Tue Dec 18 14:10:17 2018
@@ -468,10 +468,10 @@ static void ARM64EmitUnwindInfo(MCStream
   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;
 

Added: llvm/trunk/test/MC/AArch64/seh.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AArch64/seh.s?rev=349549&view=auto
==============================================================================
--- llvm/trunk/test/MC/AArch64/seh.s (added)
+++ llvm/trunk/test/MC/AArch64/seh.s Tue Dec 18 14:10:17 2018
@@ -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