[LLDB] Always interpret arm instructions as thumb on windows

Windows on ARM always uses thumb mode, and doesn't have most of the
mechanisms that are used in e.g. ELF for distinguishing between arm
and thumb.

Differential Revision: https://reviews.llvm.org/D70796

diff --git a/lldb/source/Utility/ArchSpec.cpp b/lldb/source/Utility/ArchSpec.cpp
index 62d9d24..38f6752 100644 (file)
--- a/lldb/source/Utility/ArchSpec.cpp
+++ b/lldb/source/Utility/ArchSpec.cpp
@@ -1443,6 +1443,9 @@ bool ArchSpec::IsAlwaysThumbInstructions() const {
         GetCore() == ArchSpec::Core::eCore_thumbv6m) {
       return true;
     }
+    // Windows on ARM is always thumb.
+    if (GetTriple().isOSWindows())
+      return true;
   }
   return false;
 }

diff --git a/lldb/test/Shell/ObjectFile/PECOFF/disassemble-thumb.yaml b/lldb/test/Shell/ObjectFile/PECOFF/disassemble-thumb.yaml
new file mode 100644 (file)
index 0000000..dec2357
--- /dev/null
+++ b/lldb/test/Shell/ObjectFile/PECOFF/disassemble-thumb.yaml
@@ -0,0 +1,92 @@
+# RUN: yaml2obj %s > %t.exe
+# RUN: %lldb %t.exe -o "disassemble -b -n entry" -b | FileCheck %s
+
+# CHECK: {{.*}}.exe[0x401000] <+0>: 0x0040 lsls   r0, r0, #0x1
+# CHECK: {{.*}}.exe[0x401002] <+2>: 0x4770 bx     lr
+
+--- !COFF
+OptionalHeader:
+  AddressOfEntryPoint: 4097
+  ImageBase:       4194304
+  SectionAlignment: 4096
+  FileAlignment:   512
+  MajorOperatingSystemVersion: 6
+  MinorOperatingSystemVersion: 0
+  MajorImageVersion: 0
+  MinorImageVersion: 0
+  MajorSubsystemVersion: 6
+  MinorSubsystemVersion: 0
+  Subsystem:       IMAGE_SUBSYSTEM_WINDOWS_CUI
+  DLLCharacteristics: [ IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE, IMAGE_DLL_CHARACTERISTICS_NX_COMPAT, IMAGE_DLL_CHARACTERISTICS_TERMINAL_SERVER_AWARE ]
+  SizeOfStackReserve: 1048576
+  SizeOfStackCommit: 4096
+  SizeOfHeapReserve: 1048576
+  SizeOfHeapCommit: 4096
+  ExportTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  ImportTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  ResourceTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  ExceptionTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  CertificateTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  BaseRelocationTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  Debug:
+    RelativeVirtualAddress: 0
+    Size:            0
+  Architecture:
+    RelativeVirtualAddress: 0
+    Size:            0
+  GlobalPtr:
+    RelativeVirtualAddress: 0
+    Size:            0
+  TlsTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  LoadConfigTable:
+    RelativeVirtualAddress: 0
+    Size:            0
+  BoundImport:
+    RelativeVirtualAddress: 0
+    Size:            0
+  IAT:
+    RelativeVirtualAddress: 0
+    Size:            0
+  DelayImportDescriptor:
+    RelativeVirtualAddress: 0
+    Size:            0
+  ClrRuntimeHeader:
+    RelativeVirtualAddress: 0
+    Size:            0
+header:
+  Machine:         IMAGE_FILE_MACHINE_ARMNT
+  Characteristics: [ IMAGE_FILE_EXECUTABLE_IMAGE, IMAGE_FILE_32BIT_MACHINE ]
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    VirtualAddress:  4096
+    VirtualSize:     4
+    SectionData:     '40007047'
+symbols:
+  - Name:            .text
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            entry
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+...