Generate IMAGE_REL_AMD64_ADDR32NB relocations for SEH

 data structures.

The Win64 EH data structures must be of type IMAGE_REL_AMD64_ADDR32NB
instead of IMAGE_REL_AMD64_ADDR32. This is easiely achieved by adding
the VK_COFF_IMGREL32 modifier to the symbol reference.
Change also references to start and end of the SEH range of a function
as offsets to start of the function.

Reviewed by Jim Grosbach, Charles Davis and Nico Rieck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190766 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 53 insertions, 16 deletions

diff --git a/lib/MC/MCWin64EH.cpp b/lib/MC/MCWin64EH.cpp
index 8db1fa2a93..c3d568b454 100644
--- a/lib/MC/MCWin64EH.cpp
+++ b/lib/MC/MCWin64EH.cpp
@@ -128,14 +128,29 @@ static void EmitUnwindCode(MCStreamer &streamer, MCSymbol *begin,
   }
 }
 
+static void EmitSymbolRefWithOfs(MCStreamer &streamer,
+                                 const MCSymbol *Base,
+                                 const MCSymbol *Other) {
+  MCContext &Context = streamer.getContext();
+  const MCSymbolRefExpr *BaseRef = MCSymbolRefExpr::Create(Base, Context);
+  const MCSymbolRefExpr *OtherRef = MCSymbolRefExpr::Create(Other, Context);
+  const MCExpr *Ofs = MCBinaryExpr::CreateSub(OtherRef, BaseRef, Context);
+  const MCSymbolRefExpr *BaseRefRel = MCSymbolRefExpr::Create(Base,
+                                              MCSymbolRefExpr::VK_COFF_IMGREL32,
+                                              Context);
+  streamer.EmitValue(MCBinaryExpr::CreateAdd(BaseRefRel, Ofs, Context), 4);
+}
+
 static void EmitRuntimeFunction(MCStreamer &streamer,
                                 const MCWin64EHUnwindInfo *info) {
   MCContext &context = streamer.getContext();
 
   streamer.EmitValueToAlignment(4);
-  streamer.EmitValue(MCSymbolRefExpr::Create(info->Begin, context), 4);
-  streamer.EmitValue(MCSymbolRefExpr::Create(info->End, context), 4);
-  streamer.EmitValue(MCSymbolRefExpr::Create(info->Symbol, context), 4);
+  EmitSymbolRefWithOfs(streamer, info->Function, info->Begin);
+  EmitSymbolRefWithOfs(streamer, info->Function, info->End);
+  streamer.EmitValue(MCSymbolRefExpr::Create(info->Symbol,
+                                             MCSymbolRefExpr::VK_COFF_IMGREL32,
+                                             context), 4);
 }
 
 static void EmitUnwindInfo(MCStreamer &streamer, MCWin64EHUnwindInfo *info) {
@@ -188,8 +203,9 @@ static void EmitUnwindInfo(MCStreamer &streamer, MCWin64EHUnwindInfo *info) {
     EmitRuntimeFunction(streamer, info->ChainedParent);
   else if (flags &
            ((Win64EH::UNW_TerminateHandler|Win64EH::UNW_ExceptionHandler) << 3))
-    streamer.EmitValue(MCSymbolRefExpr::Create(info->ExceptionHandler, context),
-                       4);
+    streamer.EmitValue(MCSymbolRefExpr::Create(info->ExceptionHandler,
+                                              MCSymbolRefExpr::VK_COFF_IMGREL32,
+                                              context), 4);
   else if (numCodes < 2) {
     // The minimum size of an UNWIND_INFO struct is 8 bytes. If we're not
     // a chained unwind info, if there is no handler, and if there are fewer
diff --git a/test/MC/COFF/seh.s b/test/MC/COFF/seh.s
index b1e61a9773..72d42f4b2e 100644
--- a/test/MC/COFF/seh.s
+++ b/test/MC/COFF/seh.s
@@ -1,6 +1,6 @@
 // This test checks that the SEH directives emit the correct unwind data.
 
-// RUN: llvm-mc -triple x86_64-pc-win32 -filetype=obj %s | llvm-readobj -s -u | FileCheck %s
+// RUN: llvm-mc -triple x86_64-pc-win32 -filetype=obj %s | llvm-readobj -s -u -r | FileCheck %s
 
 // CHECK:      Sections [
 // CHECK:        Section {
@@ -34,6 +34,27 @@
 // CHECK-NEXT:   }
 // CHECK-NEXT: ]
 
+// CHECK-NEXT: Relocations [
+// CHECK-NEXT:   Section (2) .xdata {
+// CHECK-NEXT:     0x14 IMAGE_REL_AMD64_ADDR32NB __C_specific_handler
+// CHECK-NEXT:     0x20 IMAGE_REL_AMD64_ADDR32NB func
+// CHECK-NEXT:     0x24 IMAGE_REL_AMD64_ADDR32NB func
+// CHECK-NEXT:     0x28 IMAGE_REL_AMD64_ADDR32NB .xdata
+// CHECK-NEXT:   }
+// CHECK-NEXT:   Section (3) .pdata {
+// CHECK-NEXT:     0x0 IMAGE_REL_AMD64_ADDR32NB func
+// CHECK-NEXT:     0x4 IMAGE_REL_AMD64_ADDR32NB func
+// CHECK-NEXT:     0x8 IMAGE_REL_AMD64_ADDR32NB .xdata
+// CHECK-NEXT:     0xC IMAGE_REL_AMD64_ADDR32NB func
+// CHECK-NEXT:     0x10 IMAGE_REL_AMD64_ADDR32NB func
+// CHECK-NEXT:     0x14 IMAGE_REL_AMD64_ADDR32NB .xdata
+// CHECK-NEXT:     0x18 IMAGE_REL_AMD64_ADDR32NB smallFunc
+// CHECK-NEXT:     0x1C IMAGE_REL_AMD64_ADDR32NB smallFunc
+// CHECK-NEXT:     0x20 IMAGE_REL_AMD64_ADDR32NB .xdata
+// CHECK-NEXT:   }
+// CHECK-NEXT: ]
+
+
 // CHECK:      UnwindInformation [
 // CHECK-NEXT:   RuntimeFunction {
 // CHECK-NEXT:     StartAddress: [[CodeSect1:[^ ]+]] [[BeginDisp1:(\+0x[A-F0-9]+)?]]
diff --git a/test/tools/llvm-objdump/win64-unwind-data.s b/test/tools/llvm-objdump/win64-unwind-data.s
index a172bfca6b..f8463fb062 100644
--- a/test/tools/llvm-objdump/win64-unwind-data.s
+++ b/test/tools/llvm-objdump/win64-unwind-data.s
@@ -3,8 +3,8 @@
 
 // CHECK:      Unwind info:
 // CHECK:      Function Table:
-// CHECK-NEXT: Start Address: .text
-// CHECK-NEXT: End Address: .text + 0x001b
+// CHECK-NEXT: Start Address: func
+// CHECK-NEXT: End Address: func + 0x001b
 // CHECK-NEXT: Unwind Info Address: .xdata
 // CHECK-NEXT: Version: 1
 // CHECK-NEXT: Flags: 1 UNW_ExceptionHandler
@@ -20,8 +20,8 @@
 // CHECK-NEXT: 0x04: UOP_AllocSmall 24
 // CHECK-NEXT: 0x00: UOP_PushMachFrame w/o error code
 // CHECK:      Function Table:
-// CHECK-NEXT: Start Address: .text + 0x0012
-// CHECK-NEXT: End Address: .text + 0x0012
+// CHECK-NEXT: Start Address: func + 0x0012
+// CHECK-NEXT: End Address: func + 0x0012
 // CHECK-NEXT: Unwind Info Address: .xdata + 0x001c
 // CHECK-NEXT: Version: 1
 // CHECK-NEXT: Flags: 4 UNW_ChainInfo
@@ -29,8 +29,8 @@
 // CHECK-NEXT: Number of Codes: 0
 // CHECK-NEXT: No frame pointer used
 // CHECK:      Function Table:
-// CHECK-NEXT: Start Address: .text + 0x001b
-// CHECK-NEXT: End Address: .text + 0x001c
+// CHECK-NEXT: Start Address: smallFunc
+// CHECK-NEXT: End Address: smallFunc + 0x0001
 // CHECK-NEXT: Unwind Info Address: .xdata + 0x002c
 // CHECK-NEXT: Version: 1
 // CHECK-NEXT: Flags: 0
@@ -38,8 +38,8 @@
 // CHECK-NEXT: Number of Codes: 0
 // CHECK-NEXT: No frame pointer used
 // CHECK:      Function Table:
-// CHECK-NEXT: Start Address: .text + 0x001c
-// CHECK-NEXT: End Address: .text + 0x0039
+// CHECK-NEXT: Start Address: allocFunc
+// CHECK-NEXT: End Address: allocFunc + 0x001d
 // CHECK-NEXT: Unwind Info Address: .xdata + 0x0034
 // CHECK-NEXT: Version: 1
 // CHECK-NEXT: Flags: 0
@@ -90,9 +90,9 @@ smallFunc:
     .seh_endproc
 
 // Function with big stack allocation.
-    .globl smallFunc
+    .globl allocFunc
     .def allocFunc; .scl 2; .type 32; .endef
-    .seh_proc smallFunc
+    .seh_proc allocFunc
 allocFunc:
     .seh_pushframe @code
     subq $65520, %rsp