[llvm][SelectionDAG] Fix up chains in lowerInvokeable. rdar://113994760

lowerInvokeable wasn't updating the returned chain after emitting the
lowerEndEH, which caused SwiftErrorVal-handling code to re-set the DAG root,
and thus accidentally skip the EH_LABEL node it was supposed to have addeed.
After fixing that, a few places needed to be adjusted that assume the specific
shape of the returned DAG.

Fixes: #64826
Fixes: rdar://113994760

Author: jroelofs

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -8592,6 +8592,7 @@ SelectionDAGBuilder::lowerInvokable(TargetLowering::CallLoweringInfo &CLI,
   if (EHPadBB) {
     DAG.setRoot(lowerEndEH(getRoot(), cast_or_null<InvokeInst>(CLI.CB), EHPadBB,
                            BeginLabel));
+    Result.second = getRoot();
   }
 
   return Result;
@@ -10389,6 +10390,8 @@ void SelectionDAGBuilder::visitPatchpoint(const CallBase &CB,
   std::pair<SDValue, SDValue> Result = lowerInvokable(CLI, EHPadBB);
 
   SDNode *CallEnd = Result.second.getNode();
+  if (CallEnd->getOpcode() == ISD::EH_LABEL)
+    CallEnd = CallEnd->getOperand(0).getNode();
   if (HasDef && (CallEnd->getOpcode() == ISD::CopyFromReg))
     CallEnd = CallEnd->getOperand(0).getNode();
 

llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp

@@ -340,6 +340,9 @@ static std::pair<SDValue, SDNode *> lowerCallFromStatepointLoweringInfo(
   // to grab the return value from the return register(s), or it can be a LOAD
   // to load a value returned by reference via a stack slot.
 
+  if (CallEnd->getOpcode() == ISD::EH_LABEL)
+    CallEnd = CallEnd->getOperand(0).getNode();
+
   bool HasDef = !SI.CLI.RetTy->isVoidTy();
   if (HasDef) {
     if (CallEnd->getOpcode() == ISD::LOAD)

llvm/test/CodeGen/X86/issue64826-switferror-eh.ll

@@ -0,0 +1,75 @@
+; RUN: llc %s -filetype=obj -o - | llvm-readobj -r - | FileCheck %s --check-prefix=RELOC
+; RUN: llc %s -mtriple=x86_64-apple-macosx -o - | FileCheck %s --check-prefix=ASM
+
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx"
+
+define swiftcc void @rdar113994760() personality ptr @__gcc_personality_v0 {
+entry:
+  %swifterror = alloca swifterror ptr, align 8
+  invoke swiftcc void null(i64 0, ptr null, ptr swifterror %swifterror)
+          to label %.noexc unwind label %tsan_cleanup
+
+.noexc:                                           ; preds = %entry
+  ret void
+
+tsan_cleanup:                                     ; preds = %entry
+  %cleanup.lpad = landingpad { ptr, i32 }
+          cleanup
+  resume { ptr, i32 } zeroinitializer
+}
+
+declare i32 @__gcc_personality_v0(...)
+
+; RELOC-LABEL: Relocations [
+; RELOC-NEXT:    Section __text {
+; RELOC-NEXT:      0x18 1 2 1 X86_64_RELOC_BRANCH 0 __Unwind_Resume
+; RELOC-NEXT:    }
+; RELOC-NEXT:    Section __eh_frame {
+; RELOC-NEXT:      0x13 1 2 1 X86_64_RELOC_GOT 0 ___gcc_personality_v0
+; RELOC-NEXT:    }
+; RELOC-NEXT:  ]
+
+; ASM-LABEL: rdar113994760:
+; ASM:       ## %bb.0: ## %entry
+; ASM-NEXT:    pushq %r12
+; ASM-NEXT:    .cfi_def_cfa_offset 16
+; ASM-NEXT:    subq $16, %rsp
+; ASM-NEXT:    .cfi_def_cfa_offset 32
+; ASM-NEXT:    .cfi_offset %r12, -16
+; ASM-NEXT:  Ltmp0:
+; ASM-NEXT:    xorl %eax, %eax
+; ASM-NEXT:    xorl %edi, %edi
+; ASM-NEXT:    xorl %esi, %esi
+; ASM-NEXT:    callq *%rax
+; ASM-NEXT:  Ltmp1:
+; ASM-NEXT:  ## %bb.1: ## %.noexc
+; ASM-NEXT:    addq $16, %rsp
+; ASM-NEXT:    popq %r12
+; ASM-NEXT:    retq
+; ASM-NEXT:  LBB0_2: ## %tsan_cleanup
+; ASM-NEXT:  Ltmp2:
+; ASM-NEXT:    xorl %edi, %edi
+; ASM-NEXT:    callq __Unwind_Resume
+; ASM-NEXT:  Lfunc_end0:
+; ASM-NEXT:    .cfi_endproc
+; ASM-NEXT:    .section        __TEXT,__gcc_except_tab
+; ASM-NEXT:    .p2align        2, 0x0
+; ASM-NEXT: GCC_except_table0:
+; ASM-NEXT: Lexception0:
+; ASM-NEXT:    .byte   255                             ## @LPStart Encoding = omit
+; ASM-NEXT:    .byte   255                             ## @TType Encoding = omit
+; ASM-NEXT:    .byte   1                               ## Call site Encoding = uleb128
+; ASM-NEXT:    .uleb128 Lcst_end0-Lcst_begin0
+; ASM-NEXT: Lcst_begin0:
+; ASM-NEXT:    .uleb128 Ltmp0-Lfunc_begin0             ## >> Call Site 1 <<
+; ASM-NEXT:    .uleb128 Ltmp1-Ltmp0                    ##   Call between Ltmp0 and Ltmp1
+; ASM-NEXT:    .uleb128 Ltmp2-Lfunc_begin0             ##     jumps to Ltmp2
+; ASM-NEXT:    .byte   0                               ##   On action: cleanup
+; ASM-NEXT:    .uleb128 Ltmp1-Lfunc_begin0             ## >> Call Site 2 <<
+; ASM-NEXT:    .uleb128 Lfunc_end0-Ltmp1               ##   Call between Ltmp1 and Lfunc_end0
+; ASM-NEXT:    .byte   0                               ##     has no landing pad
+; ASM-NEXT:    .byte   0                               ##   On action: cleanup
+; ASM-NEXT: Lcst_end0:
+; ASM-NEXT:    .p2align        2, 0x0
+; ASM-NEXT:                                         ## -- End function