[PATCH] D117040: [PowerPC][AIX] Override markFunctionEnd()

[Sean Fertile via Phabricator via llvm-commits]

sfertile created this revision.
sfertile added reviewers: xingxue, DiggerLin, daltenty.
sfertile added a project: PowerPC.
Herald added subscribers: shchenz, hiraditya, nemanjai.
sfertile requested review of this revision.
Herald added a project: LLVM.

During fast-isel calling 'markFunctionEnd' in the base class will call tidyLandingPads. This can cause an issue where we have determined that we need ehinfo and emitted a traceback table with the bits set to indicate that we will be emitting the ehinfo, but the tidying deletes all  landing pads. In this case we end up emitting a reference to __ehinfo.N symbol, but not emitting a definition to said symbol and the resulting file fails to assemble.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D117040

Files:
  llvm/lib/CodeGen/AsmPrinter/AIXException.cpp
  llvm/lib/CodeGen/AsmPrinter/DwarfException.h
  llvm/test/CodeGen/PowerPC/aix-ehinfo-sym.ll


Index: llvm/test/CodeGen/PowerPC/aix-ehinfo-sym.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/PowerPC/aix-ehinfo-sym.ll
@@ -0,0 +1,50 @@
+; RUN: llc -mtriple powerpc64-ibm-aix -verify-machineinstrs < %s | \
+; RUN:  FileCheck %s
+
+; RUN: llc -mtriple powerpc64-ibm-aix -fast-isel -verify-machineinstrs < %s | \
+; RUN:  FileCheck %s
+
+; Function Attrs: nounwind
+declare i32 @func1() #0
+
+declare i32 @__xlcxx_personality_v1(...)
+
+; Function Attrs: mustprogress noinline optnone
+define linkonce_odr void @func2() #1 align 2 personality i8* bitcast (i32 (...)* @__xlcxx_personality_v1 to i8*) {
+entry:
+  %0 = alloca i8*, align 8
+  %1 = alloca i32, align 4
+  br label %2
+
+2:                                                ; preds = %3, %entry
+  br i1 false, label %3, label %8
+
+3:                                                ; preds = %2
+  %4 = invoke i32 @func1()
+          to label %2 unwind label %lpad
+
+lpad:                                                ; preds = %3
+  %5 = landingpad { i8*, i32 }
+          cleanup
+  %6 = extractvalue { i8*, i32 } %5, 0
+  store i8* %6, i8** %0, align 8
+  %7 = extractvalue { i8*, i32 } %5, 1
+  store i32 %7, i32* %1, align 4
+  br label %eh.resume
+
+8:                                               ; preds = 2%
+  ret void
+
+eh.resume:                                               ; preds = %lpad
+  %9 = load i8*, i8** %0, align 8
+  %10 = load i32, i32* %1, align 4
+  %11 = insertvalue { i8*, i32 } undef, i8* %9, 0
+  %12 = insertvalue { i8*, i32 } %11, i32 %10, 1
+  resume { i8*, i32 } %12
+}
+
+attributes #0 = { nounwind }
+attributes #1 = { mustprogress noinline optnone }
+
+; CHECK: __ehinfo.0:
+; CHECK: .tc __ehinfo.0[TC],__ehinfo.0
Index: llvm/lib/CodeGen/AsmPrinter/DwarfException.h
===================================================================
--- llvm/lib/CodeGen/AsmPrinter/DwarfException.h
+++ llvm/lib/CodeGen/AsmPrinter/DwarfException.h
@@ -98,6 +98,8 @@
 public:
   AIXException(AsmPrinter *A);
 
+  void markFunctionEnd() override;
+
   void endModule() override {}
   void beginFunction(const MachineFunction *MF) override {}
 
Index: llvm/lib/CodeGen/AsmPrinter/AIXException.cpp
===================================================================
--- llvm/lib/CodeGen/AsmPrinter/AIXException.cpp
+++ llvm/lib/CodeGen/AsmPrinter/AIXException.cpp
@@ -23,6 +23,10 @@
 
 AIXException::AIXException(AsmPrinter *A) : DwarfCFIExceptionBase(A) {}
 
+void AIXException::markFunctionEnd() {
+  endFragment();
+}
+
 void AIXException::emitExceptionInfoTable(const MCSymbol *LSDA,
                                           const MCSymbol *PerSym) {
   // Generate EH Info Table.


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