[PowerPC][AIX] Override markFunctionEnd()

[sfertile]

Summary

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.

[sfertile]

Fixed formatting.

[xingxue]

LGTM; thanks!

llvm/lib/CodeGen/AsmPrinter/AIXException.cpp

 #include "llvm/MC/MCStreamer.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
 #include "llvm/Target/TargetMachine.h"
 
 namespace llvm {
 
 AIXException::AIXException(AsmPrinter *A) : DwarfCFIExceptionBase(A) {}
 
+void AIXException::markFunctionEnd() { endFragment(); }
+
 void AIXException::emitExceptionInfoTable(const MCSymbol *LSDA,
                                           const MCSymbol *PerSym) {
   // Generate EH Info Table.
   // The EH Info Table, aka, 'compat unwind section' on AIX, have the following
   // format: struct eh_info_t {
   //   unsigned version;           /* EH info verion 0 */
   // #if defined(__64BIT__)
   //   char _pad[4];               /* padding */

llvm/lib/CodeGen/AsmPrinter/DwarfException.h

 class LLVM_LIBRARY_VISIBILITY AIXException : public DwarfCFIExceptionBase {
   /// This is AIX's compat unwind section, which unwinder would use
   /// to find the location of LSDA area and personality rountine.
   void emitExceptionInfoTable(const MCSymbol *LSDA, const MCSymbol *PerSym);
 
 public:
   AIXException(AsmPrinter *A);
 
+  void markFunctionEnd() override;
+
   void endModule() override {}
   void beginFunction(const MachineFunction *MF) override {}
 
   void endFunction(const MachineFunction *MF) override;
 };
 } // End of namespace llvm
 
 #endif

llvm/test/CodeGen/PowerPC/aix-ehinfo-sym.ll

+; 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