Revert "[WebAssembly] LSDA info generation"

This reverts commit r344575.
Newly introduced test eh-lsda.ll.test fails with use-after-free under
ASAN build.

llvm-svn: 344639

6 files changed, 8 insertions, 140 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 526f7ce3083..63c5b262edc 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -16,7 +16,6 @@
 #include "CodeViewDebug.h"
 #include "DwarfDebug.h"
 #include "DwarfException.h"
-#include "WasmException.h"
 #include "WinCFGuard.h"
 #include "WinException.h"
 #include "llvm/ADT/APFloat.h"
@@ -357,7 +356,7 @@ bool AsmPrinter::doInitialization(Module &M) {
     }
     break;
   case ExceptionHandling::Wasm:
-    ES = new WasmException(this);
+    // TODO to prevent warning
     break;
   }
   if (ES)
diff --git a/llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt b/llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt
index 3fb088ab6f0..6cba4a0d4b8 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt
+++ b/llvm/lib/CodeGen/AsmPrinter/CMakeLists.txt
@@ -23,7 +23,6 @@ add_llvm_library(LLVMAsmPrinter
   WinCFGuard.cpp
   WinException.cpp
   CodeViewDebug.cpp
-  WasmException.cpp
 
   DEPENDS
   intrinsics_gen
diff --git a/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp b/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp
index 7599121de2b..be04b9a6e8c 100644
--- a/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/EHStreamer.cpp
@@ -345,9 +345,7 @@ computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
 ///     unwound and handling continues.
 ///  3. Type ID table contains references to all the C++ typeinfo for all
 ///     catches in the function.  This tables is reverse indexed base 1.
-///
-/// Returns the starting symbol of an exception table.
-MCSymbol *EHStreamer::emitExceptionTable() {
+void EHStreamer::emitExceptionTable() {
   const MachineFunction *MF = Asm->MF;
   const std::vector<const GlobalValue *> &TypeInfos = MF->getTypeInfos();
   const std::vector<unsigned> &FilterIds = MF->getFilterIds();
@@ -377,7 +375,6 @@ MCSymbol *EHStreamer::emitExceptionTable() {
   computeCallSiteTable(CallSites, LandingPads, FirstActions);
 
   bool IsSJLJ = Asm->MAI->getExceptionHandlingType() == ExceptionHandling::SjLj;
-  bool IsWasm = Asm->MAI->getExceptionHandlingType() == ExceptionHandling::Wasm;
   unsigned CallSiteEncoding =
       IsSJLJ ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_uleb128;
   bool HaveTTData = !TypeInfos.empty() || !FilterIds.empty();
@@ -460,8 +457,8 @@ MCSymbol *EHStreamer::emitExceptionTable() {
   Asm->EmitLabelDifferenceAsULEB128(CstEndLabel, CstBeginLabel);
   Asm->OutStreamer->EmitLabel(CstBeginLabel);
 
-  // SjLj / Wasm Exception handling
-  if (IsSJLJ || IsWasm) {
+  // SjLj Exception handling
+  if (IsSJLJ) {
     unsigned idx = 0;
     for (SmallVectorImpl<CallSiteEntry>::const_iterator
          I = CallSites.begin(), E = CallSites.end(); I != E; ++I, ++idx) {
@@ -607,7 +604,6 @@ MCSymbol *EHStreamer::emitExceptionTable() {
   }
 
   Asm->EmitAlignment(2);
-  return GCCETSym;
 }
 
 void EHStreamer::emitTypeInfos(unsigned TTypeEncoding, MCSymbol *TTBaseLabel) {
diff --git a/llvm/lib/CodeGen/AsmPrinter/EHStreamer.h b/llvm/lib/CodeGen/AsmPrinter/EHStreamer.h
index e3a6f8e9d58..b89421a1e06 100644
--- a/llvm/lib/CodeGen/AsmPrinter/EHStreamer.h
+++ b/llvm/lib/CodeGen/AsmPrinter/EHStreamer.h
@@ -85,10 +85,9 @@ protected:
   /// zero for the landing pad and the action.  Calls marked 'nounwind' have
   /// no entry and must not be contained in the try-range of any entry - they
   /// form gaps in the table.  Entries must be ordered by try-range address.
-  virtual void computeCallSiteTable(
-      SmallVectorImpl<CallSiteEntry> &CallSites,
-      const SmallVectorImpl<const LandingPadInfo *> &LandingPads,
-      const SmallVectorImpl<unsigned> &FirstActions);
+  void computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
+                            const SmallVectorImpl<const LandingPadInfo *> &LandingPads,
+                            const SmallVectorImpl<unsigned> &FirstActions);
 
   /// Emit landing pads and actions.
   ///
@@ -109,9 +108,7 @@ protected:
   ///     found the frame is unwound and handling continues.
   ///  3. Type id table contains references to all the C++ typeinfo for all
   ///     catches in the function.  This tables is reversed indexed base 1.
-  ///
-  /// Returns the starting symbol of an exception table.
-  MCSymbol *emitExceptionTable();
+  void emitExceptionTable();
 
   virtual void emitTypeInfos(unsigned TTypeEncoding, MCSymbol *TTBaseLabel);
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/WasmException.cpp b/llvm/lib/CodeGen/AsmPrinter/WasmException.cpp
deleted file mode 100644
index 46745d08c9f..00000000000
--- a/llvm/lib/CodeGen/AsmPrinter/WasmException.cpp
+++ /dev/null
@@ -1,81 +0,0 @@
-//===-- CodeGen/AsmPrinter/WasmException.cpp - Wasm Exception Impl --------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file contains support for writing WebAssembly exception info into asm
-// files.
-//
-//===----------------------------------------------------------------------===//
-
-#include "WasmException.h"
-#include "llvm/MC/MCStreamer.h"
-using namespace llvm;
-
-void WasmException::markFunctionEnd() {
-  // Get rid of any dead landing pads.
-  if (!Asm->MF->getLandingPads().empty()) {
-    auto *NonConstMF = const_cast<MachineFunction *>(Asm->MF);
-    // Wasm does not set BeginLabel and EndLabel information for landing pads,
-    // so we should set the second argument false.
-    NonConstMF->tidyLandingPads(nullptr, /* TidyIfNoBeginLabels */ false);
-  }
-}
-
-void WasmException::endFunction(const MachineFunction *MF) {
-  bool ShouldEmitExceptionTable = false;
-  for (const LandingPadInfo &Info : MF->getLandingPads()) {
-    if (MF->hasWasmLandingPadIndex(Info.LandingPadBlock)) {
-      ShouldEmitExceptionTable = true;
-      break;
-    }
-  }
-  if (!ShouldEmitExceptionTable)
-    return;
-  MCSymbol *LSDALabel = emitExceptionTable();
-  assert(LSDALabel && ".GCC_exception_table has not been emitted!");
-
-  // Wasm requires every data section symbol to have a .size set. So we emit an
-  // end marker and set the size as the difference between the start end the end
-  // marker.
-  MCSymbol *LSDAEndLabel = Asm->createTempSymbol("GCC_except_table_end");
-  Asm->OutStreamer->EmitLabel(LSDAEndLabel);
-  MCContext &OutContext = Asm->OutStreamer->getContext();
-  const MCExpr *SizeExp = MCBinaryExpr::createSub(
-      MCSymbolRefExpr::create(LSDAEndLabel, OutContext),
-      MCSymbolRefExpr::create(LSDALabel, OutContext), OutContext);
-  Asm->OutStreamer->emitELFSize(LSDALabel, SizeExp);
-}
-
-// Compute the call-site table for wasm EH. Even though we use the same function
-// name to share the common routines, a call site entry in the table corresponds
-// to not a call site for possibly-throwing functions but a landing pad. In wasm
-// EH the VM is responsible for stack unwinding. After an exception occurs and
-// the stack is unwound, the control flow is transferred to wasm 'catch'
-// instruction by the VM, after which the personality function is called from
-// the compiler-generated code. Refer to WasmEHPrepare pass for more
-// information.
-void WasmException::computeCallSiteTable(
-    SmallVectorImpl<CallSiteEntry> &CallSites,
-    const SmallVectorImpl<const LandingPadInfo *> &LandingPads,
-    const SmallVectorImpl<unsigned> &FirstActions) {
-  MachineFunction &MF = *Asm->MF;
-  for (unsigned I = 0, N = LandingPads.size(); I < N; ++I) {
-    const LandingPadInfo *Info = LandingPads[I];
-    MachineBasicBlock *LPad = Info->LandingPadBlock;
-    // We don't emit LSDA for single catch (...).
-    if (!MF.hasWasmLandingPadIndex(LPad))
-      continue;
-    // Wasm EH must maintain the EH pads in the order assigned to them by the
-    // WasmEHPrepare pass.
-    unsigned LPadIndex = MF.getWasmLandingPadIndex(LPad);
-    CallSiteEntry Site = {nullptr, nullptr, Info, FirstActions[I]};
-    if (CallSites.size() < LPadIndex + 1)
-      CallSites.resize(LPadIndex + 1);
-    CallSites[LPadIndex] = Site;
-  }
-}
diff --git a/llvm/lib/CodeGen/AsmPrinter/WasmException.h b/llvm/lib/CodeGen/AsmPrinter/WasmException.h
deleted file mode 100644
index 09a9a25ce8d..00000000000
--- a/llvm/lib/CodeGen/AsmPrinter/WasmException.h
+++ /dev/null
@@ -1,42 +0,0 @@
-//===-- WasmException.h - Wasm Exception Framework -------------*- C++ -*--===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file contains support for writing WebAssembly exception info into asm
-// files.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_WASMEXCEPTION_H
-#define LLVM_LIB_CODEGEN_ASMPRINTER_WASMEXCEPTION_H
-
-#include "EHStreamer.h"
-#include "llvm/CodeGen/AsmPrinter.h"
-
-namespace llvm {
-
-class LLVM_LIBRARY_VISIBILITY WasmException : public EHStreamer {
-public:
-  WasmException(AsmPrinter *A) : EHStreamer(A) {}
-
-  void endModule() override {}
-  void beginFunction(const MachineFunction *MF) override {}
-  virtual void markFunctionEnd() override;
-  void endFunction(const MachineFunction *MF) override;
-
-protected:
-  // Compute the call site table for wasm EH.
-  void computeCallSiteTable(
-      SmallVectorImpl<CallSiteEntry> &CallSites,
-      const SmallVectorImpl<const LandingPadInfo *> &LandingPads,
-      const SmallVectorImpl<unsigned> &FirstActions) override;
-};
-
-} // End of namespace llvm
-
-#endif