[CodeView] Saturate values bigger than supported by APInt.

This fixes an assert firing when compiling code which involves 128 bit
integrals.

This would trigger runtime checks similar to this:
```
Assertion failed: getMinSignedBits() <= 64 && "Too many bits for int64_t", file llvm/include/llvm/ADT/APInt.h, line 1646
```

To get around this, we just saturate those big values.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D105320

1 files changed, 25 insertions, 35 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index cbfdd04..bbb0504 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -2116,6 +2116,7 @@ TypeIndex CodeViewDebug::lowerTypeEnum(const DICompositeType *Ty) {
       // We assume that the frontend provides all members in source declaration
       // order, which is what MSVC does.
       if (auto *Enumerator = dyn_cast_or_null<DIEnumerator>(Element)) {
+        // FIXME: Is it correct to always emit these as unsigned here?
         EnumeratorRecord ER(MemberAccess::Public,
                             APSInt(Enumerator->getValue(), true),
                             Enumerator->getName());
@@ -3157,6 +3158,27 @@ void CodeViewDebug::emitGlobalVariableList(ArrayRef<CVGlobalVariable> Globals) {
   }
 }
 
+void CodeViewDebug::emitConstantSymbolRecord(const DIType *DTy, APSInt &Value,
+                                             const std::string &QualifiedName) {
+  MCSymbol *SConstantEnd = beginSymbolRecord(SymbolKind::S_CONSTANT);
+  OS.AddComment("Type");
+  OS.emitInt32(getTypeIndex(DTy).getIndex());
+
+  OS.AddComment("Value");
+
+  // Encoded integers shouldn't need more than 10 bytes.
+  uint8_t Data[10];
+  BinaryStreamWriter Writer(Data, llvm::support::endianness::little);
+  CodeViewRecordIO IO(Writer);
+  cantFail(IO.mapEncodedInteger(Value));
+  StringRef SRef((char *)Data, Writer.getOffset());
+  OS.emitBinaryData(SRef);
+
+  OS.AddComment("Name");
+  emitNullTerminatedSymbolName(OS, QualifiedName);
+  endSymbolRecord(SConstantEnd);
+}
+
 void CodeViewDebug::emitStaticConstMemberList() {
   for (const DIDerivedType *DTy : StaticConstMembers) {
     const DIScope *Scope = DTy->getScope();
@@ -3172,24 +3194,8 @@ void CodeViewDebug::emitStaticConstMemberList() {
     else
       llvm_unreachable("cannot emit a constant without a value");
 
-    std::string QualifiedName = getFullyQualifiedName(Scope, DTy->getName());
-
-    MCSymbol *SConstantEnd = beginSymbolRecord(SymbolKind::S_CONSTANT);
-    OS.AddComment("Type");
-    OS.emitInt32(getTypeIndex(DTy->getBaseType()).getIndex());
-    OS.AddComment("Value");
-
-    // Encoded integers shouldn't need more than 10 bytes.
-    uint8_t Data[10];
-    BinaryStreamWriter Writer(Data, llvm::support::endianness::little);
-    CodeViewRecordIO IO(Writer);
-    cantFail(IO.mapEncodedInteger(Value));
-    StringRef SRef((char *)Data, Writer.getOffset());
-    OS.emitBinaryData(SRef);
-
-    OS.AddComment("Name");
-    emitNullTerminatedSymbolName(OS, QualifiedName);
-    endSymbolRecord(SConstantEnd);
+    emitConstantSymbolRecord(DTy->getBaseType(), Value,
+                             getFullyQualifiedName(Scope, DTy->getName()));
   }
 }
 
@@ -3253,22 +3259,6 @@ void CodeViewDebug::emitDebugInfoForGlobal(const CVGlobalVariable &CVGV) {
                           ? true
                           : DebugHandlerBase::isUnsignedDIType(DIGV->getType());
     APSInt Value(APInt(/*BitWidth=*/64, DIE->getElement(1)), isUnsigned);
-
-    MCSymbol *SConstantEnd = beginSymbolRecord(SymbolKind::S_CONSTANT);
-    OS.AddComment("Type");
-    OS.emitInt32(getTypeIndex(DIGV->getType()).getIndex());
-    OS.AddComment("Value");
-
-    // Encoded integers shouldn't need more than 10 bytes.
-    uint8_t data[10];
-    BinaryStreamWriter Writer(data, llvm::support::endianness::little);
-    CodeViewRecordIO IO(Writer);
-    cantFail(IO.mapEncodedInteger(Value));
-    StringRef SRef((char *)data, Writer.getOffset());
-    OS.emitBinaryData(SRef);
-
-    OS.AddComment("Name");
-    emitNullTerminatedSymbolName(OS, QualifiedName);
-    endSymbolRecord(SConstantEnd);
+    emitConstantSymbolRecord(DIGV->getType(), Value, QualifiedName);
   }
 }