Revert "[DebugInfo] Enforce implicit constraints on `distinct` MDNodes"

This reverts commit 8cd35ad854ab4458fd509447359066ea3578b494.

It breaks `TestMembersAndLocalsWithSameName.py` on GreenDragon and
Mikael Holmén points out in D104827 that bitcode files created with the
patch cannot be parsed with binaries built before it.

1 files changed, 2 insertions, 15 deletions

diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 1ad55e2..bdb973e 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1758,6 +1758,7 @@ void ModuleBitcodeWriter::writeDIFile(const DIFile *N,
 void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
                                              SmallVectorImpl<uint64_t> &Record,
                                              unsigned Abbrev) {
+  assert(N->isDistinct() && "Expected distinct compile units");
   Record.push_back(/* IsDistinct */ true);
   Record.push_back(N->getSourceLanguage());
   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
@@ -2008,7 +2009,7 @@ void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
                                             SmallVectorImpl<uint64_t> &Record,
                                             unsigned Abbrev) {
   Record.reserve(N->getElements().size() + 1);
-  const uint64_t Version = 4 << 1;
+  const uint64_t Version = 3 << 1;
   Record.push_back((uint64_t)N->isDistinct() | Version);
   Record.append(N->elements_begin(), N->elements_end());
 
@@ -2153,20 +2154,6 @@ void ModuleBitcodeWriter::writeMetadataRecords(
     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
       assert(N->isResolved() && "Expected forward references to be resolved");
 
-#ifndef NDEBUG
-      switch (N->getMetadataID()) {
-#define HANDLE_MDNODE_LEAF_UNIQUED(CLASS)                                      \
-  case Metadata::CLASS##Kind:                                                  \
-    assert(!N->isDistinct() && "Expected non-distinct " #CLASS);               \
-    break;
-#define HANDLE_MDNODE_LEAF_DISTINCT(CLASS)                                     \
-  case Metadata::CLASS##Kind:                                                  \
-    assert(N->isDistinct() && "Expected distinct " #CLASS);                    \
-    break;
-#include "llvm/IR/Metadata.def"
-      }
-#endif
-
       switch (N->getMetadataID()) {
       default:
         llvm_unreachable("Invalid MDNode subclass");