[llvm-pdbutil] Create public symbols in yaml2pdb (#157362)

pdb2yaml dumps the public symbols, but yaml2pdb didn't create these in
the exported PDB. With this PR, they're added to the final PDB.

Author: Nerixyz

llvm/test/tools/llvm-pdbutil/publics-yaml2pdb.test

@@ -0,0 +1,55 @@
+# RUN: llvm-pdbutil yaml2pdb %s --pdb=%t.pdb
+# RUN: llvm-pdbutil dump --publics %t.pdb | FileCheck --check-prefix=CHECK-YAML2PDB %s
+
+# RUN: llvm-pdbutil pdb2yaml --publics-stream %t.pdb > %t.yaml
+# RUN: FileCheck --input-file=%t.yaml --check-prefix=CHECK-PDB2YAML %s
+
+# CHECK-YAML2PDB: S_PUB32 [size = 44] `?AMethod@AClass@@QEAAXHPEAD@Z`
+# CHECK-YAML2PDB:      flags = function, addr = 0001:0480
+# CHECK-YAML2PDB: S_PUB32 [size = 28] `??_7Base@@6B@`
+# CHECK-YAML2PDB:      flags = none, addr = 0002:0000
+# CHECK-YAML2PDB: S_PUB32 [size = 32] `??0Base@@QEAA@XZ`
+# CHECK-YAML2PDB:      flags = function, addr = 0001:0000
+
+# CHECK-PDB2YAML: - Kind:            S_PUB32
+# CHECK-PDB2YAML:   PublicSym32:
+# CHECK-PDB2YAML:     Flags:           [ Function ]
+# CHECK-PDB2YAML:     Offset:          480
+# CHECK-PDB2YAML:     Segment:         1
+# CHECK-PDB2YAML:     Name:            '?AMethod@AClass@@QEAAXHPEAD@Z'
+# CHECK-PDB2YAML: - Kind:            S_PUB32
+# CHECK-PDB2YAML:   PublicSym32:
+# CHECK-PDB2YAML:     Flags:           [  ]
+# CHECK-PDB2YAML:     Offset:          0
+# CHECK-PDB2YAML:     Segment:         2
+# CHECK-PDB2YAML:     Name:            '??_7Base@@6B@'
+# CHECK-PDB2YAML: - Kind:            S_PUB32
+# CHECK-PDB2YAML:   PublicSym32:
+# CHECK-PDB2YAML:     Flags:           [ Function ]
+# CHECK-PDB2YAML:     Offset:          0
+# CHECK-PDB2YAML:     Segment:         1
+# CHECK-PDB2YAML:     Name:            '??0Base@@QEAA@XZ'
+
+---
+PublicsStream:
+  Records:
+    - Kind:            S_PUB32
+      PublicSym32:
+        Flags:           [ Function ]
+        Offset:          480
+        Segment:         1
+        Name:            '?AMethod@AClass@@QEAAXHPEAD@Z'
+    - Kind:            S_PUB32
+      PublicSym32:
+        Flags:           [  ]
+        Offset:          0
+        Segment:         2
+        Name:            '??_7Base@@6B@'
+    - Kind:            S_PUB32
+      PublicSym32:
+        Flags:           [ Function ]
+        Offset:          0
+        Segment:         1
+        Name:            '??0Base@@QEAA@XZ'
+...
+

llvm/tools/llvm-pdbutil/llvm-pdbutil.cpp

@@ -38,6 +38,7 @@
 #include "llvm/DebugInfo/CodeView/LazyRandomTypeCollection.h"
 #include "llvm/DebugInfo/CodeView/MergingTypeTableBuilder.h"
 #include "llvm/DebugInfo/CodeView/StringsAndChecksums.h"
+#include "llvm/DebugInfo/CodeView/SymbolDeserializer.h"
 #include "llvm/DebugInfo/CodeView/TypeStreamMerger.h"
 #include "llvm/DebugInfo/MSF/MSFBuilder.h"
 #include "llvm/DebugInfo/MSF/MappedBlockStream.h"
@@ -49,6 +50,7 @@
 #include "llvm/DebugInfo/PDB/IPDBSession.h"
 #include "llvm/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.h"
 #include "llvm/DebugInfo/PDB/Native/DbiStreamBuilder.h"
+#include "llvm/DebugInfo/PDB/Native/GSIStreamBuilder.h"
 #include "llvm/DebugInfo/PDB/Native/InfoStream.h"
 #include "llvm/DebugInfo/PDB/Native/InfoStreamBuilder.h"
 #include "llvm/DebugInfo/PDB/Native/InputFile.h"
@@ -880,6 +882,24 @@ static void yamlToPdb(StringRef Path) {
     IpiBuilder.addTypeRecord(Type.RecordData, std::nullopt);
   }
 
+  if (YamlObj.PublicsStream) {
+    auto &GsiBuilder = Builder.getGsiBuilder();
+    std::vector<BulkPublic> BulkPublics;
+    for (const auto &P : YamlObj.PublicsStream->PubSyms) {
+      CVSymbol CV = P.toCodeViewSymbol(Allocator, CodeViewContainer::Pdb);
+      auto PS = cantFail(SymbolDeserializer::deserializeAs<PublicSym32>(CV));
+
+      BulkPublic BP;
+      BP.Name = PS.Name.data();
+      BP.NameLen = PS.Name.size();
+      BP.setFlags(PS.Flags);
+      BP.Offset = PS.Offset;
+      BP.Segment = PS.Segment;
+      BulkPublics.emplace_back(BP);
+    }
+    GsiBuilder.addPublicSymbols(std::move(BulkPublics));
+  }
+
   Builder.getStringTableBuilder().setStrings(*Strings.strings());
 
   codeview::GUID IgnoredOutGuid;