[PDB] Correctly link S_FILESTATIC records.

This is not a record type that clang currently generates,
but it is a record that is encountered in object files generated
by cl.  This record is unusual in that it refers directly to
the string table instead of indirectly to the string table via
the FileChecksums table.  Because of this, it was previously
overlooked and we weren't remapping the string indices at all.
This would lead to crashes in MSVC when trying to display a
variable whose debug info involved an S_FILESTATIC.

Original bug report by Alexander Ganea

Differential Revision: https://reviews.llvm.org/D41718

llvm-svn: 321883

tools/llvm-pdbutil/DumpOutputStyle.cpp

@@ -848,14 +848,7 @@ Error DumpOutputStyle::dumpXme() {
   return Error::success();
 }
 
-Error DumpOutputStyle::dumpStringTable() {
-  printHeader(P, "String Table");
-
-  if (File.isObj()) {
-    P.formatLine("Dumping string table is not supported for object files");
-    return Error::success();
-  }
-
+Error DumpOutputStyle::dumpStringTableFromPdb() {
   AutoIndent Indent(P);
   auto IS = getPdb().getStringTable();
   if (!IS) {
@@ -895,6 +888,36 @@ Error DumpOutputStyle::dumpStringTable() {
   return Error::success();
 }
 
+Error DumpOutputStyle::dumpStringTableFromObj() {
+  iterateModuleSubsections<DebugStringTableSubsectionRef>(
+      File, PrintScope{P, 4},
+      [&](uint32_t Modi, const SymbolGroup &Strings,
+          DebugStringTableSubsectionRef &Strings2) {
+        BinaryStreamRef StringTableBuffer = Strings2.getBuffer();
+        BinaryStreamReader Reader(StringTableBuffer);
+        while (Reader.bytesRemaining() > 0) {
+          StringRef Str;
+          uint32_t Offset = Reader.getOffset();
+          cantFail(Reader.readCString(Str));
+          if (Str.empty())
+            continue;
+
+          P.formatLine("{0} | {1}", fmt_align(Offset, AlignStyle::Right, 4),
+                       Str);
+        }
+      });
+  return Error::success();
+}
+
+Error DumpOutputStyle::dumpStringTable() {
+  printHeader(P, "String Table");
+
+  if (File.isPdb())
+    return dumpStringTableFromPdb();
+
+  return dumpStringTableFromObj();
+}
+
 static void buildDepSet(LazyRandomTypeCollection &Types,
                         ArrayRef<TypeIndex> Indices,
                         std::map<TypeIndex, CVType> &DepSet) {
@@ -1124,6 +1147,7 @@ Error DumpOutputStyle::dumpModuleSymsForObj() {
       File, PrintScope{P, 2},
       [&](uint32_t Modi, const SymbolGroup &Strings,
           DebugSymbolsSubsectionRef &Symbols) {
+        Dumper.setSymbolGroup(&Strings);
         for (auto Symbol : Symbols) {
           if (auto EC = Visitor.visitSymbolRecord(Symbol)) {
             SymbolError = llvm::make_unique<Error>(std::move(EC));
@@ -1165,8 +1189,8 @@ Error DumpOutputStyle::dumpModuleSymsForPdb() {
 
         SymbolVisitorCallbackPipeline Pipeline;
         SymbolDeserializer Deserializer(nullptr, CodeViewContainer::Pdb);
-        MinimalSymbolDumper Dumper(P, opts::dump::DumpSymRecordBytes, Ids,
-                                   Types);
+        MinimalSymbolDumper Dumper(P, opts::dump::DumpSymRecordBytes, Strings,
+                                   Ids, Types);
 
         Pipeline.addCallbackToPipeline(Deserializer);
         Pipeline.addCallbackToPipeline(Dumper);

tools/llvm-pdbutil/DumpOutputStyle.h

@@ -75,6 +75,8 @@ private:
   Error dumpSymbolStats();
   Error dumpUdtStats();
   Error dumpStringTable();
+  Error dumpStringTableFromPdb();
+  Error dumpStringTableFromObj();
   Error dumpLines();
   Error dumpInlineeLines();
   Error dumpXmi();

tools/llvm-pdbutil/MinimalSymbolDumper.cpp

@@ -10,6 +10,7 @@
 #include "MinimalSymbolDumper.h"
 
 #include "FormatUtil.h"
+#include "InputFile.h"
 #include "LinePrinter.h"
 
 #include "llvm/DebugInfo/CodeView/CVRecord.h"
@@ -18,6 +19,7 @@
 #include "llvm/DebugInfo/CodeView/LazyRandomTypeCollection.h"
 #include "llvm/DebugInfo/CodeView/SymbolRecord.h"
 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/PDB/Native/PDBStringTable.h"
 #include "llvm/Support/FormatVariadic.h"
 
 using namespace llvm;
@@ -450,6 +452,17 @@ Error MinimalSymbolDumper::visitKnownRecord(CVSymbol &CVR,
 Error MinimalSymbolDumper::visitKnownRecord(CVSymbol &CVR, FileStaticSym &FS) {
   P.format(" `{0}`", FS.Name);
   AutoIndent Indent(P, 7);
+  if (SymGroup) {
+    Expected<StringRef> FileName =
+        SymGroup->getNameFromStringTable(FS.ModFilenameOffset);
+    if (FileName) {
+      P.formatLine("type = {0}, file name = {1} ({2}), flags = {3}",
+                   typeIndex(FS.Index), FS.ModFilenameOffset, *FileName,
+                   formatLocalSymFlags(P.getIndentLevel() + 9, FS.Flags));
+    }
+    return Error::success();
+  }
+
   P.formatLine("type = {0}, file name offset = {1}, flags = {2}",
                typeIndex(FS.Index), FS.ModFilenameOffset,
                formatLocalSymFlags(P.getIndentLevel() + 9, FS.Flags));

tools/llvm-pdbutil/MinimalSymbolDumper.h

@@ -19,6 +19,7 @@ class LazyRandomTypeCollection;
 
 namespace pdb {
 class LinePrinter;
+class SymbolGroup;
 
 class MinimalSymbolDumper : public codeview::SymbolVisitorCallbacks {
 public:
@@ -26,11 +27,19 @@ public:
                       codeview::LazyRandomTypeCollection &Ids,
                       codeview::LazyRandomTypeCollection &Types)
       : P(P), RecordBytes(RecordBytes), Ids(Ids), Types(Types) {}
+  MinimalSymbolDumper(LinePrinter &P, bool RecordBytes,
+                      const SymbolGroup &SymGroup,
+                      codeview::LazyRandomTypeCollection &Ids,
+                      codeview::LazyRandomTypeCollection &Types)
+      : P(P), RecordBytes(RecordBytes), SymGroup(&SymGroup), Ids(Ids),
+        Types(Types) {}
 
   Error visitSymbolBegin(codeview::CVSymbol &Record) override;
   Error visitSymbolBegin(codeview::CVSymbol &Record, uint32_t Offset) override;
   Error visitSymbolEnd(codeview::CVSymbol &Record) override;
 
+  void setSymbolGroup(const SymbolGroup *Group) { SymGroup = Group; }
+
 #define SYMBOL_RECORD(EnumName, EnumVal, Name)                                 \
   virtual Error visitKnownRecord(codeview::CVSymbol &CVR,                      \
                                  codeview::Name &Record) override;
@@ -45,6 +54,7 @@ private:
 
   LinePrinter &P;
   bool RecordBytes;
+  const SymbolGroup *SymGroup = nullptr;
   codeview::LazyRandomTypeCollection &Ids;
   codeview::LazyRandomTypeCollection &Types;
 };