[codeview] Decode and dump FP regs from S_FRAMEPROC records

Summary:
There are two registers encoded in the S_FRAMEPROC flags: one for locals
and one for parameters. The encoding is described by the
ExpandEncodedBasePointerReg function in cvinfo.h. Two bits are used to
indicate one of four possible values:

  0: no register - Used when there are no variables.
  1: SP / standard - Variables are stored relative to the standard SP
     for the ISA.
  2: FP - Variables are addressed relative to the ISA frame
     pointer, i.e. EBP on x86. If realignment is required, parameters
     use this. If a dynamic alloca is used, locals will be EBP relative.
  3: Alternative - Variables are stored relative to some alternative
     third callee-saved register. This is required to address highly
     aligned locals when there are dynamic stack adjustments. In this
     case, both the incoming SP saved in the standard FP and the current
     SP are at some dynamic offset from the locals. LLVM uses ESI in
     this case, MSVC uses EBX.

Most of the changes in this patch are to pass around the CPU so that we
can decode these into real, named architectural registers.

Subscribers: hiraditya

Differential Revision: https://reviews.llvm.org/D51894

llvm-svn: 341999

10 files changed, 98 insertions, 11 deletions

diff --git a/lld/test/COFF/pdb-procid-remapping.test b/lld/test/COFF/pdb-procid-remapping.test
index e42616dae47..d9b4faa8c0a 100644
--- a/lld/test/COFF/pdb-procid-remapping.test
+++ b/lld/test/COFF/pdb-procid-remapping.test
@@ -14,6 +14,7 @@ CHECK-NEXT:                type = `0x1004 (int (<no type>))`, debug start = 4, d
 CHECK-NEXT:          136 | S_FRAMEPROC [size = 32]
 CHECK-NEXT:                size = 40, padding size = 0, offset to padding = 0
 CHECK-NEXT:                bytes of callee saved registers = 0, exception handler addr = 0000:0000
+CHECK-NEXT:                local fp reg = NONE, param fp reg = NONE
 CHECK-NEXT:                flags = has async eh | opt speed
 CHECK-NEXT:          168 | S_END [size = 4]
 CHECK-LABEL:    Mod 0001 |
@@ -23,6 +24,7 @@ CHECK-NEXT:                type = `0x1001 (int ())`, debug start = 0, debug end
 CHECK-NEXT:          136 | S_FRAMEPROC [size = 32]
 CHECK-NEXT:                size = 0, padding size = 0, offset to padding = 0
 CHECK-NEXT:                bytes of callee saved registers = 0, exception handler addr = 0000:0000
+CHECK-NEXT:                local fp reg = NONE, param fp reg = NONE
 CHECK-NEXT:                flags = has async eh | opt speed
 CHECK-NEXT:          168 | S_END [size = 4]
 CHECK-LABEL:    Mod 0002 |
diff --git a/llvm/include/llvm/DebugInfo/CodeView/CodeView.h b/llvm/include/llvm/DebugInfo/CodeView/CodeView.h
index 4ce9f68cffd..fd2a66551ae 100644
--- a/llvm/include/llvm/DebugInfo/CodeView/CodeView.h
+++ b/llvm/include/llvm/DebugInfo/CodeView/CodeView.h
@@ -231,6 +231,8 @@ enum class FrameProcedureOptions : uint32_t {
   Inlined = 0x00000800,
   StrictSecurityChecks = 0x00001000,
   SafeBuffers = 0x00002000,
+  EncodedLocalBasePointerMask = 0x0000C000,
+  EncodedParamBasePointerMask = 0x00030000,
   ProfileGuidedOptimization = 0x00040000,
   ValidProfileCounts = 0x00080000,
   OptimizedForSpeed = 0x00100000,
diff --git a/llvm/include/llvm/DebugInfo/CodeView/SymbolDumper.h b/llvm/include/llvm/DebugInfo/CodeView/SymbolDumper.h
index 293daa851bd..215da2e2b52 100644
--- a/llvm/include/llvm/DebugInfo/CodeView/SymbolDumper.h
+++ b/llvm/include/llvm/DebugInfo/CodeView/SymbolDumper.h
@@ -27,10 +27,10 @@ class CVSymbolDumper {
 public:
   CVSymbolDumper(ScopedPrinter &W, TypeCollection &Types,
                  CodeViewContainer Container,
-                 std::unique_ptr<SymbolDumpDelegate> ObjDelegate,
+                 std::unique_ptr<SymbolDumpDelegate> ObjDelegate, CPUType CPU,
                  bool PrintRecordBytes)
       : W(W), Types(Types), Container(Container),
-        ObjDelegate(std::move(ObjDelegate)),
+        ObjDelegate(std::move(ObjDelegate)), CompilationCPUType(CPU),
         PrintRecordBytes(PrintRecordBytes) {}
 
   /// Dumps one type record.  Returns false if there was a type parsing error,
@@ -43,12 +43,14 @@ public:
   /// parse error, and true otherwise.
   Error dump(const CVSymbolArray &Symbols);
 
+  CPUType getCompilationCPUType() const { return CompilationCPUType; }
+
 private:
   ScopedPrinter &W;
   TypeCollection &Types;
   CodeViewContainer Container;
   std::unique_ptr<SymbolDumpDelegate> ObjDelegate;
-
+  CPUType CompilationCPUType;
   bool PrintRecordBytes;
 };
 } // end namespace codeview
diff --git a/llvm/include/llvm/DebugInfo/CodeView/SymbolRecord.h b/llvm/include/llvm/DebugInfo/CodeView/SymbolRecord.h
index 93306824012..039d390ed10 100644
--- a/llvm/include/llvm/DebugInfo/CodeView/SymbolRecord.h
+++ b/llvm/include/llvm/DebugInfo/CodeView/SymbolRecord.h
@@ -761,7 +761,51 @@ public:
   uint16_t SectionIdOfExceptionHandler;
   FrameProcedureOptions Flags;
 
+  /// Extract the register this frame uses to refer to local variables.
+  RegisterId getLocalFramePtrReg(CPUType CPU) const {
+    return decodeFramePtrReg((uint32_t(Flags) >> 14U) & 0x3U, CPU);
+  }
+
+  /// Extract the register this frame uses to refer to parameters.
+  RegisterId getParamFramePtrReg(CPUType CPU) const {
+    return decodeFramePtrReg((uint32_t(Flags) >> 16U) & 0x3U, CPU);
+  }
+
   uint32_t RecordOffset;
+
+private:
+  static RegisterId decodeFramePtrReg(uint32_t EncodedReg, CPUType CPU) {
+    assert(EncodedReg < 4);
+    switch (CPU) {
+    // FIXME: Add ARM and AArch64 variants here.
+    default:
+      break;
+    case CPUType::Intel8080:
+    case CPUType::Intel8086:
+    case CPUType::Intel80286:
+    case CPUType::Intel80386:
+    case CPUType::Intel80486:
+    case CPUType::Pentium:
+    case CPUType::PentiumPro:
+    case CPUType::Pentium3:
+      switch (EncodedReg) {
+      case 0: return RegisterId::NONE;
+      case 1: return RegisterId::VFRAME;
+      case 2: return RegisterId::EBP;
+      case 3: return RegisterId::EBX;
+      }
+      llvm_unreachable("bad encoding");
+    case CPUType::X64:
+      switch (EncodedReg) {
+      case 0: return RegisterId::NONE;
+      case 1: return RegisterId::RSP;
+      case 2: return RegisterId::RBP;
+      case 3: return RegisterId::R13;
+      }
+      llvm_unreachable("bad encoding");
+    }
+    return RegisterId::NONE;
+  }
 };
 
 // S_CALLSITEINFO
diff --git a/llvm/lib/DebugInfo/CodeView/EnumTables.cpp b/llvm/lib/DebugInfo/CodeView/EnumTables.cpp
index d8301cab165..ef4e42f79eb 100644
--- a/llvm/lib/DebugInfo/CodeView/EnumTables.cpp
+++ b/llvm/lib/DebugInfo/CodeView/EnumTables.cpp
@@ -200,6 +200,8 @@ static const EnumEntry<uint32_t> FrameProcSymFlagNames[] = {
     CV_ENUM_CLASS_ENT(FrameProcedureOptions, Inlined),
     CV_ENUM_CLASS_ENT(FrameProcedureOptions, StrictSecurityChecks),
     CV_ENUM_CLASS_ENT(FrameProcedureOptions, SafeBuffers),
+    CV_ENUM_CLASS_ENT(FrameProcedureOptions, EncodedLocalBasePointerMask),
+    CV_ENUM_CLASS_ENT(FrameProcedureOptions, EncodedParamBasePointerMask),
     CV_ENUM_CLASS_ENT(FrameProcedureOptions, ProfileGuidedOptimization),
     CV_ENUM_CLASS_ENT(FrameProcedureOptions, ValidProfileCounts),
     CV_ENUM_CLASS_ENT(FrameProcedureOptions, OptimizedForSpeed),
diff --git a/llvm/lib/DebugInfo/CodeView/SymbolDumper.cpp b/llvm/lib/DebugInfo/CodeView/SymbolDumper.cpp
index f8bf961f22a..4cb267e857e 100644
--- a/llvm/lib/DebugInfo/CodeView/SymbolDumper.cpp
+++ b/llvm/lib/DebugInfo/CodeView/SymbolDumper.cpp
@@ -32,8 +32,8 @@ namespace {
 class CVSymbolDumperImpl : public SymbolVisitorCallbacks {
 public:
   CVSymbolDumperImpl(TypeCollection &Types, SymbolDumpDelegate *ObjDelegate,
-                     ScopedPrinter &W, bool PrintRecordBytes)
-      : Types(Types), ObjDelegate(ObjDelegate), W(W),
+                     ScopedPrinter &W, CPUType CPU, bool PrintRecordBytes)
+      : Types(Types), ObjDelegate(ObjDelegate), W(W), CompilationCPUType(CPU),
         PrintRecordBytes(PrintRecordBytes), InFunctionScope(false) {}
 
 /// CVSymbolVisitor overrides.
@@ -46,6 +46,8 @@ public:
   Error visitSymbolEnd(CVSymbol &Record) override;
   Error visitUnknownSymbol(CVSymbol &Record) override;
 
+  CPUType getCompilationCPUType() const { return CompilationCPUType; }
+
 private:
   void printLocalVariableAddrRange(const LocalVariableAddrRange &Range,
                                    uint32_t RelocationOffset);
@@ -56,6 +58,9 @@ private:
   SymbolDumpDelegate *ObjDelegate;
   ScopedPrinter &W;
 
+  /// Save the machine or CPU type when dumping a compile symbols.
+  CPUType CompilationCPUType = CPUType::X64;
+
   bool PrintRecordBytes;
   bool InFunctionScope;
 };
@@ -235,6 +240,7 @@ Error CVSymbolDumperImpl::visitKnownRecord(CVSymbol &CVR,
   W.printEnum("Language", Compile2.getLanguage(), getSourceLanguageNames());
   W.printFlags("Flags", Compile2.getFlags(), getCompileSym2FlagNames());
   W.printEnum("Machine", unsigned(Compile2.Machine), getCPUTypeNames());
+  CompilationCPUType = Compile2.Machine;
   std::string FrontendVersion;
   {
     raw_string_ostream Out(FrontendVersion);
@@ -258,6 +264,7 @@ Error CVSymbolDumperImpl::visitKnownRecord(CVSymbol &CVR,
   W.printEnum("Language", Compile3.getLanguage(), getSourceLanguageNames());
   W.printFlags("Flags", Compile3.getFlags(), getCompileSym3FlagNames());
   W.printEnum("Machine", unsigned(Compile3.Machine), getCPUTypeNames());
+  CompilationCPUType = Compile3.Machine;
   std::string FrontendVersion;
   {
     raw_string_ostream Out(FrontendVersion);
@@ -415,6 +422,12 @@ Error CVSymbolDumperImpl::visitKnownRecord(CVSymbol &CVR,
              FrameProc.SectionIdOfExceptionHandler);
   W.printFlags("Flags", static_cast<uint32_t>(FrameProc.Flags),
                getFrameProcSymFlagNames());
+  W.printEnum("LocalFramePtrReg",
+              uint16_t(FrameProc.getLocalFramePtrReg(CompilationCPUType)),
+              getRegisterNames());
+  W.printEnum("ParamFramePtrReg",
+              uint16_t(FrameProc.getParamFramePtrReg(CompilationCPUType)),
+              getRegisterNames());
   return Error::success();
 }
 
@@ -625,21 +638,27 @@ Error CVSymbolDumperImpl::visitUnknownSymbol(CVSymbol &CVR) {
 Error CVSymbolDumper::dump(CVRecord<SymbolKind> &Record) {
   SymbolVisitorCallbackPipeline Pipeline;
   SymbolDeserializer Deserializer(ObjDelegate.get(), Container);
-  CVSymbolDumperImpl Dumper(Types, ObjDelegate.get(), W, PrintRecordBytes);
+  CVSymbolDumperImpl Dumper(Types, ObjDelegate.get(), W, CompilationCPUType,
+                            PrintRecordBytes);
 
   Pipeline.addCallbackToPipeline(Deserializer);
   Pipeline.addCallbackToPipeline(Dumper);
   CVSymbolVisitor Visitor(Pipeline);
-  return Visitor.visitSymbolRecord(Record);
+  auto Err = Visitor.visitSymbolRecord(Record);
+  CompilationCPUType = Dumper.getCompilationCPUType();
+  return Err;
 }
 
 Error CVSymbolDumper::dump(const CVSymbolArray &Symbols) {
   SymbolVisitorCallbackPipeline Pipeline;
   SymbolDeserializer Deserializer(ObjDelegate.get(), Container);
-  CVSymbolDumperImpl Dumper(Types, ObjDelegate.get(), W, PrintRecordBytes);
+  CVSymbolDumperImpl Dumper(Types, ObjDelegate.get(), W, CompilationCPUType,
+                            PrintRecordBytes);
 
   Pipeline.addCallbackToPipeline(Deserializer);
   Pipeline.addCallbackToPipeline(Dumper);
   CVSymbolVisitor Visitor(Pipeline);
-  return Visitor.visitSymbolStream(Symbols);
+  auto Err = Visitor.visitSymbolStream(Symbols);
+  CompilationCPUType = Dumper.getCompilationCPUType();
+  return Err;
 }
diff --git a/llvm/test/DebugInfo/PDB/pdbdump-headers.test b/llvm/test/DebugInfo/PDB/pdbdump-headers.test
index b05e62078b7..99c37218e92 100644
--- a/llvm/test/DebugInfo/PDB/pdbdump-headers.test
+++ b/llvm/test/DebugInfo/PDB/pdbdump-headers.test
@@ -487,6 +487,7 @@ ALL-NEXT:          type = `0x1001 (int ())`, debug start = 3, debug end = 8, fla
 ALL-NEXT:    164 | S_FRAMEPROC [size = 32]
 ALL-NEXT:          size = 0, padding size = 0, offset to padding = 0
 ALL-NEXT:          bytes of callee saved registers = 0, exception handler addr = 0000:0000
+ALL-NEXT:          local fp reg = EBP, param fp reg = EBP
 ALL-NEXT:          flags = has async eh | opt speed
 ALL-NEXT:    196 | S_END [size = 4]
 ALL-NEXT:    200 | S_BUILDINFO [size = 8] BuildId = `0x100E`
diff --git a/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.cpp b/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.cpp
index f8b2ecc6060..5dc4f85c9bc 100644
--- a/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.cpp
+++ b/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.cpp
@@ -490,6 +490,7 @@ Error MinimalSymbolDumper::visitKnownRecord(CVSymbol &CVR,
   AutoIndent Indent(P, 7);
   SourceLanguage Lang = static_cast<SourceLanguage>(
       Compile2.Flags & CompileSym2Flags::SourceLanguageMask);
+  CompilationCPU = Compile2.Machine;
   P.formatLine("machine = {0}, ver = {1}, language = {2}",
                formatMachineType(Compile2.Machine), Compile2.Version,
                formatSourceLanguage(Lang));
@@ -510,6 +511,7 @@ Error MinimalSymbolDumper::visitKnownRecord(CVSymbol &CVR,
   AutoIndent Indent(P, 7);
   SourceLanguage Lang = static_cast<SourceLanguage>(
       Compile3.Flags & CompileSym3Flags::SourceLanguageMask);
+  CompilationCPU = Compile3.Machine;
   P.formatLine("machine = {0}, Ver = {1}, language = {2}",
                formatMachineType(Compile3.Machine), Compile3.Version,
                formatSourceLanguage(Lang));
@@ -629,6 +631,9 @@ Error MinimalSymbolDumper::visitKnownRecord(CVSymbol &CVR, FrameProcSym &FP) {
                FP.BytesOfCalleeSavedRegisters,
                formatSegmentOffset(FP.SectionIdOfExceptionHandler,
                                    FP.OffsetOfExceptionHandler));
+  P.formatLine("local fp reg = {0}, param fp reg = {1}",
+               formatRegisterId(FP.getLocalFPReg(CompilationCPU)),
+               formatRegisterId(FP.getParamFPReg(CompilationCPU)));
   P.formatLine("flags = {0}",
                formatFrameProcedureOptions(P.getIndentLevel() + 9, FP.Flags));
   return Error::success();
diff --git a/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.h b/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.h
index 1c26a85a4ea..033e193cee6 100644
--- a/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.h
+++ b/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.h
@@ -53,6 +53,11 @@ private:
   std::string idIndex(codeview::TypeIndex TI) const;
 
   LinePrinter &P;
+
+  /// Dumping certain records requires knowing what machine this is. The
+  /// S_COMPILE3 record will tell us, but if we don't see one, default to X64.
+  codeview::CPUType CompilationCPU = codeview::CPUType::X64;
+
   bool RecordBytes;
   const SymbolGroup *SymGroup = nullptr;
   codeview::LazyRandomTypeCollection &Ids;
@@ -61,4 +66,4 @@ private:
 } // namespace pdb
 } // namespace llvm
 
-#endif
\ No newline at end of file
+#endif
diff --git a/llvm/tools/llvm-readobj/COFFDumper.cpp b/llvm/tools/llvm-readobj/COFFDumper.cpp
index e9944908982..8da5fc4234e 100644
--- a/llvm/tools/llvm-readobj/COFFDumper.cpp
+++ b/llvm/tools/llvm-readobj/COFFDumper.cpp
@@ -179,6 +179,10 @@ private:
 
   DebugStringTableSubsectionRef CVStringTable;
 
+  /// Track the compilation CPU type. S_COMPILE3 symbol records typically come
+  /// first, but if we don't see one, just assume an X64 CPU type. It is common.
+  CPUType CompilationCPUType = CPUType::X64;
+
   ScopedPrinter &Writer;
   BinaryByteStream TypeContents;
   LazyRandomTypeCollection Types;
@@ -1150,7 +1154,7 @@ void COFFDumper::printCodeViewSymbolsSubsection(StringRef Subsection,
   auto CODD = llvm::make_unique<COFFObjectDumpDelegate>(*this, Section, Obj,
                                                         SectionContents);
   CVSymbolDumper CVSD(W, Types, CodeViewContainer::ObjectFile, std::move(CODD),
-                      opts::CodeViewSubsectionBytes);
+                      CompilationCPUType, opts::CodeViewSubsectionBytes);
   CVSymbolArray Symbols;
   BinaryStreamReader Reader(BinaryData, llvm::support::little);
   if (auto EC = Reader.readArray(Symbols, Reader.getLength())) {
@@ -1163,6 +1167,7 @@ void COFFDumper::printCodeViewSymbolsSubsection(StringRef Subsection,
     W.flush();
     error(std::move(EC));
   }
+  CompilationCPUType = CVSD.getCompilationCPUType();
   W.flush();
 }