[llvm-objdump] Add warning messages if disassembly + source for probl…

…ematic inputs

Summary: Addresses https://bugs.llvm.org/show_bug.cgi?id=41905

Reviewers: jhenderson, rupprecht, grimar

Reviewed By: jhenderson, grimar

Subscribers: RKSimon, MaskRay, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62462

llvm-svn: 368963

llvm/include/llvm/DebugInfo/DIContext.h

@@ -28,6 +28,10 @@ namespace llvm {
 
 /// A format-neutral container for source line information.
 struct DILineInfo {
+  // DILineInfo contains "<invalid>" for function/filename it cannot fetch.
+  static constexpr const char *const BadString = "<invalid>";
+  // Use "??" instead of "<invalid>" to make our output closer to addr2line.
+  static constexpr const char *const Addr2LineBadString = "??";
   std::string FileName;
   std::string FunctionName;
   Optional<StringRef> Source;
@@ -38,7 +42,7 @@ struct DILineInfo {
   // DWARF-specific.
   uint32_t Discriminator = 0;
 
-  DILineInfo() : FileName("<invalid>"), FunctionName("<invalid>") {}
+  DILineInfo() : FileName(BadString), FunctionName(BadString) {}
 
   bool operator==(const DILineInfo &RHS) const {
     return Line == RHS.Line && Column == RHS.Column &&
@@ -61,9 +65,9 @@ struct DILineInfo {
 
   void dump(raw_ostream &OS) {
     OS << "Line info: ";
-    if (FileName != "<invalid>")
+    if (FileName != BadString)
       OS << "file '" << FileName << "', ";
-    if (FunctionName != "<invalid>")
+    if (FunctionName != BadString)
       OS << "function '" << FunctionName << "', ";
     OS << "line " << Line << ", ";
     OS << "column " << Column << ", ";
@@ -109,7 +113,7 @@ struct DIGlobal {
   uint64_t Start = 0;
   uint64_t Size = 0;
 
-  DIGlobal() : Name("<invalid>") {}
+  DIGlobal() : Name(DILineInfo::BadString) {}
 };
 
 struct DILocal {

llvm/lib/DebugInfo/DWARF/DWARFContext.cpp

@@ -1111,8 +1111,8 @@ DILineInfoTable DWARFContext::getLineInfoForAddressRange(
   if (!CU)
     return Lines;
 
-  std::string FunctionName = "<invalid>";
   uint32_t StartLine = 0;
+  std::string FunctionName(DILineInfo::BadString);
   getFunctionNameAndStartLineForAddress(CU, Address.Address, Spec.FNKind,
                                         FunctionName, StartLine);
 

llvm/lib/DebugInfo/Symbolize/DIPrinter.cpp

@@ -30,11 +30,6 @@
 namespace llvm {
 namespace symbolize {
 
-// By default, DILineInfo contains "<invalid>" for function/filename it
-// cannot fetch. We replace it to "??" to make our output closer to addr2line.
-static const char kDILineInfoBadString[] = "<invalid>";
-static const char kBadString[] = "??";
-
 // Prints source code around in the FileName the Line.
 void DIPrinter::printContext(const std::string &FileName, int64_t Line) {
   if (PrintSourceContext <= 0)
@@ -68,16 +63,16 @@ void DIPrinter::printContext(const std::string &FileName, int64_t Line) {
 void DIPrinter::print(const DILineInfo &Info, bool Inlined) {
   if (PrintFunctionNames) {
     std::string FunctionName = Info.FunctionName;
-    if (FunctionName == kDILineInfoBadString)
-      FunctionName = kBadString;
+    if (FunctionName == DILineInfo::BadString)
+      FunctionName = DILineInfo::Addr2LineBadString;
 
     StringRef Delimiter = PrintPretty ? " at " : "\n";
     StringRef Prefix = (PrintPretty && Inlined) ? " (inlined by) " : "";
     OS << Prefix << FunctionName << Delimiter;
   }
   std::string Filename = Info.FileName;
-  if (Filename == kDILineInfoBadString)
-    Filename = kBadString;
+  if (Filename == DILineInfo::BadString)
+    Filename = DILineInfo::Addr2LineBadString;
   else if (Basenames)
     Filename = llvm::sys::path::filename(Filename);
   if (!Verbose) {
@@ -115,8 +110,8 @@ DIPrinter &DIPrinter::operator<<(const DIInliningInfo &Info) {
 
 DIPrinter &DIPrinter::operator<<(const DIGlobal &Global) {
   std::string Name = Global.Name;
-  if (Name == kDILineInfoBadString)
-    Name = kBadString;
+  if (Name == DILineInfo::BadString)
+    Name = DILineInfo::Addr2LineBadString;
   OS << Name << "\n";
   OS << Global.Start << " " << Global.Size << "\n";
   return *this;

llvm/test/tools/llvm-objdump/X86/source-interleave-invalid-source.test

@@ -1,5 +1,5 @@
 ## Test llvm-objdump's --source behaviour when a line number is greater than the
-## file length.
+## file length and ensure that we emit a warning.
 
 # RUN: sed -e "s,SRC_COMPDIR,%/p/Inputs,g" %p/Inputs/source-interleave.ll > %t.ll
 # RUN: sed -e "s,line: 7,line: 9999,g" %t.ll > %t2.ll
@@ -8,9 +8,11 @@
 # RUN: llc -o %t2.o -filetype=obj -mtriple=x86_64-pc-linux %t2.ll
 
 # RUN: llvm-objdump --source %t.o | FileCheck %s --check-prefixes=CHECK,GOOD
-# RUN: llvm-objdump --source %t2.o | FileCheck %s --implicit-check-not="int *b = &a;"
+# RUN: llvm-objdump --source %t2.o 2> %t2.e | FileCheck %s --check-prefixes=CHECK --implicit-check-not="int *b = &a;"
+# RUN: FileCheck %s --input-file %t2.e --check-prefixes=WARN
 
 # CHECK:      main:
 # CHECK-NEXT: ; int main() {
+# WARN:       warning: debug info line number 9999 exceeds the number of lines in {{.*}}source-interleave-x86_64.c
 # GOOD:       ;   int *b = &a;
 # CHECK:      ;   return *b + foo();

llvm/test/tools/llvm-objdump/X86/source-interleave-missing-source.test

@@ -1,15 +1,17 @@
 ## Test that if the source cannot be found that disassembly is still printed,
-## and that no source is printed.
+## that no source is printed, and that we emit a warning.
 
 # RUN: sed -e "s,SRC_COMPDIR,%/t,g" %p/Inputs/source-interleave.ll > %t.ll
 # RUN: sed -e "s,SRC_COMPDIR,%/p/Inputs,g" %p/Inputs/source-interleave.ll > %t2.ll
 
 # RUN: llc -o %t.o -filetype=obj -mtriple=x86_64-pc-linux %t.ll
 # RUN: llc -o %t2.o -filetype=obj -mtriple=x86_64-pc-linux %t2.ll
 
-# RUN: llvm-objdump --source %t.o | FileCheck %s --implicit-check-not='main()'
+# RUN: llvm-objdump --source %t.o 2> %t.e | FileCheck %s --check-prefixes=CHECK --implicit-check-not='main()'
 # RUN: llvm-objdump --source %t2.o | FileCheck %s --check-prefixes=CHECK,SOURCE
+# RUN: FileCheck %s --input-file %t.e --check-prefixes=WARN
 
+# WARN:        warning: failed to find source {{.*}}source-interleave-x86_64.c
 # CHECK:       0000000000000010 main:
 # SOURCE-NEXT: ; int main() {
 # CHECK-NEXT:   10:   55                      pushq   %rbp

llvm/test/tools/llvm-objdump/X86/source-interleave-no-debug-info.test

@@ -1,13 +1,15 @@
 ## Test that if an object has no debug information, only the disassembly is
-## printed when --source is specified.
+## printed when --source is specified, and that we emit a warning.
 
 # RUN: sed -e "s,SRC_COMPDIR,%/p/Inputs,g" %p/Inputs/source-interleave.ll > %t.ll
 # RUN: llc -o %t.o -filetype=obj -mtriple=x86_64-pc-linux %t.ll
 # RUN: llvm-objcopy --strip-debug %t.o %t2.o
 
 # RUN: llvm-objdump --source %t.o | FileCheck %s --check-prefixes=CHECK,SOURCE
-# RUN: llvm-objdump --source %t2.o | FileCheck %s --implicit-check-not='main()'
+# RUN: llvm-objdump --source %t2.o 2> %t2.e | FileCheck %s --check-prefixes=CHECK --implicit-check-not='main()'
+# RUN: FileCheck %s --input-file %t2.e --check-prefixes=WARN
 
+# WARN:        warning: failed to parse debug information for {{.*}}2.o
 # CHECK:       0000000000000010 main:
 # SOURCE-NEXT: ; int main() {
 # CHECK-NEXT:   10:   55                      pushq   %rbp

llvm/tools/llvm-cfi-verify/lib/FileAnalysis.cpp

@@ -521,7 +521,7 @@ void FileAnalysis::parseSectionContents(ArrayRef<uint8_t> SectionBytes,
         continue;
       }
 
-      if (LineInfo->FileName == "<invalid>")
+      if (LineInfo->FileName == DILineInfo::BadString)
         continue;
     }
 

llvm/tools/llvm-objdump/llvm-objdump.cpp

@@ -51,6 +51,7 @@
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/GraphWriter.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/InitLLVM.h"
@@ -385,12 +386,7 @@ LLVM_ATTRIBUTE_NORETURN void error(Twine Message) {
   exit(1);
 }
 
-void warn(StringRef Message) {
-  WithColor::warning(errs(), ToolName) << Message << ".\n";
-  errs().flush();
-}
-
-static void warn(Twine Message) {
+void warn(Twine Message) {
   // Output order between errs() and outs() matters especially for archive
   // files where the output is per member object.
   outs().flush();
@@ -552,17 +548,22 @@ class SourcePrinter {
   DILineInfo OldLineInfo;
   const ObjectFile *Obj = nullptr;
   std::unique_ptr<symbolize::LLVMSymbolizer> Symbolizer;
-  // File name to file contents of source
+  // File name to file contents of source.
   std::unordered_map<std::string, std::unique_ptr<MemoryBuffer>> SourceCache;
-  // Mark the line endings of the cached source
+  // Mark the line endings of the cached source.
   std::unordered_map<std::string, std::vector<StringRef>> LineCache;
+  // Keep track of missing sources.
+  StringSet<> MissingSources;
+  // Only emit 'no debug info' warning once.
+  bool WarnedNoDebugInfo;
 
 private:
   bool cacheSource(const DILineInfo& LineInfoFile);
 
 public:
   SourcePrinter() = default;
-  SourcePrinter(const ObjectFile *Obj, StringRef DefaultArch) : Obj(Obj) {
+  SourcePrinter(const ObjectFile *Obj, StringRef DefaultArch)
+      : Obj(Obj), WarnedNoDebugInfo(false) {
     symbolize::LLVMSymbolizer::Options SymbolizerOpts;
     SymbolizerOpts.PrintFunctions = DILineInfoSpecifier::FunctionNameKind::None;
     SymbolizerOpts.Demangle = false;
@@ -572,6 +573,7 @@ class SourcePrinter {
   virtual ~SourcePrinter() = default;
   virtual void printSourceLine(raw_ostream &OS,
                                object::SectionedAddress Address,
+                               StringRef ObjectFilename,
                                StringRef Delimiter = "; ");
 };
 
@@ -581,8 +583,12 @@ bool SourcePrinter::cacheSource(const DILineInfo &LineInfo) {
     Buffer = MemoryBuffer::getMemBuffer(*LineInfo.Source);
   } else {
     auto BufferOrError = MemoryBuffer::getFile(LineInfo.FileName);
-    if (!BufferOrError)
+    if (!BufferOrError) {
+      if (MissingSources.insert(LineInfo.FileName).second)
+        warn("failed to find source " + LineInfo.FileName);
+
       return false;
+    }
     Buffer = std::move(*BufferOrError);
   }
   // Chomp the file to get lines
@@ -603,20 +609,33 @@ bool SourcePrinter::cacheSource(const DILineInfo &LineInfo) {
 
 void SourcePrinter::printSourceLine(raw_ostream &OS,
                                     object::SectionedAddress Address,
+                                    StringRef ObjectFilename,
                                     StringRef Delimiter) {
   if (!Symbolizer)
     return;
 
   DILineInfo LineInfo = DILineInfo();
   auto ExpectedLineInfo = Symbolizer->symbolizeCode(*Obj, Address);
+  std::string ErrorMessage;
   if (!ExpectedLineInfo)
-    consumeError(ExpectedLineInfo.takeError());
+    ErrorMessage = toString(ExpectedLineInfo.takeError());
   else
     LineInfo = *ExpectedLineInfo;
 
-  if ((LineInfo.FileName == "<invalid>") || LineInfo.Line == 0 ||
-      ((OldLineInfo.Line == LineInfo.Line) &&
-       (OldLineInfo.FileName == LineInfo.FileName)))
+  if (LineInfo.FileName == DILineInfo::BadString) {
+    if (!WarnedNoDebugInfo) {
+      std::string Warning =
+          "failed to parse debug information for " + ObjectFilename.str();
+      if (!ErrorMessage.empty())
+        Warning += ": " + ErrorMessage;
+      warn(Warning);
+      WarnedNoDebugInfo = true;
+    }
+    return;
+  }
+
+  if (LineInfo.Line == 0 || ((OldLineInfo.Line == LineInfo.Line) &&
+                             (OldLineInfo.FileName == LineInfo.FileName)))
     return;
 
   if (PrintLines)
@@ -627,8 +646,12 @@ void SourcePrinter::printSourceLine(raw_ostream &OS,
         return;
     auto LineBuffer = LineCache.find(LineInfo.FileName);
     if (LineBuffer != LineCache.end()) {
-      if (LineInfo.Line > LineBuffer->second.size())
+      if (LineInfo.Line > LineBuffer->second.size()) {
+        warn(formatv(
+            "debug info line number {0} exceeds the number of lines in {1}",
+            LineInfo.Line, LineInfo.FileName));
         return;
+      }
       // Vector begins at 0, line numbers are non-zero
       OS << Delimiter << LineBuffer->second[LineInfo.Line - 1] << '\n';
     }
@@ -667,10 +690,10 @@ class PrettyPrinter {
                          ArrayRef<uint8_t> Bytes,
                          object::SectionedAddress Address, raw_ostream &OS,
                          StringRef Annot, MCSubtargetInfo const &STI,
-                         SourcePrinter *SP,
+                         SourcePrinter *SP, StringRef ObjectFilename,
                          std::vector<RelocationRef> *Rels = nullptr) {
     if (SP && (PrintSource || PrintLines))
-      SP->printSourceLine(OS, Address);
+      SP->printSourceLine(OS, Address, ObjectFilename);
 
     size_t Start = OS.tell();
     if (!NoLeadingAddr)
@@ -711,9 +734,10 @@ class HexagonPrettyPrinter : public PrettyPrinter {
   void printInst(MCInstPrinter &IP, const MCInst *MI, ArrayRef<uint8_t> Bytes,
                  object::SectionedAddress Address, raw_ostream &OS,
                  StringRef Annot, MCSubtargetInfo const &STI, SourcePrinter *SP,
+                 StringRef ObjectFilename,
                  std::vector<RelocationRef> *Rels) override {
     if (SP && (PrintSource || PrintLines))
-      SP->printSourceLine(OS, Address, "");
+      SP->printSourceLine(OS, Address, ObjectFilename, "");
     if (!MI) {
       printLead(Bytes, Address.Address, OS);
       OS << " <unknown>";
@@ -750,7 +774,7 @@ class HexagonPrettyPrinter : public PrettyPrinter {
       OS << Separator;
       Separator = "\n";
       if (SP && (PrintSource || PrintLines))
-        SP->printSourceLine(OS, Address, "");
+        SP->printSourceLine(OS, Address, ObjectFilename, "");
       printLead(Bytes, Address.Address, OS);
       OS << Preamble;
       Preamble = "   ";
@@ -780,9 +804,10 @@ class AMDGCNPrettyPrinter : public PrettyPrinter {
   void printInst(MCInstPrinter &IP, const MCInst *MI, ArrayRef<uint8_t> Bytes,
                  object::SectionedAddress Address, raw_ostream &OS,
                  StringRef Annot, MCSubtargetInfo const &STI, SourcePrinter *SP,
+                 StringRef ObjectFilename,
                  std::vector<RelocationRef> *Rels) override {
     if (SP && (PrintSource || PrintLines))
-      SP->printSourceLine(OS, Address);
+      SP->printSourceLine(OS, Address, ObjectFilename);
 
     if (MI) {
       SmallString<40> InstStr;
@@ -831,9 +856,10 @@ class BPFPrettyPrinter : public PrettyPrinter {
   void printInst(MCInstPrinter &IP, const MCInst *MI, ArrayRef<uint8_t> Bytes,
                  object::SectionedAddress Address, raw_ostream &OS,
                  StringRef Annot, MCSubtargetInfo const &STI, SourcePrinter *SP,
+                 StringRef ObjectFilename,
                  std::vector<RelocationRef> *Rels) override {
     if (SP && (PrintSource || PrintLines))
-      SP->printSourceLine(OS, Address);
+      SP->printSourceLine(OS, Address, ObjectFilename);
     if (!NoLeadingAddr)
       OS << format("%8" PRId64 ":", Address.Address / 8);
     if (!NoShowRawInsn) {
@@ -1382,10 +1408,10 @@ static void disassembleObject(const Target *TheTarget, const ObjectFile *Obj,
         if (Size == 0)
           Size = 1;
 
-        PIP.printInst(
-            *IP, Disassembled ? &Inst : nullptr, Bytes.slice(Index, Size),
-            {SectionAddr + Index + VMAAdjustment, Section.getIndex()}, outs(),
-            "", *STI, &SP, &Rels);
+        PIP.printInst(*IP, Disassembled ? &Inst : nullptr,
+                      Bytes.slice(Index, Size),
+                      {SectionAddr + Index + VMAAdjustment, Section.getIndex()},
+                      outs(), "", *STI, &SP, Obj->getFileName(), &Rels);
         outs() << CommentStream.str();
         Comments.clear();
 

llvm/tools/llvm-objdump/llvm-objdump.h

@@ -129,7 +129,7 @@ void printSectionHeaders(const object::ObjectFile *O);
 void printSectionContents(const object::ObjectFile *O);
 void printSymbolTable(const object::ObjectFile *O, StringRef ArchiveName,
                       StringRef ArchitectureName = StringRef());
-void warn(StringRef Message);
+void warn(Twine Message);
 LLVM_ATTRIBUTE_NORETURN void error(Twine Message);
 LLVM_ATTRIBUTE_NORETURN void report_error(StringRef File, Twine Message);
 LLVM_ATTRIBUTE_NORETURN void report_error(Error E, StringRef File);

llvm/tools/llvm-xray/func-id-helper.cpp

@@ -36,7 +36,7 @@ std::string FuncIdConversionHelper::SymbolOrNumber(int32_t FuncId) const {
   ModuleAddress.SectionIndex = object::SectionedAddress::UndefSection;
   if (auto ResOrErr = Symbolizer.symbolizeCode(BinaryInstrMap, ModuleAddress)) {
     auto &DI = *ResOrErr;
-    if (DI.FunctionName == "<invalid>")
+    if (DI.FunctionName == DILineInfo::BadString)
       F << "@(" << std::hex << It->second << ")";
     else
       F << DI.FunctionName;