[CSSPGO][llvm-profgen] Renovate perfscript check and command line input validation

This include some changes related with PerfReader's the input check and command line change:

1) It appears there might be thousands of leading MMAP-Event line in the perfscript for large workload. For this case, the 4k threshold is not eligible to determine it's a hybrid sample. This change renovated the `isHybridPerfScript` by going through the script without threshold limitation checking whether there is a non-empty call stack immediately followed by a LBR sample. It will stop once it find a valid one.

2) Added several input validations for the command line switches in PerfReader.

3) Changed the command line `show-disassembly` to `show-disassembly-only`, it will print to stdout and exit early which leave an empty output profile.

Reviewed By: hoy, wenlei

Differential Revision: https://reviews.llvm.org/D96387

Author: wlei-llvm

llvm/test/tools/llvm-profgen/disassemble.s

@@ -1,6 +1,6 @@
 # REQUIRES: x86-registered-target
 # RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t
-# RUN: llvm-profgen --binary=%t --perfscript=%s --output=%t1 -show-disassembly -x86-asm-syntax=intel | FileCheck %s --match-full-lines
+# RUN: llvm-profgen --binary=%t --perfscript=%s --output=%t1 -show-disassembly-only -x86-asm-syntax=intel | FileCheck %s --match-full-lines
 
 # CHECK: Disassembly of section .text [0x0, 0x66]:
 # CHECK: <foo1>:

llvm/test/tools/llvm-profgen/invalid-perfscript.test

@@ -0,0 +1,9 @@
+; RUN: llvm-profgen --perfscript=%s --binary=%S/Inputs/noinline-cs-noprobe.perfbin --output=%t 2>%t1
+; RUN: FileCheck %s --input-file %t1
+
+	          4005dc
+	          400634
+	          400684
+	    7f68c5788793
+
+; XFAIL: *

llvm/test/tools/llvm-profgen/pseudoprobe-decoding.test

@@ -1,4 +1,4 @@
-; RUN: llvm-profgen --perfscript=%s  --binary=%S/Inputs/inline-cs-pseudoprobe.perfbin --output=%t --show-pseudo-probe --show-disassembly | FileCheck %s
+; RUN: llvm-profgen --perfscript=%s  --binary=%S/Inputs/inline-cs-pseudoprobe.perfbin --output=%t --show-pseudo-probe --show-disassembly-only | FileCheck %s
 
 PERF_RECORD_MMAP2 2854748/2854748: [0x400000(0x1000) @ 0 00:1d 123291722 526021]: r-xp /home/inline-cs-pseudoprobe.perfbin
 

llvm/test/tools/llvm-profgen/symbolize.ll

@@ -1,6 +1,6 @@
 ; REQUIRES: x86-registered-target
 ; RUN: llc -filetype=obj %s -o %t
-; RUN: llvm-profgen --binary=%t --perfscript=%s --output=%t1 --show-disassembly -x86-asm-syntax=intel --show-source-locations | FileCheck %s --match-full-lines
+; RUN: llvm-profgen --binary=%t --perfscript=%s --output=%t1 --show-disassembly-only -x86-asm-syntax=intel --show-source-locations | FileCheck %s --match-full-lines
 
 ; CHECK: Disassembly of section .text [0x0, 0x4a]:
 ; CHECK: <funcA>:

llvm/tools/llvm-profgen/PerfReader.cpp

@@ -17,6 +17,9 @@ static cl::opt<bool> ShowUnwinderOutput("show-unwinder-output",
                                         cl::ZeroOrMore,
                                         cl::desc("Print unwinder output"));
 
+extern cl::opt<bool> ShowDisassemblyOnly;
+extern cl::opt<bool> ShowSourceLocations;
+
 namespace llvm {
 namespace sampleprof {
 
@@ -230,7 +233,44 @@ bool VirtualUnwinder::unwind(const HybridSample *Sample, uint64_t Repeat) {
   return true;
 }
 
-PerfReader::PerfReader(cl::list<std::string> &BinaryFilenames) {
+void PerfReader::validateCommandLine(
+    cl::list<std::string> &BinaryFilenames,
+    cl::list<std::string> &PerfTraceFilenames) {
+  // Allow the invalid perfscript if we only use to show binary disassembly
+  if (!ShowDisassemblyOnly) {
+    for (auto &File : PerfTraceFilenames) {
+      if (!llvm::sys::fs::exists(File)) {
+        std::string Msg = "Input perf script(" + File + ") doesn't exist!";
+        exitWithError(Msg);
+      }
+    }
+  }
+  if (BinaryFilenames.size() > 1) {
+    // TODO: remove this if everything is ready to support multiple binaries.
+    exitWithError(
+        "Currently only support one input binary, multiple binaries' "
+        "profile will be merged in one profile and make profile "
+        "summary info inaccurate. Please use `llvm-perfdata` to merge "
+        "profiles from multiple binaries.");
+  }
+  for (auto &Binary : BinaryFilenames) {
+    if (!llvm::sys::fs::exists(Binary)) {
+      std::string Msg = "Input binary(" + Binary + ") doesn't exist!";
+      exitWithError(Msg);
+    }
+  }
+  if (CSProfileGenerator::MaxCompressionSize < -1) {
+    exitWithError("Value of --compress-recursion should >= -1");
+  }
+  if (ShowSourceLocations && !ShowDisassemblyOnly) {
+    exitWithError("--show-source-locations should work together with "
+                  "--show-disassembly-only!");
+  }
+}
+
+PerfReader::PerfReader(cl::list<std::string> &BinaryFilenames,
+                       cl::list<std::string> &PerfTraceFilenames) {
+  validateCommandLine(BinaryFilenames, PerfTraceFilenames);
   // Load the binaries.
   for (auto Filename : BinaryFilenames)
     loadBinary(Filename, /*AllowNameConflict*/ false);
@@ -591,27 +631,13 @@ void PerfReader::parseAndAggregateTrace(StringRef Filename) {
 
 void PerfReader::checkAndSetPerfType(
     cl::list<std::string> &PerfTraceFilenames) {
-  bool HasHybridPerf = true;
   for (auto FileName : PerfTraceFilenames) {
-    if (!isHybridPerfScript(FileName)) {
-      HasHybridPerf = false;
-      break;
-    }
-  }
-
-  if (HasHybridPerf) {
-    PerfType = PERF_LBR_STACK;
-  } else {
-    // TODO: Support other type of perf script
-    PerfType = PERF_INVILID;
-  }
-
-  if (BinaryTable.size() > 1) {
-    // TODO: remove this if everything is ready to support multiple binaries.
-    exitWithError("Currently only support one input binary, multiple binaries' "
-                  "profile will be merged in one profile and make profile "
-                  "summary info inaccurate. Please use `perfdata` to merge "
-                  "profiles from multiple binaries.");
+    PerfScriptType Type = checkPerfScriptType(FileName);
+    if (Type == PERF_INVALID)
+      exitWithError("Invalid perf script input!");
+    if (PerfType != PERF_UNKNOWN && PerfType != Type)
+      exitWithError("Inconsistent sample among different perf scripts");
+    PerfType = Type;
   }
 }
 

llvm/tools/llvm-profgen/PerfReader.h

@@ -59,9 +59,10 @@ class TraceStream {
 
 // The type of perfscript
 enum PerfScriptType {
-  PERF_INVILID = 0,
-  PERF_LBR = 1,       // Only LBR sample
-  PERF_LBR_STACK = 2, // Hybrid sample including call stack and LBR stack.
+  PERF_UNKNOWN = 0,
+  PERF_INVALID = 1,
+  PERF_LBR = 2,       // Only LBR sample
+  PERF_LBR_STACK = 3, // Hybrid sample including call stack and LBR stack.
 };
 
 // The parsed LBR sample entry.
@@ -502,19 +503,52 @@ using BinarySampleCounterMap =
 class PerfReader {
 
 public:
-  PerfReader(cl::list<std::string> &BinaryFilenames);
-
-  // Hybrid sample(call stack + LBRs) profile traces are seprated by double line
-  // break, search for that within the first 4k charactors to avoid going
-  // through the whole file.
-  static bool isHybridPerfScript(StringRef FileName) {
-    auto BufOrError = MemoryBuffer::getFileOrSTDIN(FileName, 4000);
-    if (!BufOrError)
-      exitWithError(BufOrError.getError(), FileName);
-    auto Buffer = std::move(BufOrError.get());
-    if (Buffer->getBuffer().find("\n\n") == StringRef::npos)
+  PerfReader(cl::list<std::string> &BinaryFilenames,
+             cl::list<std::string> &PerfTraceFilenames);
+
+  // A LBR sample is like:
+  // 0x5c6313f/0x5c63170/P/-/-/0  0x5c630e7/0x5c63130/P/-/-/0 ...
+  // A heuristic for fast detection by checking whether a
+  // leading "  0x" and the '/' exist.
+  static bool isLBRSample(StringRef Line) {
+    if (!Line.startswith(" 0x"))
       return false;
-    return true;
+    if (Line.find('/') != StringRef::npos)
+      return true;
+    return false;
+  }
+
+  // The raw hybird sample is like
+  // e.g.
+  // 	          4005dc    # call stack leaf
+  //	          400634
+  //	          400684    # call stack root
+  // 0x4005c8/0x4005dc/P/-/-/0   0x40062f/0x4005b0/P/-/-/0 ...
+  //          ... 0x4005c8/0x4005dc/P/-/-/0    # LBR Entries
+  // Determine the perfscript contains hybrid samples(call stack + LBRs) by
+  // checking whether there is a non-empty call stack immediately followed by
+  // a LBR sample
+  static PerfScriptType checkPerfScriptType(StringRef FileName) {
+    TraceStream TraceIt(FileName);
+    uint64_t FrameAddr = 0;
+    while (!TraceIt.isAtEoF()) {
+      int32_t Count = 0;
+      while (!TraceIt.isAtEoF() &&
+             !TraceIt.getCurrentLine().ltrim().getAsInteger(16, FrameAddr)) {
+        Count++;
+        TraceIt.advance();
+      }
+      if (!TraceIt.isAtEoF()) {
+        if (isLBRSample(TraceIt.getCurrentLine())) {
+          if (Count > 0)
+            return PERF_LBR_STACK;
+          else
+            return PERF_LBR;
+        }
+        TraceIt.advance();
+      }
+    }
+    return PERF_INVALID;
   }
 
   // The parsed MMap event
@@ -540,6 +574,9 @@ class PerfReader {
   }
 
 private:
+  /// Validate the command line input
+  void validateCommandLine(cl::list<std::string> &BinaryFilenames,
+                           cl::list<std::string> &PerfTraceFilenames);
   /// Parse a single line of a PERF_RECORD_MMAP2 event looking for a
   /// mapping between the binary name and its memory layout.
   ///
@@ -574,7 +611,7 @@ class PerfReader {
   BinarySampleCounterMap BinarySampleCounters;
   // Samples with the repeating time generated by the perf reader
   AggregatedCounter AggregatedSamples;
-  PerfScriptType PerfType;
+  PerfScriptType PerfType = PERF_UNKNOWN;
 };
 
 } // end namespace sampleprof

llvm/tools/llvm-profgen/ProfileGenerator.cpp

@@ -11,6 +11,8 @@
 static cl::opt<std::string> OutputFilename("output", cl::value_desc("output"),
                                            cl::Required,
                                            cl::desc("Output profile file"));
+static cl::alias OutputA("o", cl::desc("Alias for --output"),
+                         cl::aliasopt(OutputFilename));
 
 static cl::opt<SampleProfileFormat> OutputFormat(
     "format", cl::desc("Format of output profile"), cl::init(SPF_Text),

llvm/tools/llvm-profgen/ProfiledBinary.cpp

@@ -22,16 +22,15 @@
 using namespace llvm;
 using namespace sampleprof;
 
-static cl::opt<bool> ShowDisassembly("show-disassembly", cl::ReallyHidden,
-                                     cl::init(false), cl::ZeroOrMore,
-                                     cl::desc("Print disassembled code."));
+cl::opt<bool> ShowDisassemblyOnly("show-disassembly-only", cl::ReallyHidden,
+                                  cl::init(false), cl::ZeroOrMore,
+                                  cl::desc("Print disassembled code."));
 
-static cl::opt<bool> ShowSourceLocations("show-source-locations",
-                                         cl::ReallyHidden, cl::init(false),
-                                         cl::ZeroOrMore,
-                                         cl::desc("Print source locations."));
+cl::opt<bool> ShowSourceLocations("show-source-locations", cl::ReallyHidden,
+                                  cl::init(false), cl::ZeroOrMore,
+                                  cl::desc("Print source locations."));
 
-static cl::opt<bool> ShowPseudoProbe(
+cl::opt<bool> ShowPseudoProbe(
     "show-pseudo-probe", cl::ReallyHidden, cl::init(false), cl::ZeroOrMore,
     cl::desc("Print pseudo probe section and disassembled info."));
 
@@ -199,7 +198,6 @@ void ProfiledBinary::decodePseudoProbe(const ELFObjectFileBase *Obj) {
 bool ProfiledBinary::dissassembleSymbol(std::size_t SI, ArrayRef<uint8_t> Bytes,
                                         SectionSymbolsTy &Symbols,
                                         const SectionRef &Section) {
-
   std::size_t SE = Symbols.size();
   uint64_t SectionOffset = Section.getAddress() - PreferredBaseAddress;
   uint64_t SectSize = Section.getSize();
@@ -211,7 +209,7 @@ bool ProfiledBinary::dissassembleSymbol(std::size_t SI, ArrayRef<uint8_t> Bytes,
     return true;
 
   std::string &&SymbolName = Symbols[SI].Name.str();
-  if (ShowDisassembly)
+  if (ShowDisassemblyOnly)
     outs() << '<' << SymbolName << ">:\n";
 
   uint64_t Offset = StartOffset;
@@ -223,7 +221,7 @@ bool ProfiledBinary::dissassembleSymbol(std::size_t SI, ArrayRef<uint8_t> Bytes,
                                 Offset + PreferredBaseAddress, nulls()))
       return false;
 
-    if (ShowDisassembly) {
+    if (ShowDisassemblyOnly) {
       if (ShowPseudoProbe) {
         ProbeDecoder.printProbeForAddress(outs(),
                                           Offset + PreferredBaseAddress);
@@ -257,7 +255,7 @@ bool ProfiledBinary::dissassembleSymbol(std::size_t SI, ArrayRef<uint8_t> Bytes,
     Offset += Size;
   }
 
-  if (ShowDisassembly)
+  if (ShowDisassemblyOnly)
     outs() << "\n";
 
   FuncStartAddrMap[StartOffset] = Symbols[SI].Name.str();
@@ -323,7 +321,7 @@ void ProfiledBinary::disassemble(const ELFObjectFileBase *Obj) {
   for (std::pair<const SectionRef, SectionSymbolsTy> &SecSyms : AllSymbols)
     stable_sort(SecSyms.second);
 
-  if (ShowDisassembly)
+  if (ShowDisassemblyOnly)
     outs() << "\nDisassembly of " << FileName << ":\n";
 
   // Dissassemble a text section.
@@ -342,7 +340,7 @@ void ProfiledBinary::disassemble(const ELFObjectFileBase *Obj) {
     // Register the text section.
     TextSections.insert({SectionOffset, SectSize});
 
-    if (ShowDisassembly) {
+    if (ShowDisassemblyOnly) {
       StringRef SectionName = unwrapOrError(Section.getName(), FileName);
       outs() << "\nDisassembly of section " << SectionName;
       outs() << " [" << format("0x%" PRIx64, SectionOffset) << ", "

llvm/tools/llvm-profgen/llvm-profgen.cpp

@@ -29,6 +29,8 @@ static cl::list<std::string>
                     llvm::cl::MiscFlags::CommaSeparated,
                     cl::desc("Path of profiled binary files"));
 
+extern cl::opt<bool> ShowDisassemblyOnly;
+
 using namespace llvm;
 using namespace sampleprof;
 
@@ -43,7 +45,9 @@ int main(int argc, const char *argv[]) {
   cl::ParseCommandLineOptions(argc, argv, "llvm SPGO profile generator\n");
 
   // Load binaries and parse perf events and samples
-  PerfReader Reader(BinaryFilenames);
+  PerfReader Reader(BinaryFilenames, PerfTraceFilenames);
+  if (ShowDisassemblyOnly)
+    return EXIT_SUCCESS;
   Reader.parsePerfTraces(PerfTraceFilenames);
 
   std::unique_ptr<ProfileGenerator> Generator = ProfileGenerator::create(