[WebAssembly] Parse llvm.ident into producers section

Summary:
Everything before the word "version" is the tool, and everything after
the word "version" is the version.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D56742

llvm-svn: 351399

4 files changed, 123 insertions, 17 deletions

diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index 0cca3757be9..8e45b2f3e0c 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -224,6 +224,7 @@ class WasmObjectWriter : public MCObjectWriter {
   // Stores output data (index, relocations, content offset) for custom
   // section.
   std::vector<WasmCustomSection> CustomSections;
+  std::unique_ptr<WasmCustomSection> ProducersSection;
   // Relocations for fixing up references in the custom sections.
   DenseMap<const MCSectionWasm *, std::vector<WasmRelocationEntry>>
       CustomSectionsRelocations;
@@ -265,6 +266,8 @@ private:
     WasmIndices.clear();
     TableIndices.clear();
     DataLocations.clear();
+    CustomSections.clear();
+    ProducersSection.reset();
     CustomSectionsRelocations.clear();
     SignatureIndices.clear();
     Signatures.clear();
@@ -311,7 +314,8 @@ private:
       ArrayRef<wasm::WasmSymbolInfo> SymbolInfos,
       ArrayRef<std::pair<uint16_t, uint32_t>> InitFuncs,
       const std::map<StringRef, std::vector<WasmComdatEntry>> &Comdats);
-  void writeCustomSections(const MCAssembler &Asm, const MCAsmLayout &Layout);
+  void writeCustomSection(WasmCustomSection &CustomSection,
+                          const MCAssembler &Asm, const MCAsmLayout &Layout);
   void writeCustomRelocSections();
   void
   updateCustomSectionRelocations(const SmallVector<WasmFunction, 4> &Functions,
@@ -1045,25 +1049,24 @@ void WasmObjectWriter::writeLinkingMetaDataSection(
   endSection(Section);
 }
 
-void WasmObjectWriter::writeCustomSections(const MCAssembler &Asm,
-                                           const MCAsmLayout &Layout) {
-  for (auto &CustomSection : CustomSections) {
-    SectionBookkeeping Section;
-    auto *Sec = CustomSection.Section;
-    startCustomSection(Section, CustomSection.Name);
+void WasmObjectWriter::writeCustomSection(WasmCustomSection &CustomSection,
+                                          const MCAssembler &Asm,
+                                          const MCAsmLayout &Layout) {
+  SectionBookkeeping Section;
+  auto *Sec = CustomSection.Section;
+  startCustomSection(Section, CustomSection.Name);
 
-    Sec->setSectionOffset(W.OS.tell() - Section.ContentsOffset);
-    Asm.writeSectionData(W.OS, Sec, Layout);
+  Sec->setSectionOffset(W.OS.tell() - Section.ContentsOffset);
+  Asm.writeSectionData(W.OS, Sec, Layout);
 
-    CustomSection.OutputContentsOffset = Section.ContentsOffset;
-    CustomSection.OutputIndex = Section.Index;
+  CustomSection.OutputContentsOffset = Section.ContentsOffset;
+  CustomSection.OutputIndex = Section.Index;
 
-    endSection(Section);
+  endSection(Section);
 
-    // Apply fixups.
-    auto &Relocations = CustomSectionsRelocations[CustomSection.Section];
-    applyRelocations(Relocations, CustomSection.OutputContentsOffset);
-  }
+  // Apply fixups.
+  auto &Relocations = CustomSectionsRelocations[CustomSection.Section];
+  applyRelocations(Relocations, CustomSection.OutputContentsOffset);
 }
 
 uint32_t WasmObjectWriter::getFunctionType(const MCSymbolWasm &Symbol) {
@@ -1282,6 +1285,13 @@ uint64_t WasmObjectWriter::writeObject(MCAssembler &Asm,
           report_fatal_error("section name and begin symbol should match: " +
                              Twine(SectionName));
       }
+
+      // Separate out the producers section
+      if (Name == "producers") {
+        ProducersSection = llvm::make_unique<WasmCustomSection>(Name, &Section);
+        continue;
+      }
+
       CustomSections.emplace_back(Name, &Section);
     }
   }
@@ -1570,11 +1580,14 @@ uint64_t WasmObjectWriter::writeObject(MCAssembler &Asm,
   writeElemSection(TableElems);
   writeCodeSection(Asm, Layout, Functions);
   writeDataSection();
-  writeCustomSections(Asm, Layout);
+  for (auto &CustomSection : CustomSections)
+    writeCustomSection(CustomSection, Asm, Layout);
   writeLinkingMetaDataSection(SymbolInfos, InitFuncs, Comdats);
   writeRelocSection(CodeSectionIndex, "CODE", CodeRelocations);
   writeRelocSection(DataSectionIndex, "DATA", DataRelocations);
   writeCustomRelocSections();
+  if (ProducersSection)
+    writeCustomSection(*ProducersSection, Asm, Layout);
 
   // TODO: Translate the .comment section to the output.
   return W.OS.tell() - StartOffset;
diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index d84cb48c9fb..fd6ad9bdefe 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -10,6 +10,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/Triple.h"
@@ -659,6 +660,47 @@ Error WasmObjectFile::parseLinkingSectionComdat(ReadContext &Ctx) {
   return Error::success();
 }
 
+Error WasmObjectFile::parseProducersSection(ReadContext &Ctx) {
+  llvm::SmallSet<StringRef, 3> FieldsSeen;
+  uint32_t Fields = readVaruint32(Ctx);
+  for (size_t i = 0; i < Fields; ++i) {
+    StringRef FieldName = readString(Ctx);
+    if (!FieldsSeen.insert(FieldName).second)
+      return make_error<GenericBinaryError>(
+          "Producers section does not have unique fields",
+          object_error::parse_failed);
+    std::vector<std::pair<std::string, std::string>> *ProducerVec = nullptr;
+    if (FieldName == "language") {
+      ProducerVec = &ProducerInfo.Languages;
+    } else if (FieldName == "processed-by") {
+      ProducerVec = &ProducerInfo.Tools;
+    } else if (FieldName == "sdk") {
+      ProducerVec = &ProducerInfo.SDKs;
+    } else {
+      return make_error<GenericBinaryError>(
+          "Producers section field is not named one of language, processed-by, "
+          "or sdk",
+          object_error::parse_failed);
+    }
+    uint32_t ValueCount = readVaruint32(Ctx);
+    llvm::SmallSet<StringRef, 8> ProducersSeen;
+    for (size_t j = 0; j < ValueCount; ++j) {
+      StringRef Name = readString(Ctx);
+      StringRef Version = readString(Ctx);
+      if (!ProducersSeen.insert(Name).second) {
+        return make_error<GenericBinaryError>(
+            "Producers section contains repeated producer",
+            object_error::parse_failed);
+      }
+      ProducerVec->emplace_back(Name, Version);
+    }
+  }
+  if (Ctx.Ptr != Ctx.End)
+    return make_error<GenericBinaryError>("Producers section ended prematurely",
+                                          object_error::parse_failed);
+  return Error::success();
+}
+
 Error WasmObjectFile::parseRelocSection(StringRef Name, ReadContext &Ctx) {
   uint32_t SectionIndex = readVaruint32(Ctx);
   if (SectionIndex >= Sections.size())
@@ -757,6 +799,9 @@ Error WasmObjectFile::parseCustomSection(WasmSection &Sec, ReadContext &Ctx) {
   } else if (Sec.Name == "linking") {
     if (Error Err = parseLinkingSection(Ctx))
       return Err;
+  } else if (Sec.Name == "producers") {
+    if (Error Err = parseProducersSection(Ctx))
+      return Err;
   } else if (Sec.Name.startswith("reloc.")) {
     if (Error Err = parseRelocSection(Sec.Name, Ctx))
       return Err;
diff --git a/llvm/lib/ObjectYAML/WasmYAML.cpp b/llvm/lib/ObjectYAML/WasmYAML.cpp
index 47bf853e0d3..b45c8ce65eb 100644
--- a/llvm/lib/ObjectYAML/WasmYAML.cpp
+++ b/llvm/lib/ObjectYAML/WasmYAML.cpp
@@ -74,6 +74,14 @@ static void sectionMapping(IO &IO, WasmYAML::LinkingSection &Section) {
   IO.mapOptional("Comdats", Section.Comdats);
 }
 
+static void sectionMapping(IO &IO, WasmYAML::ProducersSection &Section) {
+  commonSectionMapping(IO, Section);
+  IO.mapRequired("Name", Section.Name);
+  IO.mapOptional("Languages", Section.Languages);
+  IO.mapOptional("Tools", Section.Tools);
+  IO.mapOptional("SDKs", Section.SDKs);
+}
+
 static void sectionMapping(IO &IO, WasmYAML::CustomSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapRequired("Name", Section.Name);
@@ -169,6 +177,10 @@ void MappingTraits<std::unique_ptr<WasmYAML::Section>>::mapping(
       if (!IO.outputting())
         Section.reset(new WasmYAML::NameSection());
       sectionMapping(IO, *cast<WasmYAML::NameSection>(Section.get()));
+    } else if (SectionName == "producers") {
+      if (!IO.outputting())
+        Section.reset(new WasmYAML::ProducersSection());
+      sectionMapping(IO, *cast<WasmYAML::ProducersSection>(Section.get()));
     } else {
       if (!IO.outputting())
         Section.reset(new WasmYAML::CustomSection(SectionName));
@@ -293,6 +305,12 @@ void MappingTraits<WasmYAML::NameEntry>::mapping(
   IO.mapRequired("Name", NameEntry.Name);
 }
 
+void MappingTraits<WasmYAML::ProducerEntry>::mapping(
+    IO &IO, WasmYAML::ProducerEntry &ProducerEntry) {
+  IO.mapRequired("Name", ProducerEntry.Name);
+  IO.mapRequired("Version", ProducerEntry.Version);
+}
+
 void MappingTraits<WasmYAML::SegmentInfo>::mapping(
     IO &IO, WasmYAML::SegmentInfo &SegmentInfo) {
   IO.mapRequired("Index", SegmentInfo.Index);
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
index c4f03dfa7f9..6d5647a7ace 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
@@ -22,6 +22,7 @@
 #include "WebAssemblyMCInstLower.h"
 #include "WebAssemblyMachineFunctionInfo.h"
 #include "WebAssemblyRegisterInfo.h"
+#include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/CodeGen/Analysis.h"
 #include "llvm/CodeGen/AsmPrinter.h"
@@ -146,6 +147,35 @@ void WebAssemblyAsmPrinter::EmitEndOfAsmFile(Module &M) {
       OutStreamer->PopSection();
     }
   }
+
+  if (const NamedMDNode *Ident = M.getNamedMetadata("llvm.ident")) {
+    llvm::SmallSet<StringRef, 4> SeenTools;
+    llvm::SmallVector<std::pair<StringRef, StringRef>, 4> Tools;
+    for (size_t i = 0, e = Ident->getNumOperands(); i < e; ++i) {
+      const auto *S = cast<MDString>(Ident->getOperand(i)->getOperand(0));
+      std::pair<StringRef, StringRef> Field = S->getString().split("version");
+      StringRef Name = Field.first.trim();
+      StringRef Version = Field.second.trim();
+      if (!SeenTools.insert(Name).second)
+        continue;
+      Tools.emplace_back(Name, Version);
+    }
+    MCSectionWasm *Producers = OutContext.getWasmSection(
+        ".custom_section.producers", SectionKind::getMetadata());
+    OutStreamer->PushSection();
+    OutStreamer->SwitchSection(Producers);
+    OutStreamer->EmitULEB128IntValue(1);
+    OutStreamer->EmitULEB128IntValue(strlen("processed-by"));
+    OutStreamer->EmitBytes("processed-by");
+    OutStreamer->EmitULEB128IntValue(Tools.size());
+    for (auto &Tool : Tools) {
+      OutStreamer->EmitULEB128IntValue(Tool.first.size());
+      OutStreamer->EmitBytes(Tool.first);
+      OutStreamer->EmitULEB128IntValue(Tool.second.size());
+      OutStreamer->EmitBytes(Tool.second);
+    }
+    OutStreamer->PopSection();
+  }
 }
 
 void WebAssemblyAsmPrinter::EmitConstantPool() {