[WebAssembly] Add WebAssembly support to llvm-symbolizer

[dschuff]

Summary

The only thing missing for basic llvm-symbolizer support is the ability on lib/Object to get a wasm symbol's section ID, which allows sorting and computation of the symbols' sizes.

Also, when the WasmAsmParser switches sections on new functions, also add the section to the list of Dwarf sections if Dwarf is being generated for assembly;
this allows writing of simple tests.

[dschuff]

@sbc100 I haven't added any tests yet but does this look like a reasonable use of the various Symbol/Ref types?

[merge_guards_bot]

Unit tests: pass. 62114 tests passed, 0 failed and 808 were skipped.

clang-tidy: pass.

clang-format: fail. Please format your changes with clang-format by running git-clang-format HEAD^ or applying this patch.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

[sbc100]

Seems reasonable to me. Does llvm-symbolizer crash today when passed wasm object files?

[dschuff]

• remove debug print

[merge_guards_bot]

Unit tests: pass. 62114 tests passed, 0 failed and 808 were skipped.

clang-tidy: pass.

clang-format: fail. Please format your changes with clang-format by running git-clang-format HEAD^ or applying this patch.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[dschuff]

• Add test and Fix WebAssemblyAsmParser to emit dwarf for all text sections

[dschuff]

• clang-format

[dschuff]

• fix newline

[merge_guards_bot]

Unit tests: fail. 62110 tests passed, 6 failed and 807 were skipped.

failed: LLVM.tools/llvm-symbolizer/wasm-basic.s
failed: libc++.std/language_support/cmp/cmp_partialord/partialord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongeq/cmp.strongeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongord/strongord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakeq/cmp.weakeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakord/weakord.pass.cpp

clang-tidy: fail. clang-tidy found 0 errors and 2 warnings. 0 of them are added as review comments below (why?).

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[merge_guards_bot]

Unit tests: fail. 62111 tests passed, 5 failed and 807 were skipped.

failed: libc++.std/language_support/cmp/cmp_partialord/partialord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongeq/cmp.strongeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongord/strongord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakeq/cmp.weakeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakord/weakord.pass.cpp

clang-tidy: fail. clang-tidy found 0 errors and 2 warnings. 0 of them are added as review comments below (why?).

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[dschuff]

• fix clang-tidy, add comment, fix whitespace

[merge_guards_bot]

Unit tests: fail. 62110 tests passed, 6 failed and 807 were skipped.

failed: LLVM.tools/llvm-symbolizer/wasm-basic.s
failed: libc++.std/language_support/cmp/cmp_partialord/partialord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongeq/cmp.strongeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongord/strongord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakeq/cmp.weakeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakord/weakord.pass.cpp

clang-tidy: fail. clang-tidy found 0 errors and 2 warnings. 0 of them are added as review comments below (why?).

clang-format: fail. Please format your changes with clang-format by running git-clang-format HEAD^ or applying this patch.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[merge_guards_bot]

Unit tests: fail. 62111 tests passed, 5 failed and 807 were skipped.

failed: libc++.std/language_support/cmp/cmp_partialord/partialord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongeq/cmp.strongeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_strongord/strongord.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakeq/cmp.weakeq.pass.cpp
failed: libc++.std/language_support/cmp/cmp_weakord/weakord.pass.cpp

clang-tidy: pass.

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[jhenderson]

llvm/test/tools/llvm-symbolizer/wasm-basic.s

5

Nit: no need for two blank lines.

17–19

Nit: Use two '##' characters for comments for readability. Also, consider putting the TODO on its own line to make it stand out better. Finally, missing trailing full stop.

[dschuff]

• review comments

[dschuff]

Thanks!

[merge_guards_bot]

Unit tests: fail. 62182 tests passed, 1 failed and 815 were skipped.

failed: LLVM.tools/llvm-symbolizer/wasm-basic.s

clang-tidy: pass.

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[dschuff]

• Update test CHECKs to account for removing the blank line (turns out the code actually works :)

[merge_guards_bot]

Unit tests: pass. 62183 tests passed, 0 failed and 815 were skipped.

clang-tidy: pass.

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[jhenderson]

Looks good from my point of view, but a wasm expert should probably sign off.

[dschuff]

Thanks! sbc and aardappel are the relevant wasm experts here.

llvm/include/llvm/Object/Wasm.h

public:
 
   Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override;
   uint64_t getWasmSymbolValue(const WasmSymbol &Sym) const;
   uint64_t getSymbolValueImpl(DataRefImpl Symb) const override;
   uint32_t getSymbolAlignment(DataRefImpl Symb) const override;
   uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override;
   Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override;
   Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override;
+  uint32_t getSymbolSectionId(SymbolRef Sym) const;
 
   // Overrides from SectionRef.
   void moveSectionNext(DataRefImpl &Sec) const override;
   Expected<StringRef> getSectionName(DataRefImpl Sec) const override;
   uint64_t getSectionAddress(DataRefImpl Sec) const override;
   uint64_t getSectionIndex(DataRefImpl Sec) const override;
   uint64_t getSectionSize(DataRefImpl Sec) const override;
   Expected<ArrayRef<uint8_t>>
private:
   bool isValidSectionSymbol(uint32_t Index) const;
   wasm::WasmFunction &getDefinedFunction(uint32_t Index);
   const wasm::WasmFunction &getDefinedFunction(uint32_t Index) const;
   wasm::WasmGlobal &getDefinedGlobal(uint32_t Index);
   wasm::WasmEvent &getDefinedEvent(uint32_t Index);
 
   const WasmSection &getWasmSection(DataRefImpl Ref) const;
   const wasm::WasmRelocation &getWasmRelocation(DataRefImpl Ref) const;
+  uint32_t getSymbolSectionIdImpl(const WasmSymbol &Symb) const;
 
   Error parseSection(WasmSection &Sec);
   Error parseCustomSection(WasmSection &Sec, ReadContext &Ctx);
 
   // Standard section types
   Error parseTypeSection(ReadContext &Ctx);
   Error parseImportSection(ReadContext &Ctx);
   Error parseFunctionSection(ReadContext &Ctx);

llvm/lib/Object/SymbolSize.cpp

 //===- SymbolSize.cpp -----------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Object/SymbolSize.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/Object/ELFObjectFile.h"
 #include "llvm/Object/MachO.h"
+#include "llvm/Object/Wasm.h"
 
 using namespace llvm;
 using namespace object;
 
 // Orders increasingly by (SectionID, Address).
 int llvm::object::compareAddress(const SymEntry *A, const SymEntry *B) {
   if (A->SectionID != B->SectionID)
     return A->SectionID < B->SectionID ? -1 : 1;
   if (A->Address != B->Address)
     return A->Address < B->Address ? -1 : 1;
   return 0;
 }
 
 static unsigned getSectionID(const ObjectFile &O, SectionRef Sec) {
   if (auto *M = dyn_cast<MachOObjectFile>(&O))
     return M->getSectionID(Sec);
+  if (const auto *M = dyn_cast<WasmObjectFile>(&O))
+    return Sec.getIndex();
+
   return cast<COFFObjectFile>(O).getSectionID(Sec);
 }
 
 static unsigned getSymbolSectionID(const ObjectFile &O, SymbolRef Sym) {
   if (auto *M = dyn_cast<MachOObjectFile>(&O))
     return M->getSymbolSectionID(Sym);
+  if (const auto *M = dyn_cast<WasmObjectFile>(&O))
+    return M->getSymbolSectionId(Sym);
   return cast<COFFObjectFile>(O).getSymbolSectionID(Sym);
 }
 
 std::vector<std::pair<SymbolRef, uint64_t>>
 llvm::object::computeSymbolSizes(const ObjectFile &O) {
   std::vector<std::pair<SymbolRef, uint64_t>> Ret;
 
   if (const auto *E = dyn_cast<ELFObjectFileBase>(&O)) {

llvm/lib/Object/WasmObjectFile.cpp

 
 Expected<section_iterator>
 WasmObjectFile::getSymbolSection(DataRefImpl Symb) const {
   const WasmSymbol &Sym = getWasmSymbol(Symb);
   if (Sym.isUndefined())
     return section_end();
 
   DataRefImpl Ref;
+  Ref.d.a = getSymbolSectionIdImpl(Sym);
+  return section_iterator(SectionRef(Ref, this));
+}
+
+uint32_t WasmObjectFile::getSymbolSectionId(SymbolRef Symb) const {
+  const WasmSymbol &Sym = getWasmSymbol(Symb);
+  return getSymbolSectionIdImpl(Sym);
+}
+
+uint32_t WasmObjectFile::getSymbolSectionIdImpl(const WasmSymbol &Sym) const {
   switch (Sym.Info.Kind) {
   case wasm::WASM_SYMBOL_TYPE_FUNCTION:
-    Ref.d.a = CodeSection;
-    break;
+    return CodeSection;
   case wasm::WASM_SYMBOL_TYPE_GLOBAL:
-    Ref.d.a = GlobalSection;
-    break;
+    return GlobalSection;
   case wasm::WASM_SYMBOL_TYPE_DATA:
-    Ref.d.a = DataSection;
-    break;
+    return DataSection;
   case wasm::WASM_SYMBOL_TYPE_SECTION:
-    Ref.d.a = Sym.Info.ElementIndex;
-    break;
+    return Sym.Info.ElementIndex;
   case wasm::WASM_SYMBOL_TYPE_EVENT:
-    Ref.d.a = EventSection;
-    break;
+    return EventSection;
   default:
     llvm_unreachable("Unknown WasmSymbol::SymbolType");
   }
-  return section_iterator(SectionRef(Ref, this));
 }
 
 void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; }
 
 Expected<StringRef> WasmObjectFile::getSectionName(DataRefImpl Sec) const {
   const WasmSection &S = Sections[Sec.d.a];
 #define ECase(X)                                                               \
   case wasm::WASM_SEC_##X:                                                     \

llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp

if (SymName.startswith(".L"))
       return; // Local Symbol.
     // Only create a new text section if we're already in one.
     auto CWS = cast<MCSectionWasm>(getStreamer().getCurrentSection().first);
     if (!CWS || !CWS->getKind().isText())
       return;
     auto SecName = ".text." + SymName;
     auto WS = getContext().getWasmSection(SecName, SectionKind::getText());
     getStreamer().SwitchSection(WS);
+    // Also generate DWARF for this section if requested.
+    if (getContext().getGenDwarfForAssembly())
+      getContext().addGenDwarfSection(WS);
   }
 
   void onEndOfFunction() {
     // Automatically output a .size directive, so it becomes optional for the
     // user.
     if (!LastFunctionLabel) return;
     auto TempSym = getContext().createLinkerPrivateTempSymbol();
     getStreamer().EmitLabel(TempSym);

llvm/test/tools/llvm-symbolizer/wasm-basic.s

+# REQUIRES: webassembly-registered-target
+# RUN: llvm-mc -triple=wasm32-unknown-unknown -filetype=obj %s -o %t.o -g
+       
+foo:
+    .functype foo () -> ()
+    nop
+    end_function
+
+bar:
+    .functype bar (i32) -> (i32)
+    return
+    end_function
+
+# RUN: llvm-symbolizer -e %t.o 3 4 7 8 | FileCheck %s
+## Byte 1 is the function length and 2 is the locals declaration.
+## Currently no line corresponds to them.
+## TODO: create a loc for .functype?
+
+## Test 2 functions to ensure wasm's function-sections system works.
+# CHECK: wasm-basic.s:6:0
+# CHECK: wasm-basic.s:7:0
+# CHECK: wasm-basic.s:11:0
+# CHECK: wasm-basic.s:12:0