[BOLT] Refactor code and data emission code

Summary: Consolidate code and data emission code in ELF-independent BinaryEmitter. The high-level interface includes only two functions emitBinaryContext() and emitFunctionBody() used by RewriteInstance and BinaryContext respectively. (cherry picked from FBD20332901)
llvm · Mar 6, 2020 · 1f3e351 · 1f3e351
1 parent 74a2777
commit 1f3e351
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Showing 14 changed files with 1,251 additions and 1,077 deletions.
diff --git a/bolt/src/BinaryContext.cpp b/bolt/src/BinaryContext.cpp
@@ -10,6 +10,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "BinaryContext.h"
+#include "BinaryEmitter.h"
 #include "BinaryFunction.h"
 #include "DataReader.h"
 #include "ParallelUtilities.h"
@@ -402,8 +403,8 @@ BinaryContext::handleAddressRef(uint64_t Address, BinaryFunction &BF,
         /// a reference to its constant island. When emitting this function,
         /// we will also emit IslandIter->second's constants. This only
         /// happens in custom AArch64 assembly code.
-        BF.IslandDependency.insert(IslandIter->second);
-        BF.ProxyIslandSymbols[IslandSym] = IslandIter->second;
+        BF.Islands.Dependency.insert(IslandIter->second);
+        BF.Islands.ProxySymbols[IslandSym] = IslandIter->second;
         return std::make_pair(IslandSym, Addend);
       }
     }
@@ -1899,9 +1900,9 @@ BinaryContext::calculateEmittedSize(BinaryFunction &BF, bool FixBranches) {
   std::unique_ptr<MCStreamer> Streamer(TheTarget->createMCObjectStreamer(
       *TheTriple, *LocalCtx, std::unique_ptr<MCAsmBackend>(MAB), VecOS,
       std::unique_ptr<MCCodeEmitter>(MCEInstance.MCE.release()), *STI,
-      /* RelaxAll */ false,
-      /* IncrementalLinkerCompatible */ false,
-      /* DWARFMustBeAtTheEnd */ false));
+      /*RelaxAll=*/false,
+      /*IncrementalLinkerCompatible=*/false,
+      /*DWARFMustBeAtTheEnd=*/false));
 
   Streamer->InitSections(false);
 
@@ -1915,7 +1916,8 @@ BinaryContext::calculateEmittedSize(BinaryFunction &BF, bool FixBranches) {
 
   Streamer->SwitchSection(Section);
   Streamer->EmitLabel(StartLabel);
-  BF.emitBody(*Streamer, /*EmitColdPart = */false, /*EmitCodeOnly = */true);
+  emitFunctionBody(*Streamer, BF, /*EmitColdPart=*/false,
+                   /*EmitCodeOnly=*/true);
   Streamer->EmitLabel(EndLabel);
 
   if (BF.isSplit()) {
@@ -1927,7 +1929,8 @@ BinaryContext::calculateEmittedSize(BinaryFunction &BF, bool FixBranches) {
 
     Streamer->SwitchSection(ColdSection);
     Streamer->EmitLabel(ColdStartLabel);
-    BF.emitBody(*Streamer, /*EmitColdPart = */true, /*EmitCodeOnly = */true);
+    emitFunctionBody(*Streamer, BF, /*EmitColdPart=*/true,
+                     /*EmitCodeOnly=*/true);
     Streamer->EmitLabel(ColdEndLabel);
   }
 

diff --git a/bolt/src/BinaryContext.h b/bolt/src/BinaryContext.h
@@ -23,6 +23,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/MC/MCAsmBackend.h"
@@ -257,6 +258,24 @@ class BinaryContext {
     return nullptr;
   }
 
+  unsigned getDWARFEncodingSize(unsigned Encoding) {
+    switch (Encoding & 0x0f) {
+    default: llvm_unreachable("unknown encoding");
+    case dwarf::DW_EH_PE_absptr:
+    case dwarf::DW_EH_PE_signed:
+      return AsmInfo->getCodePointerSize();
+    case dwarf::DW_EH_PE_udata2:
+    case dwarf::DW_EH_PE_sdata2:
+      return 2;
+    case dwarf::DW_EH_PE_udata4:
+    case dwarf::DW_EH_PE_sdata4:
+      return 4;
+    case dwarf::DW_EH_PE_udata8:
+    case dwarf::DW_EH_PE_sdata8:
+      return 8;
+    }
+  }
+
   /// [MCSymbol] -> [BinaryFunction]
   ///
   /// As we fold identical functions, multiple symbols can point
@@ -675,6 +694,11 @@ class BinaryContext {
                               ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
   }
 
+  /// Return data section with a given name.
+  MCSection *getDataSection(StringRef SectionName) const {
+    return Ctx->getELFSection(SectionName, ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
+  }
+
   /// \name Pre-assigned Section Names
   /// @{