Change how symbol sizes are handled in lib/Object.

COFF and MachO only define symbol sizes for common symbols. Reflect that
in the class hierarchy by having a method for common symbols only in the base
and a general one in ELF.

This avoids the need of using a magic value for the size, which had a few
problems
* Most callers didn't check for it.
* The ones that did could not tell the magic value from a file actually having
  that value.

llvm-svn: 240529

4 files changed, 13 insertions, 20 deletions

diff --git a/llvm/lib/Object/COFFObjectFile.cpp b/llvm/lib/Object/COFFObjectFile.cpp
index e2f559eec72..0595d38f086 100644
--- a/llvm/lib/Object/COFFObjectFile.cpp
+++ b/llvm/lib/Object/COFFObjectFile.cpp
@@ -155,11 +155,11 @@ std::error_code COFFObjectFile::getSymbolAddress(DataRefImpl Ref,
   COFFSymbolRef Symb = getCOFFSymbol(Ref);
 
   if (Symb.isAnyUndefined()) {
-    Result = UnknownAddressOrSize;
+    Result = UnknownAddress;
     return std::error_code();
   }
   if (Symb.isCommon()) {
-    Result = UnknownAddressOrSize;
+    Result = UnknownAddress;
     return std::error_code();
   }
   int32_t SectionNumber = Symb.getSectionNumber();
@@ -236,12 +236,9 @@ uint32_t COFFObjectFile::getSymbolFlags(DataRefImpl Ref) const {
   return Result;
 }
 
-uint64_t COFFObjectFile::getSymbolSize(DataRefImpl Ref) const {
+uint64_t COFFObjectFile::getCommonSymbolSizeImpl(DataRefImpl Ref) const {
   COFFSymbolRef Symb = getCOFFSymbol(Ref);
-
-  if (Symb.isCommon())
-    return Symb.getValue();
-  return UnknownAddressOrSize;
+  return Symb.getValue();
 }
 
 std::error_code
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index f76dd0d3f7c..ded81099300 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -375,14 +375,14 @@ std::error_code MachOObjectFile::getSymbolAddress(DataRefImpl Symb,
     MachO::nlist_64 Entry = getSymbol64TableEntry(Symb);
     if ((Entry.n_type & MachO::N_TYPE) == MachO::N_UNDF &&
         Entry.n_value == 0)
-      Res = UnknownAddressOrSize;
+      Res = UnknownAddress;
     else
       Res = Entry.n_value;
   } else {
     MachO::nlist Entry = getSymbolTableEntry(Symb);
     if ((Entry.n_type & MachO::N_TYPE) == MachO::N_UNDF &&
         Entry.n_value == 0)
-      Res = UnknownAddressOrSize;
+      Res = UnknownAddress;
     else
       Res = Entry.n_value;
   }
@@ -398,13 +398,10 @@ uint32_t MachOObjectFile::getSymbolAlignment(DataRefImpl DRI) const {
   return 0;
 }
 
-uint64_t MachOObjectFile::getSymbolSize(DataRefImpl DRI) const {
+uint64_t MachOObjectFile::getCommonSymbolSizeImpl(DataRefImpl DRI) const {
   uint64_t Value;
   getSymbolAddress(DRI, Value);
-  uint32_t flags = getSymbolFlags(DRI);
-  if (flags & SymbolRef::SF_Common)
-    return Value;
-  return UnknownAddressOrSize;
+  return Value;
 }
 
 std::error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
@@ -453,7 +450,7 @@ uint32_t MachOObjectFile::getSymbolFlags(DataRefImpl DRI) const {
     if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF) {
       uint64_t Value;
       getSymbolAddress(DRI, Value);
-      if (Value && Value != UnknownAddressOrSize)
+      if (Value && Value != UnknownAddress)
         Result |= SymbolRef::SF_Common;
     }
 
diff --git a/llvm/lib/Object/Object.cpp b/llvm/lib/Object/Object.cpp
index 85f243675ef..42da2e4c33e 100644
--- a/llvm/lib/Object/Object.cpp
+++ b/llvm/lib/Object/Object.cpp
@@ -187,7 +187,7 @@ uint64_t LLVMGetSymbolAddress(LLVMSymbolIteratorRef SI) {
 }
 
 uint64_t LLVMGetSymbolSize(LLVMSymbolIteratorRef SI) {
-  return (*unwrap(SI))->getSize();
+  return (*unwrap(SI))->getCommonSize();
 }
 
 // RelocationRef accessors
diff --git a/llvm/lib/Object/SymbolSize.cpp b/llvm/lib/Object/SymbolSize.cpp
index 121bf1baa7a..925a3d4df46 100644
--- a/llvm/lib/Object/SymbolSize.cpp
+++ b/llvm/lib/Object/SymbolSize.cpp
@@ -41,10 +41,9 @@ ErrorOr<std::vector<std::pair<SymbolRef, uint64_t>>>
 llvm::object::computeSymbolSizes(const ObjectFile &O) {
   std::vector<std::pair<SymbolRef, uint64_t>> Ret;
 
-  if (isa<ELFObjectFileBase>(&O)) {
-    for (SymbolRef Sym : O.symbols()) {
-      Ret.push_back({Sym, Sym.getSize()});
-    }
+  if (const auto *E = dyn_cast<ELFObjectFileBase>(&O)) {
+    for (SymbolRef Sym : E->symbols())
+      Ret.push_back({Sym, E->getSymbolSize(Sym)});
     return Ret;
   }