llvm-symbolizer: use dynamic symbol table if the regular one is stripped.

llvm-svn: 202265

test/DebugInfo/llvm-symbolizer.test

@@ -77,3 +77,9 @@ BINARY_C:       main
 BINARY_C-NEXT: /tmp/dbginfo{{[/\\]}}llvm-symbolizer-test.c:10
 BINARY_C:      _start
 BINARY_C:      {{g$}}
+
+RUN: echo "0x1f1" > %t.input6
+RUN: llvm-symbolizer --obj %p/Inputs/shared-object-stripped.elf-i386 < %t.input6 \
+RUN:   | FileCheck %s --check-prefix=STRIPPED
+
+STRIPPED:  global_func

tools/llvm-symbolizer/LLVMSymbolize.cpp

@@ -14,6 +14,7 @@
 #include "LLVMSymbolize.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Config/config.h"
+#include "llvm/Object/ELFObjectFile.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Compression.h"
@@ -54,27 +55,41 @@ ModuleInfo::ModuleInfo(ObjectFile *Obj, DIContext *DICtx)
     : Module(Obj), DebugInfoContext(DICtx) {
   for (symbol_iterator si = Module->symbol_begin(), se = Module->symbol_end();
        si != se; ++si) {
+    addSymbol(si);
+  }
+  bool NoSymbolTable = (Module->symbol_begin() == Module->symbol_end());
+  if (NoSymbolTable && Module->isELF()) {
+    // Fallback to dynamic symbol table, if regular symbol table is stripped.
+    std::pair<symbol_iterator, symbol_iterator> IDyn =
+        getELFDynamicSymbolIterators(Module);
+    for (symbol_iterator si = IDyn.first, se = IDyn.second; si != se; ++si) {
+      addSymbol(si);
+    }
+  }
+}
+
+void ModuleInfo::addSymbol(const symbol_iterator &Sym) {
   SymbolRef::Type SymbolType;
-    if (error(si->getType(SymbolType)))
-      continue;
+  if (error(Sym->getType(SymbolType)))
+    return;
   if (SymbolType != SymbolRef::ST_Function &&
       SymbolType != SymbolRef::ST_Data)
-      continue;
+    return;
   uint64_t SymbolAddress;
-    if (error(si->getAddress(SymbolAddress)) ||
+  if (error(Sym->getAddress(SymbolAddress)) ||
       SymbolAddress == UnknownAddressOrSize)
-      continue;
+    return;
   uint64_t SymbolSize;
   // Getting symbol size is linear for Mach-O files, so assume that symbol
   // occupies the memory range up to the following symbol.
-    if (isa<MachOObjectFile>(Obj))
+  if (isa<MachOObjectFile>(Module))
     SymbolSize = 0;
-    else if (error(si->getSize(SymbolSize)) ||
+  else if (error(Sym->getSize(SymbolSize)) ||
            SymbolSize == UnknownAddressOrSize)
-      continue;
+    return;
   StringRef SymbolName;
-    if (error(si->getName(SymbolName)))
-      continue;
+  if (error(Sym->getName(SymbolName)))
+    return;
   // Mach-O symbol table names have leading underscore, skip it.
   if (Module->isMachO() && SymbolName.size() > 0 && SymbolName[0] == '_')
     SymbolName = SymbolName.drop_front();
@@ -83,7 +98,6 @@ ModuleInfo::ModuleInfo(ObjectFile *Obj, DIContext *DICtx)
   SymbolMapTy &M = SymbolType == SymbolRef::ST_Function ? Functions : Objects;
   SymbolDesc SD = { SymbolAddress, SymbolSize };
   M.insert(std::make_pair(SD, SymbolName));
-  }
 }
 
 bool ModuleInfo::getNameFromSymbolTable(SymbolRef::Type Type, uint64_t Address,

tools/llvm-symbolizer/LLVMSymbolize.h

@@ -102,6 +102,7 @@ private:
   bool getNameFromSymbolTable(SymbolRef::Type Type, uint64_t Address,
                               std::string &Name, uint64_t &Addr,
                               uint64_t &Size) const;
+  void addSymbol(const symbol_iterator &Sym);
   ObjectFile *Module;
   OwningPtr<DIContext> DebugInfoContext;