Modified LLDB to be able to lookup global variables by address.

This is done by adding a "Variable *" to SymbolContext and allowing SymbolFile::ResolveSymbolContext() so if an address is resolved into a symbol context, we can include the global or static variable for that address.

This means you can now find global variables that are merged globals when doing a "image lookup --verbose --address 0x1230000". Previously we would resolve a symbol and show "_MergedGlobals123 + 1234". But now we can show the global variable name.

The eSymbolContextEverything purposely does not include the new eSymbolContextVariable in its lookup since stack frame code does many lookups and we don't want it triggering the global variable lookups.

<rdar://problem/18945678> 

llvm-svn: 226084

1 files changed, 55 insertions, 7 deletions

diff --git a/lldb/source/Symbol/SymbolContext.cpp b/lldb/source/Symbol/SymbolContext.cpp
index 129f4def006..c5cdc2d9687 100644
--- a/lldb/source/Symbol/SymbolContext.cpp
+++ b/lldb/source/Symbol/SymbolContext.cpp
@@ -21,6 +21,7 @@
 #include "lldb/Symbol/Symbol.h"
 #include "lldb/Symbol/SymbolFile.h"
 #include "lldb/Symbol/SymbolVendor.h"
+#include "lldb/Symbol/Variable.h"
 #include "lldb/Target/Target.h"
 
 using namespace lldb;
@@ -33,7 +34,8 @@ SymbolContext::SymbolContext() :
     function    (nullptr),
     block       (nullptr),
     line_entry  (),
-    symbol      (nullptr)
+    symbol      (nullptr),
+    variable    (nullptr)
 {
 }
 
@@ -44,7 +46,8 @@ SymbolContext::SymbolContext(const ModuleSP& m, CompileUnit *cu, Function *f, Bl
     function    (f),
     block       (b),
     line_entry  (),
-    symbol      (s)
+    symbol      (s),
+    variable    (nullptr)
 {
     if (le)
         line_entry = *le;
@@ -57,7 +60,8 @@ SymbolContext::SymbolContext(const TargetSP &t, const ModuleSP& m, CompileUnit *
     function    (f),
     block       (b),
     line_entry  (),
-    symbol      (s)
+    symbol      (s),
+    variable    (nullptr)
 {
     if (le)
         line_entry = *le;
@@ -70,7 +74,8 @@ SymbolContext::SymbolContext(const SymbolContext& rhs) :
     function    (rhs.function),
     block       (rhs.block),
     line_entry  (rhs.line_entry),
-    symbol      (rhs.symbol)
+    symbol      (rhs.symbol),
+    variable    (rhs.variable)
 {
 }
 
@@ -82,7 +87,8 @@ SymbolContext::SymbolContext (SymbolContextScope *sc_scope) :
     function    (nullptr),
     block       (nullptr),
     line_entry  (),
-    symbol      (nullptr)
+    symbol      (nullptr),
+    variable    (nullptr)
 {
     sc_scope->CalculateSymbolContext (this);
 }
@@ -103,6 +109,7 @@ SymbolContext::operator= (const SymbolContext& rhs)
         block       = rhs.block;
         line_entry  = rhs.line_entry;
         symbol      = rhs.symbol;
+        variable    = rhs.variable;
     }
     return *this;
 }
@@ -118,6 +125,7 @@ SymbolContext::Clear(bool clear_target)
     block       = nullptr;
     line_entry.Clear();
     symbol      = nullptr;
+    variable    = nullptr;
 }
 
 bool
@@ -309,6 +317,37 @@ SymbolContext::GetDescription(Stream *s, lldb::DescriptionLevel level, Target *t
         symbol->GetDescription(s, level, target);
         s->EOL();
     }
+
+    if (variable != nullptr)
+    {
+        s->Indent("   Variable: ");
+
+        s->Printf("id = {0x%8.8" PRIx64 "}, ", variable->GetID());
+
+        switch (variable->GetScope())
+        {
+            case eValueTypeVariableGlobal:
+                s->PutCString("kind = global, ");
+                break;
+
+            case eValueTypeVariableStatic:
+                s->PutCString("kind = static, ");
+                break;
+
+            case eValueTypeVariableArgument:
+                s->PutCString("kind = argument, ");
+                break;
+
+            case eValueTypeVariableLocal:
+                s->PutCString("kind = local, ");
+                break;
+
+            default:
+                break;
+        }
+
+        s->Printf ("name = \"%s\"\n", variable->GetName().GetCString());
+    }
 }
 
 uint32_t
@@ -322,6 +361,7 @@ SymbolContext::GetResolvedMask () const
     if (block)                  resolved_mask |= eSymbolContextBlock;
     if (line_entry.IsValid())   resolved_mask |= eSymbolContextLineEntry;
     if (symbol)                 resolved_mask |= eSymbolContextSymbol;
+    if (variable)               resolved_mask |= eSymbolContextVariable;
     return resolved_mask;
 }
 
@@ -377,6 +417,12 @@ SymbolContext::Dump(Stream *s, Target *target) const
     if (symbol != nullptr && symbol->GetMangled())
         *s << ' ' << symbol->GetMangled().GetName().AsCString();
     s->EOL();
+    *s << "Variable     = " << (void *)variable;
+    if (variable != nullptr)
+    {
+        *s << " {0x" << variable->GetID() << "} " << variable->GetType()->GetName();
+        s->EOL();
+    }
     s->IndentLess();
     s->IndentLess();
 }
@@ -389,7 +435,8 @@ lldb_private::operator== (const SymbolContext& lhs, const SymbolContext& rhs)
             && lhs.module_sp.get() == rhs.module_sp.get()
             && lhs.comp_unit == rhs.comp_unit
             && lhs.target_sp.get() == rhs.target_sp.get() 
-            && LineEntry::Compare(lhs.line_entry, rhs.line_entry) == 0;
+            && LineEntry::Compare(lhs.line_entry, rhs.line_entry) == 0
+            && lhs.variable == rhs.variable;
 }
 
 bool
@@ -400,7 +447,8 @@ lldb_private::operator!= (const SymbolContext& lhs, const SymbolContext& rhs)
             || lhs.module_sp.get() != rhs.module_sp.get()
             || lhs.comp_unit != rhs.comp_unit
             || lhs.target_sp.get() != rhs.target_sp.get() 
-            || LineEntry::Compare(lhs.line_entry, rhs.line_entry) != 0;
+            || LineEntry::Compare(lhs.line_entry, rhs.line_entry) != 0
+            || lhs.variable != rhs.variable;
 }
 
 bool