[lldb] Change synthetic symbol names to have file address

lldb/include/lldb/Symbol/Symbol.h

@@ -258,7 +258,7 @@ class Symbol : public SymbolContextScope {
   bool ContainsFileAddress(lldb::addr_t file_addr) const;
 
   static llvm::StringRef GetSyntheticSymbolPrefix() {
-    return "___lldb_unnamed_symbol";
+    return "___lldb_unnamed_symbol_";
   }
 
   /// Decode a serialized version of this object from data.

lldb/source/Symbol/Symbol.cpp

@@ -639,7 +639,9 @@ void Symbol::SynthesizeNameIfNeeded() const {
     // breakpoints on them.
     llvm::SmallString<256> name;
     llvm::raw_svector_ostream os(name);
-    os << GetSyntheticSymbolPrefix() << GetID();
+    os << GetSyntheticSymbolPrefix()
+       << llvm::format_hex_no_prefix(
+              m_addr_range.GetBaseAddress().GetFileAddress(), 0);
     m_mangled.SetDemangledName(ConstString(os.str()));
   }
 }

lldb/source/Symbol/Symtab.cpp

@@ -654,20 +654,21 @@ uint32_t Symtab::GetNameIndexes(ConstString symbol_name,
   if (count)
     return count;
   // Synthetic symbol names are not added to the name indexes, but they start
-  // with a prefix and end with a the symbol UserID. This allows users to find
-  // these symbols without having to add them to the name indexes. These
+  // with a prefix and end with the symbol file address. This allows users to
+  // find these symbols without having to add them to the name indexes. These
   // queries will not happen very often since the names don't mean anything, so
   // performance is not paramount in this case.
   llvm::StringRef name = symbol_name.GetStringRef();
   // String the synthetic prefix if the name starts with it.
   if (!name.consume_front(Symbol::GetSyntheticSymbolPrefix()))
     return 0; // Not a synthetic symbol name
 
-  // Extract the user ID from the symbol name
-  unsigned long long uid = 0;
-  if (getAsUnsignedInteger(name, /*Radix=*/10, uid))
+  // Extract the file address from the symbol name
+  unsigned long long file_address = 0;
+  if (getAsUnsignedInteger(name, /*Radix=*/16, file_address))
     return 0; // Failed to extract the user ID as an integer
-  Symbol *symbol = FindSymbolByID(uid);
+
+  Symbol *symbol = FindSymbolAtFileAddress(static_cast<addr_t>(file_address));
   if (symbol == nullptr)
     return 0;
   const uint32_t symbol_idx = GetIndexForSymbol(symbol);

lldb/test/API/python_api/unnamed_symbol_lookup/Makefile

@@ -0,0 +1,23 @@
+C_SOURCES := main.c
+
+include Makefile.rules
+
+all: a.out.stripped
+
+ifeq "$(OS)" "Darwin"
+STRIP_COMMAND = $(STRIP) -s keep_symbols.txt
+else
+STRIP_COMMAND = $(STRIP) --keep-symbol=main
+endif
+
+a.out.stripped: a.out
+ifeq "$(OS)" "Darwin"
+	echo "_main" > keep_symbols.txt
+	$(STRIP) -s keep_symbols.txt -o a.out.stripped a.out
+else
+	$(STRIP) --keep-symbol=main -o a.out.stripped a.out
+endif
+
+ifneq "$(CODESIGN)" ""
+	$(CODESIGN) -fs - a.out.stripped
+endif

lldb/test/API/python_api/unnamed_symbol_lookup/TestUnnamedSymbolLookup.py

@@ -0,0 +1,40 @@
+"""
+Test lookup unnamed symbols.
+"""
+
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestUnnamedSymbolLookup(TestBase):
+    def test_unnamed_symbol_lookup(self):
+        """Test looking up unnamed symbol synthetic name"""
+        self.build()
+        (target, process, thread, bkpt) = lldbutil.run_to_name_breakpoint(
+            self, "main", exe_name="a.out.stripped"
+        )
+
+        main_frame = thread.GetFrameAtIndex(0)
+
+        # Step until reaching the unnamed symbol called from main
+        for _ in range(100):
+            thread.StepInto()
+            if thread.GetFrameAtIndex(0) != main_frame:
+                break
+
+            thread.StepInto()
+
+        self.assertEqual(
+            main_frame, thread.GetFrameAtIndex(1), "Expected to be called from main"
+        )
+        symbol = thread.GetFrameAtIndex(0).GetSymbol()
+        self.assertIsNotNone(symbol, "unnamed symbol called from main not reached")
+        self.assertTrue(symbol.name.startswith("___lldb_unnamed_symbol"))
+
+        exe_module = symbol.GetStartAddress().GetModule()
+        found_symbols = exe_module.FindSymbols(symbol.name)
+        self.assertIsNotNone(found_symbols)
+        self.assertEqual(found_symbols.GetSize(), 1)

lldb/test/API/python_api/unnamed_symbol_lookup/main.c

@@ -0,0 +1,6 @@
+__attribute__((nodebug)) int stripped_function(int val) { return val * val; }
+
+int main(void) {
+  stripped_function(10);
+  return 0;
+}

lldb/test/Shell/ObjectFile/ELF/eh_frame-symbols.yaml

@@ -3,8 +3,8 @@
 
 # CHECK: Index   UserID DSX Type            File Address/Value Load Address       Size               Flags      Name
 # CHECK: [    0]      1     SourceFile      0x0000000000000000                    0x0000000000000000 0x00000004 -
-# CHECK: [    1]      2  SX Code            0x0000000000201180                    0x0000000000000010 0x00000000 ___lldb_unnamed_symbol{{[0-9]*}}
-# CHECK: [    2]      3  SX Code            0x0000000000201190                    0x0000000000000006 0x00000000 ___lldb_unnamed_symbol{{[0-9]*}}
+# CHECK: [    1]      2  SX Code            0x0000000000201180                    0x0000000000000010 0x00000000 ___lldb_unnamed_symbol_{{[0-9a-f]*}}
+# CHECK: [    2]      3  SX Code            0x0000000000201190                    0x0000000000000006 0x00000000 ___lldb_unnamed_symbol_{{[0-9a-f]*}}
 
 --- !ELF
 FileHeader:

lldb/test/Shell/SymbolFile/Breakpad/symtab-sorted-by-size.test

@@ -3,7 +3,7 @@
 # RUN:   -s %s | FileCheck %s
 
 # CHECK: num_symbols = 4 (sorted by size):
-# CHECK: [    0]      0  SX Code            0x0000000000400000                    0x00000000000000b0 0x00000000 ___lldb_unnamed_symbol0
+# CHECK: [    0]      0  SX Code            0x0000000000400000                    0x00000000000000b0 0x00000000 ___lldb_unnamed_symbol_400000
 # CHECK: [    1]      0   X Code            0x00000000004000d0                    0x0000000000000022 0x00000000 _start
 # CHECK: [    2]      0   X Code            0x00000000004000b0                    0x0000000000000010 0x00000000 f1
 # CHECK: [    3]      0   X Code            0x00000000004000c0                    0x0000000000000010 0x00000000 f2

lldb/test/Shell/SymbolFile/Breakpad/symtab.test

@@ -5,7 +5,7 @@
 # CHECK-LABEL: (lldb) image dump symtab symtab.out
 # CHECK: Symtab, file = {{.*}}symtab.out, num_symbols = 4:
 # CHECK: Index   UserID DSX Type            File Address/Value Load Address       Size               Flags      Name
-# CHECK: [    0]      0  SX Code            0x0000000000400000                    0x00000000000000b0 0x00000000 ___lldb_unnamed_symbol{{[0-9]*}}
+# CHECK: [    0]      0  SX Code            0x0000000000400000                    0x00000000000000b0 0x00000000 ___lldb_unnamed_symbol_{{[0-9a-f]*}}
 # CHECK: [    1]      0   X Code            0x00000000004000b0                    0x0000000000000010 0x00000000 f1
 # CHECK: [    2]      0   X Code            0x00000000004000c0                    0x0000000000000010 0x00000000 f2
 # CHECK: [    3]      0   X Code            0x00000000004000d0                    0x0000000000000022 0x00000000 _start