[lldb][Commands] Fix memory find for Swift expressions

Author: Michael137

lldb/source/Commands/CommandObjectMemory.cpp

@@ -885,6 +885,61 @@ class CommandObjectMemoryRead : public CommandObjectParsed {
 #define LLDB_OPTIONS_memory_find
 #include "CommandOptions.inc"
 
+static llvm::Error CopyExpressionResult(ValueObject &result,
+                                        DataBufferHeap &buffer,
+                                        ExecutionContextScope *scope) {
+  uint64_t value = result.GetValueAsUnsigned(0);
+  auto size_or_err = result.GetCompilerType().GetByteSize(scope);
+  if (!size_or_err)
+    return size_or_err.takeError();
+
+  switch (*size_or_err) {
+  case 1: {
+    uint8_t byte = (uint8_t)value;
+    buffer.CopyData(&byte, 1);
+  } break;
+  case 2: {
+    uint16_t word = (uint16_t)value;
+    buffer.CopyData(&word, 2);
+  } break;
+  case 4: {
+    uint32_t lword = (uint32_t)value;
+    buffer.CopyData(&lword, 4);
+  } break;
+  case 8: {
+    buffer.CopyData(&value, 8);
+  } break;
+  case 3:
+  case 5:
+  case 6:
+  case 7:
+    return llvm::createStringError("unknown type. pass a string instead");
+  default:
+    return llvm::createStringError(
+        "result size larger than 8 bytes. pass a string instead");
+  }
+
+  return llvm::Error::success();
+}
+
+static llvm::Expected<ValueObjectSP>
+EvaluateExpression(llvm::StringRef expression, StackFrame &frame,
+                   Process &process) {
+  ValueObjectSP result_sp;
+  auto status =
+      process.GetTarget().EvaluateExpression(expression, &frame, result_sp);
+  if (status != eExpressionCompleted || !result_sp)
+    return llvm::createStringError(
+        "expression evaluation failed. pass a string instead");
+
+  result_sp = result_sp->GetQualifiedRepresentationIfAvailable(
+      result_sp->GetDynamicValueType(), /*synthValue=*/true);
+  if (!result_sp)
+    return llvm::createStringError("failed to unwrap expression result type");
+
+  return result_sp;
+}
+
 // Find the specified data in memory
 class CommandObjectMemoryFind : public CommandObjectParsed {
 public:
@@ -1026,49 +1081,19 @@ class CommandObjectMemoryFind : public CommandObjectParsed {
       }
       buffer.CopyData(str);
     } else if (m_memory_options.m_expr.OptionWasSet()) {
-      StackFrame *frame = m_exe_ctx.GetFramePtr();
-      ValueObjectSP result_sp;
-      if ((eExpressionCompleted ==
-           process->GetTarget().EvaluateExpression(
-               m_memory_options.m_expr.GetValueAs<llvm::StringRef>().value_or(
-                   ""),
-               frame, result_sp)) &&
-          result_sp) {
-        uint64_t value = result_sp->GetValueAsUnsigned(0);
-        std::optional<uint64_t> size = llvm::expectedToOptional(
-            result_sp->GetCompilerType().GetByteSize(nullptr));
-        if (!size)
-          return;
-        switch (*size) {
-        case 1: {
-          uint8_t byte = (uint8_t)value;
-          buffer.CopyData(&byte, 1);
-        } break;
-        case 2: {
-          uint16_t word = (uint16_t)value;
-          buffer.CopyData(&word, 2);
-        } break;
-        case 4: {
-          uint32_t lword = (uint32_t)value;
-          buffer.CopyData(&lword, 4);
-        } break;
-        case 8: {
-          buffer.CopyData(&value, 8);
-        } break;
-        case 3:
-        case 5:
-        case 6:
-        case 7:
-          result.AppendError("unknown type. pass a string instead");
-          return;
-        default:
-          result.AppendError(
-              "result size larger than 8 bytes. pass a string instead");
-          return;
-        }
-      } else {
-        result.AppendError(
-            "expression evaluation failed. pass a string instead");
+      auto result_or_err = EvaluateExpression(
+          m_memory_options.m_expr.GetValueAs<llvm::StringRef>().value_or(""),
+          m_exe_ctx.GetFrameRef(), *process);
+      if (!result_or_err) {
+        result.AppendError(llvm::toString(result_or_err.takeError()));
+        return;
+      }
+
+      ValueObjectSP result_sp = *result_or_err;
+
+      if (auto err = CopyExpressionResult(*result_sp, buffer,
+                                          m_exe_ctx.GetFramePtr())) {
+        result.AppendError(llvm::toString(std::move(err)));
         return;
       }
     } else {

lldb/test/API/functionalities/memory/find/TestMemoryFind.py

@@ -79,3 +79,34 @@ def test_memory_find(self):
             'memory find -s "nothere" `stringdata` `stringdata+10`',
             substrs=["data not found within the range."],
         )
+
+        # Expression results with unsupported result types.
+        self.expect(
+            'memory find -e "ThreeBytes{}" `&bytedata[0]` `&bytedata[2]`',
+            substrs=["unknown type."],
+            error=True,
+        )
+
+        self.expect(
+            'memory find -e "FiveBytes{}" `&bytedata[0]` `&bytedata[2]`',
+            substrs=["unknown type."],
+            error=True,
+        )
+
+        self.expect(
+            'memory find -e "SixBytes{}" `&bytedata[0]` `&bytedata[2]`',
+            substrs=["unknown type."],
+            error=True,
+        )
+
+        self.expect(
+            'memory find -e "SevenBytes{}" `&bytedata[0]` `&bytedata[2]`',
+            substrs=["unknown type."],
+            error=True,
+        )
+
+        self.expect(
+            'memory find -e "NineBytes{}" `&bytedata[0]` `&bytedata[2]`',
+            substrs=["result size larger than 8 bytes."],
+            error=True,
+        )

lldb/test/API/functionalities/memory/find/main.cpp

@@ -1,9 +1,24 @@
 #include <stdio.h>
 #include <stdint.h>
 
+template <size_t T> struct [[gnu::packed]] Payload {
+  uint8_t data[T];
+};
+
+using ThreeBytes = Payload<3>;
+using FiveBytes = Payload<5>;
+using SixBytes = Payload<5>;
+using SevenBytes = Payload<7>;
+using NineBytes = Payload<9>;
+
 int main (int argc, char const *argv[])
 {
     const char* stringdata = "hello world; I like to write text in const char pointers";
     uint8_t bytedata[] = {0xAA,0xBB,0xCC,0xDD,0xEE,0xFF,0x00,0x11,0x22,0x33,0x44,0x55,0x66,0x77,0x88,0x99};
+    ThreeBytes b1;
+    FiveBytes b2;
+    SixBytes b3;
+    SevenBytes b4;
+    NineBytes b5;
     return 0; // break here
 }

lldb/test/API/lang/swift/command_memory_find/Makefile

@@ -0,0 +1,3 @@
+SWIFT_SOURCES := main.swift
+
+include Makefile.rules

lldb/test/API/lang/swift/command_memory_find/TestSwiftCommandMemoryFind.py

@@ -0,0 +1,31 @@
+"""
+Test that running Swift expressions in the
+`memory find` command works.
+"""
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+import lldbsuite.test.lldbutil as lldbutil
+
+
+class TestSwiftCommandMemoryFind(TestBase):
+    def memory_find(self, name: str, expr: str, target):
+        var = target.FindGlobalVariables(name, 1)
+        self.assertEqual(len(var), 1)
+        addr = var[0].AddressOf()
+        self.assertTrue(addr)
+        addr = addr.GetValueAsUnsigned()
+        self.expect(f'memory find -e {expr} {hex(addr)} {hex(addr + 8)}',
+                    substrs=["data found at location"])
+
+    @swiftTest
+    def test(self):
+        self.build()
+        target, _, _, _ = lldbutil.run_to_source_breakpoint(
+            self, 'Break', lldb.SBFileSpec('main.swift'))
+
+        self.memory_find('elem1', 'elem1', target)
+        self.memory_find('elem1', '130 + 7', target)
+
+        self.memory_find('elem2', 'elem2', target)
+        self.memory_find('elem2', '42', target)

lldb/test/API/lang/swift/command_memory_find/main.swift

@@ -0,0 +1,3 @@
+let elem1: Int32 = 137
+let elem2: Int64 = -42
+print ("Break")