[Lldb-commits] [lldb] [lldb] Support arm64e Objective-C signing in the expression evaluator (PR #187765)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-lldb

Author: Jonas Devlieghere (JDevlieghere)

<details>
<summary>Changes</summary>

When targeting arm64e, ISA pointers, class_ro_t pointers, and interface selectors are signed in Objective-C. This PR adds support for that in the expression evaluator.

---
Full diff: https://github.com/llvm/llvm-project/pull/187765.diff


4 Files Affected:

- (modified) lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp (+5) 
- (added) lldb/test/API/commands/expression/ptrauth-objc/Makefile (+10) 
- (added) lldb/test/API/commands/expression/ptrauth-objc/TestPtrAuthObjectiveC.py (+91) 
- (added) lldb/test/API/commands/expression/ptrauth-objc/main.m (+39) 


``````````diff
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
index 0956406960b23..360fe69f679a3 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
@@ -729,6 +729,11 @@ static void SetPointerAuthOptionsForArm64e(LangOptions &lang_opts) {
   lang_opts.PointerAuthIntrinsics = true;
   lang_opts.PointerAuthCalls = true;
   lang_opts.PointerAuthReturns = true;
+  lang_opts.PointerAuthVTPtrAddressDiscrimination = true;
+  lang_opts.PointerAuthVTPtrTypeDiscrimination = true;
+  lang_opts.PointerAuthObjcIsa = true;
+  lang_opts.PointerAuthObjcClassROPointers = true;
+  lang_opts.PointerAuthObjcInterfaceSel = true;
 }
 
 ClangExpressionParser::ClangExpressionParser(
diff --git a/lldb/test/API/commands/expression/ptrauth-objc/Makefile b/lldb/test/API/commands/expression/ptrauth-objc/Makefile
new file mode 100644
index 0000000000000..496df2948ac1b
--- /dev/null
+++ b/lldb/test/API/commands/expression/ptrauth-objc/Makefile
@@ -0,0 +1,10 @@
+OBJC_SOURCES := main.m
+
+override ARCH := arm64e
+
+# We need an arm64e stdlib.
+USE_SYSTEM_STDLIB := 1
+
+LD_EXTRAS := -framework Foundation
+
+include Makefile.rules
diff --git a/lldb/test/API/commands/expression/ptrauth-objc/TestPtrAuthObjectiveC.py b/lldb/test/API/commands/expression/ptrauth-objc/TestPtrAuthObjectiveC.py
new file mode 100644
index 0000000000000..0f4b50d126d51
--- /dev/null
+++ b/lldb/test/API/commands/expression/ptrauth-objc/TestPtrAuthObjectiveC.py
@@ -0,0 +1,91 @@
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestPtrAuthObjectiveC(TestBase):
+    NO_DEBUG_INFO_TESTCASE = True
+
+    @skipUnlessArm64eSupported
+    def test_objc_message_send(self):
+        self.build()
+
+        lldbutil.run_to_source_breakpoint(
+            self, "// break here", lldb.SBFileSpec("main.m", False)
+        )
+
+        self.expect_expr(
+            "[obj doubleValue]",
+            result_type="int",
+            result_value="42",
+        )
+
+    @skipUnlessArm64eSupported
+    def test_objc_message_send_with_arg(self):
+        self.build()
+
+        lldbutil.run_to_source_breakpoint(
+            self, "// break here", lldb.SBFileSpec("main.m", False)
+        )
+
+        self.expect_expr(
+            "[obj addValue:9]",
+            result_type="int",
+            result_value="30",
+        )
+
+    @skipUnlessArm64eSupported
+    def test_objc_alloc_and_message(self):
+        self.build()
+
+        lldbutil.run_to_source_breakpoint(
+            self, "// break here", lldb.SBFileSpec("main.m", False)
+        )
+
+        self.expect_expr(
+            "PtrAuthTestObj *tmp = (PtrAuthTestObj *)[[PtrAuthTestObj alloc] init]; "
+            "tmp.value = 7; [tmp doubleValue]",
+            result_type="int",
+            result_value="14",
+        )
+
+    @skipUnlessArm64eSupported
+    def test_objc_derived_class(self):
+        self.build()
+
+        lldbutil.run_to_source_breakpoint(
+            self, "// break here", lldb.SBFileSpec("main.m", False)
+        )
+
+        self.expect_expr(
+            "[derived tripleValue]",
+            result_type="int",
+            result_value="30",
+        )
+
+        self.expect_expr(
+            "[derived doubleValue]",
+            result_type="int",
+            result_value="20",
+        )
+
+    @skipUnlessArm64eSupported
+    def test_objc_isa_check(self):
+        self.build()
+
+        lldbutil.run_to_source_breakpoint(
+            self, "// break here", lldb.SBFileSpec("main.m", False)
+        )
+
+        self.expect_expr(
+            "(bool)[derived isKindOfClass:[PtrAuthTestObj class]]",
+            result_type="bool",
+            result_value="true",
+        )
+
+        self.expect_expr(
+            "(bool)[obj isKindOfClass:[PtrAuthDerived class]]",
+            result_type="bool",
+            result_value="false",
+        )
diff --git a/lldb/test/API/commands/expression/ptrauth-objc/main.m b/lldb/test/API/commands/expression/ptrauth-objc/main.m
new file mode 100644
index 0000000000000..8088fd2fef7d9
--- /dev/null
+++ b/lldb/test/API/commands/expression/ptrauth-objc/main.m
@@ -0,0 +1,39 @@
+#import <Foundation/Foundation.h>
+#include <stdio.h>
+
+ at interface PtrAuthTestObj : NSObject
+ at property(nonatomic, assign) int value;
+- (int)doubleValue;
+- (int)addValue:(int)other;
+ at end
+
+ at implementation PtrAuthTestObj
+- (int)doubleValue {
+  return self.value * 2;
+}
+- (int)addValue:(int)other {
+  return self.value + other;
+}
+ at end
+
+ at interface PtrAuthDerived : PtrAuthTestObj
+- (int)tripleValue;
+ at end
+
+ at implementation PtrAuthDerived
+- (int)tripleValue {
+  return self.value * 3;
+}
+ at end
+
+int main(int argc, const char *argv[]) {
+  PtrAuthTestObj *obj = [[PtrAuthTestObj alloc] init];
+  obj.value = 21;
+
+  PtrAuthDerived *derived = [[PtrAuthDerived alloc] init];
+  derived.value = 10;
+
+  int result = [obj doubleValue]; // break here
+  printf("%d %d\n", result, [derived tripleValue]);
+  return 0;
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/187765