[Lldb-commits] [PATCH] D132231: [lldb][ClangExpression] Remove storage-class check when creating AsmLabel

[Michael Buch via Phabricator via lldb-commits]

Michael137 created this revision.
Michael137 added a reviewer: labath.
Herald added a reviewer: shafik.
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This check was put in place to prevent static functions
from translation units outside the one that the current
expression is evaluated from taking precedence over functions
in the global namespace. However, this is really a different
bug. LLDB lumps functions from all CUs into a single AST and
ends up picking the file-static even when C++ context rules
wouldn't allow that to happen.

This patch removes the check so we apply the AsmLabel to all
FunctionDecls we create from DWARF if we have a linkage name
available. This makes the code-path easier to reason about and
allows calling static functions in contexts where we previously
would've chosen the wrong function.

We also flip the XFAILs in the API test to reflect what effect
this change has.

**Testing**

- Fixed API tests and added XFAIL


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D132231

Files:
  lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
  lldb/test/API/lang/cpp/namespace/TestNamespaceLookup.py


Index: lldb/test/API/lang/cpp/namespace/TestNamespaceLookup.py
===================================================================
--- lldb/test/API/lang/cpp/namespace/TestNamespaceLookup.py
+++ lldb/test/API/lang/cpp/namespace/TestNamespaceLookup.py
@@ -36,6 +36,26 @@
                     substrs=['stopped',
                              'stop reason = breakpoint'])
 
+    @skipIfWindows # This is flakey on Windows: llvm.org/pr38373
+    @expectedFailure("CU-local objects incorrectly scoped")
+    def test_scope_lookup_with_run_command(self):
+        """Test scope lookup of functions in lldb."""
+        self.build()
+
+        lldbutil.run_to_source_breakpoint(
+                self,
+                self.line_break_global_scope,
+                lldb.SBFileSpec("ns.cpp"))
+
+        # Evaluate func() - should call ::func()
+        # FIXME: LLDB does not correctly scope CU-local objects.
+        # LLDB currently lumps functions from all files into
+        # a single AST and depending on the order with which
+        # functions are considered, LLDB can incorrectly call
+        # the static local ns.cpp::func() instead of the expected
+        # ::func()
+        self.expect_expr("func()", expect_type="int", expect_value="1")
+
     @skipIfWindows # This is flakey on Windows: llvm.org/pr38373
     def test_scope_lookup_with_run_command(self):
         """Test scope lookup of functions in lldb."""
@@ -81,8 +101,7 @@
 
         # Run to BP_global_scope at global scope
         self.runToBkpt("run")
-        # Evaluate func() - should call ::func()
-        self.expect("expr -- func()", startstr="(int) $0 = 1")
+
         # Evaluate A::B::func() - should call A::B::func()
         self.expect("expr -- A::B::func()", startstr="(int) $1 = 4")
         # Evaluate func(10) - should call ::func(int)
@@ -174,7 +193,6 @@
         # before functions.
         self.expect("expr -- foo()", startstr="(int) $2 = 42")
 
-    @expectedFailure("lldb file scope lookup bugs")
     @skipIfWindows # This is flakey on Windows: llvm.org/pr38373
     def test_file_scope_lookup_with_run_command(self):
         """Test file scope lookup in lldb."""
@@ -191,9 +209,7 @@
         # Run to BP_file_scope at file scope
         self.runToBkpt("run")
         # Evaluate func() - should call static ns2.cpp:func()
-        # FIXME: This test fails because lldb doesn't know about file scopes so
-        # finds the global ::func().
-        self.expect("expr -- func()", startstr="(int) $0 = 2")
+        self.expect_expr("func()", result_type="int", result_value="2")
 
     @skipIfWindows # This is flakey on Windows: llvm.org/pr38373
     def test_scope_lookup_before_using_with_run_command(self):
Index: lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -1258,7 +1258,7 @@
           // example is generating calls to ABI-tagged template functions.
           // This is done separately for member functions in
           // AddMethodToCXXRecordType.
-          if (attrs.mangled_name && attrs.storage == clang::SC_Extern)
+          if (attrs.mangled_name)
             function_decl->addAttr(clang::AsmLabelAttr::CreateImplicit(
                 m_ast.getASTContext(), attrs.mangled_name, /*literal=*/false));
 


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