Fix a logic error that would prevent display of ClangImporter error in

the expression evaluator.

rdar://76217088
(cherry picked from commit a311bc5)

Author: adrian-prantl

lldb/source/Plugins/ExpressionParser/Swift/SwiftExpressionParser.cpp

@@ -1481,11 +1481,7 @@ unsigned SwiftExpressionParser::Parse(DiagnosticManager &diagnostic_manager,
                         retry = true;
                     },
                     [&](const SwiftASTContextError &SACE) {
-                      if (swift_ast_ctx->GetClangImporter())
-                        DiagnoseSwiftASTContextError();
-                      else
-                        // Discard the shared scratch context and retry.
-                        retry = true;
+                      DiagnoseSwiftASTContextError();
                     },
                     [&](const StringError &SE) {
                       diagnostic_manager.PutString(eDiagnosticSeverityError,

lldb/test/API/lang/swift/clangimporter/expr_import/Makefile

@@ -0,0 +1,5 @@
+SWIFT_SOURCES := main.swift
+SWIFTFLAGS_EXTRAS = -Xcc -I$(SRCDIR)
+
+include Makefile.rules
+

lldb/test/API/lang/swift/clangimporter/expr_import/TestSwiftExprImport.py

@@ -0,0 +1,26 @@
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+import lldbsuite.test.lldbutil as lldbutil
+import unittest2
+
+class TestSwiftExprImport(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+    
+    def setUp(self):
+        TestBase.setUp(self)
+
+    # Don't run ClangImporter tests if Clangimporter is disabled.
+    @skipIf(setting=('symbols.use-swift-clangimporter', 'false'))
+    @swiftTest
+    def test(self):
+        """Test error handling if the expression evaluator
+           encounters a Clang import failure.
+        """
+        self.build()
+
+        lldbutil.run_to_source_breakpoint(self, "break here",
+                                          lldb.SBFileSpec('main.swift'))
+        self.expect("expr -- import A", error=True,
+                    substrs=['could','not','build','module'])

lldb/test/API/lang/swift/clangimporter/expr_import/a.h

@@ -0,0 +1 @@
+int i = SYNTAX_ERROR;

lldb/test/API/lang/swift/clangimporter/expr_import/main.swift

@@ -0,0 +1,4 @@
+func f() {}
+
+print("break here")
+f()

lldb/test/API/lang/swift/clangimporter/expr_import/module.modulemap

@@ -0,0 +1,3 @@
+module A {
+header "a.h"
+}