Add a demangler option to hide the "Swift" module name.

This part of a series of patches to bring ASTPrinter and Swift Demangler to
feature parity, which is needed by LLDB, which depends on using the strings
produced by either interchangibly.

<rdar://problem/63700540>

Author: adrian-prantl

include/swift/Demangling/Demangle.h

@@ -42,7 +42,6 @@ std::string genericParameterName(uint64_t depth, uint64_t index);
 /// Display style options for the demangler.
 struct DemangleOptions {
   bool SynthesizeSugarOnTypes = false;
-  bool DisplayDebuggerGeneratedModule = true;
   bool QualifyEntities = true;
   bool DisplayExtensionContexts = true;
   bool DisplayUnmangledSuffix = true;
@@ -57,6 +56,8 @@ struct DemangleOptions {
   bool ShortenArchetype = false;
   bool ShowPrivateDiscriminators = true;
   bool ShowFunctionArgumentTypes = true;
+  bool DisplayDebuggerGeneratedModule = true;
+  bool DisplayStdlibModule = true;
   std::function<std::string(uint64_t, uint64_t)> GenericParameterName =
       genericParameterName;
 

lib/Demangling/NodePrinter.cpp

@@ -243,9 +243,11 @@ class NodePrinter {
     if (!Options.QualifyEntities)
       return false;
 
-    if (Context->getKind() == Node::Kind::Module &&
-        Context->getText().startswith(LLDB_EXPRESSIONS_MODULE_NAME_PREFIX)) {
-      return Options.DisplayDebuggerGeneratedModule;
+    if (Context->getKind() == Node::Kind::Module) {
+      if (Context->getText() == swift::STDLIB_NAME)
+        return Options.DisplayStdlibModule;
+      if (Context->getText().startswith(LLDB_EXPRESSIONS_MODULE_NAME_PREFIX))
+        return Options.DisplayDebuggerGeneratedModule;
     }
     return true;
   }
@@ -1945,8 +1947,8 @@ NodePointer NodePrinter::print(NodePointer Node, bool asPrefixContext) {
       printChildren(type_list, " & ");
       Printer << " & ";
     }
-    if (Options.QualifyEntities)
-      Printer << "Swift.";
+    if (Options.QualifyEntities && Options.DisplayStdlibModule)
+      Printer << swift::STDLIB_NAME << ".";
     Printer << "AnyObject";
     return nullptr;
   }

test/Demangle/demangle-special-options.test

@@ -0,0 +1,4 @@
+RUN: swift-demangle -display-stdlib-module=true sSi | %FileCheck %s --check-prefix=SWIFT-INT
+SWIFT-INT: {{ Swift.Int$}}
+RUN: swift-demangle -display-stdlib-module=false sSi | %FileCheck %s --check-prefix=INT
+INT: {{ Int$}}

test/Demangle/lit.local.cfg

@@ -0,0 +1,2 @@
+# suffixes: A list of file extensions to treat as test files.
+config.suffixes.add('.test')

tools/swift-demangle/swift-demangle.cpp

@@ -74,6 +74,15 @@ static llvm::cl::opt<bool>
 Classify("classify",
            llvm::cl::desc("Display symbol classification characters"));
 
+/// Options that are primarily used for testing.
+/// \{
+static llvm::cl::opt<bool> DisplayStdlibModule(
+    "display-stdlib-module", llvm::cl::init(true),
+    llvm::cl::desc("Qualify types originating from the Swift standard library"),
+    llvm::cl::Hidden);
+/// \}
+
+
 static llvm::cl::list<std::string>
 InputNames(llvm::cl::Positional, llvm::cl::desc("[mangled name...]"),
                llvm::cl::ZeroOrMore);
@@ -233,6 +242,7 @@ int main(int argc, char **argv) {
   options.SynthesizeSugarOnTypes = !DisableSugar;
   if (Simplified)
     options = swift::Demangle::DemangleOptions::SimplifiedUIDemangleOptions();
+  options.DisplayStdlibModule = DisplayStdlibModule;
 
   if (InputNames.empty()) {
     CompactMode = true;