[swift-ide-test] Introduce '-print-decl' option.

This is helpful for understanding how specific APIs are imported.

Author: akyrtzi

tools/swift-ide-test/swift-ide-test.cpp

@@ -81,6 +81,7 @@ enum class ActionType {
   PrintModule,
   PrintHeader,
   PrintSwiftFileInterface,
+  PrintDecl,
   PrintTypes,
   PrintComments,
   PrintModuleComments,
@@ -169,6 +170,8 @@ Action(llvm::cl::desc("Mode:"), llvm::cl::init(ActionType::None),
                       "print-header", "Print visible declarations in a header file"),
            clEnumValN(ActionType::PrintSwiftFileInterface,
                       "print-swift-file-interface", "Print interface of a swift file"),
+           clEnumValN(ActionType::PrintDecl,
+                      "print-decl", "Print interface of a decl"),
            clEnumValN(ActionType::PrintTypes,
                       "print-types", "Print types of all subexpressions and declarations in the AST"),
            clEnumValN(ActionType::PrintComments,
@@ -522,6 +525,10 @@ static llvm::cl::list<std::string>
 HeaderToPrint("header-to-print",
               llvm::cl::desc("Header filename to print swift interface for"));
 
+static llvm::cl::list<std::string>
+DeclToPrint("decl-to-print",
+            llvm::cl::desc("Decl name to print swift interface for"));
+
 static llvm::cl::opt<std::string>
 LineColumnPair("pos", llvm::cl::desc("Line:Column pair"));
 
@@ -1889,6 +1896,59 @@ static int doPrintSwiftFileInterface(const CompilerInvocation &InitInvok,
   return 0;
 }
 
+static int doPrintDecls(const CompilerInvocation &InitInvok,
+                        StringRef SourceFilename,
+                        ArrayRef<std::string> DeclsToPrint,
+                        const PrintOptions &Options,
+                        bool AnnotatePrint) {
+  CompilerInvocation Invocation(InitInvok);
+  Invocation.addInputFilename(SourceFilename);
+  Invocation.getFrontendOptions().PrimaryInput = 0;
+  Invocation.getLangOptions().AttachCommentsToDecls = true;
+  CompilerInstance CI;
+  // Display diagnostics to stderr.
+  PrintingDiagnosticConsumer PrintDiags;
+  CI.addDiagnosticConsumer(&PrintDiags);
+  if (CI.setup(Invocation))
+    return 1;
+  CI.performSema();
+
+  std::unique_ptr<ASTPrinter> Printer;
+  if (AnnotatePrint)
+    Printer.reset(new AnnotatingPrinter(llvm::outs()));
+  else
+    Printer.reset(new StreamPrinter(llvm::outs()));
+
+  for (const auto &name : DeclsToPrint) {
+    ASTContext &ctx = CI.getASTContext();
+    UnqualifiedLookup lookup(ctx.getIdentifier(name),
+                             CI.getPrimarySourceFile(), nullptr);
+    for (auto result : lookup.Results) {
+      result.getValueDecl()->print(*Printer, Options);
+
+      if (auto typeDecl = dyn_cast<TypeDecl>(result.getValueDecl())) {
+        if (auto typeAliasDecl = dyn_cast<TypeAliasDecl>(typeDecl)) {
+          TypeDecl *origTypeDecl = typeAliasDecl->getUnderlyingType()
+            ->getNominalOrBoundGenericNominal();
+          if (origTypeDecl) {
+            origTypeDecl->print(*Printer, Options);
+            typeDecl = origTypeDecl;
+          }
+        }
+
+        // Print extensions.
+        if (auto nominal = dyn_cast<NominalTypeDecl>(typeDecl)) {
+          for (auto extension : nominal->getExtensions()) {
+            extension->print(*Printer, Options);
+          }
+        }
+      }
+    }
+  }
+
+  return 0;
+}
+
 namespace {
 class ASTTypePrinter : public ASTWalker {
   raw_ostream &OS;
@@ -2901,6 +2961,13 @@ int main(int argc, char *argv[]) {
     break;
   }
 
+  case ActionType::PrintDecl: {
+    ExitCode = doPrintDecls(
+        InitInvok, options::SourceFilename,
+        options::DeclToPrint, PrintOpts, options::AnnotatePrint);
+    break;
+  }
+
   case ActionType::PrintTypes:
     ExitCode = doPrintTypes(InitInvok, options::SourceFilename,
                             options::FullyQualifiedTypes);