verilog/analysis: Add ParsedVerilogSourceFile class

This class is an extended version of InMemoryVerilogSourceFile.
It wraps a TextStructureView object and allows to skip loading and
parsing phase.

This class may be used in e.g. TextStructureLinterRules.

Signed-off-by: Lukasz Dalek <[email protected]>

verilog/analysis/verilog_project.cc

@@ -91,6 +91,23 @@ absl::Status InMemoryVerilogSourceFile::Open() {
   return status_;
 }
 
+absl::Status ParsedVerilogSourceFile::Open() {
+  state_ = State::kOpened;
+  status_ = absl::OkStatus();
+  return status_;
+}
+
+absl::Status ParsedVerilogSourceFile::Parse() {
+  state_ = State::kParsed;
+  status_ = absl::OkStatus();
+  return status_;
+}
+
+const verible::TextStructureView* ParsedVerilogSourceFile::GetTextStructure()
+    const {
+  return &text_structure_;
+}
+
 absl::StatusOr<VerilogSourceFile*> VerilogProject::OpenFile(
     absl::string_view referenced_filename, absl::string_view resolved_filename,
     absl::string_view corpus) {

verilog/analysis/verilog_project.h

@@ -60,12 +60,12 @@ class VerilogSourceFile {
   // Attempts to lex and parse the file (without preprocessing).
   // Will Open() if the file is not already opened.
   // Depending on context, not all files are suitable for standalone parsing.
-  absl::Status Parse();
+  virtual absl::Status Parse();
 
   // After Open(), the underlying text structure contains at least the file's
   // contents.  After Parse(), it may contain other analyzed structural forms.
   // Before Open(), this returns nullptr.
-  const verible::TextStructureView* GetTextStructure() const;
+  virtual const verible::TextStructureView* GetTextStructure() const;
 
   // Returns the first non-Ok status if there is one, else OkStatus().
   absl::Status Status() const { return status_; }
@@ -165,6 +165,30 @@ class InMemoryVerilogSourceFile : public VerilogSourceFile {
   const absl::string_view contents_for_open_;
 };
 
+// Source file that was already parsed and got its own TextStructure.
+// Doesn't require file-system access, nor create temporary files.
+class ParsedVerilogSourceFile : public VerilogSourceFile {
+ public:
+  // filename can be fake, it is not used to open any file.
+  ParsedVerilogSourceFile(absl::string_view filename,
+                          const verible::TextStructureView& text_structure,
+                          absl::string_view corpus = "")
+      : VerilogSourceFile(filename, filename, corpus),
+        text_structure_(text_structure) {}
+
+  // Do nothing (file contents already loaded)
+  absl::Status Open() override;
+
+  // Do nothing (contents already parsed)
+  absl::Status Parse() override;
+
+  // Return TextStructureView provided previously in constructor
+  const verible::TextStructureView* GetTextStructure() const override;
+
+ private:
+  const verible::TextStructureView& text_structure_;
+};
+
 // VerilogProject represents a set of files as a cohesive unit of compilation.
 // Files can include top-level translation units and preprocessor included
 // files. This is responsible for owning string memory that corresponds

verilog/analysis/verilog_project_test.cc

@@ -197,6 +197,36 @@ TEST(InMemoryVerilogSourceFileTest, ParseInvalidFile) {
   EXPECT_EQ(&text_structure->SyntaxTree(), tree);
 }
 
+TEST(ParsedVerilogSourceFileTest, ParseValidFile) {
+  constexpr absl::string_view text("localparam int p = 1;\n");
+  std::unique_ptr<VerilogAnalyzer> analyzed_structure =
+      absl::make_unique<VerilogAnalyzer>(text, "internal");
+  absl::Status status = analyzed_structure->Analyze();
+  EXPECT_TRUE(status.ok());
+  const TextStructureView& input_text_structure = analyzed_structure->Data();
+
+  ParsedVerilogSourceFile file("internal", input_text_structure);
+  // Parse automatically opens.
+  EXPECT_TRUE(file.Parse().ok());
+  EXPECT_TRUE(file.Status().ok());
+  const TextStructureView* text_structure =
+      ABSL_DIE_IF_NULL(file.GetTextStructure());
+  EXPECT_EQ(&input_text_structure, text_structure);
+  const absl::string_view owned_string_range(text_structure->Contents());
+  EXPECT_EQ(owned_string_range, text);
+  const auto* tokens = &text_structure->TokenStream();
+  EXPECT_NE(tokens, nullptr);
+  const auto* tree = &text_structure->SyntaxTree();
+  EXPECT_NE(tree, nullptr);
+
+  // Re-parsing doesn't change anything
+  EXPECT_TRUE(file.Parse().ok());
+  EXPECT_TRUE(file.Status().ok());
+  EXPECT_EQ(file.GetTextStructure(), text_structure);
+  EXPECT_EQ(&text_structure->TokenStream(), tokens);
+  EXPECT_EQ(&text_structure->SyntaxTree(), tree);
+}
+
 TEST(VerilogProjectTest, Initialization) {
   const auto tempdir = ::testing::TempDir();
   VerilogProject project(tempdir, {tempdir});