libnixf: introduce nixf-tidy, perform analysis, lints and emit json (…

…#446)

Let's bring nix world automatic linting in the CI.

default.nix

@@ -13,6 +13,7 @@
 , nix
 , nixpkgs-fmt
 , pkg-config
+, nlohmann_json
 }:
 
 stdenv.mkDerivation {
@@ -43,6 +44,7 @@ stdenv.mkDerivation {
     boost182
     llvmPackages.llvm
     fmt
+    nlohmann_json
   ];
 
   env.CXXFLAGS = "-include ${nix.dev}/include/nix/config.h";

libnixf/include/nixf/Basic/JSONDiagnostic.h

@@ -0,0 +1,32 @@
+/// \file
+/// \brief Provide jsonified diagnostic, for other languages/structured output.
+
+#include "Diagnostic.h"
+#include "nixf/Basic/Range.h"
+
+#include <nlohmann/json.hpp>
+
+namespace nixf {
+
+void to_json // NOLINT(readability-identifier-naming)
+    (nlohmann::json &R, const LexerCursor &LC);
+
+void to_json // NOLINT(readability-identifier-naming)
+    (nlohmann::json &R, const LexerCursorRange &LCR);
+
+void to_json // NOLINT(readability-identifier-naming)
+    (nlohmann::json &R, const PartialDiagnostic &D);
+
+void to_json // NOLINT(readability-identifier-naming)
+    (nlohmann::json &R, const Diagnostic &D);
+
+void to_json // NOLINT(readability-identifier-naming)
+    (nlohmann::json &R, const Note &N);
+
+void to_json // NOLINT(readability-identifier-naming)
+    (nlohmann::json &R, const TextEdit &D);
+
+void to_json // NOLINT(readability-identifier-naming)
+    (nlohmann::json &R, const Fix &F);
+
+} // namespace nixf

libnixf/meson.build

@@ -1,10 +1,11 @@
-libnixf_deps = [ boost, libnixbc ]
+libnixf_deps = [ boost, libnixbc, nlohmann_json ]
 
 libnixf_inc = include_directories('include')
 
 libnixf = library(
     'nixf',
     'src/Basic/Nodes.cpp',
+    'src/Basic/JSONDiagnostic.cpp',
     'src/Basic/Diagnostic.cpp',
     'src/Bytecode/Write.cpp',
     'src/Parse/Lexer.cpp',
@@ -77,4 +78,10 @@ test('unit/libnixf/Sema',
 
 subdir('tools')
 
+nixf_tidy = executable('nixf-tidy',
+    'tools/nixf-tidy.cpp',
+    dependencies: [ nixf ],
+    install: true
+)
+
 install_subdir('include/nixf', install_dir: 'include')

libnixf/src/Basic/JSONDiagnostic.cpp

@@ -0,0 +1,60 @@
+#include "nixf/Basic/JSONDiagnostic.h"
+#include "nixf/Basic/Diagnostic.h"
+#include "nixf/Basic/Range.h"
+
+using namespace nixf;
+using nlohmann::json;
+
+void nixf::to_json(json &R, const LexerCursor &LC) {
+  R = json{
+      {"line", LC.line()},
+      {"column", LC.column()},
+      {"offset", LC.offset()},
+  };
+}
+
+void nixf::to_json(json &R, const LexerCursorRange &LCR) {
+  R = json{
+      {"lCur", LCR.lCur()},
+      {"rCur", LCR.rCur()},
+  };
+}
+
+void nixf::to_json(json &R, const PartialDiagnostic &PD) {
+  R = json{
+      {"args", PD.args()},
+      {"tag", PD.tags()},
+      {"range", PD.range()},
+  };
+}
+
+void nixf::to_json(json &R, const Diagnostic &D) {
+  to_json(R, static_cast<const PartialDiagnostic &>(D));
+  R["kind"] = D.kind();
+  R["severity"] = Diagnostic::severity(D.kind());
+  R["message"] = D.message();
+  R["sname"] = D.sname();
+  R["notes"] = D.notes();
+  R["fixes"] = D.fixes();
+}
+
+void nixf::to_json(json &R, const Note &N) {
+  to_json(R, static_cast<const PartialDiagnostic &>(N));
+  R["kind"] = N.kind();
+  R["sname"] = N.sname();
+  R["message"] = N.message();
+}
+
+void nixf::to_json(json &R, const Fix &F) {
+  R = json{
+      {"edits", F.edits()},
+      {"message", F.message()},
+  };
+}
+
+void nixf::to_json(json &R, const TextEdit &D) {
+  R = json{
+      {"range", D.oldRange()},
+      {"newText", D.newText()},
+  };
+}

libnixf/tools/nixf-tidy.cpp

@@ -0,0 +1,55 @@
+/// \file
+/// \brief nixf-tidy, provide linting based on libnixf.
+
+#include "nixf/Basic/JSONDiagnostic.h"
+#include "nixf/Basic/Nodes/Basic.h"
+#include "nixf/Parse/Parser.h"
+#include "nixf/Sema/VariableLookup.h"
+
+#include <iostream>
+#include <sstream>
+
+using namespace nixf;
+
+namespace {
+
+/// Pretty print the output.
+bool PrettyPrint = false;
+
+/// Enable variable lookup warnings.
+bool VLA;
+
+void parseArgs(int Argc, const char *Argv[]) {
+  for (int I = 0; I < Argc; I++) {
+    if (std::string_view(Argv[I]) == "--pretty-print")
+      PrettyPrint = true;
+    else if (std::string_view(Argv[I]) == "--variable-lookup")
+      VLA = true;
+  }
+}
+
+} // namespace
+
+int main(int Argc, const char *Argv[]) {
+  parseArgs(Argc, Argv);
+  std::ostringstream Inputs;
+  Inputs << std::cin.rdbuf();
+  std::string Src = Inputs.str();
+
+  std::vector<nixf::Diagnostic> Diags;
+  std::shared_ptr<nixf::Node> AST = nixf::parse(Src, Diags);
+
+  if (VLA) {
+    VariableLookupAnalysis V(Diags);
+    if (AST)
+      V.runOnAST(*AST);
+  }
+
+  nlohmann::json V;
+  to_json(V, Diags);
+
+  if (PrettyPrint)
+    std::cout << std::setw(4);
+  std::cout << V << "\n";
+  return 0;
+}

meson.build

@@ -59,6 +59,7 @@ gtest_main = dependency('gtest_main')
 llvm = dependency('llvm')
 boost = dependency('boost')
 fmt = dependency('fmt')
+nlohmann_json = dependency('nlohmann_json')
 
 backtrace = cpp.find_library('backtrace')
 lit = find_program('lit', required: false)