nixd/Syntax: add legacy let warning

nix-community · Sep 18, 2023 · d108ee5 · d108ee5
1 parent 032f564
commit d108ee5
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Showing 3 changed files with 70 additions and 6 deletions.
diff --git a/nixd/lib/Syntax/Parser/Parser.y b/nixd/lib/Syntax/Parser/Parser.y
@@ -268,6 +268,12 @@ expr_simple
     auto N = decorateNode(new LegacyLet, *yylocp, *Data);
     N->AttrBinds = $3;
     $$ = N;
+
+    Diagnostic Diag;
+    Diag.Msg = "using deprecated `let' syntactic sugar `let {..., body = ...}' -> (rec {..., body = ...}).body'";
+    Diag.Kind = Diagnostic::Warning;
+    Diag.Range = N->Range;
+    Data->Diags.emplace_back(std::move(Diag));
   }
   | REC '{' binds '}' {
     auto N = decorateNode(new AttrSet, *yylocp, *Data);

diff --git a/nixd/tools/nixd-lint/nixd-lint.cpp b/nixd/tools/nixd-lint/nixd-lint.cpp
@@ -23,6 +23,54 @@ opt<std::string> Filename(Positional, desc("<input file>"), init("-"),
 
 const OptionCategory *Cat[] = {&Misc};
 
+static void printCodeLines(std::ostream &Out, const std::string &Prefix,
+                           const nix::AbstractPos &BeginPos,
+                           const nix::AbstractPos &EndPos,
+                           const nix::LinesOfCode &LOC) {
+  using namespace nix;
+  // previous line of code.
+  if (LOC.prevLineOfCode.has_value()) {
+    Out << std::endl
+        << fmt("%1% %|2$5d|| %3%", Prefix, (BeginPos.line - 1),
+               *LOC.prevLineOfCode);
+  }
+
+  if (LOC.errLineOfCode.has_value()) {
+    // line of code containing the error.
+    Out << std::endl
+        << fmt("%1% %|2$5d|| %3%", Prefix, (BeginPos.line), *LOC.errLineOfCode);
+    // error arrows for the column range.
+    if (BeginPos.column > 0) {
+      auto Start = BeginPos.column;
+      std::string Spaces;
+      for (auto I = 0; I < Start; ++I) {
+        Spaces.append(" ");
+      }
+
+      std::string arrows("^");
+
+      Out << std::endl
+          << fmt("%1%      |%2%" ANSI_RED "%3%" ANSI_NORMAL, Prefix, Spaces,
+                 arrows);
+
+      if (BeginPos.line == EndPos.line) {
+        Out << ANSI_RED;
+        for (auto I = BeginPos.column + 1; I < EndPos.column; I++) {
+          Out << (I == EndPos.column - 1 ? "^" : "~");
+        }
+        Out << ANSI_NORMAL;
+      }
+    }
+  }
+
+  // next line of code.
+  if (LOC.nextLineOfCode.has_value()) {
+    Out << std::endl
+        << fmt("%1% %|2$5d|| %3%", Prefix, (BeginPos.line + 1),
+               *LOC.nextLineOfCode);
+  }
+}
+
 int main(int argc, char *argv[]) {
   HideUnrelatedOptions(Cat);
   ParseCommandLineOptions(argc, argv, "nixd linter", nullptr,
@@ -49,20 +97,25 @@ int main(int argc, char *argv[]) {
   nixd::syntax::parse(Buffer, &Data);
 
   for (const auto &Diag : Data.Diags) {
-    std::shared_ptr<nix::AbstractPos> Pos = (*PTable)[Diag.Range.Begin];
+    std::shared_ptr<nix::AbstractPos> BeginAPos = (*PTable)[Diag.Range.Begin];
+    std::shared_ptr<nix::AbstractPos> EndAPos = (*PTable)[Diag.Range.End];
     switch (Diag.Kind) {
     case nixd::syntax::Diagnostic::Warning:
-      std::cout << ANSI_WARNING "warning:" ANSI_NORMAL;
+      std::cout << ANSI_WARNING "warning: " ANSI_NORMAL;
+      break;
     case nixd::syntax::Diagnostic::Error:
       std::cout << ANSI_RED "error: " ANSI_NORMAL;
+      break;
     }
     std::cout << Diag.Msg << "\n";
-    if (Pos) {
+    if (BeginAPos) {
       std::cout << "\n"
                 << ANSI_BLUE << "at " ANSI_WARNING
                 << (*PTable)[Diag.Range.Begin] << ANSI_NORMAL << ":";
-      if (auto Lines = Pos->getCodeLines()) {
-        nix::printCodeLines(std::cout, "", *Pos, *Lines);
+      if (auto Lines = BeginAPos->getCodeLines()) {
+        std::cout << "\n";
+        printCodeLines(std::cout, "", *BeginAPos, *EndAPos, *Lines);
+        std::cout << "\n";
       }
     }
 
@@ -75,7 +128,7 @@ int main(int argc, char *argv[]) {
                   << ":";
         if (auto Lines =
                 std::shared_ptr<nix::AbstractPos>(NotePos)->getCodeLines()) {
-          nix::printCodeLines(std::cout, "", *Pos, *Lines);
+          nix::printCodeLines(std::cout, "", *BeginAPos, *Lines);
         }
       }
     }

diff --git a/nixd/tools/nixd-lint/test/legacy-let.nix b/nixd/tools/nixd-lint/test/legacy-let.nix
@@ -0,0 +1,5 @@
+# RUN: nixd-lint %s | FileCheck %s
+
+let { a = 1; } # CHECK:  using deprecated `let'
+
+; # CHECK: syntax error, unexpected ';', expecting end of file