libnixf: split sema-unused-def into let, arg and formal

nix-community · Aug 1, 2024 · 37d18c1 · 37d18c1
1 parent 5c3f5ca
commit 37d18c1
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Showing 4 changed files with 70 additions and 18 deletions.
diff --git a/libnixf/include/nixf/Sema/VariableLookup.h b/libnixf/include/nixf/Sema/VariableLookup.h
@@ -39,9 +39,12 @@ class Definition {
     /// \brief From lambda formal, e.g. { a }: a + 1
     DS_LambdaFormal,
 
-    /// \brief From lambda arg with formal, e.g. { foo, bar }@a: a + 1
+    /// \brief From lambda arg with formal, e.g. `a` in `{ foo }@a: foo + 1`
     DS_LambdaArgWithFormal,
 
+    /// \brief From lambda formal with arg, e.g. `foo` in `{ foo }@a: foo + 1`
+    DS_LambdaFormalWithArg,
+
     /// \brief From recursive attribute set.  e.g. rec { }
     DS_Rec,
 

diff --git a/libnixf/src/Basic/diagnostic.py b/libnixf/src/Basic/diagnostic.py
@@ -184,10 +184,28 @@ class Diagnostic(TypedDict):
         "message": "undefined variable `{}`",
     },
     {
-        "sname": "sema-def-not-used",
-        "cname": "DefinitionNotUsed",
+        "sname": "sema-unused-def-let",
+        "cname": "UnusedDefLet",
+        "severity": "Warning",
+        "message": "variable `{}` in let-expression is not used",
+    },
+    {
+        "sname": "sema-unused-def-formal",
+        "cname": "UnusedDefFormal",
+        "severity": "Warning",
+        "message": "attribute `{}` of argument is not used",
+    },
+    {
+        "sname": "sema-unused-def-arg-with-formal",
+        "cname": "UnusedDefArgWithFormal",
+        "severity": "Warning",
+        "message": "argument `{}` in `@`-pattern is not used",
+    },
+    {
+        "sname": "sema-unused-def-formal-with-arg",
+        "cname": "UnusedDefFormalWithArg",
         "severity": "Hint",
-        "message": "definition `{}` is not used",
+        "message": "attribute `{}` of `@`-pattern argument is not used, but may be referenced from the argument",
     },
     {
         "sname": "sema-extra-rec",

diff --git a/libnixf/src/Sema/VariableLookup.cpp b/libnixf/src/Sema/VariableLookup.cpp
@@ -52,8 +52,24 @@ void VariableLookupAnalysis::emitEnvLivenessWarning(
     if (!Def->syntax())
       continue;
     if (Def->uses().empty()) {
-      Diagnostic &D = Diags.emplace_back(Diagnostic::DK_DefinitionNotUsed,
-                                         Def->syntax()->range());
+      Diagnostic::DiagnosticKind kind;
+      switch (Def->source()) {
+      case Definition::DS_Let:
+        kind = Diagnostic::DK_UnusedDefLet;
+        break;
+      case Definition::DS_LambdaFormal:
+        kind = Diagnostic::DK_UnusedDefFormal;
+        break;
+      case Definition::DS_LambdaFormalWithArg:
+        kind = Diagnostic::DK_UnusedDefFormalWithArg;
+        break;
+      case Definition::DS_LambdaArgWithFormal:
+        kind = Diagnostic::DK_UnusedDefArgWithFormal;
+        break;
+      default:
+        break;
+      }
+      Diagnostic &D = Diags.emplace_back(kind, Def->syntax()->range());
       D << Name;
       D.tag(DiagnosticTag::Faded);
     }
@@ -128,6 +144,9 @@ void VariableLookupAnalysis::dfs(const ExprLambda &Lambda,
 
   // foo: body
   // ^~~<------- add function argument.
+  // { foo, bar, ... } : body
+  //   ^~~~~~~~~<--------------  add function formals.
+
   if (Arg.id()) {
     if (!Arg.formals()) {
       ToDef.insert_or_assign(Arg.id(), DBuilder.add(Arg.id()->name(), Arg.id(),
@@ -138,16 +157,17 @@ void VariableLookupAnalysis::dfs(const ExprLambda &Lambda,
       ToDef.insert_or_assign(Arg.id(),
                              DBuilder.add(Arg.id()->name(), Arg.id(),
                                           Definition::DS_LambdaArgWithFormal));
+      for (const auto &[Name, Formal] : Arg.formals()->dedup())
+        ToDef.insert_or_assign(
+            Formal->id(), DBuilder.add(Name, Formal->id(),
+                                       Definition::DS_LambdaFormalWithArg));
     }
-  }
-
-  // { foo, bar, ... } : body
-  ///  ^~~~~~~~~<--------------  add function formals.
-  if (Arg.formals())
+  } else if (Arg.formals()) {
     for (const auto &[Name, Formal] : Arg.formals()->dedup())
       ToDef.insert_or_assign(
           Formal->id(),
           DBuilder.add(Name, Formal->id(), Definition::DS_LambdaFormal));
+  }
 
   auto NewEnv = std::make_shared<EnvNode>(Env, DBuilder.finish(), &Lambda);
 

diff --git a/libnixf/test/Sema/VariableLookup.cpp b/libnixf/test/Sema/VariableLookup.cpp
@@ -135,29 +135,27 @@ TEST_F(VLATest, LivenessRec) {
   ASSERT_EQ(Diags[0].kind(), Diagnostic::DK_ExtraRecursive);
 }
 
-TEST_F(VLATest, LivenessArg) {
+TEST_F(VLATest, LivenessFormal) {
   std::shared_ptr<Node> AST = parse("{ foo }: 1", Diags);
   VariableLookupAnalysis VLA(Diags);
   VLA.runOnAST(*AST);
 
   ASSERT_EQ(Diags.size(), 1);
 
-  ASSERT_EQ(Diags[0].kind(), Diagnostic::DK_DefinitionNotUsed);
+  ASSERT_EQ(Diags[0].kind(), Diagnostic::DK_UnusedDefFormal);
   ASSERT_EQ(Diags[0].tags().size(), 1);
-  ASSERT_EQ(Diags[0].tags()[0], DiagnosticTag::Faded);
 }
 
-TEST_F(VLATest, LivenessNested) {
+TEST_F(VLATest, LivenessLet) {
   std::shared_ptr<Node> AST = parse("let y = 1; in x: y: x + y", Diags);
   VariableLookupAnalysis VLA(Diags);
   VLA.runOnAST(*AST);
 
   ASSERT_EQ(Diags.size(), 1);
 
-  ASSERT_EQ(Diags[0].kind(), Diagnostic::DK_DefinitionNotUsed);
+  ASSERT_EQ(Diags[0].kind(), Diagnostic::DK_UnusedDefLet);
   ASSERT_EQ(Diags[0].range().lCur().column(), 4);
   ASSERT_EQ(Diags[0].tags().size(), 1);
-  ASSERT_EQ(Diags[0].tags()[0], DiagnosticTag::Faded);
 }
 
 TEST_F(VLATest, LivenessDupSymbol) {
@@ -179,12 +177,25 @@ TEST_F(VLATest, LivenessArgWithFormal) {
 
   ASSERT_EQ(Diags.size(), 1);
 
-  ASSERT_EQ(Diags[0].kind(), Diagnostic::DK_DefinitionNotUsed);
+  ASSERT_EQ(Diags[0].kind(), Diagnostic::DK_UnusedDefArgWithFormal);
   ASSERT_EQ(Diags[0].range().lCur().column(), 8);
   ASSERT_EQ(Diags[0].tags().size(), 1);
+}
+
+TEST_F(VLATest, LivenessFormalWithArg) {
+  std::shared_ptr<Node> AST = parse("{ foo }@bar: bar", Diags);
+  VariableLookupAnalysis VLA(Diags);
+  VLA.runOnAST(*AST);
+
+  ASSERT_EQ(Diags.size(), 1);
+
+  ASSERT_EQ(Diags[0].kind(), Diagnostic::DK_UnusedDefFormalWithArg);
+  ASSERT_EQ(Diags[0].range().lCur().column(), 2);
+  ASSERT_EQ(Diags[0].tags().size(), 1);
   ASSERT_EQ(Diags[0].tags()[0], DiagnosticTag::Faded);
 }
 
+
 TEST_F(VLATest, ToDefAttrs) {
   std::shared_ptr<Node> AST = parse("rec { x = 1; y = x; z = x; }", Diags);
   VariableLookupAnalysis VLA(Diags);