Merge pull request #9829 from smowton/smowton/fix/kotlin-underscore-parameter-names

Kotlin: Don't extract a name for a '_' parameter

java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt

@@ -4,6 +4,7 @@ import com.github.codeql.comments.CommentExtractor
 import com.github.codeql.utils.*
 import com.github.codeql.utils.versions.functionN
 import com.github.codeql.utils.versions.getIrStubFromDescriptor
+import com.github.codeql.utils.versions.isUnderscoreParameter
 import com.semmle.extractor.java.OdasaOutput
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
 import org.jetbrains.kotlin.backend.common.lower.parents
@@ -642,7 +643,7 @@ open class KotlinFileExtractor(
             if (extractTypeAccess) {
                 extractTypeAccessRecursive(substitutedType, location, id, -1)
             }
-            val syntheticParameterNames = (vp.parent as? IrFunction)?.let { hasSynthesizedParameterNames(it) } ?: true
+            val syntheticParameterNames = isUnderscoreParameter(vp) || ((vp.parent as? IrFunction)?.let { hasSynthesizedParameterNames(it) } ?: true)
             return extractValueParameter(id, substitutedType, vp.name.asString(), location, parent, idx, useValueParameter(vp, parentSourceDeclaration), vp.isVararg, syntheticParameterNames)
         }
     }

java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_4_32/IsUnderscoreParameter.kt

@@ -0,0 +1,19 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
+import org.jetbrains.kotlin.ir.declarations.IrValueParameter
+import org.jetbrains.kotlin.psi.KtParameter
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
+import org.jetbrains.kotlin.resolve.calls.util.isSingleUnderscore
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+fun isUnderscoreParameter(vp: IrValueParameter) =
+    try {
+        DescriptorToSourceUtils.getSourceFromDescriptor(vp.descriptor)
+            ?.safeAs<KtParameter>()?.isSingleUnderscore == true
+    } catch(e: NotImplementedError) {
+        // Some kinds of descriptor throw in `getSourceFromDescriptor` as that method is not normally expected to
+        // be applied to synthetic functions.
+        false
+    }

java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/IsUnderscoreParameter.kt

@@ -0,0 +1,19 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
+import org.jetbrains.kotlin.ir.declarations.IrValueParameter
+import org.jetbrains.kotlin.psi.KtParameter
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
+import org.jetbrains.kotlin.resolve.calls.util.isSingleUnderscore
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+fun isUnderscoreParameter(vp: IrValueParameter) =
+    try {
+        DescriptorToSourceUtils.getSourceFromDescriptor(vp.descriptor)
+            ?.safeAs<KtParameter>()?.isSingleUnderscore == true
+    } catch(e: NotImplementedError) {
+        // Some kinds of descriptor throw in `getSourceFromDescriptor` as that method is not normally expected to
+        // be applied to synthetic functions.
+        false
+    }

java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_10/IsUnderscoreParameter.kt

@@ -0,0 +1,19 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
+import org.jetbrains.kotlin.ir.declarations.IrValueParameter
+import org.jetbrains.kotlin.psi.KtParameter
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
+import org.jetbrains.kotlin.resolve.calls.util.isSingleUnderscore
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+fun isUnderscoreParameter(vp: IrValueParameter) =
+    try {
+        DescriptorToSourceUtils.getSourceFromDescriptor(vp.descriptor)
+            ?.safeAs<KtParameter>()?.isSingleUnderscore == true
+    } catch(e: NotImplementedError) {
+        // Some kinds of descriptor throw in `getSourceFromDescriptor` as that method is not normally expected to
+        // be applied to synthetic functions.
+        false
+    }

java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_21/IsUnderscoreParameter.kt

@@ -0,0 +1,19 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
+import org.jetbrains.kotlin.ir.declarations.IrValueParameter
+import org.jetbrains.kotlin.psi.KtParameter
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
+import org.jetbrains.kotlin.resolve.calls.util.isSingleUnderscore
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+fun isUnderscoreParameter(vp: IrValueParameter) =
+    try {
+        DescriptorToSourceUtils.getSourceFromDescriptor(vp.descriptor)
+            ?.safeAs<KtParameter>()?.isSingleUnderscore == true
+    } catch(e: NotImplementedError) {
+        // Some kinds of descriptor throw in `getSourceFromDescriptor` as that method is not normally expected to
+        // be applied to synthetic functions.
+        false
+    }

java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_31/IsUnderscoreParameter.kt

@@ -0,0 +1,19 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
+import org.jetbrains.kotlin.ir.declarations.IrValueParameter
+import org.jetbrains.kotlin.psi.KtParameter
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
+import org.jetbrains.kotlin.resolve.calls.util.isSingleUnderscore
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+fun isUnderscoreParameter(vp: IrValueParameter) =
+    try {
+        DescriptorToSourceUtils.getSourceFromDescriptor(vp.descriptor)
+            ?.safeAs<KtParameter>()?.isSingleUnderscore == true
+    } catch(e: NotImplementedError) {
+        // Some kinds of descriptor throw in `getSourceFromDescriptor` as that method is not normally expected to
+        // be applied to synthetic functions.
+        false
+    }

java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_6_10/IsUnderscoreParameter.kt

@@ -0,0 +1,19 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
+import org.jetbrains.kotlin.ir.declarations.IrValueParameter
+import org.jetbrains.kotlin.psi.KtParameter
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
+import org.jetbrains.kotlin.resolve.calls.util.isSingleUnderscore
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+fun isUnderscoreParameter(vp: IrValueParameter) =
+    try {
+        DescriptorToSourceUtils.getSourceFromDescriptor(vp.descriptor)
+            ?.safeAs<KtParameter>()?.isSingleUnderscore == true
+    } catch(e: NotImplementedError) {
+        // Some kinds of descriptor throw in `getSourceFromDescriptor` as that method is not normally expected to
+        // be applied to synthetic functions.
+        false
+    }

java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_6_20/IsUnderscoreParameter.kt

@@ -0,0 +1,6 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
+import org.jetbrains.kotlin.ir.declarations.IrValueParameter
+
+fun isUnderscoreParameter(vp: IrValueParameter) = vp.origin == IrDeclarationOrigin.UNDERSCORE_PARAMETER

java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_7_0/IsUnderscoreParameter.kt

@@ -0,0 +1,6 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
+import org.jetbrains.kotlin.ir.declarations.IrValueParameter
+
+fun isUnderscoreParameter(vp: IrValueParameter) = vp.origin == IrDeclarationOrigin.UNDERSCORE_PARAMETER

java/ql/test/kotlin/library-tests/exprs/PrintAst.expected

@@ -3583,7 +3583,7 @@ funcExprs.kt:
 #   27|                 2: [Method] invoke
 #   27|                   3: [TypeAccess] int
 #-----|                   4: (Parameters)
-#   27|                     0: [Parameter] <anonymous parameter 0>
+#   27|                     0: [Parameter] p0
 #   27|                       0: [TypeAccess] int
 #   27|                   5: [BlockStmt] { ... }
 #   27|                     0: [ReturnStmt] return ...
@@ -3629,9 +3629,9 @@ funcExprs.kt:
 #   30|                 2: [Method] invoke
 #   30|                   3: [TypeAccess] int
 #-----|                   4: (Parameters)
-#   30|                     0: [Parameter] <anonymous parameter 0>
+#   30|                     0: [Parameter] p0
 #   30|                       0: [TypeAccess] int
-#   30|                     1: [Parameter] <anonymous parameter 1>
+#   30|                     1: [Parameter] p1
 #   30|                       0: [TypeAccess] int
 #   30|                   5: [BlockStmt] { ... }
 #   30|                     0: [ReturnStmt] return ...
@@ -3652,9 +3652,9 @@ funcExprs.kt:
 #   31|                 2: [Method] invoke
 #   31|                   3: [TypeAccess] int
 #-----|                   4: (Parameters)
-#   31|                     0: [Parameter] <anonymous parameter 0>
+#   31|                     0: [Parameter] p0
 #   31|                       0: [TypeAccess] int
-#   31|                     1: [Parameter] <anonymous parameter 1>
+#   31|                     1: [Parameter] p1
 #   31|                       0: [TypeAccess] int
 #   31|                   5: [BlockStmt] { ... }
 #   31|                     0: [ReturnStmt] return ...

java/ql/test/kotlin/library-tests/underscore-parameters/test.expected

@@ -0,0 +1 @@
+| test.kt:5:9:5:9 | p0 | p0 |

java/ql/test/kotlin/library-tests/underscore-parameters/test.kt

@@ -0,0 +1,7 @@
+class A {
+
+  var x: Int
+    get() = 1
+    set(_) { }
+
+}

java/ql/test/kotlin/library-tests/underscore-parameters/test.ql

@@ -0,0 +1,5 @@
+import java
+
+from Parameter p
+where p.getCallable().fromSource()
+select p, p.getName()