Rework global statement extraction without DB scheme change

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CSharp/Entities/OrdinaryMethod.cs

@@ -51,11 +51,6 @@ public override void Populate(TextWriter trapFile)
             Overrides(trapFile);
             ExtractRefReturn(trapFile, symbol, this);
             ExtractCompilerGenerated(trapFile);
-
-            if (SymbolEqualityComparer.Default.Equals(symbol, Context.Compilation.GetEntryPoint(System.Threading.CancellationToken.None)))
-            {
-                trapFile.entry_methods(this);
-            }
         }
 
         public static new OrdinaryMethod Create(Context cx, IMethodSymbol method) => OrdinaryMethodFactory.Instance.CreateEntityFromSymbol(cx, method);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/GlobalStatementsBlock.cs

@@ -7,16 +7,19 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
 {
     internal class GlobalStatementsBlock : Statement
     {
+        private readonly Method parent;
+
         private GlobalStatementsBlock(Context cx, Method parent)
-            : base(cx, StmtKind.BLOCK, parent, 0) { }
+            : base(cx, StmtKind.BLOCK, parent, 0)
+        {
+            this.parent = parent;
+        }
 
         public override Microsoft.CodeAnalysis.Location ReportingLocation
         {
             get
             {
-                // We only create a `GlobalStatementsBlock` if there are global statements. This also means that the
-                // entry point is going to be the generated method around those global statements
-                return cx.Compilation.GetEntryPoint(System.Threading.CancellationToken.None)
+                return parent.symbol
                     ?.DeclaringSyntaxReferences
                     .FirstOrDefault()
                     ?.GetSyntax()
@@ -33,8 +36,6 @@ public static GlobalStatementsBlock Create(Context cx, Method parent)
 
         protected override void PopulateStatement(TextWriter trapFile)
         {
-            trapFile.global_stmt_block(this);
-
             trapFile.stmt_location(this, cx.CreateLocation(ReportingLocation));
         }
     }

csharp/extractor/Semmle.Extraction.CSharp/Tuples.cs

@@ -379,11 +379,6 @@ internal static void methods(this TextWriter trapFile, Method method, string nam
             trapFile.WriteTuple("methods", method, name, declType, retType, originalDefinition);
         }
 
-        internal static void entry_methods(this TextWriter trapFile, Method method)
-        {
-            trapFile.WriteTuple("entry_methods", method);
-        }
-
         internal static void modifiers(this TextWriter trapFile, Label entity, string modifier)
         {
             trapFile.WriteTuple("modifiers", entity, modifier);
@@ -514,11 +509,6 @@ internal static void stackalloc_array_creation(this TextWriter trapFile, Express
             trapFile.WriteTuple("stackalloc_array_creation", array);
         }
 
-        internal static void global_stmt_block(this TextWriter trapFile, Entities.Statements.GlobalStatementsBlock block)
-        {
-            trapFile.WriteTuple("global_stmt_block", block);
-        }
-
         internal static void stmt_location(this TextWriter trapFile, Statement stmt, Location location)
         {
             trapFile.WriteTuple("stmt_location", stmt, location);

csharp/ql/src/semmle/code/csharp/Callable.qll

@@ -292,9 +292,6 @@ class Method extends Callable, Virtualizable, Attributable, @method {
   }
 
   override string getAPrimaryQlClass() { result = "Method" }
-
-  /** Holds if this method is the entry method of the compilation. */
-  predicate isEntry() { entry_methods(this) }
 }
 
 /**

csharp/ql/src/semmle/code/csharp/Stmt.qll

@@ -74,7 +74,9 @@ class BlockStmt extends Stmt, @block_stmt {
   predicate isEmpty() { not exists(this.getAStmt()) }
 
   /** Holds if this block is the container of the global statements. */
-  predicate isGlobalStatementContainer() { global_stmt_block(this) }
+  predicate isGlobalStatementContainer() {
+    this.getEnclosingCallable().hasQualifiedName("<Program>$.<Main>$")
+  }
 
   override Stmt stripSingletonBlocks() {
     if getNumberOfStmts() = 1

csharp/ql/src/semmle/code/csharp/commons/Util.qll

@@ -5,7 +5,11 @@ import csharp
 /** A `Main` method. */
 class MainMethod extends Method {
   MainMethod() {
-    this.hasName("Main") and
+    (
+      this.hasName("Main")
+      or
+      this.hasQualifiedName("<Program>$.<Main>$")
+    ) and
     this.isStatic() and
     (this.getReturnType() instanceof VoidType or this.getReturnType() instanceof IntType) and
     if this.getNumberOfParameters() = 1

csharp/ql/src/semmlecode.csharp.dbscheme

@@ -843,9 +843,6 @@ local_function_stmts(
     unique int fn: @local_function_stmt ref,
     int stmt: @local_function ref);
 
-entry_methods(
-  unique int id: @method ref);
-
 /** VARIABLES **/
 
 @variable = @local_scope_variable | @field;
@@ -975,8 +972,6 @@ case @stmt.kind of
 
 @goto_any_stmt = @goto_default_stmt | @goto_case_stmt | @goto_stmt;
 
-global_stmt_block(
-  unique int id: @block_stmt ref);
 
 stmt_location(
   unique int id: @stmt ref,

csharp/ql/test/library-tests/csharp9/globalStmt.ql

@@ -1,4 +1,5 @@
 import csharp
+private import semmle.code.csharp.commons.Util
 
 query predicate global_stmt(Stmt stmt) { stmt.isGlobal() }
 
@@ -11,5 +12,5 @@ query predicate globalBlock(BlockStmt block, Method m, Parameter p, Type t) {
 
 query predicate methods(Method m, string entry) {
   m.getFile().getStem() = "GlobalStmt" and
-  if m.isEntry() then entry = "entry" else entry = "non-entry"
+  if m instanceof MainMethod then entry = "entry" else entry = "non-entry"
 }