// // codegen.cs: The code generator // // Author: // Miguel de Icaza (miguel@ximian.com) // // (C) 2001 Ximian, Inc. // using System; using System.IO; using System.Collections; using System.Reflection; using System.Reflection.Emit; using System.Runtime.InteropServices; using System.Security.Cryptography; using Mono.Security.Cryptography; namespace Mono.CSharp { /// /// Code generator class. /// public class CodeGen { static AppDomain current_domain; static public SymbolWriter SymbolWriter; public static AssemblyClass Assembly; public static ModuleClass Module; static CodeGen () { Assembly = new AssemblyClass (); Module = new ModuleClass (RootContext.Unsafe); } public static string Basename (string name) { int pos = name.LastIndexOf ('/'); if (pos != -1) return name.Substring (pos + 1); pos = name.LastIndexOf ('\\'); if (pos != -1) return name.Substring (pos + 1); return name; } public static string Dirname (string name) { int pos = name.LastIndexOf ('/'); if (pos != -1) return name.Substring (0, pos); pos = name.LastIndexOf ('\\'); if (pos != -1) return name.Substring (0, pos); return "."; } static string TrimExt (string name) { int pos = name.LastIndexOf ('.'); return name.Substring (0, pos); } static public string FileName; // // Initializes the symbol writer // static void InitializeSymbolWriter () { SymbolWriter = SymbolWriter.GetSymbolWriter (Module.Builder); // // If we got an ISymbolWriter instance, initialize it. // if (SymbolWriter == null) { Report.Warning ( -18, "Could not find the symbol writer assembly (Mono.CSharp.Debugger.dll). This is normally an installation problem. Please make sure to compile and install the mcs/class/Mono.CSharp.Debugger directory."); return; } } // // Initializes the code generator variables // static public void Init (string name, string output, bool want_debugging_support) { FileName = output; AssemblyName an = Assembly.GetAssemblyName (name, output); current_domain = AppDomain.CurrentDomain; try { Assembly.Builder = current_domain.DefineDynamicAssembly (an, AssemblyBuilderAccess.Save, Dirname (name)); } catch (ArgumentException) { // specified key may not be exportable outside it's container if (RootContext.StrongNameKeyContainer != null) { Report.Error (1548, "Could not access the key inside the container `" + RootContext.StrongNameKeyContainer + "'."); Environment.Exit (1); } throw; } catch (CryptographicException) { if ((RootContext.StrongNameKeyContainer != null) || (RootContext.StrongNameKeyFile != null)) { Report.Error (1548, "Could not use the specified key to strongname the assembly."); Environment.Exit (1); } throw; } // // Pass a path-less name to DefineDynamicModule. Wonder how // this copes with output in different directories then. // FIXME: figure out how this copes with --output /tmp/blah // // If the third argument is true, the ModuleBuilder will dynamically // load the default symbol writer. // Module.Builder = Assembly.Builder.DefineDynamicModule ( Basename (name), Basename (output), want_debugging_support); if (want_debugging_support) InitializeSymbolWriter (); } static public void Save (string name) { try { Assembly.Builder.Save (Basename (name)); } catch (COMException) { if ((RootContext.StrongNameKeyFile == null) || (!RootContext.StrongNameDelaySign)) throw; // FIXME: it seems Microsoft AssemblyBuilder doesn't like to delay sign assemblies Report.Error (1548, "Couldn't delay-sign the assembly with the '" + RootContext.StrongNameKeyFile + "', Use MCS with the Mono runtime or CSC to compile this assembly."); } catch (System.IO.IOException io) { Report.Error (16, "Could not write to file `"+name+"', cause: " + io.Message); } } } // // Provides "local" store across code that can yield: locals // or fields, notice that this should not be used by anonymous // methods to create local storage, those only require // variable mapping. // public class VariableStorage { ILGenerator ig; FieldBuilder fb; LocalBuilder local; static int count; public VariableStorage (EmitContext ec, Type t) { count++; if (ec.InIterator) fb = IteratorHandler.Current.MapVariable ("s_", count.ToString (), t); else local = ec.ig.DeclareLocal (t); ig = ec.ig; } public void EmitThis () { if (fb != null) ig.Emit (OpCodes.Ldarg_0); } public void EmitStore () { if (fb == null) ig.Emit (OpCodes.Stloc, local); else ig.Emit (OpCodes.Stfld, fb); } public void EmitLoad () { if (fb == null) ig.Emit (OpCodes.Ldloc, local); else ig.Emit (OpCodes.Ldfld, fb); } public void EmitCall (MethodInfo mi) { // FIXME : we should handle a call like tostring // here, where boxing is needed. However, we will // never encounter that with the current usage. bool value_type_call; EmitThis (); if (fb == null) { value_type_call = local.LocalType.IsValueType; if (value_type_call) ig.Emit (OpCodes.Ldloca, local); else ig.Emit (OpCodes.Ldloc, local); } else { value_type_call = fb.FieldType.IsValueType; if (value_type_call) ig.Emit (OpCodes.Ldflda, fb); else ig.Emit (OpCodes.Ldfld, fb); } ig.Emit (value_type_call ? OpCodes.Call : OpCodes.Callvirt, mi); } } /// /// An Emit Context is created for each body of code (from methods, /// properties bodies, indexer bodies or constructor bodies) /// public class EmitContext { public DeclSpace DeclSpace; public DeclSpace TypeContainer; public ILGenerator ig; /// /// This variable tracks the `checked' state of the compilation, /// it controls whether we should generate code that does overflow /// checking, or if we generate code that ignores overflows. /// /// The default setting comes from the command line option to generate /// checked or unchecked code plus any source code changes using the /// checked/unchecked statements or expressions. Contrast this with /// the ConstantCheckState flag. /// public bool CheckState; /// /// The constant check state is always set to `true' and cant be changed /// from the command line. The source code can change this setting with /// the `checked' and `unchecked' statements and expressions. /// public bool ConstantCheckState; /// /// Whether we are emitting code inside a static or instance method /// public bool IsStatic; /// /// Whether we are emitting a field initializer /// public bool IsFieldInitializer; /// /// The value that is allowed to be returned or NULL if there is no /// return type. /// public Type ReturnType; /// /// Points to the Type (extracted from the TypeContainer) that /// declares this body of code /// public Type ContainerType; /// /// Whether this is generating code for a constructor /// public bool IsConstructor; /// /// Whether we're control flow analysis enabled /// public bool DoFlowAnalysis; /// /// Keeps track of the Type to LocalBuilder temporary storage created /// to store structures (used to compute the address of the structure /// value on structure method invocations) /// public Hashtable temporary_storage; public Block CurrentBlock; public int CurrentFile; /// /// The location where we store the return value. /// LocalBuilder return_value; /// /// The location where return has to jump to return the /// value /// public Label ReturnLabel; /// /// If we already defined the ReturnLabel /// public bool HasReturnLabel; /// /// Whether we are inside an iterator block. /// public bool InIterator; public bool IsLastStatement; /// /// Whether remapping of locals, parameters and fields is turned on. /// Used by iterators and anonymous methods. /// public bool RemapToProxy; /// /// Whether we are inside an unsafe block /// public bool InUnsafe; /// /// Whether we are in a `fixed' initialization /// public bool InFixedInitializer; /// /// Whether we are inside an anonymous method. /// public bool InAnonymousMethod; /// /// Location for this EmitContext /// public Location loc; /// /// Used to flag that it is ok to define types recursively, as the /// expressions are being evaluated as part of the type lookup /// during the type resolution process /// public bool ResolvingTypeTree; /// /// Inside an enum definition, we do not resolve enumeration values /// to their enumerations, but rather to the underlying type/value /// This is so EnumVal + EnumValB can be evaluated. /// /// There is no "E operator + (E x, E y)", so during an enum evaluation /// we relax the rules /// public bool InEnumContext; FlowBranching current_flow_branching; public EmitContext (DeclSpace parent, DeclSpace ds, Location l, ILGenerator ig, Type return_type, int code_flags, bool is_constructor) { this.ig = ig; TypeContainer = parent; DeclSpace = ds; CheckState = RootContext.Checked; ConstantCheckState = true; IsStatic = (code_flags & Modifiers.STATIC) != 0; InIterator = (code_flags & Modifiers.METHOD_YIELDS) != 0; RemapToProxy = InIterator; ReturnType = return_type; IsConstructor = is_constructor; CurrentBlock = null; CurrentFile = 0; if (parent != null){ // Can only be null for the ResolveType contexts. ContainerType = parent.TypeBuilder; if (parent.UnsafeContext) InUnsafe = true; else InUnsafe = (code_flags & Modifiers.UNSAFE) != 0; } loc = l; if (ReturnType == TypeManager.void_type) ReturnType = null; } public EmitContext (TypeContainer tc, Location l, ILGenerator ig, Type return_type, int code_flags, bool is_constructor) : this (tc, tc, l, ig, return_type, code_flags, is_constructor) { } public EmitContext (TypeContainer tc, Location l, ILGenerator ig, Type return_type, int code_flags) : this (tc, tc, l, ig, return_type, code_flags, false) { } public FlowBranching CurrentBranching { get { return current_flow_branching; } } // // Starts a new code branching. This inherits the state of all local // variables and parameters from the current branching. // public FlowBranching StartFlowBranching (FlowBranching.BranchingType type, Location loc) { current_flow_branching = FlowBranching.CreateBranching (CurrentBranching, type, null, loc); return current_flow_branching; } // // Starts a new code branching for block `block'. // public FlowBranching StartFlowBranching (Block block) { FlowBranching.BranchingType type; if (CurrentBranching.Type == FlowBranching.BranchingType.Switch) type = FlowBranching.BranchingType.SwitchSection; else type = FlowBranching.BranchingType.Block; current_flow_branching = FlowBranching.CreateBranching (CurrentBranching, type, block, block.StartLocation); return current_flow_branching; } // // Ends a code branching. Merges the state of locals and parameters // from all the children of the ending branching. // public FlowBranching.UsageVector DoEndFlowBranching () { FlowBranching old = current_flow_branching; current_flow_branching = current_flow_branching.Parent; return current_flow_branching.MergeChild (old); } // // Ends a code branching. Merges the state of locals and parameters // from all the children of the ending branching. // public FlowBranching.Reachability EndFlowBranching () { FlowBranching.UsageVector vector = DoEndFlowBranching (); return vector.Reachability; } // // Kills the current code branching. This throws away any changed state // information and should only be used in case of an error. // public void KillFlowBranching () { current_flow_branching = current_flow_branching.Parent; } public void EmitTopBlock (Block block, InternalParameters ip, Location loc) { bool unreachable = false; if (!Location.IsNull (loc)) CurrentFile = loc.File; if (block != null){ try { int errors = Report.Errors; block.EmitMeta (this, ip); if (Report.Errors == errors){ bool old_do_flow_analysis = DoFlowAnalysis; DoFlowAnalysis = true; current_flow_branching = FlowBranching.CreateBranching ( null, FlowBranching.BranchingType.Block, block, loc); if (!block.Resolve (this)) { current_flow_branching = null; DoFlowAnalysis = old_do_flow_analysis; return; } FlowBranching.Reachability reachability = current_flow_branching.MergeTopBlock (); current_flow_branching = null; DoFlowAnalysis = old_do_flow_analysis; block.Emit (this); if (reachability.AlwaysReturns || reachability.AlwaysThrows || reachability.IsUnreachable) unreachable = true; } #if FIXME } catch (Exception e) { Console.WriteLine ("Exception caught by the compiler while compiling:"); Console.WriteLine (" Block that caused the problem begin at: " + loc); if (CurrentBlock != null){ Console.WriteLine (" Block being compiled: [{0},{1}]", CurrentBlock.StartLocation, CurrentBlock.EndLocation); } Console.WriteLine (e.GetType ().FullName + ": " + e.Message); Console.WriteLine (Report.FriendlyStackTrace (e)); Environment.Exit (1); #else } finally { #endif } } if (ReturnType != null && !unreachable){ if (!InIterator){ Report.Error (161, loc, "Not all code paths return a value"); return; } } if (HasReturnLabel) ig.MarkLabel (ReturnLabel); if (return_value != null){ ig.Emit (OpCodes.Ldloc, return_value); ig.Emit (OpCodes.Ret); } else { // // If `HasReturnLabel' is set, then we already emitted a // jump to the end of the method, so we must emit a `ret' // there. // // Unfortunately, System.Reflection.Emit automatically emits // a leave to the end of a finally block. This is a problem // if no code is following the try/finally block since we may // jump to a point after the end of the method. // As a workaround, we're always creating a return label in // this case. // if ((block != null) && block.IsDestructor) { // Nothing to do; S.R.E automatically emits a leave. } else if (HasReturnLabel || (!unreachable && !InIterator)) { if (ReturnType != null) ig.Emit (OpCodes.Ldloc, TemporaryReturn ()); ig.Emit (OpCodes.Ret); } } } /// /// This is called immediately before emitting an IL opcode to tell the symbol /// writer to which source line this opcode belongs. /// public void Mark (Location loc, bool check_file) { if ((CodeGen.SymbolWriter == null) || Location.IsNull (loc)) return; if (check_file && (CurrentFile != loc.File)) return; ig.MarkSequencePoint (null, loc.Row, 0, 0, 0); } /// /// Returns a temporary storage for a variable of type t as /// a local variable in the current body. /// public LocalBuilder GetTemporaryLocal (Type t) { LocalBuilder location = null; if (temporary_storage != null){ object o = temporary_storage [t]; if (o != null){ if (o is ArrayList){ ArrayList al = (ArrayList) o; for (int i = 0; i < al.Count; i++){ if (al [i] != null){ location = (LocalBuilder) al [i]; al [i] = null; break; } } } else location = (LocalBuilder) o; if (location != null) return location; } } return ig.DeclareLocal (t); } public void FreeTemporaryLocal (LocalBuilder b, Type t) { if (temporary_storage == null){ temporary_storage = new Hashtable (); temporary_storage [t] = b; return; } object o = temporary_storage [t]; if (o == null){ temporary_storage [t] = b; return; } if (o is ArrayList){ ArrayList al = (ArrayList) o; for (int i = 0; i < al.Count; i++){ if (al [i] == null){ al [i] = b; return; } } al.Add (b); return; } ArrayList replacement = new ArrayList (); replacement.Add (o); temporary_storage.Remove (t); temporary_storage [t] = replacement; } /// /// Current loop begin and end labels. /// public Label LoopBegin, LoopEnd; /// /// Default target in a switch statement. Only valid if /// InSwitch is true /// public Label DefaultTarget; /// /// If this is non-null, points to the current switch statement /// public Switch Switch; /// /// ReturnValue creates on demand the LocalBuilder for the /// return value from the function. By default this is not /// used. This is only required when returns are found inside /// Try or Catch statements. /// public LocalBuilder TemporaryReturn () { if (return_value == null){ return_value = ig.DeclareLocal (ReturnType); ReturnLabel = ig.DefineLabel (); HasReturnLabel = true; } return return_value; } public void NeedReturnLabel () { if (!HasReturnLabel) { ReturnLabel = ig.DefineLabel (); HasReturnLabel = true; } } // // Creates a field `name' with the type `t' on the proxy class // public FieldBuilder MapVariable (string name, Type t) { if (InIterator){ return IteratorHandler.Current.MapVariable ("v_", name, t); } throw new Exception ("MapVariable for an unknown state"); } // // Invoke this routine to remap a VariableInfo into the // proper MemberAccess expression // public Expression RemapLocal (LocalInfo local_info) { FieldExpr fe = new FieldExpr (local_info.FieldBuilder, loc); fe.InstanceExpression = new ProxyInstance (); return fe.DoResolve (this); } public Expression RemapLocalLValue (LocalInfo local_info, Expression right_side) { FieldExpr fe = new FieldExpr (local_info.FieldBuilder, loc); fe.InstanceExpression = new ProxyInstance (); return fe.DoResolveLValue (this, right_side); } public Expression RemapParameter (int idx) { FieldExpr fe = new FieldExprNoAddress (IteratorHandler.Current.parameter_fields [idx], loc); fe.InstanceExpression = new ProxyInstance (); return fe.DoResolve (this); } public Expression RemapParameterLValue (int idx, Expression right_side) { FieldExpr fe = new FieldExprNoAddress (IteratorHandler.Current.parameter_fields [idx], loc); fe.InstanceExpression = new ProxyInstance (); return fe.DoResolveLValue (this, right_side); } // // Emits the proper object to address fields on a remapped // variable/parameter to field in anonymous-method/iterator proxy classes. // public void EmitThis () { ig.Emit (OpCodes.Ldarg_0); if (!IsStatic){ if (InIterator) ig.Emit (OpCodes.Ldfld, IteratorHandler.Current.this_field); else throw new Exception ("EmitThis for an unknown state"); } } public Expression GetThis (Location loc) { This my_this; if (CurrentBlock != null) my_this = new This (CurrentBlock, loc); else my_this = new This (loc); if (!my_this.ResolveBase (this)) my_this = null; return my_this; } } public abstract class CommonAssemblyModulClass: IAttributeSupport { protected Hashtable m_attributes; protected CommonAssemblyModulClass () { m_attributes = new Hashtable (); } // // Adds a global attribute that was declared in `container', // the attribute is in `attr', and it was defined at `loc' // public void AddAttribute (TypeContainer container, AttributeSection attr) { NamespaceEntry ns = container.NamespaceEntry; Attributes a = (Attributes) m_attributes [ns]; if (a == null) { m_attributes [ns] = new Attributes (attr); return; } a.AddAttributeSection (attr); } public virtual void Emit () { if (m_attributes.Count < 1) return; TypeContainer dummy = new TypeContainer (); EmitContext temp_ec = new EmitContext (dummy, Mono.CSharp.Location.Null, null, null, 0, false); foreach (DictionaryEntry de in m_attributes) { NamespaceEntry ns = (NamespaceEntry) de.Key; Attributes attrs = (Attributes) de.Value; dummy.NamespaceEntry = ns; Attribute.ApplyAttributes (temp_ec, null, this, attrs); } } protected Attribute GetClsCompliantAttribute () { if (m_attributes.Count < 1) return null; EmitContext temp_ec = new EmitContext (new TypeContainer (), Mono.CSharp.Location.Null, null, null, 0, false); foreach (DictionaryEntry de in m_attributes) { NamespaceEntry ns = (NamespaceEntry) de.Key; Attributes attrs = (Attributes) de.Value; temp_ec.TypeContainer.NamespaceEntry = ns; foreach (AttributeSection attr_section in attrs.AttributeSections) { foreach (Attribute a in attr_section.Attributes) { TypeExpr attributeType = RootContext.LookupType (temp_ec.DeclSpace, Attributes.GetAttributeFullName (a.Name), true, Location.Null); if (attributeType != null && attributeType.Type == TypeManager.cls_compliant_attribute_type) { a.Resolve (temp_ec); return a; } } } } return null; } #region IAttributeSupport Members public abstract void SetCustomAttribute(CustomAttributeBuilder customBuilder); #endregion } public class AssemblyClass: CommonAssemblyModulClass { // TODO: make it private and move all builder based methods here public AssemblyBuilder Builder; bool is_cls_compliant; public AssemblyClass (): base () { is_cls_compliant = false; } public bool IsClsCompliant { get { return is_cls_compliant; } } public void ResolveClsCompliance () { Attribute a = GetClsCompliantAttribute (); if (a == null) return; is_cls_compliant = a.GetClsCompliantAttributeValue (null); } public AssemblyName GetAssemblyName (string name, string output) { // scan assembly attributes for strongname related attr foreach (DictionaryEntry nsattr in m_attributes) { ArrayList list = ((Attributes)nsattr.Value).AttributeSections; for (int i=0; i < list.Count; i++) { AttributeSection asect = (AttributeSection) list [i]; if (asect.Target != "assembly") continue; // strongname attributes don't support AllowMultiple Attribute a = (Attribute) asect.Attributes [0]; switch (a.Name) { case "AssemblyKeyFile": if (RootContext.StrongNameKeyFile != null) { Report.Warning (1616, "Compiler option -keyfile overrides " + "AssemblyKeyFileAttribute"); } else { string value = a.GetString (); if (value != String.Empty) RootContext.StrongNameKeyFile = value; } break; case "AssemblyKeyName": if (RootContext.StrongNameKeyContainer != null) { Report.Warning (1616, "Compiler option -keycontainer overrides " + "AssemblyKeyNameAttribute"); } else { string value = a.GetString (); if (value != String.Empty) RootContext.StrongNameKeyContainer = value; } break; case "AssemblyDelaySign": RootContext.StrongNameDelaySign = a.GetBoolean (); break; } } } AssemblyName an = new AssemblyName (); an.Name = Path.GetFileNameWithoutExtension (name); // note: delay doesn't apply when using a key container if (RootContext.StrongNameKeyContainer != null) { an.KeyPair = new StrongNameKeyPair (RootContext.StrongNameKeyContainer); return an; } // strongname is optional if (RootContext.StrongNameKeyFile == null) return an; string AssemblyDir = Path.GetDirectoryName (output); // the StrongName key file may be relative to (a) the compiled // file or (b) to the output assembly. See bugzilla #55320 // http://bugzilla.ximian.com/show_bug.cgi?id=55320 // (a) relative to the compiled file string filename = Path.GetFullPath (RootContext.StrongNameKeyFile); bool exist = File.Exists (filename); if ((!exist) && (AssemblyDir != null) && (AssemblyDir != String.Empty)) { // (b) relative to the outputed assembly filename = Path.GetFullPath (Path.Combine (AssemblyDir, RootContext.StrongNameKeyFile)); exist = File.Exists (filename); } if (exist) { using (FileStream fs = new FileStream (filename, FileMode.Open, FileAccess.Read)) { byte[] snkeypair = new byte [fs.Length]; fs.Read (snkeypair, 0, snkeypair.Length); if (RootContext.StrongNameDelaySign) { // delayed signing - DO NOT include private key try { // check for possible ECMA key if (snkeypair.Length == 16) { // will be rejected if not "the" ECMA key an.KeyPair = new StrongNameKeyPair (snkeypair); } else { // take it, with or without, a private key RSA rsa = CryptoConvert.FromCapiKeyBlob (snkeypair); // and make sure we only feed the public part to Sys.Ref byte[] publickey = CryptoConvert.ToCapiPublicKeyBlob (rsa); an.KeyPair = new StrongNameKeyPair (publickey); } } catch (Exception) { Report.Error (1548, "Could not strongname the assembly. File `" + RootContext.StrongNameKeyFile + "' incorrectly encoded."); Environment.Exit (1); } } else { // no delay so we make sure we have the private key try { CryptoConvert.FromCapiPrivateKeyBlob (snkeypair); an.KeyPair = new StrongNameKeyPair (snkeypair); } catch (CryptographicException) { if (snkeypair.Length == 16) { // error # is different for ECMA key Report.Error (1606, "Could not strongname the assembly. " + "ECMA key can only be used to delay-sign assemblies"); } else { Report.Error (1548, "Could not strongname the assembly. File `" + RootContext.StrongNameKeyFile + "' doesn't have a private key."); } Environment.Exit (1); } } } } else { Report.Error (1548, "Could not strongname the assembly. File `" + RootContext.StrongNameKeyFile + "' not found."); Environment.Exit (1); } return an; } public override void SetCustomAttribute(CustomAttributeBuilder customBuilder) { Builder.SetCustomAttribute (customBuilder); } } public class ModuleClass: CommonAssemblyModulClass { // TODO: make it private and move all builder based methods here public ModuleBuilder Builder; bool m_module_is_unsafe; public ModuleClass (bool is_unsafe) { m_module_is_unsafe = is_unsafe; } public override void Emit () { base.Emit (); Attribute a = GetClsCompliantAttribute (); if (a != null) { Report.Warning (3012, a.Location); } if (!m_module_is_unsafe) return; if (TypeManager.unverifiable_code_ctor == null) { Console.WriteLine ("Internal error ! Cannot set unverifiable code attribute."); return; } SetCustomAttribute (new CustomAttributeBuilder (TypeManager.unverifiable_code_ctor, new object [0])); } public override void SetCustomAttribute(CustomAttributeBuilder customBuilder) { Builder.SetCustomAttribute (customBuilder); } } }