[Mono-bugs] [Bug 65352][Maj] New - bogus code generated for DllImport with CallingConvention

[bugzilla-daemon@bugzilla.ximian.com]

Please do not reply to this email- if you want to comment on the bug, go to the
URL shown below and enter your comments there.

Changed by vladimir@pobox.com.

http://bugzilla.ximian.com/show_bug.cgi?id=65352

--- shadow/65352	2004-09-04 19:55:54.000000000 -0400
+++ shadow/65352.tmp.14183	2004-09-04 19:55:54.000000000 -0400
@@ -0,0 +1,115 @@
+Bug#: 65352
+Product: Mono: Runtime
+Version: unspecified
+OS: 
+OS Details: 
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Major
+Component: misc
+AssignedTo: mono-bugs@ximian.com                            
+ReportedBy: vladimir@pobox.com               
+QAContact: mono-bugs@ximian.com
+TargetMilestone: ---
+URL: 
+Cc: bmaurer@users.sf.net,jackson@ximian.com
+Summary: bogus code generated for DllImport with CallingConvention
+
+[There may be multiple bugs here, one of which seems to be in monodis]
+
+Given this code compiled into a library.dll:
+
+==== library.cs ====
+using System;
+using System.Runtime.InteropServices;
+using System.Security;
+ 
+namespace Library {
+  public sealed class TestClass {
+    [DllImport("SDL.dll", CallingConvention=CallingConvention.Cdecl,
+ExactSpelling=true), SuppressUnmanagedCodeSecurity]
+    public static extern int SDL_Init (int flags);
+ }
+}
+==== end library.cs ====
+
+and this code, into app.exe with /r:library.dll:
+
+==== app.cs ====
+using System;
+using System.Runtime.InteropServices;
+using System.Security;
+using Library;
+ 
+public class Driver {
+  [DllImport("SDL.dll", CallingConvention=CallingConvention.Cdecl,
+ExactSpelling=true), SuppressUnmanagedCodeSecurity]
+  public static extern int SDL_Init (int flags);
+ 
+  public static void Main () {
+    int j = SDL_Init (0);
+    int k = TestClass.SDL_Init (0);
+  }
+}
+==== app.cs ====
+
+If the mono runtime is used to compile app.cs and the resulting .exe is
+used with the .NET runtime, a System.MissingMethodException is generated on
+the first SDL_Init invocation.  Here's the relevant IL, and note the
+difference between ildasm and monodis:
+
+==== mcs 1.0.1/mono 1.0.1 compiled, monodis output ====
+        IL_0000:  ldc.i4.0
+        IL_0001:  call vararg int32 class
+[library]Library.TestClass::SDL_Init(int32)
+        IL_0006:  stloc.0
+        IL_0007:  ldc.i4.0
+        IL_0008:  call int32 class Driver::SDL_Init(int32)
+        IL_000d:  stloc.1
+        IL_000e:  ret
+==== end ====
+
+==== mcs 1.0.1/mono 1.0.1 compiled, ildasm output ====
+    IL_0000:  ldc.i4.0
+    IL_0001:  call       unmanaged cdecl int32
+[library]Library.TestClass::SDL_Init(int32)
+    IL_0006:  stloc.0
+    IL_0007:  ldc.i4.0
+    IL_0008:  call       int32 Driver::SDL_Init(int32)
+    IL_000d:  stloc.1
+    IL_000e:  ret
+==== end ===
+
+Note that while the second call to the SDL_Init defined within App's class
+looks identical, the first call, which is defined in Library.TestClass, is
+very different -- ildasm interprets it as "unmanaged cdecl", monodis
+interprets it as "vararg".
+
+For comparison, here's the same chunk of code compiled using CSC, and fed
+through both disassemblers again.  Note that I'm only recompiling app.exe
+-- I'm using the mono-compiled library.dll.
+
+==== csc/dotnet 1.1 compiled, monodis output ====
+        IL_0000:  ldc.i4.0
+        IL_0001:  call int32 class [library]Library.TestClass::SDL_Init(int32)
+        IL_0006:  stloc.0
+        IL_0007:  ldc.i4.0
+        IL_0008:  call int32 class Driver::SDL_Init(int32)
+        IL_000d:  stloc.1
+        IL_000e:  ret
+==== end ====
+
+==== csc/dotnet 1.1 compiled, ildasm output ====
+    IL_0000:  ldc.i4.0
+    IL_0001:  call       int32 [library]Library.TestClass::SDL_Init(int32)
+    IL_0006:  stloc.0
+    IL_0007:  ldc.i4.0
+    IL_0008:  call       int32 Driver::SDL_Init(int32)
+    IL_000d:  stloc.1
+    IL_000e:  ret
+==== end ====
+
+Note that if 'CallingConvention=blah' is removed from library.cs, then the
+code is generated identically to the csc/dotnet compiled code.  Also, if
+mcs.exe is used on the dotnet runtime, the correct code is generated.