FIX: C1001 Fatal Error in File Main.c, Line 413 for /O1 or /O2

ID: Q150884

The information in this article applies to:

The C/C++ Compiler (CL.EXE), included with:
- Microsoft Visual C++, 32-bit Editions, versions 4.0, 4.1

SYMPTOMS

Using /O1 (minimize size) or /O2 (maximize speed) causes a C1001 error in a try block with the following error message:


   fatal error C1001: INTERNAL COMPILER ERROR
    (compiler file '\school.tp3\test\c10\src\P2\main.c', line 413)

Additionally, C++ exception handling must be enabled (/GX). If the warning level is set to 4 (/W4), C4702 (unreachable code) warnings are issued before the C1001 fatal error.

CAUSE

The cause of the problem is having both /Og (global optimizations) and inline function expansion /Ob1 (Only __inline) or /Ob2 (Any Suitable) compiling. /O1 and /O2 are both compound switches, including /Og and /Ob1.

RESOLUTION

Disable either global optimizations (/Og-) or inline function expansion (/Ob1- or /Ob2-). Please see the More Information section below.

STATUS

Microsoft has confirmed this to be bug in the Microsoft products listed at the beginning of this article. This bug was corrected in Visual C++ 32-bit Edition version 4.2.

MORE INFORMATION

The following code reproduces the error when compiled:


   // Compile option needed are: /GX, /W4, and /O1(minimize size)
   // or /O2 (maximize speed)
   struct A
   {
           ~A(){}
   };
   struct B
   {
           A       a;
   };
   void main(void)
   {
           try                     // line 17
           {
               B       *pB = new B[4];
               delete [] pB;  // line 20, warning C4702: unreachable code
           }
           catch(...)
           {
           }
   }

The following error message is generated:


   test.cpp(17) : fatal error C1001: INTERNAL COMPILER ERROR
     (compiler file '\school.tp3\test\c10\src\P2\main.c', line 413)

Compiling from command line with both /Og (global optimizations) and in-line function expansion, /Ob1(Only __inline) or /Ob2 (Any Suitable), reproduces the error. For instance, using:


   cl  /Og /Ob1 /GX /W4 test.cpp

Compiling with the following switch settings in command line does not produce errors:


   cl  /Og /GX /W4 test.cpp

- or -


   cl  /Ob1 /GX /W4 test.cpp

One workaround when using /O1 or /O2 in Developer Studio is to disable In-line function expansion (Build:Settings, C++ Tab, Optimizations category). Another workaround is to disable global optimizations. To accomplish this, choose Custom for the type of optimization (Build:Settings, C++ Tab, Optimizations category). Check all categories that apply, but do not check global optimizations. This behavior is similar to using the components of /O1 or /O2 and eliminating /Og). An additional method is to leave /O1 or /O2 intact and manually add /Og- to the Project Options.

Additional query words: kbVC400bug 4.00 4.10 4.20 vcfixlist420 CPPIss

Keywords : kbCompiler kbCPPonly kbVC
Version : 4.00 4.10
Platform : NT WINDOWS
Issue type :