Have you ever crashed the compiler?

Question

Everyone (at least everyone who uses a compiled language) has faced compilation errors but how many times do you get to actually crash the compiler?

I've had my fair share of "internal compiler errors" but most went away just by re-compiling. Do you have a (minimal) piece of code that crashes the compiler?

Answer 1

Yes, especially when it's an old or undermaintained compiler (GCC 2.95, Tendra in C++ mode). I don't keep the pieces of code around, though.

Answer 2

I write the compiler we use, so it crashes sometimes.

Answer 3

VC++ has crashed on me when compiling C++ if template usage is messed up (e.g., missing out on a closing ">").

Answer 4

I've seen a few compiler bugs in the C# compiler (all edge cases, all reported appropriately) and confirmed some crashes provoked by other people.

The scariest compiler (of a sort) bug I've encountered was a JIT bug in one version of Java. It was quite reproducible, but caused the VM to go down. Adding a fairly no-op statement (I can't remember exactly what offhand - possibly just declaring an extra local variable with an initial value) moved it away from whatever corner case it happened to be - and it was fixed in a later version.

Answer 5

I did. Some Delphi versions (lets say #4) crashed very often with cryptic error messages.

The newer versions (2006 and more) are stable but not rock solid. (7 was great in that case).

Compiler crashes often occur with large edits, and debug sessions of complex projects (lots of dll's). Most of the time a restart of the ide is enough. But sometimes you need to restart the PC.

O and I once crashed OS2 along with the compiler because the swapfile grew too large.

Answer 6

Actionscript 3.0:

switch(on_some_variable)
{
}

Empty switch = Kaboom!

Answer 7

Visual C++ 5. 'Nuff said.

Answer 8

easy.

// -*- C++ -*-

template <int n>
class Foo : public Foo<n+1>
{

};

int main(int, char*[])
{
    Foo<0> x;
    return 0;
};

ejgottl@luna:~/tmp$ g++ -ftemplate-depth-1000000 -Wall foo.cpp -o foo
g++: Internal error: Segmentation fault (program cc1plus)
Please submit a full bug report.
See <URL:http://gcc.gnu.org/bugs.html&amp;gt; for instructions.
For Debian GNU/Linux specific bug reporting instructions, see
<URL:file:///usr/share/doc/gcc-4.2/README.Bugs>.

Answer 9

VC catches it gracefully now, but in the mid 90's, this would crashed both Microsoft C++ and Borland C++ compilers:

struct MyClass
{
    MyClass operator->() { return *this; }
};


int main(int argc, char* argv[])
{
    MyClass A;
    A->x;
}

An overloaded operator-> is intrinsically recursive. The function is expected to return a pointer, which oper-> is again applied to. This fragment made code generation infinitely recursive.

Answer 10

One time when I used the generators example from the Python docs, it broke the version of Python we were using. The same week, one of my colleagues managed to misuse the FFI such that any calculation involving the number 3 would crash python.

Answer 11

In a project I was working in, some specific usages of Boost Lambda expressions could make the Visual C++ compiler crash. (We were using Visual Studio 2003)
The compiler would only crash during the release build, a debug build would work fine.

There had been a religious war raging through the team about the appropriate usage of the lambda libraries, I was almost grateful that the compiler settled it for us. :-)

Answer 12

I haven't made GHC (a Haskell compiler) crash yet, but I've gotten it to error out with a

My brain just exploded.
I can't handle pattern bindings for existentially-quantified constructors.

It's pretty easy to work around, and you don't hit this unless you have some tricky (and usually wrong) design, but it probably wins as the best compiler error message ever.

Answer 13

The Microsoft Xbox 360 compiler can crash easily. I was given source code with Japanese comments and when converted to regular text one of the last characters on the line was a '\' so it continued the comment onto the next line. If the next line was a switch command, then the compiler crashes.

//wierd japanese characters here %^$$\
switch(n)
{
case 0:
    .....
break;
case 1:
    .....
break;
}

Answer 14

In version 1.2.x of the Mono C# compiler would crash quite a bit with complicated code (if I remember correctly, nested anonymous delegates). Fortunately with 2.x release, I haven't seen any crashes.

Answer 15

At my previous job we had a simulator which was notorious for being able to crash (ICE) compilers or cause them to generate incorrect code. And when the code actually was generated correctly, ofter the compiler took 15 minutes for a single source file. Visual Studio was never (as long as I worked there) able to compile the simulator core.

The core was automatically generated from a DSL, and the generated code often pushed the compiler to its limits.

Upgrading to a new version of GCC often caused widespread nervosity: will the new version work?

Answer 16

I have crashed Delphi 7 many times asking it to compile legacy dos code.

The prime culprit seems to be any qualification of something as being in the system unit. This won't always blow it up but when it blows up on such stuff I look through and rewrite anything that requires such an override and the problem goes away.

The blowups are 100% reproduceable but I have never managed to make a simple test case. It doesn't actually crash the compiler most of the time, you usually get an error that has nothing to do with the problem and may be hundreds of lines from it. The environment is destabilized, save and exit is ok but don't think of doing anything else.

Back in the stone age with Borland Pascal 7 (the last dos version) I broke it many times. No crash, just incorrect and inconsistent code emission. I finally learned to keep the .EXE (not counting debug info) below 3mb. The farther beyond that I went the more unstable it got.

Answer 17

I've crashed VC++ a number of times, usually with template code. But that's not the most interesting crash...

I crashed the VS2005 Team System compiler with the /analyze option compiling my shared code library which compiled without error without the switch, and on VS2008 with and without the switch. Of course MS wasn't very interested because it was a bug in the old version of the compiler, but I thought it was pretty interesting.

Answer 18

This crashed the C64 BASIC:

PRINT 0 + "" +- 0

Answer 19

Visual C++ 9.0 SP1

this just happened to me

------ Build started: Project: pdfp, Configuration: Debug Win32 ------
Compiling...
reader.cpp
xref.cpp
c:\projects\pdfp\xref.cpp(52) : fatal error C1001: An internal error has occurred in the compiler.
(compiler file 'f:\dd\vctools\compiler\cxxfe\sl\p1\c\toil.c', line 8569)
 To work around this problem, try simplifying or changing the program near the locations listed above.
Please choose the Technical Support command on the Visual C++ 
 Help menu, or open the Technical Support help file for more information
Generating Code...
Build log was saved at "file://c:\Projects\pdfp\Debug\BuildLog.htm"
pdfp - 1 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Answer 20

Well, this didn't actually crash the compiler -- It was merely a bug were VC++ wouldn't accept perfectly good code. (details provided here).

The odd this about it was that it was only triggered when three fairly obscure conditions were all met. Moving one line of code was all that was needed for an effective workaround. And one of the needed pre-conditions was "using namespace std;" which is widely discouraged in production code.

Nevertheless, messages asking how to fix the problem were a staple on Microsoft VC++ newsgroups. I couldn't figure out how so many people stumbled onto an obscure bug. So, eventually, I asked someone.....

The exact code needed to trigger the bug was an example in Stroustrup's "The C++ Programming Langauge". (*)

(*) Note, I'm not saying he did it on purpose. I sure he tested it under a UNIX variant of C++, and was completely unaware of it's affect on VC++.

Answer 21

Thanks to @Nick, this crashes VS2005.

 template<typename Res, typename T>
 Res operator_cast(const T& t)
 {
     return t.operator Res();
 }

 int main()
 {
    return operator_cast<int>(0);
 }

Answer 22

I managed to segfault the Python interpreter. Of course, I was working on a C extension at the time and getting it not-quite-right.

Answer 23

Oops, forgot an 'e' in typedef and crashed the compiler.

typdef struct kGUIColor GameColor;

c:\source\kgui\samples\space\space.cpp(35) : fatal error C1001: INTERNAL COMPILER ERROR
        (compiler file 'msc1.cpp', line 2708) 
         Please choose the Technical Support command on the Visual C++ 
         Help menu, or open the Technical Support help file for more information

Answer 24

It doesn't happen as much as it used to, but occasionally the ASP.net precompiler has issues - I haven't seen it personally, but I have fixed a problem on another project once where they had name clashes because they weren't using namespaces properly (caused compiler crashes) during pre-compile.

In the good old days (unmanaged MSVC++) we had the odd compiler crash usually due to linking in external static win32 classes (.lib) and a couple of odd bits of code occasionally caused issues, but these were all picked up very quickly.

Answer 25

I've crashed a compiler before by running it out of memory.

Give a DOS compiler about 0.5mb of source code. Crunch.

Answer 26

I don't know if I would call it crashing, but sdcc (Small Device C Compiler) fails at compiling code formed in a particular way:

• Target: 8051
• Code had to execute in a 512 byte cache loaded from an external tester
• Tester is in control and stores the code - cache can't fetch the next page
• No function calls allowed - the PC (program counter) would skip to a place not resident in cache; preprocessor macros were used to accomplish modular coding practice
• Jumps (branching) allowed if it doesn't skip out of the cache
• No const values - in the data section of the program code which causes code in cache to fetch something not in cache - preprocessor constant (#define) OK here

The preprocessor macros are unrolled resulting in flat, but large code - everything in main(); execution skips the startup code (setting up the stack, etc) and starts at the beginning of main()

Relevant part of this answer:

Occasionally, sdcc would refuse to compile syntactically correct code, with a message about running out of memory. This even happened compiling on 64-bit boxes with 8GB of RAM.

The solution in these cases was to split the firmware into separate pieces and compile them separately and execute them separately. The pieces may have been able to be linked back together, but at that point it didn't matter.

I didn't try it, but the Keil 8051 compiler probably could have handled the problematic code.

Answer 27

I've managed to crash the F# compiler a bunch of times; but that's not fair as it was a beta/alpha/research/etc compiler.

Answer 28

When you get a message "Catastrophic Failure" you know you're trying....

Michael

Answer 29

I've never tried to crash the compiler, but the VB compiler/debugger was going out several times a day on me. Even though it's VB, does that count?

Answer 30

My team often had random internal compiler errors with the csharp compiler on our build machines. We resolved the problem by cleaning all the bin/obj folders between the build of each target.

Answer 31

I've crashed VVIS when compiling a map for the Source engine.

Does that count?

Answer 32

Today VS2003SP1 gave me a C1001 (Internal Compiler Error) complaining about compiler file 'msc1.cpp', line 2708) because of this:

struct PATTERN {
  …
};

It turns out that the problem was that the structure name I was trying to define (PATTERN) was already a typedef in the GDI for a brush type. However instead of telling me that the symbol is already defined (like it does for most other things) it not only did not point to the structure as the problem—I narrowed the problem down to it by selectively commenting out blocks until the error went away—but it also gave me the aforementioned cryptic error which has nothing to do with the file specified—which I can’t even find to examine the line in question. :|


I was able to reproduce it with the following code:

    typedef int SOMETHINGOROTHER;
    struct SOMETHINGOROTHER {};

> fatal error C1001: INTERNAL COMPILER ERROR
> (compiler file 'msc1.cpp', line 2708) …


Whereas the following code gives the expected error message:

    struct SOMETHINGOROTHER {};
    typedef int SOMETHINGOROTHER;

> 'SOMETHINGOROTHER' : redefinition; different basic types


Clearly the problem is in the compiler’s structure handling routine.

I wonder if VS2005+ do better…

Answer 33

A long time ago, I worked on COBOL on a Control Data computer. (If that sounds funny, it is. Control Data was known for its high-performance scientific computing systems, and the COBOL compiler was a bit of an afterthought.) I don't remember the details, but I had a program I was trying to port to a newer version. I tried things several different ways, and found out I had a choice between crashing the compiler or putting it into an infinite loop.

Answer 34

I use both pcc and gcc to compile my old OS project.

I found a bug with how both pcc and gcc handle a non-trivial piece of code and it crashed pcc. (chars are signed on my platform)

struct{
  char myvalue:1;
}mystruct;

pcc crashed because all bitfield values must be int though, so it's really more buggy there, but gcc handles it wrongly. See, if you think about it, it is signed, but only has room for one bit. So therefore, it only can store 0 and -1. Well, gcc handles it wrong by storing 0 or 1.

Answer 35

Not the compiler, but the linker in Visual Studio 2008 crashes several times per day for me under Windows 7 64 bit. Immediately building again always works without a crash. Microsoft don't seem to care...

Not really an answer to your question because it's not the code itself causing it, but I'm always willing to rant about this particular issue :-)

Answer 36

Template support in GCC 2.95 (though I might be misremembering the version) was buggy. Various constructs would cause it to crash. I can't find the test case, but I think inner classes of templates (or inner classes that were templates) were one way of getting an compiler error.

Answer 37

Hey,

I had something more interesting: Linker internal error...

Do you know how to cause THAT?

Answer 38

Here's a way to crash the VS2003 C++ compiler.

typedef map<int,int> Tmap;
private: Tmap; * m_map;

This will result in a crash and the following error message

fatal error C1001: INTERNAL COMPILER ERROR (compiler file 'msc1.cpp', line 2708) Please choose the Technical Support command on the Visual C++ Help menu, or open the Technical Support help file for more information

Remove the semicolon immediately after Tmap (second line which defines m_map) to eliminate the error.

Answer 39

I once wrote a C program that would make the computer spontaneously reboot. One downside is that it didn't really have anything to do with mergesort which I was trying to implement at the time.

Fortunately it went away once I'd gotten my pointer errors figured out.