Crash with LLVMBuildStore when trying to store a boolean (LLVMInt1Type)

[wedesoft]

Hi, I am using the LLVM C library to do JIT compilation for a Guile extension.
Here is some C code calling LLVMBuildStore (see here for complete file).

SCM llvm_build_store(SCM scm_function, SCM scm_type, SCM scm_value, SCM scm_address)
{
  struct llvm_function_t *function = get_llvm_function(scm_function);
  struct llvm_value_t *value = get_llvm_value(scm_value);
  struct llvm_value_t *address = get_llvm_value(scm_address);
  int type = scm_to_int(scm_type);
  LLVMValueRef pointer = LLVMBuildIntToPtr(function->builder, address->value, LLVMPointerType(llvm_type(type), 0), "x");
  LLVMBuildStore(function->builder, value->value, pointer);
  return SCM_UNSPECIFIED;
}

Basically this code works for most datatypes but when llvm_type returns LLVMInt1Type() (used for boolean values), it crashes in llvm::DataLayout::getAlignment(llvm::Type*, bool) const ().
The code used to work with LLVM 14. Now I tried to upgrade to LLVM 17, 18, and now 19. With 17 I got infinite recursion (and crash) and with 19 I just get a crash.

Thread 1 "guile" received signal SIGSEGV, Segmentation fault.
0x00007fffe596256a in llvm::DataLayout::getAlignment(llvm::Type*, bool) const () from /lib/x86_64-linux-gnu/libLLVM.so.19.1
(gdb) p function->builder
No symbol "function" in current context.
(gdb) up
#1  0x00007fffe596299c in llvm::DataLayout::getPrefTypeAlignment(llvm::Type*) const () from /lib/x86_64-linux-gnu/libLLVM.so.19.1
(gdb)
#2  0x0000000000000000 in ?? ()

Let me know if you have any suggestions.
Kind regards
Jan

[wedesoft]

#include <llvm-c/Core.h>
#include <llvm-c/ExecutionEngine.h>
#include <llvm-c/Target.h>
#include <llvm-c/TargetMachine.h>

int main() {
    LLVMModuleRef module = LLVMModuleCreateWithName("my_module");
    LLVMBuilderRef builder = LLVMCreateBuilder();

    LLVMTypeRef paramTypes[] = { LLVMInt64Type() };
    LLVMTypeRef funcType = LLVMFunctionType(LLVMVoidType(), paramTypes, 1, 0);
    LLVMValueRef function = LLVMAddFunction(module, "store_byte", funcType);

    LLVMBasicBlockRef entry = LLVMAppendBasicBlock(function, "entry");
    LLVMPositionBuilderAtEnd(builder, entry);

    LLVMValueRef intValue = LLVMGetParam(function, 0);
    LLVMValueRef ptr = LLVMBuildIntToPtr(builder, intValue, LLVMPointerType(LLVMInt1Type(), 0), "ptr");
    LLVMValueRef value = LLVMConstInt(LLVMInt1Type(), 1, 0);
    LLVMBuildStore(builder, value, ptr);

    LLVMBuildRetVoid(builder);

    LLVMDumpModule(module);

    LLVMDisposeBuilder(builder);
    LLVMDisposeModule(module);

    return 0;
}

/*
gcc -o llvm-store `llvm-config-19 --cflags` llvm-store.c `llvm-config-19 --libs`
*/

Ok, I am unable to reproduce it with this code.

[EugeneZelenko]

Could you please try 21 or main branch? Only most recent release is maintained.

[wedesoft]

The code was specifying a void pointer for some reason, so the problem is somewhere else. I need to investigate.

[wedesoft]

I had set the boolean type index to "SCM_FOREIGN_TYPE_LAST + 1" in C and incorrectly to int64 + 1 in Guile. In the meantime guile has introduced foreign types for complex numbers, so the SCM_FOREIGN_TYPE_LAST is not int64 any more. Sorry for filing an issue here.