ICE when providing mismatched _d_assert_msg() declaration

[timotheecour]

ldc2 -c -oq -od=/tmp/d08 fun.d

fun.d:

import std.string;
void fun(){
  format("");
}
extern(C)void _d_assert_msg();

ldc2 --version
LDC - the LLVM D compiler (cf0589):
based on DMD v2.066.1 and LLVM 3.6.1
Default target: x86_64-apple-darwin14.3.0
Host CPU: core-avx2

0 ldc2 0x0000000104878ad1 llvm::sys::PrintStackTrace(sFILE) + 57
1 ldc2 0x0000000104879027 SignalHandler(int) + 217
2 libsystem_platform.dylib 0x00007fff9a658f1a sigtramp + 26
3 ldc2 0x0000000104c0ec36 nuls + 69742
4 ldc2 0x0000000104878eb6 abort + 22
5 ldc2 0x0000000104878ea0 abort + 0
6 ldc2 0x000000010480c0d8 llvm::CallInst::init(llvm::Value, llvm::Twine const&) + 0
7 ldc2 0x0000000103f38f99 llvm::IRBuilder<true, llvm::ConstantFolder, llvm::IRBuilderDefaultInserter >::CreateCall(llvm::Value, llvm::ArrayRefllvm::Value_, llvm::Twine const&) + 201
8 ldc2 0x0000000103f3fbde llvm::CallSite IRState::CreateCallOrInvoke<llvm::SmallVector<llvm::Value*, 3u> >(llvm::Value_, llvm::SmallVector<llvm::Value_, 3u> const&, char const_) + 686
9 ldc2 0x0000000103f39af8 DtoAssert(Module_, Loc&, DValue_) + 312
10 ldc2 0x0000000103f7427b ToElemVisitor::visit(AssertExp_) + 763
11 ldc2 0x0000000103f70236 toElemDtor(Expression_) + 614
12 ldc2 0x0000000103f5f502 ToIRVisitor::visit(ExpStatement_) + 130
13 ldc2 0x0000000103f5f594 ToIRVisitor::visit(CompoundStatement_) + 116
14 ldc2 0x0000000103f5f3ee codegenFunction(Statement_, IRState_) + 190
15 ldc2 0x0000000103f35eee DtoDefineFunction(FuncDeclaration_) + 3982
16 ldc2 0x0000000103f2cf4f CodegenVisitor::visit(StructDeclaration_) + 223
17 ldc2 0x0000000103f2cd3f CodegenVisitor::visit(TemplateInstance_) + 143
18 ldc2 0x0000000103f2c352 Declaration_codegen(Dsymbol*) + 50
19 ldc2 0x0000000103f42ea6 Module::genLLVMModule(llvm::LLVMContext&) + 3206
20 ldc2 0x0000000103de260c main + 6044
21 libdyld.dylib 0x00007fff8c15d5c9 start + 1
22 libdyld.dylib 0x0000000000000011 start + 1944726089

[redstar]

This is a nasty one. A call to _d_assert_msg() is generated for an assert expression. Inside the same module, the prototype is checked. E.g.

void fun(int x){
  assert(x > 1, "x should be greater than 1");
}
extern(C)void _d_assert_msg();

triggers the error message:

ldc_github_958.d(4): Error: Function type does not match previously declared fun ction with the same mangled name: _d_assert_msg

But the import for std.string indirectly imports assert expressions. Here the prototype is not checked. Then 2 different prototypes are used, which triggers the assertion.

[dnadlinger]

Are you sure? At first glance, the difference simply seems to be that the imported asserts would be codegen'd after the declaration, so instead of copying over the _d_assert_msg declaration from our internal runtime module we just use the existing ones. The code that declares runtime functions should check for matching types if the functions already exist.

[kinke]

Seems like we forgot to close this. Failing now with a proper error msg: https://godbolt.org/g/1Wqm1u