LDC emits wrong code

[CyberShadow]

Hello,

This program segfaults crashes with "Memory allocation failed" (attempts to append to array at wrong memory address) when built with LDC, but runs fine when built with DMD:

@safe:

template listDir(alias handler)
{
	struct Context
	{
		void callHandler() { handler(); }
	}

	void listDir()
	{
		string s;
		lazyFun(s);

		(new Context).callHandler();
	}
}

void lazyFun(lazy string s) { }

void main()
{
	string[] result;
	listDir!(() { result ~= ""; })();
}

I'm using LDC as packaged in Arch Linux:

LDC - the LLVM D compiler (1.13.0):
  based on DMD v2.083.1 and LLVM 7.0.1
  built with LDC - the LLVM D compiler (1.12.0)
  Default target: x86_64-pc-linux-gnu

[thewilsonator]

Hmm, interestingly it loops forever for me, which would explain the crashes with "Memory allocation failed".

Ignore that, my command line was completely wrong.

[CyberShadow]

With this amendment, it should behave more consistently, I think:

void main()
{
	int magic = 0xDEADBEEF;
	listDir!(() { assert(magic == 0xDEADBEEF); })();
}

[thewilsonator]

Now I get

core.exception.AssertError@./test.d(24): Assertion failure
----------------
??:? _d_assert [0x10cffc907]
??:? pure nothrow @nogc @safe void test.main().__lambda1() [0x10ceb5f83]
??:? pure nothrow @nogc @safe void test.listDir!(test.main().__lambda1()).Context.callHandler() [0x10ceb5f4f]
??:? void test.listDir!(test.main().__lambda1()).listDir() [0x10ceb5f2c]
??:? _Dmain [0x10ceb5edb]

Will take a look.

[kinke]

Somewhat reduced, showing that there must be some confusion wrt. local frame and context for the Context struct in listDir():

template listDir(alias handler)
{
	struct Context
	{
		void callHandler() { handler(); }
	}

	void listDir()
	{
		int a = 123;
		void blub() { assert(a == 123); } // working if commented out
		Context().callHandler();
	}
}

void main()
{
	int s = 0xDEADBEEF;
	listDir!(() { assert(s == 0xDEADBEEF); })();
}

[kinke]

listDir() sets up a wrong context for the Context struct, the one it would pass if it called nested blub() (nest.listDir* instead of parent nest.main*). Interestingly, a call to a sibling function works, e.g.,

template listDir(alias handler)
{
	void test() { handler(); }

	void listDir()
	{
		int a = 123;
		void blub() { assert(a == 123); }
		blub();
		test();
	}
}

void main()
{
	int s = 0xDEADBEEF;
	listDir!(() { assert(s == 0xDEADBEEF); })();
}

[kinke]

Thx for the nice reduced testcase; fixed by #2969.

[CyberShadow]

Very belated thank you :)