[llvm-gcc] Constant initializer translation is broken

[llvmbot]

Bugzilla Link	156
Resolution	DUPLICATE
Resolved on	Feb 22, 2010 12:44
Version	1.0
OS	All
Depends On	llvm/llvm-bugzilla-archive#162
Blocks	#509 llvm/llvm-bugzilla-archive#269 llvm/llvm-bugzilla-archive#285
Reporter	LLVM Bugzilla Contributor
CC	@markus-oberhumer

Extended Description

Test case comes from same source as bug 155:

% cat it.i

struct task_struct {
char comm[16];
};
union task_union {
struct task_struct task;
unsigned long stack[2048*sizeof(long)/sizeof(long)];
};
union task_union init_task_union = { { comm: "swapper" } };

% llvm-gcc it.i

cc1: ../../gcc-3.4/gcc/llvm-expand.c:3186: ExpandConstantInto: Assertion
`Val->VTy == ConstantAggregate && "Constant initializer translation is broken!"'
failed.
it.i:8: internal compiler error: Aborted
Please submit a full bug report,
with preprocessed source if appropriate.
See URL:http://llvm.cs.uiuc.edu for instructions.

[llvmbot]

assigned to @lattner

[lattner]

This is going to take a substantial rework of the C front-end to fix, so it's
not going to happen for 1.1.

In the interim, get rid of the union (taking the array out), and use casting
instead to simulate it. Either that, or eliminate the constant initializer,
changing it to be a dynamic initialization.

-Chris

[lattner]

Looks like not 1.2

[lattner]

Here's another testcase from reduced from the one in Bug 295:

union inflate_huft_s {
struct {
unsigned char Exop;
unsigned char Bits;
} what;
unsigned pad;
} fixed_tl = {96,7};

The problem is that we attempt to expand an initializer for a two element struct
into an LLVM type of { uint }, which the CFE doesn't know how to do.

-Chris

[lattner]

*** Bug llvm/llvm-bugzilla-archive#295 has been marked as a duplicate of this bug. ***

[lattner]

*** Bug llvm/llvm-bugzilla-archive#574 has been marked as a duplicate of this bug. ***

[lattner]

*** Bug llvm/llvm-bugzilla-archive#568 has been marked as a duplicate of this bug. ***

[lattner]

*** This bug has been marked as a duplicate of 162 ***

[lattner]

Testcase here: llvm-test/SingleSource/UnitTests/2006-01-23-UnionInit.c
This is fixed by the new frontend and will be closed when it is the default.

-Chris

[llvmbot]

mentioned in issue llvm/llvm-bugzilla-archive#162

[lattner]

mentioned in issue llvm/llvm-bugzilla-archive#269

[llvmbot]

mentioned in issue llvm/llvm-bugzilla-archive#285