• Per =?UTF-8?B?Tm9yZGzDtnc=?= (5/5) Nov 12 2020 Why don't I get a stack trace on Memory allocation exceptions?
• Per =?UTF-8?B?Tm9yZGzDtnc=?= (2/3) Nov 12 2020 Is it because the stack may be corrupted?
• Steven Schveighoffer (6/14) Nov 12 2020 Certain errors are flagged as not able to allocate memory. So you don't
• mw (5/18) Jun 02 2021 Hit this one today, since it's a mistake, what does it take to
• Mathias LANG (18/39) Jun 02 2021 It is fixable, but it'll take a lot of work. The main blocker is

Per =?UTF-8?B?Tm9yZGzDtnc=?= <per.nordlow gmail.com> writes:

Why don't I get a stack trace on Memory allocation exceptions?

In my case I only get:

src/core/exception.d(647): [unittest] Memory allocation failed
core.exception.OutOfMemoryError src/core/exception.d(647): Memory 
allocation failed

Per =?UTF-8?B?Tm9yZGzDtnc=?= <per.nordlow gmail.com> writes:

On Thursday, 12 November 2020 at 09:22:10 UTC, Per Nordlöw wrote:
 Why don't I get a stack trace on Memory allocation exceptions?

Is it because the stack may be corrupted?

Steven Schveighoffer <schveiguy gmail.com> writes:

On 11/12/20 4:22 AM, Per Nordlöw wrote:
 Why don't I get a stack trace on Memory allocation exceptions?
 
 In my case I only get:
 
 src/core/exception.d(647): [unittest] Memory allocation failed
 core.exception.OutOfMemoryError src/core/exception.d(647): Memory 
 allocation failed
 

Certain errors are flagged as not able to allocate memory. So you don't 
get a stack trace.

I think it's a huge mistake, and we don't need memory allocation to do 
stack trace printing. But that's the way it is.

-Steve

mw <mingwu gmail.com> writes:

On Thursday, 12 November 2020 at 13:16:21 UTC, Steven 
Schveighoffer wrote:
 On 11/12/20 4:22 AM, Per Nordlöw wrote:
 Why don't I get a stack trace on Memory allocation exceptions?
 
 In my case I only get:
 
 src/core/exception.d(647): [unittest] Memory allocation failed
 core.exception.OutOfMemoryError src/core/exception.d(647): 
 Memory allocation failed
 

 Certain errors are flagged as not able to allocate memory. So 
 you don't get a stack trace.

 I think it's a huge mistake, and we don't need memory 
 allocation to do stack trace printing. But that's the way it is.

Hit this one today, since it's a mistake, what does it take to 
fix it? or you are saying it's unfix-able in the current D 
runtime?

Mathias LANG <geod24 gmail.com> writes:

On Wednesday, 2 June 2021 at 17:52:12 UTC, mw wrote:
 On Thursday, 12 November 2020 at 13:16:21 UTC, Steven 
 Schveighoffer wrote:
 On 11/12/20 4:22 AM, Per Nordlöw wrote:
 Why don't I get a stack trace on Memory allocation exceptions?
 
 In my case I only get:
 
 src/core/exception.d(647): [unittest] Memory allocation failed
 core.exception.OutOfMemoryError src/core/exception.d(647): 
 Memory allocation failed
 

 Certain errors are flagged as not able to allocate memory. So 
 you don't get a stack trace.

 I think it's a huge mistake, and we don't need memory 
 allocation to do stack trace printing. But that's the way it 
 is.

 Hit this one today, since it's a mistake, what does it take to 
 fix it? or you are saying it's unfix-able in the current D 
 runtime?

It is fixable, but it'll take a lot of work. The main blocker is 
that the interface that is exposed to the user relies on memory 
allocation.
Namely, the `TraceInfo` interface is: 
https://github.com/dlang/druntime/blob/2d8b28da39e8bc3bc3172c69bb96c35d77f40d2a/src/object.d#L2257-L2261

Note that:
1) `toString` returns a `string` (allocation);
2) The `opApply`'s delegate use a `char[]` as parameter;

What we *should* have is an `opApply` on a struct that contains 
all necessary info, which itself writes to a sink / OutputRange.
Such struct exists 
(https://github.com/dlang/druntime/blob/a17bb23b418405e1ce8e4a317651039758013f39/src/core/internal/backtra
e/dwarf.d#L77-L160) but need to be exposed to user code.
Then *printing* the stack trace will no longer allocate. However, 
`defaultTraceHandler` still returns an object, so acquiring the 
handler will also need to be addressed. There have been talks of 
deprecating chained Exceptions, and that would make such a task 
much simpler.