Some tests that were checking for prints inside/outside `target` regions
needed to be updated to work on systems where the ordering wasn't
deterministic.
Reverts llvm/llvm-project#184240
Original description from #165494:
-----
OpenMP allows cases like the following:
```c
int *p1, *p2, x;
p1 = p2 = &x;
...
#pragma omp target_exit_data map(delete: p1[:]) from(p2[0])
```
Which means, when the runtime encounters the `from` entry, the ref-count
may
not be zero, but it will go down to zero at the end of the current
construct,
which should cause the "from" transfer to happen.
Similarly, a user may have:
```c
struct S {
int *p;
};
#pragma omp declare_mapper (id1: S s) map(s.p) map(present, alloc: s.p[0:10])
#pragma omp declare_mapper (id2: S s) map(s.p, s.p[0:10])
S s1;
// present-check should fail here
#pragma omp target_enter_data map(alloc: s.p[0:10]) map(mapper(id1), to: s)
// "to" should be honored here
#pragma omp target_enter_data map(alloc: s.p[0:10]) map(mapper(id2), to: s)
```
Where the allocation happens before the "to" entry is encountered by the
runtime. Or, an allocation happens before a "present" entry is
encountered.
To handle cases like this, we need to use the state information of
previously
seen new allocations, deletions, "from" entries, when honoring
`to`/`from`/`present` map entries.
-----
OpenMP allows cases like the following:
```c
int *p1, *p2, x;
p1 = p2 = &x;
...
#pragma omp target_exit_data map(delete: p1[:]) from(p2[0])
```
Which means, when the runtime encounters the `from` entry, the ref-count
may not be zero, but it will go down to zero at the end of the current
construct, which should cause the "from" transfer to happen.
Similarly, a user may have:
```c
struct S {
int *p;
};
#pragma omp declare_mapper (id1: S s) map(s.p) map(present, alloc: s.p[0:10])
#pragma omp declare_mapper (id2: S s) map(s.p, s.p[0:10])
S s1;
// present-check should fail here
#pragma omp target_enter_data map(alloc: s.p[0:10]) map(mapper(id1), to: s)
// "to" should be honored here
#pragma omp target_enter_data map(alloc: s.p[0:10]) map(mapper(id2), to: s)
```
Where the allocation happens before the "to" entry is encountered by the
runtime. Or, an allocation happens before a "present" entry is
encountered.
To handle cases like this, we need to use the state information of
previously seen new allocations, deletions, "from" entries, when
honoring `to`/`from`/`present` map entries.
There are a few places where data types based on character array or
string are printed in the debug message while they do not represent
strings. Such expressions should be casted to `void *` unless they
represent actual strings. Change also includes casting from integral
type to pointer type when appropriate.
Update debug messages based on the new method from #170425. Added a new
debug type `Tool` and updated the following files.
- include/OffloadPolicy.h
- include/OpenMP/OMPT/Connector.h
- include/Shared/Debug.h
- include/Shared/EnvironmentVar.h
- libomptarget/OpenMP/Mapping.cpp
- libomptarget/OpenMP/OMPT/Callback.cpp
- libomptarget/PluginManager.cpp
OpenMP allows duplicate mappings, i.e. in OpenMP 6.0, 7.9.6 "map
Clause":
Two list items of the map clauses on the same construct must not share
original storage unless one of the following is true: they are the same
list item [or other omitted reasons]"
Duplicate mappings can arise as a result of user-defined mapper
processing (which I think is a separate bug, and is not addressed here),
but also in straightforward cases such as:
#pragma omp target map(tofrom: s.mem[0:10]) map(tofrom: s.mem[0:10])
Both these cases cause crashes at runtime at present, due to an
unfortunate interaction between reference counting behaviour and shadow
pointer handling for blocks. This is what happens:
1. The member "s.mem" is copied to the target
2. A shadow pointer is created, modifying the pointer on the target
3. The member "s.mem" is copied to the target again
4. The previous shadow pointer metadata is still present, so the runtime doesn't modify the target pointer a second time.
The fix is to disable step 3 if we've already done step 2 for a given
block that has the "is new" flag set.
