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| author | Pavel Labath <pavel@labath.sk> | 2024-06-03 10:34:44 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-06-03 10:34:44 +0200 |
| commit | 763b96c86d81d51d0db430791a61fd1e8a406bce (patch) | |
| tree | e5a7f1ba5b3f930a4363d535d5087e95c5afb348 /lldb/test/API/functionalities/data-formatter | |
| parent | ce73e17e3ab5ccfa33a977843e82a9bbfb6b4ce3 (diff) | |
[lldb] Avoid (unlimited) GetNumChildren calls when printing values (#93946)
For some data formatters, even getting the number of children can be an
expensive operations (e.g., needing to walk a linked list to determine
the number of elements). This is then wasted work when we know we will
be printing only small number of them.
This patch replaces the calls to GetNumChildren (at least those on the
"frame var" path) with the calls to the capped version, passing the
value of `max-children-count` setting (plus one)
Diffstat (limited to 'lldb/test/API/functionalities/data-formatter')
| -rw-r--r-- | lldb/test/API/functionalities/data-formatter/synthcapping/TestSyntheticCapping.py | 11 | ||||
| -rw-r--r-- | lldb/test/API/functionalities/data-formatter/synthcapping/fooSynthProvider.py | 15 |
2 files changed, 25 insertions, 1 deletions
diff --git a/lldb/test/API/functionalities/data-formatter/synthcapping/TestSyntheticCapping.py b/lldb/test/API/functionalities/data-formatter/synthcapping/TestSyntheticCapping.py index d53dadef836e..9ca232abefa0 100644 --- a/lldb/test/API/functionalities/data-formatter/synthcapping/TestSyntheticCapping.py +++ b/lldb/test/API/functionalities/data-formatter/synthcapping/TestSyntheticCapping.py @@ -68,6 +68,11 @@ class SyntheticCappingTestCase(TestBase): "r = 34", ], ) + # num_children() should be called with at most max_num_children=257 + # (target.max-children-count + 1) + self.expect( + "script fooSynthProvider.reset_max_num_children_max()", substrs=["257"] + ) # check that capping works self.runCmd("settings set target.max-children-count 2", check=False) @@ -80,9 +85,15 @@ class SyntheticCappingTestCase(TestBase): "...", ], ) + self.expect( + "script fooSynthProvider.reset_max_num_children_max()", substrs=["3"] + ) self.expect("frame variable f00_1", matching=False, substrs=["r = 34"]) self.runCmd("settings set target.max-children-count 256", check=False) self.expect("frame variable f00_1", matching=True, substrs=["r = 34"]) + self.expect( + "script fooSynthProvider.reset_max_num_children_max()", substrs=["257"] + ) diff --git a/lldb/test/API/functionalities/data-formatter/synthcapping/fooSynthProvider.py b/lldb/test/API/functionalities/data-formatter/synthcapping/fooSynthProvider.py index 3bfa3130cc01..5ea392ac8829 100644 --- a/lldb/test/API/functionalities/data-formatter/synthcapping/fooSynthProvider.py +++ b/lldb/test/API/functionalities/data-formatter/synthcapping/fooSynthProvider.py @@ -2,11 +2,24 @@ import lldb class fooSynthProvider: + # For testing purposes, we'll keep track of the maximum value of + # max_num_children we've been called with. + MAX_NUM_CHILDREN_MAX = 0 + + @classmethod + def reset_max_num_children_max(cls): + old_value = fooSynthProvider.MAX_NUM_CHILDREN_MAX + fooSynthProvider.MAX_NUM_CHILDREN_MAX = 0 + return old_value + def __init__(self, valobj, dict): self.valobj = valobj self.int_type = valobj.GetType().GetBasicType(lldb.eBasicTypeInt) - def num_children(self): + def num_children(self, max_num_children): + fooSynthProvider.MAX_NUM_CHILDREN_MAX = max( + fooSynthProvider.MAX_NUM_CHILDREN_MAX, max_num_children + ) return 3 def get_child_at_index(self, index): |