Add check_env, getenv api (#59052)
Summary:
Related Issue: https://github.com/pytorch/pytorch/issues/57691
This PR introduces an API for checking environment variables:
```c++
optional<bool> check_env(const char *name)
```
Reads the environment variable name and returns
- `optional<true>`, if set equal to "1"
- `optional<false>`, if set equal to "0"
- `nullopt`, otherwise
Issues a warning if the environment variable was set to any value other than 0 or 1
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59052
Test Plan:
Manually run the following test case:
- Apply this diff to the repo
```
diff --git a/torch/csrc/Exceptions.cpp b/torch/csrc/Exceptions.cpp
index d008643f70..990d254f0d 100644
--- a/torch/csrc/Exceptions.cpp
+++ b/torch/csrc/Exceptions.cpp
@@ -9,6 +9,9 @@
#include <torch/csrc/THP.h>
+#include <c10/util/Optional.h>
+#include <c10/util/env.h>
+
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
PyObject *THPException_FatalError;
@@ -23,18 +26,7 @@ bool THPException_init(PyObject *module)
namespace torch {
static bool compute_cpp_stack_traces_enabled() {
- auto envar = std::getenv("TORCH_SHOW_CPP_STACKTRACES");
- if (envar) {
- if (strcmp(envar, "0") == 0) {
- return false;
- }
- if (strcmp(envar, "1") == 0) {
- return true;
- }
- TORCH_WARN("ignoring invalid value for TORCH_SHOW_CPP_STACKTRACES: ", envar,
- " valid values are 0 or 1.");
- }
- return false;
+ return c10::utils::check_env("TORCH_SHOW_CPP_STACKTRACES").value_or(false);
}
bool get_cpp_stacktraces_enabled() {
```
This patch replaces the prior `std::getenv` usage in `torch/csrc/Exceptions.cpp` to use the new api.
- Run the following python3 script
```python
import torch
print(torch.__version__) # should print local version (not release)
a1 = torch.tensor([1,2,3])
a2 = torch.tensor([2])
a1 @ a2
```
using the following commands
```bash
python3 test.py # should not output CPP trace
TORCH_SHOW_CPP_STACKTRACES=1 python3 test.py # should output CPP trace
```
Reviewed By: ngimel
Differential Revision: D28799873
Pulled By: 1ntEgr8
fbshipit-source-id: 3e23353f48679ba8ce0364c049420ba4ff86ff09
