Revert "Use std::string_view in torchgen (#157050)"

This reverts commit 064288cbab.

Reverted https://github.com/pytorch/pytorch/pull/157050 on behalf of https://github.com/jeanschmidt due to Seems to have broken internal builds, more details on D77449943. @ezyang may I count on your help to get those changes merged? ([comment](https://github.com/pytorch/pytorch/pull/157050#issuecomment-3020222668))

test/test_overrides.py

@@ -675,6 +675,8 @@ def generate_tensor_like_override_tests(cls):
                 return None
             elif arg_type == "ScalarType":
                 return torch.float32
+            elif arg_type == "c10::string_view":
+                return ""
             elif arg_type in ("std::string_view", "::std::string_view"):
                 return ""
             elif arg_type == "SymInt":

tools/autograd/load_derivatives.py

@@ -969,7 +969,7 @@ def saved_variables(
         if nctype.type == OptionalCType(BaseCType(stringT)):
             formula = re.sub(
                 rf"\b{name}\b",
-                f"{name}.has_value() ? std::optional<::std::string_view>({name}.value()) : std::nullopt",
+                f"{name}.has_value() ? std::optional<std::string_view>({name}.value()) : std::nullopt",
                 formula,
             )
 

torch/csrc/utils/python_arg_parser.cpp

@@ -46,6 +46,7 @@ static std::unordered_map<std::string, ParameterType> type_map = {
     {"DeviceIndex", ParameterType::INT64},
     {"Stream", ParameterType::STREAM},
     {"std::string", ParameterType::STRING},
+    {"c10::string_view", ParameterType::STRING},
     {"std::string_view", ParameterType::STRING},
     {"::std::string_view", ParameterType::STRING},
     {"Dimname", ParameterType::DIMNAME},

torchgen/api/python.py

@@ -683,7 +683,7 @@ def argument_type_str(
         elif t.name == BaseTy.float:
             return "double"
         elif t.name == BaseTy.str:
-            return "std::string_view"
+            return "c10::string_view"
         elif t.name in [
             BaseTy.Tensor,
             BaseTy.bool,

torchgen/api/types/types.py

@@ -52,7 +52,7 @@ float8_e5m2fnuzT = BaseCppType("at", "Float8_e5m2fnuz")
 float8_e4m3fnT = BaseCppType("at", "Float8_e4m3fn")
 float8_e4m3fnuzT = BaseCppType("at", "Float8_e4m3fnuz")
 float8_e8m0fnuT = BaseCppType("at", "Float8_e8m0fnu")
-stringT = BaseCppType("::std", "string_view")
+stringT = BaseCppType("c10", "string_view")
 generatorT = BaseCppType("at", "Generator")
 scalarTypeT = BaseCppType("at", "ScalarType")
 tensorT = BaseCppType("at", "Tensor")

torchgen/dest/lazy_ir.py

@@ -256,11 +256,7 @@ class GenLazyIR(ABC):
             [
                 # This code is just special casing the mapping from string_view -> strings
                 f"{a.name}({a.name}.has_value() ? ::std::make_optional(std::string(*{a.name})) : ::std::nullopt)"
-                if a.lazy_type.cpp_type()
+                if a.lazy_type.cpp_type() == "::std::optional<c10::string_view>"
-                in (
-                    "::std::optional<::std::string_view>",
-                    "::std::optional<std::string_view>",
-                )
                 else f"{a.name}({a.name})"
                 for a in scalar_args
             ]
@@ -270,13 +266,9 @@ class GenLazyIR(ABC):
         scalar_decls = "\n  ".join(
             [
                 f"std::string {a.name};"
-                if a.lazy_type.cpp_type() in ("::std::string_view", "std::string_view")
+                if a.lazy_type.cpp_type() == "c10::string_view"
                 else f"::std::optional<std::string> {a.name};"
-                if a.lazy_type.cpp_type()
+                if a.lazy_type.cpp_type() == "::std::optional<c10::string_view>"
-                in (
-                    "::std::optional<::std::string_view>",
-                    "::std::optional<std::string_view>",
-                )
                 else f"{a.lazy_type.cpp_type()} {a.name};"
                 for a in scalar_args
             ]

torchgen/gen_aoti_c_shim.py

@@ -54,7 +54,7 @@ base_type_to_aten_type = {
     BaseTy.SymInt: "c10::SymInt",
     BaseTy.Scalar: "c10::Scalar",
     BaseTy.float: "double",
-    BaseTy.str: "std::string_view",
+    BaseTy.str: "::std::string_view",
     BaseTy.DeviceIndex: "c10::DeviceIndex",
     BaseTy.Layout: "c10::Layout",
     BaseTy.MemoryFormat: "c10::MemoryFormat",

torchgen/static_runtime/generator.py

@@ -323,7 +323,8 @@ def ivalue_type_conversion_method(
         ),
         BaseTy.str: (
             (False, "toStringView()"),
-            (False, "toOptional<std::string_view>()"),
+            (False, "toOptional<c10::string_view>()"),
+            (False, "toOptional<::std::string_view>()"),
         ),
     }