[Reland] Use std::string_view in torchgen (pytorch#158625)

cyyever · pytorchmergebot · commit 972e40982934 · 2025-09-12T08:31:54.000Z
Reland of pytorch#157050, which is incidentally closed. Pull Request resolved: pytorch#158625 Approved by: https://github.com/albanD
diff --git a/test/test_overrides.py b/test/test_overrides.py
@@ -940,8 +940,6 @@ def _simple_type_parser(func, arg_name, arg_type):
                 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":
diff --git a/tools/autograd/load_derivatives.py b/tools/autograd/load_derivatives.py
@@ -969,7 +969,7 @@ def repl(m: re.Match[str]) -> str:
         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,
             )
 
diff --git a/torch/csrc/utils/python_arg_parser.cpp b/torch/csrc/utils/python_arg_parser.cpp
@@ -46,7 +46,6 @@ 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},
diff --git a/torchgen/api/python.py b/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 "c10::string_view"
+            return "std::string_view"
         elif t.name in [
             BaseTy.Tensor,
             BaseTy.bool,
diff --git a/torchgen/api/types/types.py b/torchgen/api/types/types.py
@@ -52,7 +52,7 @@
 float8_e4m3fnT = BaseCppType("at", "Float8_e4m3fn")
 float8_e4m3fnuzT = BaseCppType("at", "Float8_e4m3fnuz")
 float8_e8m0fnuT = BaseCppType("at", "Float8_e8m0fnu")
-stringT = BaseCppType("c10", "string_view")
+stringT = BaseCppType("std", "string_view")
 generatorT = BaseCppType("at", "Generator")
 scalarTypeT = BaseCppType("at", "ScalarType")
 tensorT = BaseCppType("at", "Tensor")
diff --git a/torchgen/api/types/types_base.py b/torchgen/api/types/types_base.py
@@ -81,6 +81,8 @@ class BaseCType(CType):
     type: BaseCppType
 
     def cpp_type(self, *, strip_ref: bool = False) -> str:
+        if self.type.ns == "std":
+            return "::" + str(self.type)
         return str(self.type)
 
     def remove_const_ref(self) -> CType:
diff --git a/torchgen/dest/lazy_ir.py b/torchgen/dest/lazy_ir.py
@@ -256,7 +256,7 @@ def gen(self, schema: LazyIrSchema) -> list[str]:
             [
                 # 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() == "::std::optional<c10::string_view>"
+                if a.lazy_type.cpp_type() == "::std::optional<::std::string_view>"
                 else f"{a.name}({a.name})"
                 for a in scalar_args
             ]
@@ -266,9 +266,9 @@ def gen(self, schema: LazyIrSchema) -> list[str]:
         scalar_decls = "\n  ".join(
             [
                 f"std::string {a.name};"
-                if a.lazy_type.cpp_type() == "c10::string_view"
+                if a.lazy_type.cpp_type() == "::std::string_view"
                 else f"::std::optional<std::string> {a.name};"
-                if a.lazy_type.cpp_type() == "::std::optional<c10::string_view>"
+                if a.lazy_type.cpp_type() == "::std::optional<::std::string_view>"
                 else f"{a.lazy_type.cpp_type()} {a.name};"
                 for a in scalar_args
             ]
diff --git a/torchgen/static_runtime/generator.py b/torchgen/static_runtime/generator.py
@@ -323,8 +323,7 @@ def ivalue_type_conversion_method(
         ),
         BaseTy.str: (
             (False, "toStringView()"),
-            (False, "toOptional<c10::string_view>()"),
-            (False, "toOptional<::std::string_view>()"),
+            (False, "toOptional<std::string_view>()"),
         ),
     }
 

Original file line number	Diff line number	Diff line change
`@@ -969,7 +969,7 @@ def repl(m: re.Match[str]) -> str:`
`969`	`969`	`if nctype.type == OptionalCType(BaseCType(stringT)):`
`970`	`970`	`formula = re.sub(`
`971`	`971`	`rf"\b{name}\b",`
`972`		`- f"{name}.has_value() ? std::optional<std::string_view>({name}.value()) : std::nullopt",`
	`972`	`+ f"{name}.has_value() ? std::optional<::std::string_view>({name}.value()) : std::nullopt",`
`973`	`973`	`formula,`
`974`	`974`	`)`
`975`	`975`
Original file line number	Diff line number	Diff line change
`@@ -256,7 +256,7 @@ def gen(self, schema: LazyIrSchema) -> list[str]:`
`256`	`256`	`[`
`257`	`257`	`# This code is just special casing the mapping from string_view -> strings`
`258`	`258`	`f"{a.name}({a.name}.has_value() ? ::std::make_optional(std::string(*{a.name})) : ::std::nullopt)"`
`259`		`- if a.lazy_type.cpp_type() == "::std::optional<c10::string_view>"`
	`259`	`+ if a.lazy_type.cpp_type() == "::std::optional<::std::string_view>"`
`260`	`260`	`else f"{a.name}({a.name})"`
`261`	`261`	`for a in scalar_args`
`262`	`262`	`]`
`@@ -266,9 +266,9 @@ def gen(self, schema: LazyIrSchema) -> list[str]:`
`266`	`266`	`scalar_decls = "\n ".join(`
`267`	`267`	`[`
`268`	`268`	`f"std::string {a.name};"`
`269`		`- if a.lazy_type.cpp_type() == "c10::string_view"`
	`269`	`+ if a.lazy_type.cpp_type() == "::std::string_view"`
`270`	`270`	`else f"::std::optional<std::string> {a.name};"`
`271`		`- if a.lazy_type.cpp_type() == "::std::optional<c10::string_view>"`
	`271`	`+ if a.lazy_type.cpp_type() == "::std::optional<::std::string_view>"`
`272`	`272`	`else f"{a.lazy_type.cpp_type()} {a.name};"`
`273`	`273`	`for a in scalar_args`
`274`	`274`	`]`
Original file line number	Diff line number	Diff line change
`@@ -323,8 +323,7 @@ def ivalue_type_conversion_method(`
`323`	`323`	`),`
`324`	`324`	`BaseTy.str: (`
`325`	`325`	`(False, "toStringView()"),`
`326`		`- (False, "toOptional<c10::string_view>()"),`
`327`		`- (False, "toOptional<::std::string_view>()"),`
	`326`	`+ (False, "toOptional<std::string_view>()"),`
`328`	`327`	`),`
`329`	`328`	`}`
`330`	`329`