Use std::string_view, remove experimental or pre-14 variants, NFC (#12460)

Author: Krzysztof Parzyszek

include/tvm/runtime/container/string.h

@@ -36,36 +36,9 @@
 #include <initializer_list>
 #include <memory>
 #include <string>
-#include <unordered_map>
-#include <utility>
-// We use c++14 std::experimental::string_view for optimizing hash computation
-// only right now, its usage is limited in this file. Any broader usage of
-// std::experiment in our core codebase is discouraged and needs community
-// discussion for each use case. Reference for feature test macros of
-// string_view:
-// https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations
-// https://en.cppreference.com/w/User:D41D8CD98F/feature_testing_macros
-#if defined(__cpp_lib_experimental_string_view) && __cpp_lib_experimental_string_view >= 201411
-#define TVM_USE_CXX14_STRING_VIEW_HASH 1
-#else
-#define TVM_USE_CXX14_STRING_VIEW_HASH 0
-#endif
-
-// Tested with clang version 9.0.1 and c++17. It will detect string_view support
-// correctly.
-#if defined(__cpp_lib_string_view) && __cpp_lib_string_view >= 201606
-#define TVM_USE_CXX17_STRING_VIEW_HASH 1
-#else
-#define TVM_USE_CXX17_STRING_VIEW_HASH 0
-#endif
-
-#if TVM_USE_CXX17_STRING_VIEW_HASH
 #include <string_view>
-#elif TVM_USE_CXX14_STRING_VIEW_HASH
-#include <experimental/string_view>
-#endif
-
 #include <type_traits>
+#include <unordered_map>
 #include <utility>
 #include <vector>
 
@@ -277,13 +250,7 @@ class String : public ObjectRef {
   static size_t HashBytes(const char* data, size_t size) {
     // This function falls back to string copy with c++11 compiler and is
     // recommended to be compiled with c++14
-#if TVM_USE_CXX17_STRING_VIEW_HASH
     return std::hash<std::string_view>()(std::string_view(data, size));
-#elif TVM_USE_CXX14_STRING_VIEW_HASH
-    return std::hash<std::experimental::string_view>()(std::experimental::string_view(data, size));
-#else
-    return std::hash<std::string>()(std::string(data, size));
-#endif
   }
 
   TVM_DEFINE_NOTNULLABLE_OBJECT_REF_METHODS(String, ObjectRef, StringObj);

python/setup.py

@@ -122,7 +122,10 @@ def config_cython():
         if os.name == "nt":
             library_dirs = ["tvm", "../build/Release", "../build"]
             libraries = ["tvm"]
-            extra_compile_args = None
+            extra_compile_args = [
+                "/std:c++17",
+                "/D DMLC_USE_LOGGING_LIBRARY=<tvm/runtime/logging.h>",
+            ]
             # library is available via conda env.
             if CONDA_BUILD:
                 library_dirs = [os.environ["LIBRARY_LIB"]]

python/tvm/contrib/cutlass/build.py

@@ -62,7 +62,7 @@ def _get_cutlass_compile_options(sm, threads, use_fast_math=False):
         "-Xcompiler=-Wconversion",
         "-Xcompiler=-fno-strict-aliasing",
         "-O3",
-        "-std=c++14",
+        "-std=c++17",
         "-I" + cutlass_include,
         "-I" + cutlass_util_include,
     ]

python/tvm/contrib/emcc.py

@@ -41,7 +41,7 @@ def create_tvmjs_wasm(output, objects, options=None, cc="emcc"):
     cmd = [cc]
     cmd += ["-O3"]
 
-    cmd += ["-std=c++14"]
+    cmd += ["-std=c++17"]
     cmd += ["--no-entry"]
     cmd += ["-s", "ERROR_ON_UNDEFINED_SYMBOLS=0"]
     cmd += ["-s", "STANDALONE_WASM=1"]

python/tvm/rpc/minrpc.py

@@ -67,7 +67,7 @@ def with_minrpc(compile_func, server="posix_popen_server", runtime="libtvm"):
     runtime_path = libinfo.find_lib_path([runtime, runtime + ".so", runtime + ".dylib"])[0]
 
     runtime_dir = os.path.abspath(os.path.dirname(runtime_path))
-    options = ["-std=c++14"]
+    options = ["-std=c++17"]
     # Make sure the rpath to the libtvm is set so we can do local tests.
     # Note that however, this approach won't work on remote.
     # Always recommend to to link statically.

tests/python/relay/test_pass_annotate_target.py

@@ -41,7 +41,7 @@ def update_lib(lib):
         contrib_path = os.path.join(source_dir, "src", "runtime", "contrib")
 
         kwargs = {}
-        kwargs["options"] = ["-O2", "-std=c++14", "-I" + contrib_path]
+        kwargs["options"] = ["-O2", "-std=c++17", "-I" + contrib_path]
         tmp_path = utils.tempdir()
         lib_name = "lib.so"
         lib_path = tmp_path.relpath(lib_name)

tests/python/relay/test_pass_partition_graph.py

@@ -142,7 +142,7 @@ def update_lib(lib):
         contrib_path = os.path.join(source_dir, "src", "runtime", "contrib")
 
         kwargs = {}
-        kwargs["options"] = ["-O2", "-std=c++14", "-I" + contrib_path]
+        kwargs["options"] = ["-O2", "-std=c++17", "-I" + contrib_path]
         tmp_path = utils.tempdir()
         lib_name = "lib.so"
         lib_path = tmp_path.relpath(lib_name)

tests/python/relay/utils/external_codegen.py

@@ -62,7 +62,7 @@ def update_lib(lib):
     contrib_path = os.path.join(source_dir, "src", "runtime", "contrib")
 
     kwargs = {}
-    kwargs["options"] = ["-O2", "-std=c++14", "-I" + contrib_path]
+    kwargs["options"] = ["-O2", "-std=c++17", "-I" + contrib_path]
     tmp_path = utils.tempdir()
     lib_name = "lib.so"
     lib_path = tmp_path.relpath(lib_name)

tests/python/unittest/test_runtime_module_export.py

@@ -202,7 +202,7 @@ def verify_multi_c_mod_export():
         path_lib = temp.relpath(file_name)
         synthetic_cpu_lib.import_module(f)
         synthetic_cpu_lib.import_module(engine_module)
-        kwargs = {"options": ["-O2", "-std=c++14", "-I" + header_file_dir_path.relpath("")]}
+        kwargs = {"options": ["-O2", "-std=c++17", "-I" + header_file_dir_path.relpath("")]}
         synthetic_cpu_lib.export_library(path_lib, fcompile=False, **kwargs)
         loaded_lib = tvm.runtime.load_module(path_lib)
         assert loaded_lib.type_key == "library"