chore: import upstream snapshot with attribution

python/tvm/support/clang.py

@@ -0,0 +1,110 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""Util to invoke clang in the system."""
+
+# pylint: disable=invalid-name
+import subprocess
+
+import tvm.target
+
+from . import utils
+
+
+def find_clang(required=True):
+    """Find clang in system.
+
+    Parameters
+    ----------
+    required : bool
+        Whether it is required,
+        runtime error will be raised if the compiler is required.
+
+    Returns
+    -------
+    valid_list : list of str
+        List of possible paths.
+
+    Note
+    ----
+    This function will first search clang that
+    matches the major llvm version that built with tvm
+    """
+    cc_list = []
+    major = tvm.target.codegen.llvm_version_major(allow_none=True)
+    if major is not None:
+        cc_list += [f"clang-{major}.0"]
+        cc_list += [f"clang-{major}"]
+    cc_list += ["clang"]
+    cc_list += ["clang.exe"]
+    valid_list = [utils.which(x) for x in cc_list]
+    valid_list = [x for x in valid_list if x]
+    if not valid_list and required:
+        raise RuntimeError("cannot find clang, candidates are: " + str(cc_list))
+    return valid_list
+
+
+def create_llvm(inputs, output=None, options=None, cc=None):
+    """Create llvm text ir.
+
+    Parameters
+    ----------
+    inputs : list of str
+        List of input files name or code source.
+
+    output : str, optional
+        Output file, if it is none
+        a temporary file is created
+
+    options : list
+        The list of additional options string.
+
+    cc : str, optional
+        The clang compiler, if not specified,
+        we will try to guess the matched clang version.
+
+    Returns
+    -------
+    code : str
+        The generated llvm text IR.
+    """
+    cc = cc if cc else find_clang()[0]
+    cmd = [cc]
+    cmd += ["-S", "-emit-llvm"]
+    temp = utils.tempdir()
+    output = output if output else temp.relpath("output.ll")
+    inputs = [inputs] if isinstance(inputs, str) else inputs
+    input_files = []
+    for i, code in enumerate(inputs):
+        if utils.is_source_path(code):
+            input_files.append(code)
+        else:
+            temp_path = temp.relpath(f"input{i}.cc")
+            with open(temp_path, "w") as output_file:
+                output_file.write(code)
+            input_files.append(temp_path)
+    if options:
+        cmd += options
+    cmd += ["-o", output]
+    cmd += input_files
+    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+    (out, _) = proc.communicate()
+    if proc.returncode != 0:
+        msg = "Compilation error:\n"
+        msg += out.decode("utf-8", errors="replace")
+        raise RuntimeError(msg)
+
+    return open(output).read()