[libc][hdrgen] Sort identifiers with leading underscores specially

libc/include/locale.yaml

@@ -1,7 +1,7 @@
 header: locale.h
 header_template: locale.h.def
 macros:
-  - macro_name: NULL
+  - macro_name: "NULL"
     macro_header: null-macro.h
 types:
   - type_name: locale_t

libc/include/stdio.yaml

@@ -1,7 +1,7 @@
 header: stdio.h
 header_template: stdio.h.def
 macros:
-  - macro_name: NULL
+  - macro_name: "NULL"
     macro_header: null-macro.h
   - macro_name: stdout
     macro_value: stdout

libc/include/stdlib.yaml

@@ -5,7 +5,7 @@ standards:
 merge_yaml_files:
   - stdlib-malloc.yaml
 macros:
-  - macro_name: NULL
+  - macro_name: "NULL"
     macro_header: null-macro.h
 types:
   - type_name: __atexithandler_t

libc/include/string.yaml

@@ -2,7 +2,7 @@ header: string.h
 standards:
   - stdc
 macros:
-  - macro_name: NULL
+  - macro_name: "NULL"
     macro_header: null-macro.h
 types:
   - type_name: locale_t

libc/include/time.yaml

@@ -1,7 +1,7 @@
 header: time.h
 header_template: time.h.def
 macros:
-  - macro_name: NULL
+  - macro_name: "NULL"
     macro_header: null-macro.h
 types:
   - type_name: struct_timeval

libc/include/wchar.yaml

@@ -1,7 +1,7 @@
 header: wchar.h
 header_template: wchar.h.def
 macros:
-  - macro_name: NULL
+  - macro_name: "NULL"
     macro_header: null-macro.h
 types:
   - type_name: FILE
@@ -188,8 +188,8 @@ functions:
     standards:
       - stdc
     return_type: wchar_t *
-    arguments: 
-      - type: wchar_t *__restrict 
+    arguments:
+      - type: wchar_t *__restrict
       - type: const wchar_t *__restrict
       - type: size_t
   - name: wmemmove
@@ -212,7 +212,7 @@ functions:
     standards:
       - stdc
     return_type: wchar_t *
-    arguments: 
+    arguments:
       - type: wchar_t *__restrict
       - type: const wchar_t *__restrict
   - name: wcslcat

libc/utils/hdrgen/hdrgen/enumeration.py

@@ -6,24 +6,14 @@
 #
 # ==-------------------------------------------------------------------------==#
 
-from functools import total_ordering
+from hdrgen.symbol import Symbol
 
 
-@total_ordering
-class Enumeration:
+class Enumeration(Symbol):
     def __init__(self, name, value):
-        self.name = name
+        super().__init__(name)
         self.value = value
 
-    def __eq__(self, other):
-        return self.name == other.name
-
-    def __lt__(self, other):
-        return self.name < other.name
-
-    def __hash__(self):
-        return self.name.__hash__()
-
     def __str__(self):
         if self.value != None:
             return f"{self.name} = {self.value}"

libc/utils/hdrgen/hdrgen/function.py

@@ -7,7 +7,7 @@
 # ==-------------------------------------------------------------------------==#
 
 import re
-from functools import total_ordering
+from hdrgen.symbol import Symbol
 from hdrgen.type import Type
 
 
@@ -37,14 +37,13 @@
 NONIDENTIFIER = re.compile("[^a-zA-Z0-9_]+")
 
 
-@total_ordering
-class Function:
+class Function(Symbol):
     def __init__(
         self, return_type, name, arguments, standards, guard=None, attributes=[]
     ):
+        super().__init__(name)
         assert return_type
         self.return_type = return_type
-        self.name = name
         self.arguments = [
             arg if isinstance(arg, str) else arg["type"] for arg in arguments
         ]
@@ -53,15 +52,6 @@ def __init__(
         self.guard = guard
         self.attributes = attributes or []
 
-    def __eq__(self, other):
-        return self.name == other.name
-
-    def __lt__(self, other):
-        return self.name < other.name
-
-    def __hash__(self):
-        return self.name.__hash__()
-
     def signature_types(self):
         def collapse(type_string):
             assert type_string

libc/utils/hdrgen/hdrgen/header.py

@@ -147,8 +147,8 @@ def includes(self):
             }
             | {
                 COMPILER_HEADER_TYPES.get(
-                    typ.type_name,
-                    PurePosixPath("llvm-libc-types") / f"{typ.type_name}.h",
+                    typ.name,
+                    PurePosixPath("llvm-libc-types") / f"{typ.name}.h",
                 )
                 for typ in self.all_types()
             }
@@ -227,7 +227,7 @@ def relpath(file):
             )
         ]
 
-        for macro in self.macros:
+        for macro in sorted(self.macros):
             # When there is nothing to define, the Macro object converts to str
             # as an empty string.  Don't emit a blank line for those cases.
             if str(macro):
@@ -242,7 +242,12 @@ def relpath(file):
         content.append("\n__BEGIN_C_DECLS\n")
 
         current_guard = None
-        for function in self.functions:
+        last_name = None
+        for function in sorted(self.functions):
+            # If the last function's name was the same after underscores,
+            # elide the blank line between the declarations.
+            if last_name == function.name_without_underscores():
+                content.pop()
             if function.guard == None and current_guard == None:
                 content.append(str(function) + " __NOEXCEPT;")
                 content.append("")
@@ -264,6 +269,7 @@ def relpath(file):
                         content.append(f"#ifdef {current_guard}")
                     content.append(str(function) + " __NOEXCEPT;")
                     content.append("")
+            last_name = function.name_without_underscores()
         if current_guard != None:
             content.pop()
             content.append(f"#endif // {current_guard}")

libc/utils/hdrgen/hdrgen/macro.py

@@ -6,25 +6,15 @@
 #
 # ==-------------------------------------------------------------------------==#
 
-from functools import total_ordering
+from hdrgen.symbol import Symbol
 
 
-@total_ordering
-class Macro:
+class Macro(Symbol):
     def __init__(self, name, value=None, header=None):
-        self.name = name
+        super().__init__(name)
         self.value = value
         self.header = header
 
-    def __eq__(self, other):
-        return self.name == other.name
-
-    def __lt__(self, other):
-        return self.name < other.name
-
-    def __hash__(self):
-        return self.name.__hash__()
-
     def __str__(self):
         if self.header != None:
             return ""

libc/utils/hdrgen/hdrgen/main.py

@@ -105,6 +105,7 @@ def merge_from(paths):
                 return 2
             header.merge(merge_from_header)
 
+        assert header.name, f"`header: name.h` line is required in {yaml_file}"
         return header
 
     if args.json:

libc/utils/hdrgen/hdrgen/object.py

@@ -6,23 +6,13 @@
 #
 # ==-------------------------------------------------------------------------==#
 
-from functools import total_ordering
+from hdrgen.symbol import Symbol
 
 
-@total_ordering
-class Object:
+class Object(Symbol):
     def __init__(self, name, type):
-        self.name = name
+        super().__init__(name)
         self.type = type
 
-    def __eq__(self, other):
-        return self.name == other.name
-
-    def __lt__(self, other):
-        return self.name < other.name
-
-    def __hash__(self):
-        return self.name.__hash__()
-
     def __str__(self):
         return f"extern {self.type} {self.name};"

libc/utils/hdrgen/hdrgen/symbol.py

@@ -0,0 +1,41 @@
+# ====-- Symbol class for libc function headers----------------*- python -*--==#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+# ==-------------------------------------------------------------------------==#
+
+from functools import total_ordering
+
+
+@total_ordering
+class Symbol:
+    """
+    Symbol is the common superclass for each kind of entity named by an
+    identifier.  It provides the name field, and defines sort ordering,
+    hashing, and equality based only on the name.  The sorting is pretty
+    presentation order for identifiers, which is to say it first sorts
+    lexically but ignores leading underscores and secondarily sorts with the
+    fewest underscores first.
+    """
+
+    def __init__(self, name):
+        assert name
+        self.name = name
+
+    def __eq__(self, other):
+        return self.name == other.name
+
+    def __hash__(self):
+        return self.name.__hash__()
+
+    def name_without_underscores(self):
+        return self.name.lstrip("_")
+
+    def name_sort_key(self):
+        ident = self.name_without_underscores()
+        return ident, len(self.name) - len(ident)
+
+    def __lt__(self, other):
+        return self.name_sort_key() < other.name_sort_key()

libc/utils/hdrgen/hdrgen/type.py

@@ -6,20 +6,10 @@
 #
 # ==-------------------------------------------------------------------------==#
 
-from functools import total_ordering
+from hdrgen.symbol import Symbol
 
 
-@total_ordering
-class Type:
-    def __init__(self, type_name):
-        assert type_name
-        self.type_name = type_name
-
-    def __eq__(self, other):
-        return self.type_name == other.type_name
-
-    def __lt__(self, other):
-        return self.type_name < other.type_name
-
-    def __hash__(self):
-        return self.type_name.__hash__()
+class Type(Symbol):
+    # A type so far carries no specific information beyond its name.
+    def __init__(self, name):
+        super().__init__(name)

libc/utils/hdrgen/tests/expected_output/sorting.h

@@ -0,0 +1,24 @@
+//===-- Standard C header <sorting.h> --===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===---------------------------------------------------------------------===//
+
+#ifndef _LLVM_LIBC_SORTING_H
+#define _LLVM_LIBC_SORTING_H
+
+#include "__llvm-libc-common.h"
+
+__BEGIN_C_DECLS
+
+void func_with_aliases(int) __NOEXCEPT;
+void _func_with_aliases(int) __NOEXCEPT;
+void __func_with_aliases(int) __NOEXCEPT;
+
+void gunk(const char *) __NOEXCEPT;
+
+__END_C_DECLS
+
+#endif // _LLVM_LIBC_SORTING_H

libc/utils/hdrgen/tests/input/sorting.yaml

@@ -0,0 +1,20 @@
+header: sorting.h
+standards:
+  - stdc
+functions:
+  - name: gunk
+    return_type: void
+    arguments:
+      - type: const char *
+  - name: _func_with_aliases
+    return_type: void
+    arguments:
+      - type: int
+  - name: func_with_aliases
+    return_type: void
+    arguments:
+      - type: int
+  - name: __func_with_aliases
+    return_type: void
+    arguments:
+      - type: int

libc/utils/hdrgen/tests/test_integration.py

@@ -75,6 +75,13 @@ def test_generate_json(self):
 
         self.compare_files(output_file, expected_output_file)
 
+    def test_sorting(self):
+        yaml_file = self.source_dir / "input" / "sorting.yaml"
+        expected_output_file = self.source_dir / "expected_output" / "sorting.h"
+        output_file = self.output_dir / "sorting.h"
+        self.run_script(yaml_file, output_file)
+        self.compare_files(output_file, expected_output_file)
+
 
 def main():
     parser = argparse.ArgumentParser(description="TestHeaderGenIntegration arguments")