[libc] added grouping of guarded functions in header generation

[RoseZhang03]

Instead of #ifdef guards for each individual function, #ifdef and #endif
will surround all functions that have the same guard.

[llvmbot]

@llvm/pr-subscribers-libc

Author: None (RoseZhang03)

Changes

Instead of #ifdef guards for each individual function, #ifdef and #endif
will surround all functions that have the same guard.

---

Full diff: https://github.com/llvm/llvm-project/pull/98532.diff

2 Files Affected:

• (modified) libc/newhdrgen/class_implementation/classes/function.py (-2)
• (modified) libc/newhdrgen/header.py (+27-1)

diff --git a/libc/newhdrgen/class_implementation/classes/function.py b/libc/newhdrgen/class_implementation/classes/function.py
index da26358e74506..ea5e8223a538e 100644
--- a/libc/newhdrgen/class_implementation/classes/function.py
+++ b/libc/newhdrgen/class_implementation/classes/function.py
@@ -29,6 +29,4 @@ def __str__(self):
             result = f"{self.return_type} {self.name}({arguments_str}) __NOEXCEPT;"
         else:
             result = f"{attributes_str} {self.return_type} {self.name}({arguments_str}) __NOEXCEPT;"
-        if self.guard:
-            result = f"#ifdef {self.guard}\n{result}\n#endif // {self.guard}"
         return result
diff --git a/libc/newhdrgen/header.py b/libc/newhdrgen/header.py
index d9e9c68dfc5f4..eb8199550ba33 100644
--- a/libc/newhdrgen/header.py
+++ b/libc/newhdrgen/header.py
@@ -57,9 +57,35 @@ def __str__(self):
 
         content.append("\n__BEGIN_C_DECLS\n")
 
+        current_guard = None
         for function in self.functions:
-            content.append(str(function))
+            # due to sorting, all guarded functions will be at the end
+            if function.guard == None:
+                content.append(str(function))
+                content.append("")
+            else:
+                if current_guard == None:
+                    current_guard = function.guard
+                    content.append(f"#ifdef {current_guard}")
+                    content.append(str(function))
+                    content.append("")
+                elif current_guard == function.guard:
+                    content.append(str(function))
+                    content.append("")
+                else:
+                    content.pop()
+                    content.append(f"#endif // {current_guard}")
+                    content.append("")
+                    current_guard = function.guard
+                    content.append(f"#ifdef {current_guard}")
+                    content.append(str(function))
+                    content.append("")
+        if current_guard != None:
+            content.pop()
+            content.append(f"#endif // {current_guard}")
             content.append("")
+                                        
+
         for object in self.objects:
             content.append(str(object))
         content.append("__END_C_DECLS")

[github-actions]

⚠️ Python code formatter, darker found issues in your code. ⚠️

You can test this locally with the following command:

darker --check --diff -r ac304d5ffdea7676582e987f75caeba33355a5dd...da8c625ae8da7ebf7bf8e0162e4deee9b624a19a libc/newhdrgen/class_implementation/classes/function.py libc/newhdrgen/header.py

View the diff from darker here.

--- header.py	2024-07-12 17:39:26.000000 +0000
+++ header.py	2024-07-12 17:43:16.762413 +0000
@@ -80,11 +80,11 @@
                     content.append(str(function))
                     content.append("")
         if current_guard != None:
             content.pop()
             content.append(f"#endif // {current_guard}")
-            content.append("")      
+            content.append("")
 
         for object in self.objects:
             content.append(str(object))
         if self.objects:
             content.append("\n__END_C_DECLS")

[aaryanshukla]

if this has been tested on guarded files then LGTM!

[michaelrj-google]

LGTM

[michaelrj-google]

This code looks good, but you should add tests to check that it works before landing it