[flang-commits] [flang] 44e8ee7 - [flang][doc] refine zero initialization extension documentation (#121956)

[via flang-commits]

Author: jeanPerier
Date: 2025-01-08T10:56:03+01:00
New Revision: 44e8ee73591bad22ae19748be825c4b66d7b3dde

URL: https://github.com/llvm/llvm-project/commit/44e8ee73591bad22ae19748be825c4b66d7b3dde
DIFF: https://github.com/llvm/llvm-project/commit/44e8ee73591bad22ae19748be825c4b66d7b3dde.diff

LOG: [flang][doc] refine zero initialization extension documentation (#121956)

Following-up on [comments
](https://github.com/llvm/llvm-project/issues/62432#issuecomment-2555316522)
in the issue that motivated this extension.

Added: 
    

Modified: 
    flang/docs/Extensions.md

Removed: 
    


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diff  --git a/flang/docs/Extensions.md b/flang/docs/Extensions.md
index 2d1c967a6068de..907f01204a3871 100644
--- a/flang/docs/Extensions.md
+++ b/flang/docs/Extensions.md
@@ -160,7 +160,11 @@ end
 * `<>` as synonym for `.NE.` and `/=`
 * `$` and `@` as legal characters in names
 * Initialization in type declaration statements using `/values/`
-* Saved variables without explicit or default initializers are zero initialized.
+* Saved variables without explicit or default initializers are zero initialized,
+  except for scalar variables from the main program that are not explicitly
+  initialized or marked with an explicit SAVE attribute (these variables may be
+  placed on the stack by flang and not zero initialized). It is not advised to
+  rely on this extension in new code.
 * In a saved entity of a type with a default initializer, components without default
   values are zero initialized.
 * Kind specification with `*`, e.g. `REAL*4`