[PATCH] D93422: [LangRef] Update new ssp/sspstrong/sspreq semantics after D91816

[Fangrui Song via Phabricator via llvm-commits]

MaskRay updated this revision to Diff 312531.
MaskRay added a comment.

Clarify


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D93422/new/

https://reviews.llvm.org/D93422

Files:
  llvm/docs/LangRef.rst


Index: llvm/docs/LangRef.rst
===================================================================
--- llvm/docs/LangRef.rst
+++ llvm/docs/LangRef.rst
@@ -1840,13 +1840,14 @@
     Variables that are identified as requiring a protector will be arranged
     on the stack such that they are adjacent to the stack protector guard.
 
-    If a function that has an ``ssp`` attribute is inlined into a
-    function that doesn't have an ``ssp`` attribute, then the resulting
-    function will have an ``ssp`` attribute.
+    A function with the ``ssp`` attribute but without the ``alwaysinline``
+    attribute cannot be inlined into a function without a
+    ``ssp/sspreq/sspstrong`` attribute. If inlined, the caller will get the
+    ``ssp`` attribute.
 ``sspreq``
-    This attribute indicates that the function should *always* emit a
-    stack smashing protector. This overrides the ``ssp`` function
-    attribute.
+    This attribute indicates that the function should *always* emit a stack
+    smashing protector. This overrides the ``ssp`` and ``sspstrong`` function
+    attributes.
 
     Variables that are identified as requiring a protector will be arranged
     on the stack such that they are adjacent to the stack protector guard.
@@ -1859,10 +1860,10 @@
     #. Variables that have had their address taken are 3rd closest to the
        protector.
 
-    If a function that has an ``sspreq`` attribute is inlined into a
-    function that doesn't have an ``sspreq`` attribute or which has an
-    ``ssp`` or ``sspstrong`` attribute, then the resulting function will have
-    an ``sspreq`` attribute.
+    A function with the ``sspreq`` attribute but without the ``alwaysinline``
+    attribute cannot be inlined into a function without a
+    ``ssp/sspstrong/sspreq`` attribute. If inlined, the caller will get the
+    ``sspreq`` attribute.
 ``sspstrong``
     This attribute indicates that the function should emit a stack smashing
     protector. This attribute causes a strong heuristic to be used when
@@ -1887,9 +1888,11 @@
 
     This overrides the ``ssp`` function attribute.
 
-    If a function that has an ``sspstrong`` attribute is inlined into a
-    function that doesn't have an ``sspstrong`` attribute, then the
-    resulting function will have an ``sspstrong`` attribute.
+    A function with the ``sspstrong`` attribute but without the
+    ``alwaysinline`` attribute cannot be inlined into a function without a
+    ``ssp/sspstrong/sspreq`` attribute. If inlined, the caller will get the
+    ``sspstrong`` attribute unless ``sspreq`` exists.
+
 ``strictfp``
     This attribute indicates that the function was called from a scope that
     requires strict floating-point semantics.  LLVM will not attempt any


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