Implement -fsemantic-interposition
First attempt at implementing -fsemantic-interposition.
Rely on GlobalValue::isInterposable that already captures most of the expected
behavior.
Rely on a ModuleFlag to state whether we should respect SemanticInterposition or
not. The default remains no.
So this should be a no-op if -fsemantic-interposition isn't used, and if it is,
isInterposable being already used in most optimisation, they should honor it
properly.
Note that it only impacts architecture compiled with -fPIC and no pie.
Differential Revision: https://reviews.llvm.org/D72829
diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst
index eb05199..24c8ee2 100644
--- a/clang/docs/ClangCommandLineReference.rst
+++ b/clang/docs/ClangCommandLineReference.rst
@@ -904,6 +904,12 @@
Turn on runtime checks for various forms of undefined or suspicious behavior. See user manual for available checks
+.. option:: -fno-semantic-interposition, -fsemantic-interposition
+
+Enable semantic interposition. Semantic interposition allows for the
+interposition of a symbol by another at runtime, thus preventing a range of
+inter-procedural optimisation.
+
.. option:: -moutline, -mno-outline
Enable function outlining (AArch64 only)