[COMMITTED] ada: hardcfr: optionally disable in leaf functions
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Commit Message
From: Alexandre Oliva <oliva@adacore.com>
Document -fhardcfr-skip-leaf.
gcc/ada/
* doc/gnat_rm/security_hardening_features.rst (Control Flow
Hardening): Document -fhardcfr-skip-leaf.
* gnat_rm.texi: Regenerate.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/doc/gnat_rm/security_hardening_features.rst | 5 +++++
gcc/ada/gnat_rm.texi | 5 +++++
2 files changed, 10 insertions(+)
@@ -369,6 +369,11 @@ basic blocks take note as control flows through them, and, before
returning, subprograms verify that the taken notes are consistent with
the control-flow graph.
+The performance impact of verification on leaf subprograms can be much
+higher, while the averted risks are much lower on them.
+Instrumentation can be disabled for leaf subprograms with
+:switch:`-fhardcfr-skip-leaf`.
+
Functions with too many basic blocks, or with multiple return points,
call a run-time function to perform the verification. Other functions
perform the verification inline before returning.
@@ -29515,6 +29515,11 @@ basic blocks take note as control flows through them, and, before
returning, subprograms verify that the taken notes are consistent with
the control-flow graph.
+The performance impact of verification on leaf subprograms can be much
+higher, while the averted risks are much lower on them.
+Instrumentation can be disabled for leaf subprograms with
+@code{-fhardcfr-skip-leaf}.
+
Functions with too many basic blocks, or with multiple return points,
call a run-time function to perform the verification. Other functions
perform the verification inline before returning.