[COMMITTED] ada: Add leafy mode for zero-call-used-regs
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Commit Message
From: Alexandre Oliva <oliva@adacore.com>
Document leafy mode.
gcc/ada/
* doc/gnat_rm/security_hardening_features.rst (Register
Scrubbing): Document leafy mode.
* gnat_rm.texi: Regenerate.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/doc/gnat_rm/security_hardening_features.rst | 6 ++++++
gcc/ada/gnat_rm.texi | 8 +++++++-
2 files changed, 13 insertions(+), 1 deletion(-)
@@ -34,6 +34,12 @@ subprograms.
pragma Machine_Attribute (Bar, "zero_call_used_regs", "all");
-- Before returning, Bar scrubs all call-clobbered registers.
+ function Baz return Integer;
+ pragma Machine_Attribute (Bar, "zero_call_used_regs", "leafy");
+ -- Before returning, Bar scrubs call-clobbered registers, either
+ -- those it uses itself, if it can be identified as a leaf
+ -- function, or all of them otherwise.
+
For usage and more details on the command-line option, on the
``zero_call_used_regs`` attribute, and on their use with other
@@ -19,7 +19,7 @@
@copying
@quotation
-GNAT Reference Manual , Jul 04, 2023
+GNAT Reference Manual , Jul 10, 2023
AdaCore
@@ -29191,6 +29191,12 @@ pragma Machine_Attribute (Foo, "zero_call_used_regs", "used");
function Bar return Integer;
pragma Machine_Attribute (Bar, "zero_call_used_regs", "all");
-- Before returning, Bar scrubs all call-clobbered registers.
+
+function Baz return Integer;
+pragma Machine_Attribute (Bar, "zero_call_used_regs", "leafy");
+-- Before returning, Bar scrubs call-clobbered registers, either
+-- those it uses itself, if it can be identified as a leaf
+-- function, or all of them otherwise.
@end example
For usage and more details on the command-line option, on the