https://gcc.gnu.org/g:ac357a72ddc6d558546fd610739441be3fefd619
commit r16-2338-gac357a72ddc6d558546fd610739441be3fefd619
Author: Marc Poulhiès <poulh...@adacore.com>
Date: Fri Jun 20 16:10:25 2025 +0200
ada: Do not inline function returning on the secondary stack
When inlining function calls that return on the secondary stack used as
function actual or in a return statement, the compiler creates an
invalid GNAT Tree with a variable of an unconstrained type without an
initializer.
Also add an extra assertion to catch problematic cases directly in
Expand_Inlined_Call.
gcc/ada/ChangeLog:
* exp_ch6.adb (Convert): Do not call Expand_Inlined_Call for
unsupported cases.
* inline.adb (Expand_Inlined_Call): Add assert to catch unsupported
case.
Co-authored-by: Eric Botcazou <botca...@adacore.com>
Diff:
---
gcc/ada/exp_ch6.adb | 6 ++++++
gcc/ada/inline.adb | 11 +++++++++++
2 files changed, 17 insertions(+)
diff --git a/gcc/ada/exp_ch6.adb b/gcc/ada/exp_ch6.adb
index c24c8c63ef1f..6ea96d7498a6 100644
--- a/gcc/ada/exp_ch6.adb
+++ b/gcc/ada/exp_ch6.adb
@@ -5227,6 +5227,10 @@ package body Exp_Ch6 is
-- also Build_Renamed_Body) cannot be expanded here because this may
-- give rise to order-of-elaboration issues for the types of the
-- parameters of the subprogram, if any.
+ --
+ -- Expand_Inlined_Call procedure does not support the frontend
+ -- inlining of calls that return unconstrained types used as actuals
+ -- or in return statements.
elsif Present (Unit_Declaration_Node (Subp))
and then Nkind (Unit_Declaration_Node (Subp)) =
@@ -5235,6 +5239,8 @@ package body Exp_Ch6 is
and then
Nkind (Body_To_Inline (Unit_Declaration_Node (Subp))) not in
N_Entity
+ and then Nkind (Parent (N)) /= N_Function_Call
+ and then Nkind (Parent (N)) /= N_Simple_Return_Statement
then
Expand_Inlined_Call (Call_Node, Subp, Orig_Subp);
diff --git a/gcc/ada/inline.adb b/gcc/ada/inline.adb
index e8eeebd2d002..5e2f033b913d 100644
--- a/gcc/ada/inline.adb
+++ b/gcc/ada/inline.adb
@@ -3797,6 +3797,17 @@ package body Inline is
and then Is_Unc;
end if;
+ -- Inlining function calls returning an object of unconstrained type as
+ -- function actuals or in a return statement is not supported: a
+ -- temporary variable will be declared of unconstrained type without
+ -- initializing expression.
+
+ pragma Assert
+ (not Uses_Back_End
+ or else Nkind (Parent (N)) not in
+ N_Function_Call | N_Simple_Return_Statement
+ or else not Is_Unc);
+
-- Check for an illegal attempt to inline a recursive procedure. If the
-- subprogram has parameters this is detected when trying to supply a
-- binding for parameters that already have one. For parameterless
