diff mbox series

[COMMITTED] ada: Fix missing finalization for aggregates nested in conditional expressions

Message ID 20230615080415.939740-1-poulhies@adacore.com
State Committed
Commit 985d6045f66281bd3783523360375431ee343b08
Headers
Series [COMMITTED] ada: Fix missing finalization for aggregates nested in conditional expressions |

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Commit Message

Marc Poulhiès June 15, 2023, 8:04 a.m. UTC 
  From: Eric Botcazou <ebotcazou@adacore.com>

The finalization actions for the components of the aggregates are blocked
by Expand_Ctrl_Function_Call, which sets Is_Ignored_Transient on all the
temporaries generated from within a conditional expression whatever the
intermediate constructs.  Now aggregates and their expansion in the form
of block and loop statements are "impenetrable" as far as temporaries are
concerned, i.e. the lifetime of temporaries generated within them does
not extend beyond them, so their finalization must not be blocked there.

gcc/ada/

	* exp_util.ads (Within_Case_Or_If_Expression): Adjust description.
	* exp_util.adb (Find_Hook_Context): Stop the search for the topmost
	conditional expression, if within one, at contexts where temporaries
	may be contained.
	(Within_Case_Or_If_Expression): Return false upon first encoutering
	contexts where temporaries may be contained.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/exp_util.adb | 20 ++++++++++++++++++++
 gcc/ada/exp_util.ads |  4 +++-
 2 files changed, 23 insertions(+), 1 deletion(-)
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Patch

diff --git a/gcc/ada/exp_util.adb b/gcc/ada/exp_util.adb
index b032336523d..a4aa5f64447 100644
--- a/gcc/ada/exp_util.adb
+++ b/gcc/ada/exp_util.adb
@@ -6500,6 +6500,16 @@  package body Exp_Util is
             then
                Top := Par;
 
+            --  Stop at contexts where temporaries may be contained
+
+            elsif Nkind (Par) in N_Aggregate
+                               | N_Delta_Aggregate
+                               | N_Extension_Aggregate
+                               | N_Block_Statement
+                               | N_Loop_Statement
+            then
+               exit;
+
             --  Prevent the search from going too far
 
             elsif Is_Body_Or_Package_Declaration (Par) then
@@ -14222,6 +14232,16 @@  package body Exp_Util is
          then
             return True;
 
+         --  Stop at contexts where temporaries may be contained
+
+         elsif Nkind (Par) in N_Aggregate
+                            | N_Delta_Aggregate
+                            | N_Extension_Aggregate
+                            | N_Block_Statement
+                            | N_Loop_Statement
+         then
+            return False;
+
          --  Prevent the search from going too far
 
          elsif Is_Body_Or_Package_Declaration (Par) then
diff --git a/gcc/ada/exp_util.ads b/gcc/ada/exp_util.ads
index 66c4dc6be4c..24065b6f7b6 100644
--- a/gcc/ada/exp_util.ads
+++ b/gcc/ada/exp_util.ads
@@ -1240,7 +1240,9 @@  package Exp_Util is
    --  extension to verify legality rules on inherited conditions.
 
    function Within_Case_Or_If_Expression (N : Node_Id) return Boolean;
-   --  Determine whether arbitrary node N is within a case or an if expression
+   --  Determine whether arbitrary node N is immediately within a case or an if
+   --  expression. The criterion is whether temporaries created by the actions
+   --  attached to N need to outlive an enclosing case or if expression.
 
 private
    pragma Inline (Duplicate_Subexpr);