From 667c8e33270e267c764202021c350ef2d5d861e7 Mon Sep 17 00:00:00 2001
From: Alexandre Oliva <oliva@adacore.com>
Date: Mon, 25 Jan 2021 21:45:58 -0300
Subject: [PATCH] skip asan-poisoning of discarded vars
GNAT may create temporaries to hold return values of function calls.
If such a temporary is created as part of a dynamic initializer of a
variable in a unit other than the one being compiled, the initializer
is dropped, including the temporary and its binding block.
Don't issue asan mark calls for such variables, they are gone.
for gcc/ChangeLog
* gimplify.c (gimplify_decl_expr): Skip asan marking calls for
temporaries not seen in binding block, and not about to be
added as gimple variables.
for gcc/testsuite/ChangeLog
* gnat.dg/asan1.adb: New test.
* gnat.dg/asan1_pkg.ads: New additional source.
---
gcc/gimplify.c | 8 +++++++-
gcc/testsuite/gnat.dg/asan1.adb | 15 +++++++++++++++
gcc/testsuite/gnat.dg/asan1_pkg.ads | 9 +++++++++
3 files changed, 31 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gnat.dg/asan1.adb
create mode 100644 gcc/testsuite/gnat.dg/asan1_pkg.ads
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index d2ac5f913593..95d55bb8ba4c 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -1795,7 +1795,13 @@ gimplify_decl_expr (tree *stmt_p, gimple_seq *seq_p)
&& !DECL_HAS_VALUE_EXPR_P (decl)
&& DECL_ALIGN (decl) <= MAX_SUPPORTED_STACK_ALIGNMENT
&& dbg_cnt (asan_use_after_scope)
- && !gimplify_omp_ctxp)
+ && !gimplify_omp_ctxp
+ /* GNAT introduces temporaries to hold return values of calls in
+ initializers of variables defined in other units, so the
+ declaration of the variable is discarded completely. We do not
+ want to issue poison calls for such dropped variables. */
+ && (DECL_SEEN_IN_BIND_EXPR_P (decl)
+ || (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)))
{
asan_poisoned_variables->add (decl);
asan_poison_variable (decl, false, seq_p);
diff --git a/gcc/testsuite/gnat.dg/asan1.adb b/gcc/testsuite/gnat.dg/asan1.adb
new file mode 100644
index 000000000000..a4bc59a9a214
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/asan1.adb
@@ -0,0 +1,15 @@
+-- { dg-do compile }
+-- { dg-additional-sources asan1_pkg.ads }
+-- { dg-options "-fsanitize=address" }
+-- { dg-skip-if "" no_fsanitize_address }
+
+with Asan1_Pkg;
+
+procedure Asan1 is
+ use Asan1_Pkg;
+
+ X, Y : E;
+begin
+ X := C (N);
+ Y := V;
+end Asan1;
diff --git a/gcc/testsuite/gnat.dg/asan1_pkg.ads b/gcc/testsuite/gnat.dg/asan1_pkg.ads
new file mode 100644
index 000000000000..fbbc1c5e7f5b
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/asan1_pkg.ads
@@ -0,0 +1,9 @@
+package Asan1_Pkg is
+ subtype E is Integer;
+ type T is array (1..32) of E;
+
+ function N return T;
+ function C (P : T) return E;
+
+ V : constant E := C (N);
+end Asan1_Pkg;
--
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