[gcc r13-2360] ipa: Fix throw in multi-versioned functions [PR106627]

[gcc r13-2360] ipa: Fix throw in multi-versioned functions [PR106627]

[Richard Biener]

https://gcc.gnu.org/g:0b0a3cdbff64d97e7de3e0e2c26e965708064193

commit r13-2360-g0b0a3cdbff64d97e7de3e0e2c26e965708064193
Author: Simon Rainer <gcc.gnu@vvalter.com>
Date:   Wed Aug 31 23:00:08 2022 +0200

    ipa: Fix throw in multi-versioned functions [PR106627]
    
    Any multi-versioned function was implicitly declared as noexcept, which
    leads to an abort if an exception is thrown inside the function.
    The reason for this is that the function declaration is replaced by a
    newly created dispatcher declaration, which has TREE_NOTHROW always set
    to 1. Instead we need to set TREE_NOTHROW to the value of the original
    declaration.
    
            PR ipa/106627
    
    gcc/ChangeLog:
    
            * config/i386/i386-features.cc (ix86_get_function_versions_dispatcher):
            Set TREE_NOTHROW correctly for dispatcher declaration.
            * config/rs6000/rs6000.cc (rs6000_get_function_versions_dispatcher):
            Likewise.
    
    gcc/testsuite/ChangeLog:
    
            * g++.target/i386/pr106627.C: New test.

Diff:
---
 gcc/config/i386/i386-features.cc         |  1 +
 gcc/config/rs6000/rs6000.cc              |  1 +
 gcc/testsuite/g++.target/i386/pr106627.C | 28 ++++++++++++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc
index d6bb66cbe01..fd212262f50 100644
--- a/gcc/config/i386/i386-features.cc
+++ b/gcc/config/i386/i386-features.cc
@@ -3268,6 +3268,7 @@ ix86_get_function_versions_dispatcher (void *decl)
 
       /* Right now, the dispatching is done via ifunc.  */
       dispatch_decl = make_dispatcher_decl (default_node->decl);
+      TREE_NOTHROW (dispatch_decl) = TREE_NOTHROW (fn);
 
       dispatcher_node = cgraph_node::get_create (dispatch_decl);
       gcc_assert (dispatcher_node != NULL);
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 2f3146e56f8..937954b6351 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -24861,6 +24861,7 @@ rs6000_get_function_versions_dispatcher (void *decl)
 
       /* Right now, the dispatching is done via ifunc.  */
       dispatch_decl = make_dispatcher_decl (default_node->decl);
+      TREE_NOTHROW (dispatch_decl) = TREE_NOTHROW (fn);
 
       dispatcher_node = cgraph_node::get_create (dispatch_decl);
       gcc_assert (dispatcher_node != NULL);
diff --git a/gcc/testsuite/g++.target/i386/pr106627.C b/gcc/testsuite/g++.target/i386/pr106627.C
new file mode 100644
index 00000000000..e993d825f20
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/pr106627.C
@@ -0,0 +1,28 @@
+/* PR c++/103012 Exception handling with multiversioned functions */
+/* { dg-do run } */
+/* { dg-require-ifunc "" }  */
+
+extern "C" void abort (void);
+
+__attribute__((target("default")))
+void f() {
+    throw 1;
+}
+
+__attribute__((target("sse4.2,bmi")))
+void f() {
+    throw 2;
+}
+
+int main()
+{
+    try {
+        f();
+    }
+    catch(...)
+    {
+        return 0;
+    }
+
+    abort ();
+}