c++: section attribute on templates [PR70435, PR88061]

The section attribute currently has no effect on templates because the
call to set_decl_section_name only happens at parse time (on the
dependent decl) and not also at instantiation time.  This patch fixes
this by propagating the section name from the template to the
instantiation.

	PR c++/70435
	PR c++/88061

gcc/cp/ChangeLog:

	* pt.cc (tsubst_function_decl): Propagate DECL_SECTION_NAME
	via set_decl_section_name.
	(tsubst_decl) <case VAR_DECL>: Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/ext/attr-section1.C: New test.
	* g++.dg/ext/attr-section1a.C: New test.
	* g++.dg/ext/attr-section2.C: New test.
	* g++.dg/ext/attr-section2a.C: New test.
	* g++.dg/ext/attr-section2b.C: New test.

6 files changed, 59 insertions, 0 deletions

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 50e6f06..a82d7ae 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -14607,6 +14607,8 @@ tsubst_function_decl (tree t, tree args, tsubst_flags_t complain,
 	= remove_attribute ("visibility", DECL_ATTRIBUTES (r));
     }
   determine_visibility (r);
+  if (DECL_SECTION_NAME (t))
+    set_decl_section_name (r, t);
   if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
       && !processing_template_decl)
     defaulted_late_check (r);
@@ -15423,6 +15425,8 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain,
 		  = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
 	      }
 	    determine_visibility (r);
+	    if ((!local_p || TREE_STATIC (t)) && DECL_SECTION_NAME (t))
+	      set_decl_section_name (r, t);
 	  }
 
 	if (!local_p)
diff --git a/gcc/testsuite/g++.dg/ext/attr-section1.C b/gcc/testsuite/g++.dg/ext/attr-section1.C
new file mode 100644
index 0000000..b8ac65b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attr-section1.C
@@ -0,0 +1,9 @@
+// PR c++/70435
+// { dg-do compile { target { c++11 && named_sections } } }
+
+template<class T>
+[[gnu::section(".foo")]] void fun() { }
+
+template void fun<int>();
+
+// { dg-final { scan-assembler {.section[ \t]+.foo} } }
diff --git a/gcc/testsuite/g++.dg/ext/attr-section1a.C b/gcc/testsuite/g++.dg/ext/attr-section1a.C
new file mode 100644
index 0000000..be24be2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attr-section1a.C
@@ -0,0 +1,11 @@
+// PR c++/70435
+// { dg-do compile { target { c++11 && named_sections } } }
+
+template<class T>
+struct A {
+  [[gnu::section(".foo")]] void fun() { }
+};
+
+template struct A<int>;
+
+// { dg-final { scan-assembler {.section[ \t]+.foo} } }
diff --git a/gcc/testsuite/g++.dg/ext/attr-section2.C b/gcc/testsuite/g++.dg/ext/attr-section2.C
new file mode 100644
index 0000000..a76f43b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attr-section2.C
@@ -0,0 +1,9 @@
+// PR c++/88061
+// { dg-do compile { target { c++14 && named_sections } } }
+
+template<class T>
+[[gnu::section(".foo")]] int var = 42;
+
+template int var<int>;
+
+// { dg-final { scan-assembler {.section[ \t]+.foo} } }
diff --git a/gcc/testsuite/g++.dg/ext/attr-section2a.C b/gcc/testsuite/g++.dg/ext/attr-section2a.C
new file mode 100644
index 0000000..a0b01cd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attr-section2a.C
@@ -0,0 +1,14 @@
+// PR c++/88061
+// { dg-do compile { target { c++11 && named_sections } } }
+
+template<class T>
+struct A {
+  [[gnu::section(".foo")]] static int var;
+};
+
+template<class T>
+int A<T>::var = 42;
+
+template struct A<int>;
+
+// { dg-final { scan-assembler {.section[ \t]+.foo} } }
diff --git a/gcc/testsuite/g++.dg/ext/attr-section2b.C b/gcc/testsuite/g++.dg/ext/attr-section2b.C
new file mode 100644
index 0000000..7b8313b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attr-section2b.C
@@ -0,0 +1,12 @@
+// PR c++/88061
+// { dg-do compile { target { c++11 && named_sections } } }
+
+template<class T>
+int* fun() {
+  [[gnu::section(".foo")]] static int var;
+  return &var;
+};
+
+template int* fun<int>();
+
+// { dg-final { scan-assembler {.section[ \t]+.foo} } }