testsuite: fix allocator-opt1.C FAIL with old ABI

Running
$ make check-g++ RUNTESTFLAGS='--target_board=unix\{-D_GLIBCXX_USE_CXX11_ABI=0,\} dg.exp=allocator-opt1.C'
yields:

FAIL: g++.dg/tree-ssa/allocator-opt1.C  -std=c++98  scan-tree-dump-times gimple "struct allocator D" 1
FAIL: g++.dg/tree-ssa/allocator-opt1.C  -std=c++14  scan-tree-dump-times gimple "struct allocator D" 1
FAIL: g++.dg/tree-ssa/allocator-opt1.C  -std=c++17  scan-tree-dump-times gimple "struct allocator D" 1
FAIL: g++.dg/tree-ssa/allocator-opt1.C  -std=c++20  scan-tree-dump-times gimple "struct allocator D" 1

		=== g++ Summary for unix/-D_GLIBCXX_USE_CXX11_ABI=0 ===

		=== g++ Summary for unix ===

because in the old ABI we get two "struct allocator D".  This patch
follows r14-658 although I'm not quite sure I follow the logic there.

gcc/testsuite/ChangeLog:

	* g++.dg/tree-ssa/allocator-opt1.C: Force _GLIBCXX_USE_CXX11_ABI to 1.

diff --git a/gcc/testsuite/g++.dg/tree-ssa/allocator-opt1.C b/gcc/testsuite/g++.dg/tree-ssa/allocator-opt1.C
index e8394c7ad702059b65af477144400ac1eef6d7e2..51c470dee372fa516b504399bd0376e01d9aec39 100644 (file)
--- a/gcc/testsuite/g++.dg/tree-ssa/allocator-opt1.C
+++ b/gcc/testsuite/g++.dg/tree-ssa/allocator-opt1.C
@@ -5,8 +5,20 @@
 // Currently the dump doesn't print the allocator template arg in this context.
 // { dg-final { scan-tree-dump-times "struct allocator D" 1 "gimple" } }
 
+// In the pre-C++11 ABI we get two allocator variables.
+#undef _GLIBCXX_USE_CXX11_ABI
+#define _GLIBCXX_USE_CXX11_ABI 1
+
 #include <string>
+
+// When the library is not dual-ABI and defaults to old just compile
+// an empty TU.  NB: We test _GLIBCXX_USE_CXX11_ABI again because the
+// #include above might have undef'd _GLIBCXX_USE_CXX11_ABI.
+#if _GLIBCXX_USE_CXX11_ABI
+
 void f (const char *p)
 {
   std::string lst[] = { p, p, p, p };
 }
+
+#endif