Adapt and integrate string_view tests

The previous patch copied the string_view tests from libstdc++.  This
patch adjusts them in a similar way that the libstdc++ optional tests
are integrated in our unit test suite.

Not all tests are used, some of them require language features not
present in c++11.  For example, we can't use a string_view constructor
where the length is not explicit in a constexpr, because
std::char_traits::length is not a constexpr itself (it is in c++17
though).  Nevertheless, a good number of tests are integrated, which
covers pretty well the string_view features.

gdb/ChangeLog:

	* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
	string_view-selftests.c.
	* unittests/basic_string_view/capacity/1.cc: Adapt to GDB
	testsuite.
	* unittests/basic_string_view/cons/char/1.cc: Likewise.
	* unittests/basic_string_view/cons/char/2.cc: Likewise.
	* unittests/basic_string_view/cons/char/3.cc: Likewise.
	* unittests/basic_string_view/element_access/char/1.cc:
	Likewise.
	* unittests/basic_string_view/element_access/char/empty.cc:
	Likewise.
	* unittests/basic_string_view/element_access/char/front_back.cc:
	Likewise.
	* unittests/basic_string_view/inserters/char/2.cc: Likewise.
	* unittests/basic_string_view/modifiers/remove_prefix/char/1.cc:
	Likewise.
	* unittests/basic_string_view/modifiers/remove_suffix/char/1.cc:
	Likewise.
	* unittests/basic_string_view/modifiers/swap/char/1.cc:
	Likewise.
	* unittests/basic_string_view/operations/compare/char/1.cc:
	Likewise.
	* unittests/basic_string_view/operations/compare/char/13650.cc:
	Likewise.
	* unittests/basic_string_view/operations/copy/char/1.cc:
	Likewise.
	* unittests/basic_string_view/operations/data/char/1.cc:
	Likewise.
	* unittests/basic_string_view/operations/find/char/1.cc:
	Likewise.
	* unittests/basic_string_view/operations/find/char/2.cc:
	Likewise.
	* unittests/basic_string_view/operations/find/char/3.cc:
	Likewise.
	* unittests/basic_string_view/operations/find/char/4.cc:
	Likewise.
	* unittests/basic_string_view/operations/rfind/char/1.cc:
	Likewise.
	* unittests/basic_string_view/operations/rfind/char/2.cc:
	Likewise.
	* unittests/basic_string_view/operations/rfind/char/3.cc:
	Likewise.
	* unittests/basic_string_view/operations/substr/char/1.cc:
	Likewise.
	* unittests/basic_string_view/operators/char/2.cc: Likewise.
	* unittests/string_view-selftests.c: New file.

3 files changed, 19 insertions, 21 deletions

diff --git a/gdb/unittests/basic_string_view/cons/char/1.cc b/gdb/unittests/basic_string_view/cons/char/1.cc
index f80ae92..cfe9cce 100644
--- a/gdb/unittests/basic_string_view/cons/char/1.cc
+++ b/gdb/unittests/basic_string_view/cons/char/1.cc
@@ -19,43 +19,40 @@
 
 // basic_string_view constructors.
 
-#include <string_view>
-#include <string>
-#include <cstring>
-#include <testsuite_hooks.h>
+namespace cons_1 {
 
 void
 test01()
 {
-  typedef std::string_view::size_type csize_type;
+  typedef gdb::string_view::size_type csize_type;
 
   // basic_string_view()
-  const std::string_view str00{};
+  const gdb::string_view str00{};
   VERIFY( str00.length() == 0 );
   VERIFY( str00.data() == nullptr );
 
   // basic_string_view(const char*)
   const char str_lit01[] = "rodeo beach, marin";
-  const std::string_view str01{str_lit01};
+  const gdb::string_view str01{str_lit01};
   VERIFY( str01.length() == 18 );
   VERIFY( str01.data() == str_lit01 );
-  const std::string_view str02{"baker beach, san francisco"};
+  const gdb::string_view str02{"baker beach, san francisco"};
   VERIFY( str02.length() == 26 );
 
   // basic_string_view(const string_view&)
-  std::string_view str04{str01};
+  gdb::string_view str04{str01};
   VERIFY( str04.length() == str01.length() );
   VERIFY( str04.data() == str01.data() );
 
   // basic_string_view(const char* s)
   csize_type len_lit01 = strlen(str_lit01);
-  std::string_view str05{str_lit01, len_lit01};
+  gdb::string_view str05{str_lit01, len_lit01};
   VERIFY( str05.length() == len_lit01 );
   VERIFY( str05.data() == str_lit01 );
 
   // basic_string_view(basic_string& s)
   std::string istr07(10, 'z');
-  std::string_view str07{istr07};
+  gdb::string_view str07{istr07};
   VERIFY( str07.length() == 10 );
 }
 
@@ -66,3 +63,5 @@ main()
 
   return 0;
 }
+
+} // namespace cons_1
diff --git a/gdb/unittests/basic_string_view/cons/char/2.cc b/gdb/unittests/basic_string_view/cons/char/2.cc
index 8dbca7a..a1b4536 100644
--- a/gdb/unittests/basic_string_view/cons/char/2.cc
+++ b/gdb/unittests/basic_string_view/cons/char/2.cc
@@ -19,10 +19,7 @@
 
 // basic_string_view constructors.
 
-#include <new>
-#include <string_view>
-#include <stdexcept>
-#include <testsuite_hooks.h>
+namespace cons_2 {
 
 void
 test03()
@@ -32,9 +29,9 @@ test03()
   // These are tests to see how basic_string_view handles data with NUL
   // bytes.  Obviously basic_string_view(char*) will halt at the first one, but
   // nothing else should.
-  std::string_view s1(with_nulls, 28);
+  gdb::string_view s1(with_nulls, 28);
   VERIFY( s1.size() == 28 );
-  std::string_view s2(s1);
+  gdb::string_view s2(s1);
   VERIFY( s2.size() == 28 );
 }
 
@@ -45,3 +42,5 @@ main()
 
   return 0;
 }
+
+} // namespace cons_2
diff --git a/gdb/unittests/basic_string_view/cons/char/3.cc b/gdb/unittests/basic_string_view/cons/char/3.cc
index c892cbc..358c118 100644
--- a/gdb/unittests/basic_string_view/cons/char/3.cc
+++ b/gdb/unittests/basic_string_view/cons/char/3.cc
@@ -19,15 +19,13 @@
 
 // basic_string_view constructors.
 
-#include <string_view>
-#include <vector>
-#include <testsuite_hooks.h>
+namespace cons_3 {
 
 void
 test05()
 {
   char const * s = 0;
-  std::string_view zero_length_built_with_NULL(s, 0);
+  gdb::string_view zero_length_built_with_NULL(s, 0);
 }
 
 int
@@ -37,3 +35,5 @@ main()
 
   return 0;
 }
+
+} // namespace cons_3