[PATCH 1/2] c++: modules and non-dependent auto deduction

[PATCH 1/2] c++: modules and non-dependent auto deduction

[Patrick Palka]

The modules streaming code seems to rely on the invariant that a
TEMPLATE_DECL and its DECL_TEMPLATE_RESULT have the same TREE_TYPE.
But for a templated VAR_DECL with deduced non-dependent type, the two
TREE_TYPEs end up diverging: cp_finish_decl deduces the type of the
initializer ahead of time and updates the TREE_TYPE of the VAR_DECL, but
neglects to update the corresponding TEMPLATE_DECL as well, which leads
to a "conflicting global module declaration" error for each of the
__phase_alignment decls in the below testcase (and for the xtreme-header
testcases if we try including <barrier>).

This patch makes cp_finish_decl update the TREE_TYPE of the corresponding
TEMPLATE_DECL so that the invariant is maintained.

Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?

gcc/cp/ChangeLog:

	* decl.cc (cp_finish_decl): After updating the deduced type of a
	VAR_DECL, also update the corresponding TEMPLATE_DECL if there
	is one.

gcc/testsuite/ChangeLog:

	* g++.dg/modules/auto-3.h: New test.
	* g++.dg/modules/auto-3_a.H: New test.
	* g++.dg/modules/auto-3_b.C: New test.
---
 gcc/cp/decl.cc                          |  6 ++++++
 gcc/testsuite/g++.dg/modules/auto-3.h   | 10 ++++++++++
 gcc/testsuite/g++.dg/modules/auto-3_a.H |  4 ++++
 gcc/testsuite/g++.dg/modules/auto-3_b.C |  4 ++++
 4 files changed, 24 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/modules/auto-3.h
 create mode 100644 gcc/testsuite/g++.dg/modules/auto-3_a.H
 create mode 100644 gcc/testsuite/g++.dg/modules/auto-3_b.C

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 070f673c3a2..80467c19254 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -8180,6 +8180,12 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
 	  return;
 	}
       cp_apply_type_quals_to_decl (cp_type_quals (type), decl);
+
+      /* Update the type of the corresponding TEMPLATE_DECL to match.  */
+      if (DECL_LANG_SPECIFIC (decl)
+	  && DECL_TEMPLATE_INFO (decl)
+	  && DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (decl)) == decl)
+	TREE_TYPE (DECL_TI_TEMPLATE (decl)) = type;
     }
 
   if (ensure_literal_type_for_constexpr_object (decl) == error_mark_node)
diff --git a/gcc/testsuite/g++.dg/modules/auto-3.h b/gcc/testsuite/g++.dg/modules/auto-3.h
new file mode 100644
index 00000000000..f129433cbcb
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/auto-3.h
@@ -0,0 +1,10 @@
+template<class>
+struct __tree_barrier {
+  static const auto __phase_alignment_1 = 0;
+
+  template<class>
+  static const auto __phase_alignment_2 = 0;
+};
+
+template<class>
+inline auto __phase_alignment_3 = 0;
diff --git a/gcc/testsuite/g++.dg/modules/auto-3_a.H b/gcc/testsuite/g++.dg/modules/auto-3_a.H
new file mode 100644
index 00000000000..25a7a73e73e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/auto-3_a.H
@@ -0,0 +1,4 @@
+// { dg-additional-options "-fmodule-header" }
+// { dg-module-cmi {} }
+
+#include "auto-3.h"
diff --git a/gcc/testsuite/g++.dg/modules/auto-3_b.C b/gcc/testsuite/g++.dg/modules/auto-3_b.C
new file mode 100644
index 00000000000..03b6d46f476
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/auto-3_b.C
@@ -0,0 +1,4 @@
+// { dg-additional-options "-fmodules-ts -fno-module-lazy" }
+
+#include "auto-3.h"
+import "auto-3_a.H";
-- 
2.38.0.rc0.52.gdda7228a83

[PATCH 2/2] c++: xtreme-header modules tests cleanups

[Patrick Palka]

This adds some recently implemented C++20/23 library headers to the
xtreme-header tests as appropriate.  Also, it looks like we can safely
re-add <execution> and remove the NO_ASSOCIATED_LAMBDA workaround.

Tested on x86_64-pc-linux-gnu, does this look OK for trunk?

gcc/testsuite/ChangeLog:

	* g++.dg/modules/xtreme-header-2.h: Include <execution>.
	* g++.dg/modules/xtreme-header-6.h: Include <barrier>, <latch>,
	<semaphore>, <source_location> and <syncstream>.
	* g++.dg/modules/xtreme-header.h: Likewise.  Remove
	NO_ASSOCIATED_LAMBDA workaround.  Include implemented C++23
	library headers.
---
 .../g++.dg/modules/xtreme-header-2.h          |  3 +-
 .../g++.dg/modules/xtreme-header-6.h          | 10 ++--
 gcc/testsuite/g++.dg/modules/xtreme-header.h  | 60 +++++++------------
 3 files changed, 29 insertions(+), 44 deletions(-)

diff --git a/gcc/testsuite/g++.dg/modules/xtreme-header-2.h b/gcc/testsuite/g++.dg/modules/xtreme-header-2.h
index ded093e533c..dfe94aa6988 100644
--- a/gcc/testsuite/g++.dg/modules/xtreme-header-2.h
+++ b/gcc/testsuite/g++.dg/modules/xtreme-header-2.h
@@ -1,8 +1,7 @@
 // Everything that transitively includes <ranges>
 
 #include <algorithm>
-// FIXME: PR 97549
-// #include <execution>
+#include <execution>
 #include <functional>
 #include <future>
 #include <memory>
diff --git a/gcc/testsuite/g++.dg/modules/xtreme-header-6.h b/gcc/testsuite/g++.dg/modules/xtreme-header-6.h
index 85894b2b20a..8d024b69bac 100644
--- a/gcc/testsuite/g++.dg/modules/xtreme-header-6.h
+++ b/gcc/testsuite/g++.dg/modules/xtreme-header-6.h
@@ -1,22 +1,22 @@
 // C++20 headers
 #if __cplusplus > 201703
 #include <version>
+#include <barrier>
 #include <bit>
 #include <compare>
 #include <concepts>
 #if __cpp_coroutines
 #include <coroutine>
 #endif
+#include <latch>
 #include <numbers>
+#include <semaphore>
+#include <source_location>
 #include <span>
 #include <stop_token>
+#include <syncstream>
 #if 0
 // Unimplemented
-#include <barrier>
 #include <format>
-#include <latch>
-#include <semaphore>
-#include <source_location>
-#include <syncstream>
 #endif
 #endif
diff --git a/gcc/testsuite/g++.dg/modules/xtreme-header.h b/gcc/testsuite/g++.dg/modules/xtreme-header.h
index 41302c780b5..124e2f82277 100644
--- a/gcc/testsuite/g++.dg/modules/xtreme-header.h
+++ b/gcc/testsuite/g++.dg/modules/xtreme-header.h
@@ -1,17 +1,8 @@
 // All the headers!
 
-#if __cplusplus > 201703L
-// FIXME: if we include everything, something goes wrong with location
-// information.  We used to not handle lambdas attached to global
-// vars, and this is a convienient flag to stop including everything.
-#define NO_ASSOCIATED_LAMBDA 1
-#endif
-
 // C++ 17 and below
 #if 1
-#if !NO_ASSOCIATED_LAMBDA
 #include <algorithm>
-#endif
 #include <any>
 #include <array>
 #include <atomic>
@@ -26,19 +17,12 @@
 #include <cwctype>
 #include <deque>
 #include <exception>
-#if !NO_ASSOCIATED_LAMBDA
-// FIXME: PR 97549
-//#include <execution>
-#endif
+#include <execution>
 #include <filesystem>
 #include <forward_list>
 #include <fstream>
-#if !NO_ASSOCIATED_LAMBDA
 #include <functional>
-#endif
-#if !NO_ASSOCIATED_LAMBDA
 #include <future>
-#endif
 #include <initializer_list>
 #include <iomanip>
 #include <ios>
@@ -49,12 +33,8 @@
 #include <list>
 #include <locale>
 #include <map>
-#if !NO_ASSOCIATED_LAMBDA
 #include <memory>
-#endif
-#if !NO_ASSOCIATED_LAMBDA
 #include <memory_resource>
-#endif
 #include <mutex>
 #include <new>
 #include <numeric>
@@ -63,12 +43,8 @@
 #include <queue>
 #include <random>
 #include <ratio>
-#if !NO_ASSOCIATED_LAMBDA
 #include <regex>
-#endif
-#if !NO_ASSOCIATED_LAMBDA
 #include <scoped_allocator>
-#endif
 #include <set>
 #include <shared_mutex>
 #include <sstream>
@@ -78,9 +54,7 @@
 #include <string>
 #include <string_view>
 #include <system_error>
-#if !NO_ASSOCIATED_LAMBDA
 #include <thread>
-#endif
 #include <tuple>
 #include <type_traits>
 #include <typeindex>
@@ -88,9 +62,7 @@
 #include <unordered_map>
 #include <unordered_set>
 #include <utility>
-#if !NO_ASSOCIATED_LAMBDA
 #include <valarray>
-#endif
 #include <variant>
 #include <vector>
 #endif
@@ -119,26 +91,40 @@
 #if __cplusplus > 201703
 #if 1
 #include <version>
+#include <barrier>
 #include <bit>
 #include <compare>
 #include <concepts>
 #if __cpp_coroutines
 #include <coroutine>
 #endif
-#if !NO_ASSOCIATED_LAMBDA
-#include <ranges>
-#endif
+#include <latch>
 #include <numbers>
+#include <ranges>
+#include <semaphore>
+#include <source_location>
 #include <span>
 #include <stop_token>
+#include <syncstream>
 #if 0
 // Unimplemented
-#include <barrier>
 #include <format>
-#include <latch>
-#include <semaphore>
-#include <source_location>
-#include <syncstream>
 #endif
 #endif
 #endif
+
+// C++23
+#if __cplusplus > 202002L
+#include <expected>
+#include <spanstream>
+#include <stacktrace>
+#if 0
+// Unimplemented
+#include <flat_map>
+#include <flat_set>
+#include <generator>
+#include <mdspan>
+#include <print>
+#endif
+#endif
+
-- 
2.38.0.rc0.52.gdda7228a83

Re: [PATCH 1/2] c++: modules and non-dependent auto deduction

[Nathan Sidwell]

On 9/20/22 15:54, Patrick Palka wrote:
> The modules streaming code seems to rely on the invariant that a
> TEMPLATE_DECL and its DECL_TEMPLATE_RESULT have the same TREE_TYPE.

It does indeed.

> But for a templated VAR_DECL with deduced non-dependent type, the two
> TREE_TYPEs end up diverging: cp_finish_decl deduces the type of the
> initializer ahead of time and updates the TREE_TYPE of the VAR_DECL, but
> neglects to update the corresponding TEMPLATE_DECL as well, which leads
> to a "conflicting global module declaration" error for each of the
> __phase_alignment decls in the below testcase (and for the xtreme-header
> testcases if we try including <barrier>).
> 
> This patch makes cp_finish_decl update the TREE_TYPE of the corresponding
> TEMPLATE_DECL so that the invariant is maintained >
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
> trunk?

Ok, thanks


> 
> gcc/cp/ChangeLog:
> 
> 	* decl.cc (cp_finish_decl): After updating the deduced type of a
> 	VAR_DECL, also update the corresponding TEMPLATE_DECL if there
> 	is one.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.dg/modules/auto-3.h: New test.
> 	* g++.dg/modules/auto-3_a.H: New test.
> 	* g++.dg/modules/auto-3_b.C: New test.
> ---
>   gcc/cp/decl.cc                          |  6 ++++++
>   gcc/testsuite/g++.dg/modules/auto-3.h   | 10 ++++++++++
>   gcc/testsuite/g++.dg/modules/auto-3_a.H |  4 ++++
>   gcc/testsuite/g++.dg/modules/auto-3_b.C |  4 ++++
>   4 files changed, 24 insertions(+)
>   create mode 100644 gcc/testsuite/g++.dg/modules/auto-3.h
>   create mode 100644 gcc/testsuite/g++.dg/modules/auto-3_a.H
>   create mode 100644 gcc/testsuite/g++.dg/modules/auto-3_b.C
> 
> diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
> index 070f673c3a2..80467c19254 100644
> --- a/gcc/cp/decl.cc
> +++ b/gcc/cp/decl.cc
> @@ -8180,6 +8180,12 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
>   	  return;
>   	}
>         cp_apply_type_quals_to_decl (cp_type_quals (type), decl);
> +
> +      /* Update the type of the corresponding TEMPLATE_DECL to match.  */
> +      if (DECL_LANG_SPECIFIC (decl)
> +	  && DECL_TEMPLATE_INFO (decl)
> +	  && DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (decl)) == decl)
> +	TREE_TYPE (DECL_TI_TEMPLATE (decl)) = type;
>       }
>   
>     if (ensure_literal_type_for_constexpr_object (decl) == error_mark_node)
> diff --git a/gcc/testsuite/g++.dg/modules/auto-3.h b/gcc/testsuite/g++.dg/modules/auto-3.h
> new file mode 100644
> index 00000000000..f129433cbcb
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/modules/auto-3.h
> @@ -0,0 +1,10 @@
> +template<class>
> +struct __tree_barrier {
> +  static const auto __phase_alignment_1 = 0;
> +
> +  template<class>
> +  static const auto __phase_alignment_2 = 0;
> +};
> +
> +template<class>
> +inline auto __phase_alignment_3 = 0;
> diff --git a/gcc/testsuite/g++.dg/modules/auto-3_a.H b/gcc/testsuite/g++.dg/modules/auto-3_a.H
> new file mode 100644
> index 00000000000..25a7a73e73e
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/modules/auto-3_a.H
> @@ -0,0 +1,4 @@
> +// { dg-additional-options "-fmodule-header" }
> +// { dg-module-cmi {} }
> +
> +#include "auto-3.h"
> diff --git a/gcc/testsuite/g++.dg/modules/auto-3_b.C b/gcc/testsuite/g++.dg/modules/auto-3_b.C
> new file mode 100644
> index 00000000000..03b6d46f476
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/modules/auto-3_b.C
> @@ -0,0 +1,4 @@
> +// { dg-additional-options "-fmodules-ts -fno-module-lazy" }
> +
> +#include "auto-3.h"
> +import "auto-3_a.H";

-- 
Nathan Sidwell

Re: [PATCH 2/2] c++: xtreme-header modules tests cleanups

[Nathan Sidwell]

On 9/20/22 15:54, Patrick Palka wrote:
> This adds some recently implemented C++20/23 library headers to the
> xtreme-header tests as appropriate.  Also, it looks like we can safely
> re-add <execution> and remove the NO_ASSOCIATED_LAMBDA workaround.
> 
> Tested on x86_64-pc-linux-gnu, does this look OK for trunk?

cool, more bits working.  thanks!

> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.dg/modules/xtreme-header-2.h: Include <execution>.
> 	* g++.dg/modules/xtreme-header-6.h: Include <barrier>, <latch>,
> 	<semaphore>, <source_location> and <syncstream>.
> 	* g++.dg/modules/xtreme-header.h: Likewise.  Remove
> 	NO_ASSOCIATED_LAMBDA workaround.  Include implemented C++23
> 	library headers.
> ---
>   .../g++.dg/modules/xtreme-header-2.h          |  3 +-
>   .../g++.dg/modules/xtreme-header-6.h          | 10 ++--
>   gcc/testsuite/g++.dg/modules/xtreme-header.h  | 60 +++++++------------
>   3 files changed, 29 insertions(+), 44 deletions(-)
> 
> diff --git a/gcc/testsuite/g++.dg/modules/xtreme-header-2.h b/gcc/testsuite/g++.dg/modules/xtreme-header-2.h
> index ded093e533c..dfe94aa6988 100644
> --- a/gcc/testsuite/g++.dg/modules/xtreme-header-2.h
> +++ b/gcc/testsuite/g++.dg/modules/xtreme-header-2.h
> @@ -1,8 +1,7 @@
>   // Everything that transitively includes <ranges>
>   
>   #include <algorithm>
> -// FIXME: PR 97549
> -// #include <execution>
> +#include <execution>
>   #include <functional>
>   #include <future>
>   #include <memory>
> diff --git a/gcc/testsuite/g++.dg/modules/xtreme-header-6.h b/gcc/testsuite/g++.dg/modules/xtreme-header-6.h
> index 85894b2b20a..8d024b69bac 100644
> --- a/gcc/testsuite/g++.dg/modules/xtreme-header-6.h
> +++ b/gcc/testsuite/g++.dg/modules/xtreme-header-6.h
> @@ -1,22 +1,22 @@
>   // C++20 headers
>   #if __cplusplus > 201703
>   #include <version>
> +#include <barrier>
>   #include <bit>
>   #include <compare>
>   #include <concepts>
>   #if __cpp_coroutines
>   #include <coroutine>
>   #endif
> +#include <latch>
>   #include <numbers>
> +#include <semaphore>
> +#include <source_location>
>   #include <span>
>   #include <stop_token>
> +#include <syncstream>
>   #if 0
>   // Unimplemented
> -#include <barrier>
>   #include <format>
> -#include <latch>
> -#include <semaphore>
> -#include <source_location>
> -#include <syncstream>
>   #endif
>   #endif
> diff --git a/gcc/testsuite/g++.dg/modules/xtreme-header.h b/gcc/testsuite/g++.dg/modules/xtreme-header.h
> index 41302c780b5..124e2f82277 100644
> --- a/gcc/testsuite/g++.dg/modules/xtreme-header.h
> +++ b/gcc/testsuite/g++.dg/modules/xtreme-header.h
> @@ -1,17 +1,8 @@
>   // All the headers!
>   
> -#if __cplusplus > 201703L
> -// FIXME: if we include everything, something goes wrong with location
> -// information.  We used to not handle lambdas attached to global
> -// vars, and this is a convienient flag to stop including everything.
> -#define NO_ASSOCIATED_LAMBDA 1
> -#endif
> -
>   // C++ 17 and below
>   #if 1
> -#if !NO_ASSOCIATED_LAMBDA
>   #include <algorithm>
> -#endif
>   #include <any>
>   #include <array>
>   #include <atomic>
> @@ -26,19 +17,12 @@
>   #include <cwctype>
>   #include <deque>
>   #include <exception>
> -#if !NO_ASSOCIATED_LAMBDA
> -// FIXME: PR 97549
> -//#include <execution>
> -#endif
> +#include <execution>
>   #include <filesystem>
>   #include <forward_list>
>   #include <fstream>
> -#if !NO_ASSOCIATED_LAMBDA
>   #include <functional>
> -#endif
> -#if !NO_ASSOCIATED_LAMBDA
>   #include <future>
> -#endif
>   #include <initializer_list>
>   #include <iomanip>
>   #include <ios>
> @@ -49,12 +33,8 @@
>   #include <list>
>   #include <locale>
>   #include <map>
> -#if !NO_ASSOCIATED_LAMBDA
>   #include <memory>
> -#endif
> -#if !NO_ASSOCIATED_LAMBDA
>   #include <memory_resource>
> -#endif
>   #include <mutex>
>   #include <new>
>   #include <numeric>
> @@ -63,12 +43,8 @@
>   #include <queue>
>   #include <random>
>   #include <ratio>
> -#if !NO_ASSOCIATED_LAMBDA
>   #include <regex>
> -#endif
> -#if !NO_ASSOCIATED_LAMBDA
>   #include <scoped_allocator>
> -#endif
>   #include <set>
>   #include <shared_mutex>
>   #include <sstream>
> @@ -78,9 +54,7 @@
>   #include <string>
>   #include <string_view>
>   #include <system_error>
> -#if !NO_ASSOCIATED_LAMBDA
>   #include <thread>
> -#endif
>   #include <tuple>
>   #include <type_traits>
>   #include <typeindex>
> @@ -88,9 +62,7 @@
>   #include <unordered_map>
>   #include <unordered_set>
>   #include <utility>
> -#if !NO_ASSOCIATED_LAMBDA
>   #include <valarray>
> -#endif
>   #include <variant>
>   #include <vector>
>   #endif
> @@ -119,26 +91,40 @@
>   #if __cplusplus > 201703
>   #if 1
>   #include <version>
> +#include <barrier>
>   #include <bit>
>   #include <compare>
>   #include <concepts>
>   #if __cpp_coroutines
>   #include <coroutine>
>   #endif
> -#if !NO_ASSOCIATED_LAMBDA
> -#include <ranges>
> -#endif
> +#include <latch>
>   #include <numbers>
> +#include <ranges>
> +#include <semaphore>
> +#include <source_location>
>   #include <span>
>   #include <stop_token>
> +#include <syncstream>
>   #if 0
>   // Unimplemented
> -#include <barrier>
>   #include <format>
> -#include <latch>
> -#include <semaphore>
> -#include <source_location>
> -#include <syncstream>
>   #endif
>   #endif
>   #endif
> +
> +// C++23
> +#if __cplusplus > 202002L
> +#include <expected>
> +#include <spanstream>
> +#include <stacktrace>
> +#if 0
> +// Unimplemented
> +#include <flat_map>
> +#include <flat_set>
> +#include <generator>
> +#include <mdspan>
> +#include <print>
> +#endif
> +#endif
> +

-- 
Nathan Sidwell