[libcxx-commits] [libcxx] 4bf9fa5 - [libc++][modules] Guard missing header validation on Windows. (#80478)

via libcxx-commits libcxx-commits at lists.llvm.org
Fri Feb 9 08:41:49 PST 2024


Author: Mark de Wever
Date: 2024-02-09T17:41:46+01:00
New Revision: 4bf9fa5fb50497878edf8e277574ea9fb7d6bb7f

URL: https://github.com/llvm/llvm-project/commit/4bf9fa5fb50497878edf8e277574ea9fb7d6bb7f
DIFF: https://github.com/llvm/llvm-project/commit/4bf9fa5fb50497878edf8e277574ea9fb7d6bb7f.diff

LOG: [libc++][modules] Guard missing header validation on Windows. (#80478)

On Windows the libc++ test suite sees the MSVC STL headers and may
conclude these are libc++ headers when inspecting the name. Modules
guard against forgetting to export new headers. Finding MSVC STL's
headers gives false positives. Since the CI tests non-Windows platforms
too, the validation will be disabled on Windows.

Fixes: https://github.com/llvm/llvm-project/issues/79010

---------

Co-authored-by: Louis Dionne <ldionne.2 at gmail.com>

Added: 
    

Modified: 
    libcxx/modules/std.compat.cppm.in
    libcxx/modules/std.cppm.in
    libcxx/utils/generate_libcxx_cppm_in.py

Removed: 
    


################################################################################
diff  --git a/libcxx/modules/std.compat.cppm.in b/libcxx/modules/std.compat.cppm.in
index 651d6ec7b9fe26..16363711ac7627 100644
--- a/libcxx/modules/std.compat.cppm.in
+++ b/libcxx/modules/std.compat.cppm.in
@@ -46,39 +46,48 @@ module;
 #endif
 
 // *** Headers not yet available ***
-#if __has_include(<debugging>)
-#  error "please update the header information for <debugging> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<debugging>)
-#if __has_include(<flat_map>)
-#  error "please update the header information for <flat_map> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<flat_map>)
-#if __has_include(<flat_set>)
-#  error "please update the header information for <flat_set> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<flat_set>)
-#if __has_include(<generator>)
-#  error "please update the header information for <generator> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<generator>)
-#if __has_include(<hazard_pointer>)
-#  error "please update the header information for <hazard_pointer> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<hazard_pointer>)
-#if __has_include(<linalg>)
-#  error "please update the header information for <linalg> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<linalg>)
-#if __has_include(<rcu>)
-#  error "please update the header information for <rcu> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<rcu>)
-#if __has_include(<spanstream>)
-#  error "please update the header information for <spanstream> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<spanstream>)
-#if __has_include(<stacktrace>)
-#  error "please update the header information for <stacktrace> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<stacktrace>)
-#if __has_include(<stdfloat>)
-#  error "please update the header information for <stdfloat> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<stdfloat>)
-#if __has_include(<text_encoding>)
-#  error "please update the header information for <text_encoding> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<text_encoding>)
+//
+// This validation is mainly to aid libc++ developers to add modules for new
+// headers. On Windows the Windows SDK can be in the include path. This SDK
+// contains the MSVC STL headers. This may give false positives when MSVC STL
+// provides a header libc++ has not implemented yet. Therefore this validation
+// is not done on Windows.
+//
+#ifndef _WIN32
+#  if __has_include(<debugging>)
+#    error "please update the header information for <debugging> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<debugging>)
+#  if __has_include(<flat_map>)
+#    error "please update the header information for <flat_map> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<flat_map>)
+#  if __has_include(<flat_set>)
+#    error "please update the header information for <flat_set> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<flat_set>)
+#  if __has_include(<generator>)
+#    error "please update the header information for <generator> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<generator>)
+#  if __has_include(<hazard_pointer>)
+#    error "please update the header information for <hazard_pointer> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<hazard_pointer>)
+#  if __has_include(<linalg>)
+#    error "please update the header information for <linalg> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<linalg>)
+#  if __has_include(<rcu>)
+#    error "please update the header information for <rcu> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<rcu>)
+#  if __has_include(<spanstream>)
+#    error "please update the header information for <spanstream> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<spanstream>)
+#  if __has_include(<stacktrace>)
+#    error "please update the header information for <stacktrace> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<stacktrace>)
+#  if __has_include(<stdfloat>)
+#    error "please update the header information for <stdfloat> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<stdfloat>)
+#  if __has_include(<text_encoding>)
+#    error "please update the header information for <text_encoding> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<text_encoding>)
+#endif // _WIN32
 
 export module std.compat;
 export import std;

diff  --git a/libcxx/modules/std.cppm.in b/libcxx/modules/std.cppm.in
index 6ce8e287737b88..3b59c28482b113 100644
--- a/libcxx/modules/std.cppm.in
+++ b/libcxx/modules/std.cppm.in
@@ -168,39 +168,48 @@ module;
 #include <version>
 
 // *** Headers not yet available ***
-#if __has_include(<debugging>)
-#  error "please update the header information for <debugging> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<debugging>)
-#if __has_include(<flat_map>)
-#  error "please update the header information for <flat_map> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<flat_map>)
-#if __has_include(<flat_set>)
-#  error "please update the header information for <flat_set> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<flat_set>)
-#if __has_include(<generator>)
-#  error "please update the header information for <generator> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<generator>)
-#if __has_include(<hazard_pointer>)
-#  error "please update the header information for <hazard_pointer> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<hazard_pointer>)
-#if __has_include(<linalg>)
-#  error "please update the header information for <linalg> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<linalg>)
-#if __has_include(<rcu>)
-#  error "please update the header information for <rcu> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<rcu>)
-#if __has_include(<spanstream>)
-#  error "please update the header information for <spanstream> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<spanstream>)
-#if __has_include(<stacktrace>)
-#  error "please update the header information for <stacktrace> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<stacktrace>)
-#if __has_include(<stdfloat>)
-#  error "please update the header information for <stdfloat> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<stdfloat>)
-#if __has_include(<text_encoding>)
-#  error "please update the header information for <text_encoding> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<text_encoding>)
+//
+// This validation is mainly to aid libc++ developers to add modules for new
+// headers. On Windows the Windows SDK can be in the include path. This SDK
+// contains the MSVC STL headers. This may give false positives when MSVC STL
+// provides a header libc++ has not implemented yet. Therefore this validation
+// is not done on Windows.
+//
+#ifndef _WIN32
+#  if __has_include(<debugging>)
+#    error "please update the header information for <debugging> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<debugging>)
+#  if __has_include(<flat_map>)
+#    error "please update the header information for <flat_map> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<flat_map>)
+#  if __has_include(<flat_set>)
+#    error "please update the header information for <flat_set> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<flat_set>)
+#  if __has_include(<generator>)
+#    error "please update the header information for <generator> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<generator>)
+#  if __has_include(<hazard_pointer>)
+#    error "please update the header information for <hazard_pointer> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<hazard_pointer>)
+#  if __has_include(<linalg>)
+#    error "please update the header information for <linalg> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<linalg>)
+#  if __has_include(<rcu>)
+#    error "please update the header information for <rcu> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<rcu>)
+#  if __has_include(<spanstream>)
+#    error "please update the header information for <spanstream> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<spanstream>)
+#  if __has_include(<stacktrace>)
+#    error "please update the header information for <stacktrace> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<stacktrace>)
+#  if __has_include(<stdfloat>)
+#    error "please update the header information for <stdfloat> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<stdfloat>)
+#  if __has_include(<text_encoding>)
+#    error "please update the header information for <text_encoding> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<text_encoding>)
+#endif // _WIN32
 
 export module std;
 

diff  --git a/libcxx/utils/generate_libcxx_cppm_in.py b/libcxx/utils/generate_libcxx_cppm_in.py
index 2d3f829847fb9f..0390ce5067f402 100644
--- a/libcxx/utils/generate_libcxx_cppm_in.py
+++ b/libcxx/utils/generate_libcxx_cppm_in.py
@@ -57,18 +57,31 @@ def write_file(module):
             else:
                 module_cpp_in.write(f"#include <{header}>\n")
 
-        module_cpp_in.write("\n// *** Headers not yet available ***\n")
+        module_cpp_in.write(
+            """
+// *** Headers not yet available ***
+//
+// This validation is mainly to catch when a new header is added but adding the 
+// corresponding .inc file is forgotten. However, the check based on __has_include
+// alone doesn't work on Windows because the Windows SDK is on the include path,
+// and that means the MSVC STL headers can be found as well, tricking __has_include
+// into thinking that libc++ provides the header.
+//
+#ifndef _WIN32
+"""
+        )
         for header in sorted(headers_not_available):
             module_cpp_in.write(
                 f"""\
-#if __has_include(<{header}>)
-#  error "please update the header information for <{header}> in headers_not_available in utils/libcxx/header_information.py"
-#endif // __has_include(<{header}>)
+#  if __has_include(<{header}>)
+#    error "please update the header information for <{header}> in headers_not_available in utils/libcxx/header_information.py"
+#  endif // __has_include(<{header}>)
 """
             )
 
         module_cpp_in.write(
-            f"""
+            f"""#endif // _WIN32
+
 export module {module};
 {'export import std;' if module == 'std.compat' else ''}
 


        


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