From aa874ab2417a1a9b2dc68bb132b47f7e19d99acf Mon Sep 17 00:00:00 2001
From: Vassil Vassilev <v.g.vassilev@gmail.com>
Date: Mon, 27 Mar 2023 19:43:33 +0000
Subject: [PATCH] [cxxmodules] Implement a module attribute 'optional' to allow
missing headers.
This deals with the fact that our modulemaps include headers which can vary
across library versions and that attribute is a way to express this.
---
interpreter/cling/include/cling/std.modulemap | 4 ++--
.../src/tools/clang/include/clang/Basic/Module.h | 3 +++
.../src/tools/clang/include/clang/Lex/ModuleMap.h | 5 ++++-
.../llvm/src/tools/clang/lib/Basic/Module.cpp | 3 ++-
.../llvm/src/tools/clang/lib/Lex/ModuleMap.cpp | 15 ++++++++++++++-
5 files changed, 25 insertions(+), 5 deletions(-)
diff --git a/interpreter/cling/include/cling/std.modulemap b/interpreter/cling/include/cling/std.modulemap
index d5bb22388e1..6f150355d8a 100644
--- a/interpreter/cling/include/cling/std.modulemap
+++ b/interpreter/cling/include/cling/std.modulemap
@@ -429,8 +429,8 @@ module "std" [system] {
export *
header "bits/basic_ios.h"
}
- module "bits/chrono.h" {
- requires cplusplus20
+ module "bits/chrono.h" [optional] {
+ requires cplusplus17
export *
header "bits/chrono.h"
}
diff --git a/interpreter/llvm/src/tools/clang/include/clang/Basic/Module.h b/interpreter/llvm/src/tools/clang/include/clang/Basic/Module.h
index 3476b05d2e9..f62e657fef7 100644
--- a/interpreter/llvm/src/tools/clang/include/clang/Basic/Module.h
+++ b/interpreter/llvm/src/tools/clang/include/clang/Basic/Module.h
@@ -303,6 +303,9 @@ public:
/// and headers from used modules.
unsigned NoUndeclaredIncludes : 1;
+ /// Whether the submodule is allowed to have missing headers.
+ unsigned IsOptional: 1;
+
/// Whether this module came from a "private" module map, found next
/// to a regular (public) module map.
unsigned ModuleMapIsPrivate : 1;
diff --git a/interpreter/llvm/src/tools/clang/include/clang/Lex/ModuleMap.h b/interpreter/llvm/src/tools/clang/include/clang/Lex/ModuleMap.h
index 41f85a1f572..26ed708c49e 100644
--- a/interpreter/llvm/src/tools/clang/include/clang/Lex/ModuleMap.h
+++ b/interpreter/llvm/src/tools/clang/include/clang/Lex/ModuleMap.h
@@ -241,9 +241,12 @@ private:
/// and headers from used modules.
unsigned NoUndeclaredIncludes : 1;
+ /// Whether we can have a submodule with missing header files.
+ unsigned IsOptional : 1;
+
Attributes()
: IsSystem(false), IsExternC(false), IsExhaustive(false),
- NoUndeclaredIncludes(false) {}
+ NoUndeclaredIncludes(false), IsOptional(false) {}
};
/// A directory for which framework modules can be inferred.
diff --git a/interpreter/llvm/src/tools/clang/lib/Basic/Module.cpp b/interpreter/llvm/src/tools/clang/lib/Basic/Module.cpp
index 07ee82ceb60..ff91ddcc880 100644
--- a/interpreter/llvm/src/tools/clang/lib/Basic/Module.cpp
+++ b/interpreter/llvm/src/tools/clang/lib/Basic/Module.cpp
@@ -43,7 +43,7 @@ Module::Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent,
IsSystem(false), IsExternC(false), IsInferred(false),
InferSubmodules(false), InferExplicitSubmodules(false),
InferExportWildcard(false), ConfigMacrosExhaustive(false),
- NoUndeclaredIncludes(false), ModuleMapIsPrivate(false),
+ NoUndeclaredIncludes(false), IsOptional(false), ModuleMapIsPrivate(false),
NameVisibility(Hidden) {
if (Parent) {
IsAvailable = Parent->isAvailable();
@@ -51,6 +51,7 @@ Module::Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent,
IsSystem = Parent->IsSystem;
IsExternC = Parent->IsExternC;
NoUndeclaredIncludes = Parent->NoUndeclaredIncludes;
+ IsOptional = Parent->IsOptional;
ModuleMapIsPrivate = Parent->ModuleMapIsPrivate;
Parent->SubModuleIndex[Name] = Parent->SubModules.size();
diff --git a/interpreter/llvm/src/tools/clang/lib/Lex/ModuleMap.cpp b/interpreter/llvm/src/tools/clang/lib/Lex/ModuleMap.cpp
index f9af7c2a24f..7feb88508b9 100644
--- a/interpreter/llvm/src/tools/clang/lib/Lex/ModuleMap.cpp
+++ b/interpreter/llvm/src/tools/clang/lib/Lex/ModuleMap.cpp
@@ -274,6 +274,8 @@ void ModuleMap::resolveHeader(Module *Mod,
// this was supposed to modularize the builtin header alone.
} else if (Header.Kind == Module::HK_Excluded) {
// Ignore missing excluded header files. They're optional anyway.
+ } else if (Mod->IsOptional) {
+ // Optional submodules can have missing headers.
} else {
// If we find a module that has a missing header, we mark this module as
// unavailable and store the header directive for displaying diagnostics.
@@ -1037,6 +1039,7 @@ Module *ModuleMap::inferFrameworkModule(const DirectoryEntry *FrameworkDir,
Result->IsExternC |= Attrs.IsExternC;
Result->ConfigMacrosExhaustive |= Attrs.IsExhaustive;
Result->NoUndeclaredIncludes |= Attrs.NoUndeclaredIncludes;
+ Result->IsOptional |= Attrs.IsOptional;
Result->Directory = FrameworkDir;
// Chop off the first framework bit, as that is implied.
@@ -1749,7 +1752,10 @@ namespace {
AT_exhaustive,
/// The 'no_undeclared_includes' attribute.
- AT_no_undeclared_includes
+ AT_no_undeclared_includes,
+
+ /// The 'optional' attribute.
+ AT_optional
};
} // namespace
@@ -2005,6 +2011,8 @@ void ModuleMapParser::parseModuleDecl() {
ActiveModule->IsSystem = true;
if (Attrs.IsExternC)
ActiveModule->IsExternC = true;
+ if (Attrs.IsOptional)
+ ActiveModule->IsOptional = true;
if (Attrs.NoUndeclaredIncludes ||
(!ActiveModule->Parent && ModuleName == "Darwin"))
ActiveModule->NoUndeclaredIncludes = true;
@@ -2905,6 +2913,7 @@ bool ModuleMapParser::parseOptionalAttributes(Attributes &Attrs) {
.Case("exhaustive", AT_exhaustive)
.Case("extern_c", AT_extern_c)
.Case("no_undeclared_includes", AT_no_undeclared_includes)
+ .Case("optional", AT_optional)
.Case("system", AT_system)
.Default(AT_unknown);
switch (Attribute) {
@@ -2928,6 +2937,10 @@ bool ModuleMapParser::parseOptionalAttributes(Attributes &Attrs) {
case AT_no_undeclared_includes:
Attrs.NoUndeclaredIncludes = true;
break;
+
+ case AT_optional:
+ Attrs.IsOptional = true;
+ break;
}
consumeToken();
--
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