From b6ec4a33fb2b6e9ea9bb5ace211504113fbe64a1 Mon Sep 17 00:00:00 2001 From: Bruno Cardoso Lopes Date: Thu, 4 Jan 2018 02:17:40 +0000 Subject: [Modules] Allow modules specified by -fmodule-map-file to shadow implicitly found ones When modules come from module map files explicitly specified by -fmodule-map-file= arguments, allow those to override/shadow modules with the same name that are found implicitly by header search. If such a module is looked up by name (e.g. @import), we will always find the one from -fmodule-map-file. If we try to use a shadowed module by including one of its headers report an error. This enables developers to force use of a specific copy of their module to be used if there are multiple copies that would otherwise be visible, for example if they develop modules that are installed in the default search paths. Patch originally by Ben Langmuir, http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20151116/143425.html Based on cfe-dev discussion: http://lists.llvm.org/pipermail/cfe-dev/2015-November/046164.html Differential Revision: https://reviews.llvm.org/D31269 rdar://problem/23612102 llvm-svn: 321781 --- clang/lib/Basic/Module.cpp | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'clang/lib/Basic/Module.cpp') diff --git a/clang/lib/Basic/Module.cpp b/clang/lib/Basic/Module.cpp index 7124184865c..692e138f6c1 100644 --- a/clang/lib/Basic/Module.cpp +++ b/clang/lib/Basic/Module.cpp @@ -95,11 +95,16 @@ static bool hasFeature(StringRef Feature, const LangOptions &LangOpts, bool Module::isAvailable(const LangOptions &LangOpts, const TargetInfo &Target, Requirement &Req, - UnresolvedHeaderDirective &MissingHeader) const { + UnresolvedHeaderDirective &MissingHeader, + Module *&ShadowingModule) const { if (IsAvailable) return true; for (const Module *Current = this; Current; Current = Current->Parent) { + if (Current->ShadowingModule) { + ShadowingModule = Current->ShadowingModule; + return false; + } for (unsigned I = 0, N = Current->Requirements.size(); I != N; ++I) { if (hasFeature(Current->Requirements[I].first, LangOpts, Target) != Current->Requirements[I].second) { -- cgit v1.2.3