r253398 - [modules] When a #include is mapped to a module import and appears somewhere
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Tue Nov 17 16:15:29 PST 2015
On Tue, Nov 17, 2015 at 3:40 PM, David Blaikie <dblaikie at gmail.com> wrote:
> On Tue, Nov 17, 2015 at 3:32 PM, Richard Smith via cfe-commits <
> cfe-commits at lists.llvm.org> wrote:
>
>> Author: rsmith
>> Date: Tue Nov 17 17:32:01 2015
>> New Revision: 253398
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=253398&view=rev
>> Log:
>> [modules] When a #include is mapped to a module import and appears
>> somewhere
>> other than the top level, we issue an error. This breaks a fair amount of
>> C++
>> code wrapping C libraries, where the C library is #included within a
>> namespace
>> / extern "C" combination, because the C library (probably) includes C++
>> standard library headers which may be within modules.
>>
>> Without modules, this setup is harmless if (and *only* if) the
>> corresponding
>> standard library module was already included outside the namespace,
>
>
> ^ if that's the only place it's valid, is it that much more work to just
> remove all such inclusions as pointless?
>
Yes, and that would break the build of the third-party library in a lot of
cases. The pattern looks like this:
c_header.h:
#include <stdio.h>
my decls(); // use stuff from stdio.h here
cxx_header.h:
#include <stdio.h> // important, do not remove
namespace WrappedCLibrary {
extern "C" {
#include "c_header.h"
}
}
Note that removing the include from c_header.h will potentially break all
the other (C) users of that header.
> If they ever trigger they'll do bad things, yes?
>
> (but I guess on a large enough codebase this fight is not worth fighting
> in the effort to transition to modules? even if it's just deletions (code
> review turnaround, etc))
>
>
>> so
>> downgrade the error to a default-error extension in that case, so that it
>> can
>> be selectively disabled for such misbehaving libraries.
>>
>> Modified:
>> cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>> cfe/trunk/lib/Parse/ParseDecl.cpp
>> cfe/trunk/lib/Parse/ParseDeclCXX.cpp
>> cfe/trunk/lib/Parse/ParseStmt.cpp
>> cfe/trunk/lib/Sema/SemaDecl.cpp
>> cfe/trunk/test/Modules/auto-module-import.m
>>
>> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=253398&r1=253397&r2=253398&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
>> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Tue Nov 17
>> 17:32:01 2015
>> @@ -7930,6 +7930,9 @@ def note_module_import_in_extern_c : Not
>> "extern \"C\" language linkage specification begins here">;
>> def err_module_import_not_at_top_level_fatal : Error<
>> "import of module '%0' appears within %1">, DefaultFatal;
>> +def ext_module_import_not_at_top_level_noop : ExtWarn<
>> + "redundant #include of module '%0' appears within %1">, DefaultError,
>> + InGroup<DiagGroup<"modules-import-nested-redundant">>;
>> def note_module_import_not_at_top_level : Note<"%0 begins here">;
>> def err_module_self_import : Error<
>> "import of module '%0' appears within same top-level module '%1'">;
>>
>> Modified: cfe/trunk/lib/Parse/ParseDecl.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseDecl.cpp?rev=253398&r1=253397&r2=253398&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Parse/ParseDecl.cpp (original)
>> +++ cfe/trunk/lib/Parse/ParseDecl.cpp Tue Nov 17 17:32:01 2015
>> @@ -3589,8 +3589,8 @@ void Parser::ParseStructUnionBody(Source
>> SmallVector<Decl *, 32> FieldDecls;
>>
>> // While we still have something to read, read the declarations in the
>> struct.
>> - while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof) &&
>> - !tryParseMisplacedModuleImport()) {
>> + while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
>> + Tok.isNot(tok::eof)) {
>> // Each iteration of this loop reads one struct-declaration.
>>
>> // Check for extraneous top-level semicolon.
>>
>> Modified: cfe/trunk/lib/Parse/ParseDeclCXX.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseDeclCXX.cpp?rev=253398&r1=253397&r2=253398&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Parse/ParseDeclCXX.cpp (original)
>> +++ cfe/trunk/lib/Parse/ParseDeclCXX.cpp Tue Nov 17 17:32:01 2015
>> @@ -210,8 +210,8 @@ void Parser::ParseInnerNamespace(std::ve
>> ParsedAttributes &attrs,
>> BalancedDelimiterTracker &Tracker) {
>> if (index == Ident.size()) {
>> - while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof) &&
>> - !tryParseMisplacedModuleImport()) {
>> + while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
>> + Tok.isNot(tok::eof)) {
>> ParsedAttributesWithRange attrs(AttrFactory);
>> MaybeParseCXX11Attributes(attrs);
>> MaybeParseMicrosoftAttributes(attrs);
>> @@ -3064,8 +3064,8 @@ void Parser::ParseCXXMemberSpecification
>>
>> if (TagDecl) {
>> // While we still have something to read, read the
>> member-declarations.
>> - while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof) &&
>> - !tryParseMisplacedModuleImport()) {
>> + while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
>> + Tok.isNot(tok::eof)) {
>> // Each iteration of this loop reads one member-declaration.
>> ParseCXXClassMemberDeclarationWithPragmas(
>> CurAS, AccessAttrs, static_cast<DeclSpec::TST>(TagType),
>> TagDecl);
>>
>> Modified: cfe/trunk/lib/Parse/ParseStmt.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseStmt.cpp?rev=253398&r1=253397&r2=253398&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Parse/ParseStmt.cpp (original)
>> +++ cfe/trunk/lib/Parse/ParseStmt.cpp Tue Nov 17 17:32:01 2015
>> @@ -948,8 +948,8 @@ StmtResult Parser::ParseCompoundStatemen
>> Stmts.push_back(R.get());
>> }
>>
>> - while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof) &&
>> - !tryParseMisplacedModuleImport()) {
>> + while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
>> + Tok.isNot(tok::eof)) {
>> if (Tok.is(tok::annot_pragma_unused)) {
>> HandlePragmaUnused();
>> continue;
>>
>> Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=253398&r1=253397&r2=253398&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
>> +++ cfe/trunk/lib/Sema/SemaDecl.cpp Tue Nov 17 17:32:01 2015
>> @@ -14500,8 +14500,8 @@ Decl *Sema::ActOnFileScopeAsmDecl(Expr *
>> }
>>
>> static void checkModuleImportContext(Sema &S, Module *M,
>> - SourceLocation ImportLoc,
>> - DeclContext *DC) {
>> + SourceLocation ImportLoc,
>> DeclContext *DC,
>> + bool FromInclude = false) {
>> SourceLocation ExternCLoc;
>>
>> if (auto *LSD = dyn_cast<LinkageSpecDecl>(DC)) {
>> @@ -14520,7 +14520,9 @@ static void checkModuleImportContext(Sem
>> DC = DC->getParent();
>>
>> if (!isa<TranslationUnitDecl>(DC)) {
>> - S.Diag(ImportLoc, diag::err_module_import_not_at_top_level_fatal)
>> + S.Diag(ImportLoc, (FromInclude && S.isModuleVisible(M))
>> + ? diag::ext_module_import_not_at_top_level_noop
>> + :
>> diag::err_module_import_not_at_top_level_fatal)
>> << M->getFullModuleName() << DC;
>> S.Diag(cast<Decl>(DC)->getLocStart(),
>> diag::note_module_import_not_at_top_level) << DC;
>> @@ -14579,7 +14581,7 @@ DeclResult Sema::ActOnModuleImport(Sourc
>> }
>>
>> void Sema::ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod) {
>> - checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext);
>> + checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true);
>>
>> // Determine whether we're in the #include buffer for a module. The
>> #includes
>> // in that buffer do not qualify as module imports; they're just an
>>
>> Modified: cfe/trunk/test/Modules/auto-module-import.m
>> URL:
>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/auto-module-import.m?rev=253398&r1=253397&r2=253398&view=diff
>>
>> ==============================================================================
>> --- cfe/trunk/test/Modules/auto-module-import.m (original)
>> +++ cfe/trunk/test/Modules/auto-module-import.m Tue Nov 17 17:32:01 2015
>> @@ -1,6 +1,7 @@
>> // RUN: rm -rf %t
>> // RUN: %clang_cc1 -Wauto-import -fmodules-cache-path=%t -fmodules
>> -fimplicit-module-maps -F %S/Inputs %s -verify -DERRORS
>> // RUN: %clang_cc1 -Wauto-import -fmodules-cache-path=%t -fmodules
>> -fimplicit-module-maps -F %S/Inputs %s -verify
>> +// RUN: %clang_cc1 -Wauto-import -fmodules-cache-path=%t -fmodules
>> -fimplicit-module-maps -F %S/Inputs -xobjective-c++ %s -verify
>> //
>> // Test both with and without the declarations that refer to unimported
>> // entities. For error recovery, those cases implicitly trigger an
>> import.
>> @@ -85,5 +86,16 @@ int getNotInModule() {
>>
>> void includeNotAtTopLevel() { // expected-note {{function
>> 'includeNotAtTopLevel' begins here}}
>> #include <NoUmbrella/A.h> // expected-warning {{treating #include as
>> an import}} \
>> - expected-error {{import of module
>> 'NoUmbrella.A' appears within function 'includeNotAtTopLevel'}}
>> + expected-error {{redundant #include of
>> module 'NoUmbrella.A' appears within function 'includeNotAtTopLevel'}}
>> }
>> +
>> +#ifdef __cplusplus
>> +namespace NS { // expected-note {{begins here}}
>> +#include <NoUmbrella/A.h> // expected-warning {{treating #include as an
>> import}} \
>> + expected-error {{redundant #include of
>> module 'NoUmbrella.A' appears within namespace 'NS'}}
>> +}
>> +extern "C" { // expected-note {{begins here}}
>> +#include <NoUmbrella/A.h> // expected-warning {{treating #include as an
>> import}} \
>> + expected-error {{import of C++ module
>> 'NoUmbrella.A' appears within extern "C"}}
>> +}
>> +#endif
>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20151117/52513ff9/attachment-0001.html>
More information about the cfe-commits
mailing list