Add pragma to perform module import and use it in -E output.
Many of our supported configurations support modules but do not have any
first-class syntax to perform a module import. This leaves us with a problem:
there is no way to represent the expansion of a #include that imports a module
in the -E output for such languages. (We don't want to just leave it as a
#include because that requires the consumer of the preprocessed source to have
the same file system layout and include paths as the creator.)
This patch adds a new pragma:
#pragma clang module import MODULE.NAME.HERE
that imports a module, and changes -E and -frewrite-includes to use it when
rewriting a #include that maps to a module import. We don't make any attempt
to use a native language syntax import if one exists, to get more consistent
output. (If in the future, @import and #include have different semantics in
some way, the pragma will track the #include semantics.)
llvm-svn: 301725
diff --git a/clang/lib/Frontend/PrintPreprocessedOutput.cpp b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
index 42d609c..ffedf3c 100644
--- a/clang/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -324,43 +324,50 @@
StringRef SearchPath,
StringRef RelativePath,
const Module *Imported) {
- if (Imported) {
- // When preprocessing, turn implicit imports into @imports.
- // FIXME: This is a stop-gap until a more comprehensive "preprocessing with
- // modules" solution is introduced.
+ // In -dI mode, dump #include directives prior to dumping their content or
+ // interpretation.
+ if (DumpIncludeDirectives) {
startNewLineIfNeeded();
MoveToLine(HashLoc);
- if (PP.getLangOpts().ObjC2) {
- OS << "@import " << Imported->getFullModuleName() << ";"
- << " /* clang -E: implicit import for \"" << File->getName()
- << "\" */";
- } else {
- const std::string TokenText = PP.getSpelling(IncludeTok);
- assert(!TokenText.empty());
- OS << "#" << TokenText << " "
- << (IsAngled ? '<' : '"')
- << FileName
- << (IsAngled ? '>' : '"')
- << " /* clang -E: implicit import for module "
- << Imported->getFullModuleName() << " */";
- }
- // Since we want a newline after the @import, but not a #<line>, start a new
- // line immediately.
- EmittedTokensOnThisLine = true;
+ const std::string TokenText = PP.getSpelling(IncludeTok);
+ assert(!TokenText.empty());
+ OS << "#" << TokenText << " "
+ << (IsAngled ? '<' : '"') << FileName << (IsAngled ? '>' : '"')
+ << " /* clang -E -dI */";
+ setEmittedDirectiveOnThisLine();
startNewLineIfNeeded();
- } else {
- // Not a module import; it's a more vanilla inclusion of some file using one
- // of: #include, #import, #include_next, #include_macros.
- if (DumpIncludeDirectives) {
+ }
+
+ // When preprocessing, turn implicit imports into module import pragmas.
+ if (Imported) {
+ switch (IncludeTok.getIdentifierInfo()->getPPKeywordID()) {
+ case tok::pp_include:
+ case tok::pp_import:
+ case tok::pp_include_next:
startNewLineIfNeeded();
MoveToLine(HashLoc);
- const std::string TokenText = PP.getSpelling(IncludeTok);
- assert(!TokenText.empty());
- OS << "#" << TokenText << " "
+ OS << "#pragma clang module import " << Imported->getFullModuleName()
+ << " /* clang -E: implicit import for "
+ << "#" << PP.getSpelling(IncludeTok) << " "
<< (IsAngled ? '<' : '"') << FileName << (IsAngled ? '>' : '"')
- << " /* clang -E -dI */";
- setEmittedDirectiveOnThisLine();
+ << " */";
+ // Since we want a newline after the pragma, but not a #<line>, start a
+ // new line immediately.
+ EmittedTokensOnThisLine = true;
startNewLineIfNeeded();
+ break;
+
+ case tok::pp___include_macros:
+ // #__include_macros has no effect on a user of a preprocessed source
+ // file; the only effect is on preprocessing.
+ //
+ // FIXME: That's not *quite* true: it causes the module in question to
+ // be loaded, which can affect downstream diagnostics.
+ break;
+
+ default:
+ llvm_unreachable("unknown include directive kind");
+ break;
}
}
}