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/test/Preprocessor/pp-modules.c b/clang/test/Preprocessor/pp-modules.c
index 09f3eee..8c283c6 100644
--- a/clang/test/Preprocessor/pp-modules.c
+++ b/clang/test/Preprocessor/pp-modules.c
@@ -3,13 +3,13 @@
// CHECK: int bar();
int bar();
-// CHECK: @import Module; /* clang -E: implicit import for "{{.*Headers[/\\]Module.h}}" */
+// CHECK: #pragma clang module import Module /* clang -E: implicit import for #include <Module/Module.h> */{{$}}
#include <Module/Module.h>
// CHECK: int foo();
int foo();
-// CHECK: @import Module; /* clang -E: implicit import for "{{.*Headers[/\\]Module.h}}" */
+// CHECK: #pragma clang module import Module /* clang -E: implicit import for #include <Module/Module.h> */{{$}}
#include <Module/Module.h>
#include "pp-modules.h" // CHECK: # 1 "{{.*}}pp-modules.h" 1
-// CHECK: @import Module; /* clang -E: implicit import for "{{.*}}Module.h" */{{$}}
+// CHECK: #pragma clang module import Module /* clang -E: implicit import for #include <Module/Module.h> */{{$}}
// CHECK: # 14 "{{.*}}pp-modules.c" 2