Introduce support for a simple module import declaration, which

loads the named module. The syntax itself is intentionally hideous and
will be replaced at some later point with something more
palatable. For now, we're focusing on the semantics:
  - Module imports are handled first by the preprocessor (to get macro
  definitions) and then the same tokens are also handled by the parser
  (to get declarations). If both happen (as in normal compilation),
  the second one is redundant, because we currently have no way to
  hide macros or declarations when loading a module. Chris gets credit
  for this mad-but-workable scheme.
  - The Preprocessor now holds on to a reference to a module loader,
  which is responsible for loading named modules. CompilerInstance is
  the only important module loader: it now knows how to create and
  wire up an AST reader on demand to actually perform the module load.
  - We search for modules in the include path, using the module name
  with the suffix ".pcm" (precompiled module) for the file name. This
  is a temporary hack; we hope to improve the situation in the
  future.

llvm-svn: 138679

4 files changed, 8 insertions, 0 deletions

diff --git a/clang/test/Modules/Inputs/diamond_bottom.h b/clang/test/Modules/Inputs/diamond_bottom.h
index 40afc9b1523..6351d028fbc 100644
--- a/clang/test/Modules/Inputs/diamond_bottom.h
+++ b/clang/test/Modules/Inputs/diamond_bottom.h
@@ -1 +1,4 @@
+__import__ diamond_left;
+__import__ diamond_right;
+
 char bottom(char *x);
diff --git a/clang/test/Modules/Inputs/diamond_left.h b/clang/test/Modules/Inputs/diamond_left.h
index 9758b85d974..8da494cccad 100644
--- a/clang/test/Modules/Inputs/diamond_left.h
+++ b/clang/test/Modules/Inputs/diamond_left.h
@@ -1,3 +1,5 @@
+__import__ diamond_top;
+
 float left(float *);
 
 int top_left(char *c);
diff --git a/clang/test/Modules/Inputs/diamond_right.h b/clang/test/Modules/Inputs/diamond_right.h
index 9adeb6a9a89..2efa277b1a9 100644
--- a/clang/test/Modules/Inputs/diamond_right.h
+++ b/clang/test/Modules/Inputs/diamond_right.h
@@ -1,3 +1,5 @@
+__import__ diamond_top;
+
 double right(double *);
 
 struct left_and_right {
diff --git a/clang/test/Modules/Inputs/load_failure.h b/clang/test/Modules/Inputs/load_failure.h
new file mode 100644
index 00000000000..5bcb44dcb3d
--- /dev/null
+++ b/clang/test/Modules/Inputs/load_failure.h
@@ -0,0 +1 @@
+int fail(int);