[clang-ifs] Clang Interface Stubs, first version (second landing attempt).

This change reverts r363649; effectively re-landing r363626. At this point
clang::Index::CodegenNameGeneratorImpl has been refactored into
clang::AST::ASTNameGenerator. This makes it so that the previous circular link
dependency no longer exists, fixing the previous share lib
(-DBUILD_SHARED_LIBS=ON) build issue which was the reason for r363649.

Clang interface stubs (previously referred to as clang-ifsos) is a new frontend
action in clang that allows the generation of stub files that contain mangled
name info that can be used to produce a stub library. These stub libraries can
be useful for breaking up build dependencies and controlling access to a
library's internal symbols. Generation of these stubs can be invoked by:

clang -fvisibility=<visibility> -emit-interface-stubs \
                                -interface-stub-version=<interface format>

Notice that -fvisibility (along with use of visibility attributes) can be used
to control what symbols get generated. Currently the interface format is
experimental but there are a wide range of possibilities here.

Currently clang-ifs produces .ifs files that can be thought of as analogous to
object (.o) files, but just for the mangled symbol info. In a subsequent patch
I intend to add support for merging the .ifs files into one .ifs/.ifso file
that can be the input to something like llvm-elfabi to produce something like a
.so file or .dll (but without any of the code, just symbols).

Differential Revision: https://reviews.llvm.org/D60974

llvm-svn: 363948

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
index b6a20a7bb6c..69e773658c5 100644
--- a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -64,6 +64,10 @@ CreateFrontendBaseAction(CompilerInstance &CI) {
   case GenerateHeaderModule:
     return llvm::make_unique<GenerateHeaderModuleAction>();
   case GeneratePCH:            return llvm::make_unique<GeneratePCHAction>();
+  case GenerateInterfaceYAMLExpV1:
+    return llvm::make_unique<GenerateInterfaceYAMLExpV1Action>();
+  case GenerateInterfaceTBEExpV1:
+    return llvm::make_unique<GenerateInterfaceTBEExpV1Action>();
   case InitOnly:               return llvm::make_unique<InitOnlyAction>();
   case ParseSyntaxOnly:        return llvm::make_unique<SyntaxOnlyAction>();
   case ModuleFileInfo:         return llvm::make_unique<DumpModuleInfoAction>();