libSwiftScanner: add an API to invoke compiler in process

Author: nkcsgexi

include/swift-c/DependencyScan/DependencyScan.h

@@ -359,6 +359,9 @@ swiftscan_scanner_cache_load(swiftscan_scanner_t scanner,
 SWIFTSCAN_PUBLIC void
 swiftscan_scanner_cache_reset(swiftscan_scanner_t scanner);
 
+/// An entry point to invoke the compiler via a library call.
+SWIFTSCAN_PUBLIC int invoke_swift_compiler(int argc, const char **argv);
+
 //===----------------------------------------------------------------------===//
 
 SWIFTSCAN_END_DECLS

tools/libSwiftScan/CMakeLists.txt

@@ -17,7 +17,8 @@ add_dependencies(libSwiftScan
 
 target_link_libraries(libSwiftScan PRIVATE
     swiftDependencyScan
-    swiftDriverTool)
+    swiftDriverTool
+    libswift)
 
 set_target_properties(libSwiftScan
     PROPERTIES

tools/libSwiftScan/libSwiftScan.cpp

@@ -15,6 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "swift/Basic/LLVMInitialize.h"
+#include "swift/DriverTool/DriverTool.h"
 #include "swift/DependencyScan/DependencyScanImpl.h"
 #include "swift/DependencyScan/DependencyScanningTool.h"
 #include "swift/DependencyScan/StringUtils.h"
@@ -510,3 +511,7 @@ swiftscan_compiler_supported_features_query() {
   // TODO: We are yet to figure out how "Features" will be organized.
   return nullptr;
 }
+
+int invoke_swift_compiler(int argc, const char **argv) {
+  return swift::mainEntry(argc, argv);
+}

tools/libSwiftScan/libSwiftScan.exports

@@ -57,3 +57,4 @@ swiftscan_compiler_supported_features_query
 swiftscan_scanner_cache_serialize
 swiftscan_scanner_cache_load
 swiftscan_scanner_cache_reset
+invoke_swift_compiler