[test] api-digester: add a test to ensure the dumped module content is expected.

Author: nkcsgexi

test/api-digester/Inputs/cake.swift

@@ -0,0 +1,4 @@
+public struct S1 {
+  public func foo1() {}
+  public func foo2() {}
+}

test/api-digester/Outputs/cake.json

@@ -0,0 +1,66 @@
+{
+  "kind": "Root",
+  "name": "TopLevel",
+  "printedName": "TopLevel",
+  "children": [
+    {
+      "kind": "TypeDecl",
+      "name": "S1",
+      "printedName": "S1",
+      "declKind": "Struct",
+      "usr": "s:V4cake2S1",
+      "location": "",
+      "moduleName": "cake",
+      "children": [
+        {
+          "kind": "Function",
+          "name": "foo1",
+          "printedName": "foo1()",
+          "declKind": "Func",
+          "usr": "s:FV4cake2S14foo1FT_T_",
+          "location": "",
+          "moduleName": "cake",
+          "children": [
+            {
+              "kind": "TypeNominal",
+              "name": "Void",
+              "printedName": "()"
+            }
+          ]
+        },
+        {
+          "kind": "Function",
+          "name": "foo2",
+          "printedName": "foo2()",
+          "declKind": "Func",
+          "usr": "s:FV4cake2S14foo2FT_T_",
+          "location": "",
+          "moduleName": "cake",
+          "children": [
+            {
+              "kind": "TypeNominal",
+              "name": "Void",
+              "printedName": "()"
+            }
+          ]
+        },
+        {
+          "kind": "Constructor",
+          "name": "init",
+          "printedName": "init()",
+          "declKind": "Constructor",
+          "usr": "s:FV4cake2S1cFT_S0_",
+          "location": "",
+          "moduleName": "cake",
+          "children": [
+            {
+              "kind": "TypeNominal",
+              "name": "S1",
+              "printedName": "S1"
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/api-digester/dump-module.swift

@@ -0,0 +1,7 @@
+// RUN: rm -rf %t.mod && mkdir -p %t.mod
+// RUN: rm -rf %t.sdk && mkdir -p %t.sdk
+// RUN: rm -rf %t.module-cache && mkdir -p %t.module-cache
+// RUN: %swift -emit-module -o %t.mod/cake.swiftmodule %S/Inputs/cake.swift -parse-as-library
+// RUN: %api-digester -dump-sdk -module cake -o %t.dump.json -module-cache-path %t.module-cache -sdk %t.sdk -swift-version 3.0 -I %t.mod
+// RUN: diff -u %t.dump.json %S/Outputs/cake.json
+// RUN: %api-digester -diagnose-sdk --input-paths %t.dump.json -input-paths %S/Outputs/cake.json

tools/swift-api-digester/swift-api-digester.cpp

@@ -98,6 +98,9 @@ ResourceDir("resource-dir",
 static llvm::cl::list<std::string>
 FrameworkPaths("F", llvm::cl::desc("add a directory to the framework search path"));
 
+static llvm::cl::list<std::string>
+ModuleInputPaths("I", llvm::cl::desc("add a module for input"));
+
 static llvm::cl::opt<bool>
 AbortOnModuleLoadFailure("abort-on-module-fail",
                         llvm::cl::desc("Abort if a module failed to load"));
@@ -3303,6 +3306,7 @@ static int prepareForDump(const char *Main,
     InitInvok.setRuntimeResourcePath(options::ResourceDir);
   }
   InitInvok.setFrameworkSearchPaths(options::FrameworkPaths);
+  InitInvok.setImportSearchPaths(options::ModuleInputPaths);
 
   if (!options::ModuleList.empty()) {
     if (readFileLineByLine(options::ModuleList, Modules))