[clang-diff] Add initial implementation

This is the first commit for the "Clang-based C/C++ diff tool" GSoC project.

ASTDiff is a new library that computes a structural AST diff between two ASTs
using the gumtree algorithm. Clang-diff is a new Clang tool that will show
the structural code changes between different ASTs.

Patch by Johannes Altmanninger!

Differential Revision: https://reviews.llvm.org/D34329


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@308731 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 78 insertions, 0 deletions

diff --git a/test/Tooling/clang-diff-basic.cpp b/test/Tooling/clang-diff-basic.cpp
new file mode 100644
index 0000000000..1f0a2a9357
--- /dev/null
+++ b/test/Tooling/clang-diff-basic.cpp
@@ -0,0 +1,78 @@
+// RUN: %clang_cc1 -E %s > %T/src.cpp
+// RUN: %clang_cc1 -E %s > %T/dst.cpp -DDEST
+// RUN: clang-diff -no-compilation-database %T/src.cpp %T/dst.cpp | FileCheck %s
+
+#ifndef DEST
+namespace src {
+
+void foo() {
+  int x = 321;
+}
+
+void main() { foo(); };
+
+const char *a = "foo";
+
+typedef unsigned int nat;
+
+int p = 1 * 2 * 3 * 4;
+int squared = p * p;
+
+class X {
+  const char *foo(int i) {
+    if (i == 0)
+      return "foo";
+    return 0;
+  }
+
+public:
+  X(){};
+
+  int id(int i) { return i; }
+};
+}
+#else
+// CHECK: Match TranslationUnitDecl{{.*}} to TranslationUnitDecl
+// CHECK: Match NamespaceDecl: src{{.*}} to NamespaceDecl: dst
+namespace dst {
+// CHECK-NOT: Match NamespaceDecl: src{{.*}} to NamespaceDecl: inner
+namespace inner {
+void foo() {
+  // CHECK: Match IntegerLiteral: 321{{.*}} to IntegerLiteral: 322
+  int x = 322;
+}
+}
+
+// CHECK: Match DeclRefExpr: foo{{.*}} to DeclRefExpr: inner::foo
+void main() { inner::foo(); }
+
+// CHECK: Match StringLiteral: foo{{.*}} to StringLiteral: foo
+const char *b = "f" "o" "o";
+
+// unsigned is canonicalized to unsigned int
+// CHECK: Match TypedefDecl: nat;unsigned int;{{.*}} to TypedefDecl: nat;unsigned int;
+typedef unsigned nat;
+
+// CHECK: Match VarDecl: p(int){{.*}} to VarDecl: prod(double)
+// CHECK: Match BinaryOperator: *{{.*}} to BinaryOperator: *
+// CHECK: Update VarDecl: p(int){{.*}} to prod(double)
+double prod = 1 * 2 * 10;
+// CHECK: Update DeclRefExpr
+int squared = prod * prod;
+
+class X {
+  const char *foo(int i) {
+    if (i == 0)
+      return "Bar";
+    // CHECK: Insert IfStmt{{.*}} into IfStmt
+    // CHECK: Insert BinaryOperator: =={{.*}} into IfStmt
+    else if (i == -1)
+      return "foo";
+    return 0;
+  }
+  // CHECK: Delete AccessSpecDecl: public
+  X(){};
+  // CHECK: Delete CXXMethodDecl
+};
+}
+#endif