versioner: properly handle extern "C", "C++".

extern "C" and "C++" are parsed as a LinkageSpecDecl with the real Decl
as a child node. This leads to the preprocessor sticking its guard
between the extern specifier and the declaration.

Update the AST visitor to add a special-case for calculating the
SourceRange on a LinkageSpecDecl, and add a test.

Bug: https://github.com/android-ndk/ndk/issues/440
Test: python run_tests.py
Change-Id: I76445fe366cef46cfd2f16fb93d534d410c5edca

1 files changed, 27 insertions, 0 deletions

diff --git a/tools/versioner/tests/preprocessor_extern_cpp/expected/foo.h b/tools/versioner/tests/preprocessor_extern_cpp/expected/foo.h
new file mode 100644
index 000000000..9b2d122c9
--- /dev/null
+++ b/tools/versioner/tests/preprocessor_extern_cpp/expected/foo.h
@@ -0,0 +1,27 @@
+#define __RENAME(x) asm(#x)
+
+#if defined(__cplusplus)
+
+#if __ANDROID_API__ >= 24
+extern "C++" const char* strchrnul(const char*, int) __RENAME(strchrnul) __INTRODUCED_IN(24);
+#endif /* __ANDROID_API__ >= 24 */
+
+#endif
+
+#if defined(__cplusplus)
+extern "C" int foo();
+#endif
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+
+#if __ANDROID_API__ >= 24
+char* strchrnul(char*, int) __INTRODUCED_IN(24);
+#endif /* __ANDROID_API__ >= 24 */
+
+
+#if defined(__cplusplus)
+}
+#endif