Added accessors for the data needed for PDB lookup

- The existing `get_pe_debug_guid` function has been updated to optionally output the path to the PDB as extracted from the PE header. The existing user of this function (`mono_ppdb_load_file`) passes NULL as argument for the new path argument. These are all the fields that are needed for PDB lookup in symbol servers and such.
- Added `mono_ppdb_get_signature`, which internally just calls `get_pe_debug_guid`, but is exported
- Exported the existing `mono_unity_method_get_token` function so that it can be used from profiler modules. The method token is needed for lookup of method data inside a PDB.

removing whitespace change

Author: rovarma

mono/metadata/debug-mono-ppdb.c

@@ -48,6 +48,7 @@ typedef struct {
 	gint32 signature;
 	guint8 guid [16];
 	gint32 age;
+	char path [];
 } CodeviewDebugDirectory;
 
 typedef struct {
@@ -66,7 +67,7 @@ enum {
 };
 
 static gboolean
-get_pe_debug_info (MonoImage *image, guint8 *out_guid, gint32 *out_age, gint32 *out_timestamp, guint8 **ppdb_data,
+get_pe_debug_info (MonoImage *image, const char** out_path, guint8 *out_guid, gint32 *out_age, gint32 *out_timestamp, guint8 **ppdb_data,
 				   int *ppdb_uncompressed_size, int *ppdb_compressed_size)
 {
 	MonoPEDirEntry *debug_dir_entry;
@@ -104,6 +105,10 @@ get_pe_debug_info (MonoImage *image, guint8 *out_guid, gint32 *out_age, gint32 *
 				*out_age = read32(data + 20);
 				*out_timestamp = debug_dir.time_date_stamp;
 				guid_found = TRUE;
+
+				if (out_path != NULL) {
+					*out_path = g_strdup (dir.path);
+				}
 			}
 		}
 		if (debug_dir.type == DEBUG_DIR_ENTRY_PPDB && debug_dir.major_version >= 0x100 && debug_dir.minor_version == 0x100) {
@@ -143,6 +148,14 @@ create_ppdb_file (MonoImage *ppdb_image, gboolean is_embedded_ppdb)
 	return ppdb;
 }
 
+gboolean
+mono_ppdb_get_signature(MonoImage *image, const char** out_path, guint8 *out_guid, gint32 *out_age, gint32 *out_timestamp)
+{
+	guint8 *ppdb_data = NULL;
+	int ppdb_size, ppdb_compressed_size;
+	return get_pe_debug_info (image, out_path, out_guid, out_age, out_timestamp, &ppdb_data, &ppdb_size, &ppdb_compressed_size);
+}
+
 MonoPPDBFile*
 mono_ppdb_load_file (MonoImage *image, const guint8 *raw_contents, int size)
 {
@@ -164,7 +177,7 @@ mono_ppdb_load_file (MonoImage *image, const guint8 *raw_contents, int size)
 		return create_ppdb_file (image, TRUE);
 	}
 
-	if (!get_pe_debug_info (image, pe_guid, &pe_age, &pe_timestamp, &ppdb_data, &ppdb_size, &ppdb_compressed_size)) {
+	if (!get_pe_debug_info (image, NULL, pe_guid, &pe_age, &pe_timestamp, &ppdb_data, &ppdb_size, &ppdb_compressed_size)) {
 		mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_ASSEMBLY, "Image '%s' has no debug directory.", image->name);
 		return NULL;
 	}

mono/metadata/debug-mono-ppdb.h

@@ -17,6 +17,9 @@
 #include <mono/metadata/metadata-internals.h>
 #include <mono/metadata/mono-debug.h>
 
+MONO_API gboolean
+mono_ppdb_get_signature (MonoImage *image, const char** out_path, guint8 *out_guid, gint32 *out_age, gint32 *out_timestamp);
+
 MonoPPDBFile*
 mono_ppdb_load_file (MonoImage *image, const guint8 *raw_contents, int size);
 

mono/metadata/unity-utils.h

@@ -96,7 +96,7 @@ guint64 mono_unity_method_get_hash(MonoMethod *method, gboolean inflate);
 MonoMethod* mono_unity_method_get_aot_array_helper_from_wrapper(MonoMethod *method);
 MonoObject* mono_unity_method_convert_return_type_if_needed(MonoMethod *method, void *value);
 MONO_API gboolean unity_mono_method_is_inflated(MonoMethod* method);
-guint32 mono_unity_method_get_token(MonoMethod *method);
+MONO_API guint32 mono_unity_method_get_token(MonoMethod *method);
 
 //domain
 void mono_unity_domain_install_finalize_runtime_invoke(MonoDomain* domain, RuntimeInvokeFunction callback);