plugins: add helper functions for coverage plugins

Which provide information about:
- start_code.
- end_code.
- entry.
- path to the executable binary.

Signed-off-by: Ivanov Arkady <arkadiy.ivanov@ispras.ru>
Message-Id: <163491883461.304355.8210754161847179432.stgit@pc-System-Product-Name>
[AJB: reword title, better descriptions, defaults, rm export, fix include]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220204204335.1689602-22-alex.bennee@linaro.org>

include/qemu/qemu-plugin.h

@@ -590,4 +590,38 @@ void qemu_plugin_outs(const char *string);
  */
 bool qemu_plugin_bool_parse(const char *name, const char *val, bool *ret);
 
+/**
+ * qemu_plugin_path_to_binary() - path to binary file being executed
+ *
+ * Return a string representing the path to the binary. For user-mode
+ * this is the main executable. For system emulation we currently
+ * return NULL. The user should g_free() the string once no longer
+ * needed.
+ */
+const char *qemu_plugin_path_to_binary(void);
+
+/**
+ * qemu_plugin_start_code() - returns start of text segment
+ *
+ * Returns the nominal start address of the main text segment in
+ * user-mode. Currently returns 0 for system emulation.
+ */
+uint64_t qemu_plugin_start_code(void);
+
+/**
+ * qemu_plugin_end_code() - returns end of text segment
+ *
+ * Returns the nominal end address of the main text segment in
+ * user-mode. Currently returns 0 for system emulation.
+ */
+uint64_t qemu_plugin_end_code(void);
+
+/**
+ * qemu_plugin_entry_code() - returns start address for module
+ *
+ * Returns the nominal entry address of the main text segment in
+ * user-mode. Currently returns 0 for system emulation.
+ */
+uint64_t qemu_plugin_entry_code(void);
+
 #endif /* QEMU_PLUGIN_API_H */