Added advice_header.c example plug-in.

diff --git a/src/aop-doxy-main.c b/src/aop-doxy-main.c
index 24323046a6f8f9a1011a364e667372df7aacf28e..3e97e7da22017b459d0c547a1350495bcde519e7 100644 (file)
--- a/src/aop-doxy-main.c
+++ b/src/aop-doxy-main.c
@@ -78,6 +78,22 @@
  * A plug-in adds one or more passes by calling aop_register_pass()
  * from its main function, which must be named <code>aop_main</code>.
  *
+ * See the \ref hello.c "Hello World" sample plug-in for a simple
+ * example of setting up a pass.
+ *
+ * \section advicetype Advice Function Type Safety
+ *
+ * When inserting a call to an advice function, InterAspect cannot
+ * directly check that the arguments passed to the advice match the
+ * actual advice function's prototype.  To avoid type mismatches, it
+ * is possible to use aop_write_c_header() to generate a header file
+ * that specifies the prototypes that InterAspect expects for each
+ * advice function.  You can include this header file in the file that
+ * implements your advice functions to ensure that the types match.
+ *
+ * See the \ref advice_header.c "advice_header" sample plug-in for an
+ * example of automatically generating an advice header.
+ *
  * \section memory Memory management
  *
  * InterAspect functions return various data structures that are

diff --git a/workspace/.gitignore b/workspace/.gitignore
index 8d7f82ca89529e4bc3f9f2651c2531fd5a754c0e..3260e0164834ba5c5a62bca5e74ac64459121f6b 100644 (file)
--- a/workspace/.gitignore
+++ b/workspace/.gitignore
@@ -1,6 +1,7 @@
 *.c
 *.so
 
-# There is one C file included as an example that should be
+# There are some C files included as examples that should be
 # distributed with InterAspect.
 !hello.c
+!advice_header.c

diff --git a/workspace/advice_header.c b/workspace/advice_header.c
new file mode 100644 (file)
index 0000000..875f4c0
--- /dev/null
+++ b/workspace/advice_header.c
@@ -0,0 +1,75 @@
+/* This sample plug-in demonstrates how to generate a C header with
+   prototypes for all the advice functions that InterAspect inserts
+   call to.
+
+   Whenever you compile a file with this plug-in, it will output an
+   advice.h header in the current directory.
+
+   Compile this plug-in with:
+
+   make libadvice_header.so
+*/
+
+#include <aop.h>
+#include <stdio.h>  /* For perror. */
+
+AOP_I_AM_GPL_COMPATIBLE();
+
+/* Join on a call to printf. */
+static void join_on_printf(struct aop_joinpoint *jp, void *data)
+{
+  struct aop_dynval *format;
+  struct aop_dynval *int_arg;
+
+  format = aop_capture_param(jp, 0);
+  int_arg = aop_capture_param_by_type(jp, 1, aop_t_all_signed());
+
+  if (int_arg == NULL) {
+    /* Second argument is not a signed integer. */
+    aop_insert_advice(jp, "__printf_advice", AOP_INSERT_BEFORE,
+                     AOP_DYNVAL(format), AOP_TERM_ARG);
+  }
+  else {
+    /* Second argument is a signed integer. */
+    aop_insert_advice(jp, "__printf_int_advice", AOP_INSERT_BEFORE,
+                     AOP_DYNVAL(format), AOP_DYNVAL(int_arg), AOP_TERM_ARG);
+  }
+}
+
+static unsigned int printf_instr_pass()
+{
+  struct aop_pointcut *pc;
+  const struct aop_type *char_star;
+
+  char_star = aop_t_pointer_to(aop_t_signed8());
+
+  pc = aop_match_function_call();
+  aop_filter_call_pc_by_name(pc, "printf");
+  aop_filter_call_pc_by_param(pc, 0, char_star);
+  aop_join_on(pc, join_on_printf, NULL);
+
+  return 0;
+}
+
+/* Override aop_finish() for any tasks you want to complete just
+   before compilation finishes.  This is the best place to put a call
+   to aop_write_c_header().
+
+   Note that if advice.h already exists, InterAspect will lock it (so
+   that parallel builds function correctly) and add any prototypes
+   that it is missing.  */
+void aop_finish()
+{
+  int res;
+
+  /* You may wish to use aop_get_arg_value() to get the name of the
+     header file from the command line. */
+  res = aop_write_c_header("advice.h", "_ADVICE_H_", NULL, NULL);
+  if (res != 0)
+    perror("advice.h");
+}
+
+AOP_MAIN_PROTO aop_main()
+{
+  aop_register_pass("printf-instr", printf_instr_pass);
+}