+/* If PC is in a mips16 call or return stub, return the address of the target
+ PC, which is either the callee or the caller. There are several
+ cases which must be handled:
+
+ * If the PC is in __mips16_ret_{d,s}f, this is a return stub and the
+ target PC is in $31 ($ra).
+ * If the PC is in __mips16_call_stub_{1..10}, this is a call stub
+ and the target PC is in $2.
+ * If the PC at the start of __mips16_call_stub_{s,d}f_{0..10}, i.e.
+ before the jal instruction, this is effectively a call stub
+ and the the target PC is in $2. Otherwise this is effectively
+ a return stub and the target PC is in $18.
+
+ See the source code for the stubs in gcc/config/mips/mips16.S for
+ gory details.
+
+ This function implements the SKIP_TRAMPOLINE_CODE macro.
+*/
+
+CORE_ADDR
+mips_skip_stub (pc)
+ CORE_ADDR pc;
+{
+ char *name;
+ CORE_ADDR start_addr;
+
+ /* Find the starting address and name of the function containing the PC. */
+ if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0)
+ return 0;
+
+ /* If the PC is in __mips16_ret_{d,s}f, this is a return stub and the
+ target PC is in $31 ($ra). */
+ if (strcmp (name, "__mips16_ret_sf") == 0
+ || strcmp (name, "__mips16_ret_df") == 0)
+ return read_register (RA_REGNUM);
+
+ if (strncmp (name, "__mips16_call_stub_", 19) == 0)
+ {
+ /* If the PC is in __mips16_call_stub_{1..10}, this is a call stub
+ and the target PC is in $2. */
+ if (name[19] >= '0' && name[19] <= '9')
+ return read_register (2);
+
+ /* If the PC at the start of __mips16_call_stub_{s,d}f_{0..10}, i.e.
+ before the jal instruction, this is effectively a call stub
+ and the the target PC is in $2. Otherwise this is effectively
+ a return stub and the target PC is in $18. */
+ else if (name[19] == 's' || name[19] == 'd')
+ {
+ if (pc == start_addr)
+ {
+ /* Check if the target of the stub is a compiler-generated
+ stub. Such a stub for a function bar might have a name
+ like __fn_stub_bar, and might look like this:
+ mfc1 $4,$f13
+ mfc1 $5,$f12
+ mfc1 $6,$f15
+ mfc1 $7,$f14
+ la $1,bar (becomes a lui/addiu pair)
+ jr $1
+ So scan down to the lui/addi and extract the target
+ address from those two instructions. */
+
+ CORE_ADDR target_pc = read_register (2);
+ t_inst inst;
+ int i;
+
+ /* See if the name of the target function is __fn_stub_*. */
+ if (find_pc_partial_function (target_pc, &name, NULL, NULL) == 0)
+ return target_pc;
+ if (strncmp (name, "__fn_stub_", 10) != 0
+ && strcmp (name, "etext") != 0
+ && strcmp (name, "_etext") != 0)
+ return target_pc;
+
+ /* Scan through this _fn_stub_ code for the lui/addiu pair.
+ The limit on the search is arbitrarily set to 20
+ instructions. FIXME. */
+ for (i = 0, pc = 0; i < 20; i++, target_pc += MIPS_INSTLEN)
+ {
+ inst = mips_fetch_instruction (target_pc);
+ if ((inst & 0xffff0000) == 0x3c010000) /* lui $at */
+ pc = (inst << 16) & 0xffff0000; /* high word */
+ else if ((inst & 0xffff0000) == 0x24210000) /* addiu $at */
+ return pc | (inst & 0xffff); /* low word */
+ }
+
+ /* Couldn't find the lui/addui pair, so return stub address. */
+ return target_pc;
+ }
+ else
+ /* This is the 'return' part of a call stub. The return
+ address is in $r18. */
+ return read_register (18);
+ }
+ }
+ return 0; /* not a stub */
+}
+
+
+/* Return non-zero if the PC is inside a call thunk (aka stub or trampoline).
+ This implements the IN_SOLIB_CALL_TRAMPOLINE macro. */
+
+int
+mips_in_call_stub (pc, name)
+ CORE_ADDR pc;
+ char *name;
+{
+ CORE_ADDR start_addr;
+
+ /* Find the starting address of the function containing the PC. If the
+ caller didn't give us a name, look it up at the same time. */
+ if (find_pc_partial_function (pc, name ? NULL : &name, &start_addr, NULL) == 0)
+ return 0;
+
+ if (strncmp (name, "__mips16_call_stub_", 19) == 0)
+ {
+ /* If the PC is in __mips16_call_stub_{1..10}, this is a call stub. */
+ if (name[19] >= '0' && name[19] <= '9')
+ return 1;
+ /* If the PC at the start of __mips16_call_stub_{s,d}f_{0..10}, i.e.
+ before the jal instruction, this is effectively a call stub. */
+ else if (name[19] == 's' || name[19] == 'd')
+ return pc == start_addr;
+ }
+
+ return 0; /* not a stub */
+}
+
+
+/* Return non-zero if the PC is inside a return thunk (aka stub or trampoline).
+ This implements the IN_SOLIB_RETURN_TRAMPOLINE macro. */
+
+int
+mips_in_return_stub (pc, name)
+ CORE_ADDR pc;
+ char *name;
+{
+ CORE_ADDR start_addr;
+
+ /* Find the starting address of the function containing the PC. */
+ if (find_pc_partial_function (pc, NULL, &start_addr, NULL) == 0)
+ return 0;
+
+ /* If the PC is in __mips16_ret_{d,s}f, this is a return stub. */
+ if (strcmp (name, "__mips16_ret_sf") == 0
+ || strcmp (name, "__mips16_ret_df") == 0)
+ return 1;
+
+ /* If the PC is in __mips16_call_stub_{s,d}f_{0..10} but not at the start,
+ i.e. after the jal instruction, this is effectively a return stub. */
+ if (strncmp (name, "__mips16_call_stub_", 19) == 0
+ && (name[19] == 's' || name[19] == 'd')
+ && pc != start_addr)
+ return 1;
+
+ return 0; /* not a stub */
+}
+
+
+/* Return non-zero if the PC is in a library helper function that should
+ be ignored. This implements the IGNORE_HELPER_CALL macro. */
+
+int
+mips_ignore_helper (pc)
+ CORE_ADDR pc;
+{
+ char *name;
+
+ /* Find the starting address and name of the function containing the PC. */
+ if (find_pc_partial_function (pc, &name, NULL, NULL) == 0)
+ return 0;
+
+ /* If the PC is in __mips16_ret_{d,s}f, this is a library helper function
+ that we want to ignore. */
+ return (strcmp (name, "__mips16_ret_sf") == 0
+ || strcmp (name, "__mips16_ret_df") == 0);
+}
+
+