cfs-sys: Added workaround for pointer constant

CFE_ES_TASK_STACK_ALLOCATE turns out to be a constant of a pointer
type... which appears to throw bindgen for a loop. This commit
places our replacement in cfs-shims.c and let the linker sort it out.

cfs-sys/build.rs

@@ -14,8 +14,9 @@ fn main() {
     let api_header = pb(&[&in_dir, "cfs-api.h"]).to_string_unwrap();
     let shims_header = pb(&[&in_dir, "cfs-shims.h"]).to_string_unwrap();
     let out_file = pb(&[&out_dir, "cfs-all.rs"]).to_string_unwrap();
+    let shims_c = pb(&[&out_dir, "cfs-shims.c"]).to_string_unwrap();
 
-    for f in [&api_header, &shims_header] {
+    for f in [&api_header, &shims_header, &shims_c] {
         println!("cargo:rerun-if-changed={}", f);
     }
 

cfs-sys/cfs-api.h

@@ -187,13 +187,15 @@ X(CFE_ES_COUNTERID_UNDEFINED, CFE_ES_CounterId_t)
 X(CFE_ES_LIBID_UNDEFINED, CFE_ES_LibId_t)
 X(CFE_ES_MEMHANDLE_UNDEFINED, CFE_ES_MemHandle_t)
 X(CFE_ES_TASKID_UNDEFINED, CFE_ES_TaskId_t)
-X(CFE_ES_TASK_STACK_ALLOCATE, CFE_ES_StackPointer_t)
 X(CFE_RESOURCEID_RESERVED, CFE_ResourceId_t)
 X(CFE_RESOURCEID_UNDEFINED, CFE_ResourceId_t)
 X(CFE_SB_MSGID_RESERVED, CFE_SB_MsgId_t)
 X(CFE_SB_INVALID_MSG_ID, CFE_SB_MsgId_t)
 X(CFE_TBL_BAD_TABLE_HANDLE, CFE_TBL_Handle_t)
 X(OS_OBJECT_ID_UNDEFINED, osal_id_t)
 
+/* see cfs-shims.c */
+extern CFE_ES_StackPointer_t X_CFE_ES_TASK_STACK_ALLOCATE;
+
 const uint8 X_CFE_SB_DEFAULT_QOS_PRIORITY = CFE_SB_DEFAULT_QOS.Priority;
 const uint8 X_CFE_SB_DEFAULT_QOS_RELIABILITY = CFE_SB_DEFAULT_QOS.Reliability;

cfs-sys/cfs-shims.c

@@ -22,3 +22,6 @@
     }
 
 #include "cfs-shims.h"
+
+/* Bindgen *really* doesn't want to handle pointer constants. This is a workaround for that. */
+CFE_ES_StackPointer_t X_CFE_ES_TASK_STACK_ALLOCATE = CFE_ES_TASK_STACK_ALLOCATE;