Fix multiple definition errors with GCC>=10.1.0 by seperating definit…

…ions from declarations

src/clib/CMakeLists.txt

@@ -9,7 +9,7 @@ project (PIOC C)
 add_library (pioc topology.c pio_file.c pioc_support.c pio_lists.c
   pioc.c pioc_sc.c pio_spmd.c pio_rearrange.c pio_nc4.c bget.c
   pio_nc.c pio_put_nc.c pio_get_nc.c pio_getput_int.c pio_msg.c
-  pio_darray.c pio_darray_int.c pio_get_vard.c pio_put_vard.c)
+  pio_darray.c pio_darray_int.c pio_get_vard.c pio_put_vard.c pio_error.c)
 
 # set up include-directories
 include_directories(

src/clib/pio_error.c

@@ -0,0 +1,21 @@
+/**
+ * @file
+ * Definition for Macros to handle errors in tests or libray code.
+ * @author Ed Hartnett
+ * @date 2020
+ *
+ * @see https://github.com/NCAR/ParallelIO
+ */
+
+/**
+ * Global err buffer for MPI. When there is an MPI error, this buffer
+ * is used to store the error message that is associated with the MPI
+ * error.
+ */
+char err_buffer[MPI_MAX_ERROR_STRING];
+
+/**
+ * This is the length of the most recent MPI error message, stored
+ * int the global error string.
+ */
+int resultlen;

src/clib/pio_error.h

@@ -74,12 +74,12 @@
  * is used to store the error message that is associated with the MPI
  * error.
  */
-char err_buffer[MPI_MAX_ERROR_STRING];
+extern char err_buffer[MPI_MAX_ERROR_STRING];
 
 /**
  * This is the length of the most recent MPI error message, stored
  * int the global error string.
  */
-int resultlen;
+extern int resultlen;
 
 #endif /* __PIO_ERROR__ */