Add workaround for libc problem with termination status macros, so they work with constant argument

git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@2788 9d0c8265-081b-0410-96cb-a4ca84ce46f8

1 files changed, 13 insertions, 1 deletions

diff --git a/lib/libsystem.c b/lib/libsystem.c
index e13a20ac..9491c03a 100644
--- a/lib/libsystem.c
+++ b/lib/libsystem.c
@@ -320,12 +320,24 @@ signalName(unsigned int const signalClass) {
 
 
 const char *
-pm_termStatusDesc(int const termStatus) {
+pm_termStatusDesc(int const termStatusArg) {
 /*----------------------------------------------------------------------------
    English description of  process termination status 'termStatus'.
 -----------------------------------------------------------------------------*/
     const char * retval;
 
+    /* WIFEXITED, etc. do not work with a constant argument in older GNU C
+       library.  Compilation fails with "attempt to assign read-only
+       location".  This is because The GNU C library has some magic to allow
+       for a BSD 'union wait' (instead of int) argument to WIFEXITED.  The
+       magic involves defining a variable with 'typeof' the argument and
+       assigning to that variable.
+       
+       To work around this, we make sure the argument is not constant.
+    */
+
+    int termStatus = termStatusArg;
+
     if (WIFEXITED(termStatus)) {
         int const exitStatus = WEXITSTATUS(termStatus);