[PATCH v8 05/11] osdep: build with non-working system() function

[Joelle van Dyne <j@getutm.app>]

Build without error on hosts without a working system(). If system()
is called, return -1 with ENOSYS.

Signed-off-by: Joelle van Dyne <j@getutm.app>
---
 configure            | 20 ++++++++++++++++++++
 include/qemu/osdep.h | 12 ++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/configure b/configure
index d72ab22da5..de7487a0c7 100755
--- a/configure
+++ b/configure
@@ -5302,6 +5302,22 @@ but not implemented on your system"
     fi
 fi
 
+##########################################
+# check for system()
+# make sure there is no compile error
+
+have_system_function=no
+cat > $TMPC << EOF
+#include <stdlib.h>
+int main(void) {
+    return system("");
+}
+EOF
+if compile_prog "" "" ; then
+    have_system_function=yes
+fi
+
+
 ##########################################
 # End of CC checks
 # After here, no more $cc or $ld runs
@@ -6200,6 +6216,10 @@ if test "$secret_keyring" = "yes" ; then
   echo "CONFIG_SECRET_KEYRING=y" >> $config_host_mak
 fi
 
+if test "$have_system_function" = "yes" ; then
+  echo "HAVE_SYSTEM_FUNCTION=y" >> $config_host_mak
+fi
+
 echo "ROMS=$roms" >> $config_host_mak
 echo "MAKE=$make" >> $config_host_mak
 echo "PYTHON=$python" >> $config_host_mak
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index a434382c58..5bd1a67769 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -682,4 +682,16 @@ char *qemu_get_host_name(Error **errp);
  */
 size_t qemu_get_host_physmem(void);
 
+/**
+ * Platforms which do not support system() return ENOSYS
+ */
+#ifndef HAVE_SYSTEM_FUNCTION
+#define system platform_does_not_support_system
+static inline int platform_does_not_support_system(const char *command)
+{
+    errno = ENOSYS;
+    return -1;
+}
+#endif /* !HAVE_SYSTEM_FUNCTION */
+
 #endif
-- 
2.28.0