Add VxWorks fixincludes hack, open posix API for C++

When system headers expose a strict "open" prototype with
3 args, arrange to expose a C++ overload with only two.

2021-01-10  Olivier Hainque  <hainque@adacore.com>

	* inclhack.def (vxworks_math_h_fp_c99): New hack.
	* tests/base/fcntl.h: Update.
	* fixincl.x: Regenerate.

1 files changed, 41 insertions, 0 deletions

diff --git a/fixincludes/inclhack.def b/fixincludes/inclhack.def
index 60d7fd6..8400d0c 100644
--- a/fixincludes/inclhack.def
+++ b/fixincludes/inclhack.def
@@ -5297,6 +5297,47 @@ fix = {
 };
 
 /*
+ * Likewise, open's posix interface allows two or three arguments and
+ * some VxWorks headers expose only a strict 3 arguments version.  Merely
+ * changing the prototype into a varargs one is risky as the implementation
+ * would receive garbage in the third arg for calls providing only two,
+ * which libstdc++ does.  We simply provide an always inline overload for C++
+ * instead.
+ *
+ * Both fcntl.h and ioLib.h might "feature" such a prototype for _WRS_KERNEL.
+ * The latter #includes the former though (since 1992 according to the embedded
+ * log), so just leave ioLib.h alone.
+ */
+fix = {
+    hackname    = vxworks_posix_open;
+    mach        = "*-*-vxworks*";
+    files       = fcntl.h;
+
+    select      = "extern int.*open \\(const char \\*[ a-z]*, int[ a-z]*, int[ a-z]*\\);";
+    c_fix       = format;
+    c_fix_arg = << _EOArg_
+%0
+
+#if defined(__cplusplus)
+extern "C++" {
+  inline int open (const char *, int) __attribute__((__always_inline__));
+
+  inline int
+  open (const char *name, int flags)
+  {
+    return open (name, flags, 0);
+  }
+}
+#endif
+
+_EOArg_;
+
+    test_text   =
+      "extern int open (const char *, int, int);\n"
+      "extern int open (const char *name, int flags, int mode );\n";
+};
+
+/*
  *  Another bad dependency in VxWorks 5.2 <time.h>.
  */
 fix = {