[PATCH] Add sotruss-lib.h override mechanism for ports

[Chris Metcalf <cmetcalf at tilera dot com>]

---
This allows ports to add a "sotruss-lib.h" override like the current
"tst-audit.h" override.  The HAVE_ARCH_PLTENTER and HAVE_ARCH_PLTEXIT
defines don't appear to do anything at the moment, so I removed them.

I chose to implement a "negative sense" with a define that says "no
override is available" in sysdeps/generic/sotruss-lib.h.  That way ports
overrides can just provide the function definitions, and the absence
of the "no override is available" define signals that a function was
provided and no #warning should be issued.

The enter and exit functions are provided in separate #if/#elif/#elif/...
cascades in the current code.  I think a useful cleanup would be to merge
them together, particularly since this proposed "ports" model only allows
you to provide both or neither, but I didn't want to confuse the structure
of this patch.  If people think it's appropriate, I can refactor the file
so that it provides both enter and exit macros in a single #if clause,
or even just move all the bodies to separate "sotruss-lib.h" files in
each sysdep directory.

 ChangeLog                     |    6 ++++++
 elf/sotruss-lib.c             |    9 +++++----
 sysdeps/generic/sotruss-lib.h |   32 ++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 4 deletions(-)
 create mode 100644 sysdeps/generic/sotruss-lib.h

diff --git a/ChangeLog b/ChangeLog
index 8a138ef..6013486 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -0,0 +1,6 @@
+2012-05-15  Chris Metcalf  <cmetcalf@tilera.com>
+
+	* sysdeps/generic/sotruss-lib.h: New file.
+	* elf/sotruss-lib.h: Allow using <sotruss-lib.h> to provide
+	architecture-specific pltenter/pltexit definitions.
+
diff --git a/elf/sotruss-lib.c b/elf/sotruss-lib.c
index c2ab733..9c7b205 100644
--- a/elf/sotruss-lib.c
+++ b/elf/sotruss-lib.c
@@ -322,8 +322,6 @@ la_sparc64_gnu_pltenter (Elf64_Sym *sym __attribute__ ((unused)),
 
   return sym->st_value;
 }
-#elif !defined HAVE_ARCH_PLTENTER
-# warning "pltenter for architecture not supported"
 #endif
 
 
@@ -381,6 +379,9 @@ la_sparc64_gnu_pltexit (Elf64_Sym *sym, unsigned int ndx, uintptr_t *refcook,
 
   return 0;
 }
-#elif !defined HAVE_ARCH_PLTEXIT
-# warning "pltexit for architecture not supported"
+#else
+# include <sotruss-lib.h>
+# ifdef SOTRUSS_LIB_GENERIC
+#  warning "sotruss-lib pltenter/pltexit for architecture not supported"
+# endif
 #endif
diff --git a/sysdeps/generic/sotruss-lib.h b/sysdeps/generic/sotruss-lib.h
new file mode 100644
index 0000000..1dfa921
--- /dev/null
+++ b/sysdeps/generic/sotruss-lib.h
@@ -0,0 +1,32 @@
+/* Some machines have these functions defined in elf/sotruss-lib.c directly.
+   New machines can supply a sotruss-lib.h to define these functions.
+
+ElfNN_Addr
+la_CPU_gnu_pltenter (ElfNN_Sym *sym __attribute__ ((unused)),
+		     unsigned int ndx __attribute__ ((unused)),
+		     uintptr_t *refcook, uintptr_t *defcook,
+		     La_CPU_regs *regs, unsigned int *flags,
+		     const char *symname, long int *framesizep)
+{
+  print_enter (refcook, defcook, symname,
+	       regs->lr_ARGREG0, regs->lr_ARGREG1, regs->lr_ARGREG2, *flags);
+
+  *framesizep = 0;
+
+  return sym->st_value;
+}
+
+unsigned int
+la_CPU_gnu_pltexit (ElfNN_Sym *sym, unsigned int ndx, uintptr_t *refcook,
+		    uintptr_t *defcook, const struct La_CPU_regs *inregs,
+		    struct La_CPU_retval *outregs, const char *symname)
+{
+  print_exit (refcook, defcook, symname, outregs->lrv_RETVALREG);
+
+  return 0;
+}
+
+*/
+
+/* This define indicates that no overriding sotruss-lib.h was found. */
+#define SOTRUSS_LIB_GENERIC
-- 
1.6.5.2