re PR c/34351 (Please get us the "volatile register" warning back)

2008-02-26  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>

	PR 34351
	* doc/invoke.texi (-Wall): Add -Wvolatile-register-var.
	* c-opts.c (c_common_handle_option): Wall enables
	Wvolatile-register-var.
	* common.opt: Move Wvolatile-register-var to...
	* c.opt: ...here.
testsuite/
	* gcc.dg/pr34351.c: New.

From-SVN: r132675

gcc/ChangeLog

 2008-02-26  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
 
+	PR 34351
+	* doc/invoke.texi (-Wall): Add -Wvolatile-register-var.
+	* c-opts.c (c_common_handle_option): Wall enables
+	Wvolatile-register-var.
+	* common.opt: Move Wvolatile-register-var to...
+	* c.opt: ...here.
+	
+2008-02-26  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+
 	* common.opt (Wlarger-than=): New.
 	* doc/invoke.texi (Warning Options): Replace -Wlarger-than- with
 	-Wlarger-than=.

gcc/c-opts.c

@@ -407,6 +407,7 @@ c_common_handle_option (size_t scode, const char *arg, int value)
       if (warn_strict_overflow == -1)
 	warn_strict_overflow = value;
       warn_array_bounds = value;
+      warn_volatile_register_var = value;
 
       /* Only warn about unknown pragmas that are not in system
 	 headers.  */

gcc/c.opt

@@ -465,6 +465,10 @@ Wvla
 C ObjC C++ ObjC++ Var(warn_vla) Init(-1) Warning
 Warn if a variable length array is used
 
+Wvolatile-register-var
+C ObjC C++ ObjC++ Var(warn_volatile_register_var) Warning
+Warn when a register variable is declared volatile
+
 Wwrite-strings
 C ObjC C++ ObjC++ Var(warn_write_strings) Warning
 In C++, nonzero means warn about deprecated conversion from string literals to `char *'.  In C, similar warning, except that the conversion is of course not deprecated by the ISO C standard.

gcc/common.opt

@@ -232,10 +232,6 @@ Wunused-variable
 Common Var(warn_unused_variable) Warning
 Warn when a variable is unused
 
-Wvolatile-register-var
-Common Var(warn_register_var) Warning
-Warn when a register variable is declared volatile
-
 Wcoverage-mismatch
 Common RejectNegative Var(warn_coverage_mismatch) Warning
 Warn instead of error in case profiles in -fprofile-use do not match

gcc/doc/invoke.texi

@@ -2683,6 +2683,7 @@ Options} and @ref{Objective-C and Objective-C++ Dialect Options}.
 -Wunused-label     @gol
 -Wunused-value     @gol
 -Wunused-variable  @gol
+-Wvolatile-register-var @gol
 }
 
 Note that some warning flags are not implied by @option{-Wall}.  Some of
@@ -4017,7 +4018,8 @@ the variable length array.
 @opindex Wno-volatile-register-var
 Warn if a register variable is declared volatile.  The volatile
 modifier does not inhibit all optimizations that may eliminate reads
-and/or writes to register variables.
+and/or writes to register variables.  This warning is enabled by
+@option{-Wall}.
 
 @item -Wdisabled-optimization
 @opindex Wdisabled-optimization

gcc/testsuite/ChangeLog

 2008-02-26  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+	
+	* gcc.dg/pr34351.c: New.
+	
+2008-02-26  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
 
 	* gcc.dg/Wlarger-than2.c: New.
 	

gcc/testsuite/gcc.dg/pr34351.c

+/* { dg-do compile } */
+/* { dg-options "-Wall" } */
+
+register int * volatile x asm ("r13"); /* { dg-warning "optimization may eliminate reads and/or writes to register variables" } */