Attachment 30873 Details for Bug 53001 – Patch to add -Wfloat-conversion option

[patch] Patch to add -Wfloat-conversion option

warn_float_patch.diff (text/plain), 8.39 KB, created by Joshua Cogliati on 2013-09-20 17:27:11 UTC

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Creator: Joshua Cogliati

Created: 2013-09-20 17:27:11 UTC

Size: 8.39 KB

patch

obsolete

>diff -ur gcc-4.8.1_orig/gcc/c-family/c-common.c gcc-4.8.1/gcc/c-family/c-common.c
>--- gcc-4.8.1_orig/gcc/c-family/c-common.c	2013-05-14 14:52:27.000000000 -0600
>+++ gcc-4.8.1/gcc/c-family/c-common.c	2013-09-02 13:14:01.000000000 -0600
>@@ -294,6 +294,8 @@
>   {NULL, 0, 0},
> };
> 
>+enum conversion_safety {SAFE_CONVERSION=0,UNSAFE_OTHER,UNSAFE_SIGN,UNSAFE_REAL};
>+
> /* Global visibility options.  */
> struct visibility_flags visibility_options;
> 
>@@ -375,6 +377,8 @@
> static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *);
> static int resort_field_decl_cmp (const void *, const void *);
> 
>+static enum conversion_safety unsafe_conversion_p (tree, tree, bool);
>+
> /* Reserved words.  The third field is a mask: keywords are disabled
>    if they match the mask.
> 
>@@ -2481,10 +2485,10 @@
>    Function allows conversions between types of different signedness and
>    does not return true in that case.  Function can produce signedness
>    warnings if PRODUCE_WARNS is true.  */
>-bool
>+static enum conversion_safety
> unsafe_conversion_p (tree type, tree expr, bool produce_warns)
> {
>-  bool give_warning = false;
>+  enum conversion_safety give_warning = SAFE_CONVERSION; /* is 0 or false */
>   tree expr_type = TREE_TYPE (expr);
>   location_t loc = EXPR_LOC_OR_HERE (expr);
> 
>@@ -2496,7 +2500,7 @@
> 	  && TREE_CODE (type) == INTEGER_TYPE)
> 	{
> 	  if (!real_isinteger (TREE_REAL_CST_PTR (expr), TYPE_MODE (expr_type)))
>-	    give_warning = true;
>+	    give_warning = UNSAFE_REAL;
> 	}
>       /* Warn for an integer constant that does not fit into integer type.  */
>       else if (TREE_CODE (expr_type) == INTEGER_TYPE
>@@ -2517,7 +2521,7 @@
> 			    " constant value to negative integer");
> 	    }
> 	  else
>-	    give_warning = true;
>+	    give_warning = UNSAFE_OTHER;
> 	}
>       else if (TREE_CODE (type) == REAL_TYPE)
> 	{
>@@ -2526,7 +2530,7 @@
> 	    {
> 	      REAL_VALUE_TYPE a = real_value_from_int_cst (0, expr);
> 	      if (!exact_real_truncate (TYPE_MODE (type), &a))
>-		give_warning = true;
>+		give_warning = UNSAFE_REAL;
> 	    }
> 	  /* Warn for a real constant that does not fit into a smaller
> 	     real type.  */
>@@ -2535,7 +2539,7 @@
> 	    {
> 	      REAL_VALUE_TYPE a = TREE_REAL_CST (expr);
> 	      if (!exact_real_truncate (TYPE_MODE (type), &a))
>-		give_warning = true;
>+		give_warning = UNSAFE_REAL;
> 	    }
> 	}
>     }
>@@ -2544,7 +2548,7 @@
>       /* Warn for real types converted to integer types.  */
>       if (TREE_CODE (expr_type) == REAL_TYPE
> 	  && TREE_CODE (type) == INTEGER_TYPE)
>-	give_warning = true;
>+	give_warning = UNSAFE_REAL;
> 
>       else if (TREE_CODE (expr_type) == INTEGER_TYPE
> 	       && TREE_CODE (type) == INTEGER_TYPE)
>@@ -2582,7 +2586,7 @@
> 			  && int_fits_type_p (op1, c_common_signed_type (type))
> 			  && int_fits_type_p (op1,
> 					      c_common_unsigned_type (type))))
>-		    return false;
>+		    return SAFE_CONVERSION;
> 		  /* If constant is unsigned and fits in the target
> 		     type, then the result will also fit.  */
> 		  else if ((TREE_CODE (op0) == INTEGER_CST
>@@ -2591,12 +2595,12 @@
> 			   || (TREE_CODE (op1) == INTEGER_CST
> 			       && unsigned1
> 			       && int_fits_type_p (op1, type)))
>-		    return false;
>+		    return SAFE_CONVERSION;
> 		}
> 	    }
> 	  /* Warn for integer types converted to smaller integer types.  */
> 	  if (TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
>-	    give_warning = true;
>+	    give_warning = UNSAFE_OTHER;
> 
> 	  /* When they are the same width but different signedness,
> 	     then the value may change.  */
>@@ -2632,14 +2636,14 @@
> 
> 	  if (!exact_real_truncate (TYPE_MODE (type), &real_low_bound)
> 	      || !exact_real_truncate (TYPE_MODE (type), &real_high_bound))
>-	    give_warning = true;
>+	    give_warning = UNSAFE_OTHER;
> 	}
> 
>       /* Warn for real types converted to smaller real types.  */
>       else if (TREE_CODE (expr_type) == REAL_TYPE
> 	       && TREE_CODE (type) == REAL_TYPE
> 	       && TYPE_PRECISION (type) < TYPE_PRECISION (expr_type))
>-	give_warning = true;
>+	give_warning = UNSAFE_REAL;
>     }
> 
>   return give_warning;
>@@ -2653,8 +2657,9 @@
> {
>   tree expr_type = TREE_TYPE (expr);
>   location_t loc = EXPR_LOC_OR_HERE (expr);
>+  enum conversion_safety conversion_kind;
> 
>-  if (!warn_conversion && !warn_sign_conversion)
>+  if (!warn_conversion && !warn_sign_conversion && !warn_float_conversion)
>     return;
> 
>   switch (TREE_CODE (expr))
>@@ -2681,10 +2686,21 @@
> 
>     case REAL_CST:
>     case INTEGER_CST:
>-      if (unsafe_conversion_p (type, expr, true))
>-	warning_at (loc, OPT_Wconversion,
>-		    "conversion to %qT alters %qT constant value",
>-		    type, expr_type);
>+      if ((conversion_kind = unsafe_conversion_p (type, expr, true)))
>+	{
>+	  if(conversion_kind == UNSAFE_REAL) 
>+	    {
>+	      warning_at (loc, OPT_Wfloat_conversion,
>+			  "conversion to %qT alters %qT constant value",
>+			  type, expr_type);
>+	    } 
>+	  else 
>+	    {
>+	      warning_at (loc, OPT_Wconversion,
>+			  "conversion to %qT alters %qT constant value",
>+			  type, expr_type);
>+	    }
>+	}
>       return;
> 
>     case COND_EXPR:
>@@ -2700,10 +2716,21 @@
>       }
> 
>     default: /* 'expr' is not a constant.  */
>-      if (unsafe_conversion_p (type, expr, true))
>-	warning_at (loc, OPT_Wconversion,
>-		    "conversion to %qT from %qT may alter its value",
>-		    type, expr_type);
>+      if ((conversion_kind = unsafe_conversion_p (type, expr, true)))
>+	{
>+	  if(conversion_kind == UNSAFE_REAL)
>+	    {
>+	      warning_at (loc, OPT_Wfloat_conversion,
>+			  "conversion to %qT from %qT may alter its value",
>+			  type, expr_type);
>+	    } 
>+	  else
>+	    {
>+	      warning_at (loc, OPT_Wconversion,
>+			  "conversion to %qT from %qT may alter its value",
>+			  type, expr_type);
>+	    }
>+	}
>     }
> }
> 
>Only in gcc-4.8.1/gcc/c-family: c-common.c~
>diff -ur gcc-4.8.1_orig/gcc/c-family/c-common.h gcc-4.8.1/gcc/c-family/c-common.h
>--- gcc-4.8.1_orig/gcc/c-family/c-common.h	2013-01-10 13:38:27.000000000 -0700
>+++ gcc-4.8.1/gcc/c-family/c-common.h	2013-09-02 10:39:01.000000000 -0600
>@@ -735,7 +735,6 @@
> extern tree c_common_signed_or_unsigned_type (int, tree);
> extern void c_common_init_ts (void);
> extern tree c_build_bitfield_integer_type (unsigned HOST_WIDE_INT, int);
>-extern bool unsafe_conversion_p (tree, tree, bool);
> extern bool decl_with_nonnull_addr_p (const_tree);
> extern tree c_fully_fold (tree, bool, bool *);
> extern tree decl_constant_value_for_optimization (tree);
>Only in gcc-4.8.1/gcc/c-family: c-common.h~
>diff -ur gcc-4.8.1_orig/gcc/c-family/c.opt gcc-4.8.1/gcc/c-family/c.opt
>--- gcc-4.8.1_orig/gcc/c-family/c.opt	2013-01-18 22:25:25.000000000 -0700
>+++ gcc-4.8.1/gcc/c-family/c.opt	2013-09-20 11:08:11.000000000 -0600
>@@ -379,6 +379,10 @@
> C ObjC RejectNegative Warning Alias(Werror=, implicit-function-declaration)
> This switch is deprecated; use -Werror=implicit-function-declaration instead
> 
>+Wfloat-conversion
>+C ObjC C++ ObjC++ Var(warn_float_conversion) LangEnabledBy(C ObjC C++,Wconversion) EnabledBy(Wextra)
>+Warn for implicit type conversions that cause loss of floating point precision
>+
> Wfloat-equal
> C ObjC C++ ObjC++ Var(warn_float_equal) Warning
> Warn if testing floating point numbers for equality
>Only in gcc-4.8.1/gcc/c-family: c.opt~
>diff -ur gcc-4.8.1_orig/gcc/doc/invoke.texi gcc-4.8.1/gcc/doc/invoke.texi
>--- gcc-4.8.1_orig/gcc/doc/invoke.texi	2013-03-29 07:41:29.000000000 -0600
>+++ gcc-4.8.1/gcc/doc/invoke.texi	2013-09-20 09:49:18.000000000 -0600
>@@ -260,7 +260,8 @@
> -Wpointer-arith  -Wno-pointer-to-int-cast @gol
> -Wredundant-decls  -Wno-return-local-addr @gol
> -Wreturn-type  -Wsequence-point  -Wshadow @gol
>--Wsign-compare  -Wsign-conversion  -Wsizeof-pointer-memaccess @gol
>+-Wsign-compare  -Wsign-conversion -Wfloat-conversion @gol 
>+-Wsizeof-pointer-memaccess @gol
> -Wstack-protector -Wstack-usage=@var{len} -Wstrict-aliasing @gol
> -Wstrict-aliasing=n @gol -Wstrict-overflow -Wstrict-overflow=@var{n} @gol
> -Wsuggest-attribute=@r{[}pure@r{|}const@r{|}noreturn@r{|}format@r{]} @gol
>@@ -4384,6 +4385,14 @@
> integer variable. An explicit cast silences the warning. In C, this
> option is enabled also by @option{-Wconversion}.
> 
>+@item -Wfloat-conversion
>+@opindex Wfloat-conversion
>+@opindex Wno-float-conversion
>+Warn for implicit conversions that reduce the precision of a real value. 
>+This includes conversions from real to integer, and from higher precision
>+real to lower precision real values.  This option is also enabled by 
>+@option{-Wconversion}.
>+
> @item -Wsizeof-pointer-memaccess
> @opindex Wsizeof-pointer-memaccess
> @opindex Wno-sizeof-pointer-memaccess
>Only in gcc-4.8.1/gcc/doc: invoke.texi~

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Attachments on bug 53001: 30870 | 30871 | 30873 | 30882 | 30899 | 30913 | 30937 | 30979 | 30980 | 30994 | 31014 | 31065 | 31097