GCC Bugzilla – Attachment 30979 Details for
Bug 53001
-Wfloat-conversion should be available to warn about floating point errors
Home
|
New
|
Browse
|
Search
|
[?]
|
Reports
|
Help
|
New Account
|
Log In
Remember
[x]
|
Forgot Password
Login:
[x]
[patch]
Patch to add -Wfloat-conversion option against trunk
warn_float_patch_simple_trunk.diff (text/plain), 11.29 KB, created by
Joshua Cogliati
on 2013-10-11 02:23:46 UTC
(
hide
)
Description:
Patch to add -Wfloat-conversion option against trunk
Filename:
MIME Type:
Creator:
Joshua Cogliati
Created:
2013-10-11 02:23:46 UTC
Size:
11.29 KB
patch
obsolete
>Index: gcc/c-family/c-common.c >=================================================================== >--- gcc/c-family/c-common.c (revision 203112) >+++ gcc/c-family/c-common.c (working copy) >@@ -2517,10 +2517,10 @@ shorten_binary_op (tree result_type, tre > 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 >+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); > >@@ -2532,7 +2532,7 @@ unsafe_conversion_p (tree type, tree exp > && 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 >@@ -2553,7 +2553,7 @@ unsafe_conversion_p (tree type, tree exp > " constant value to negative integer"); > } > else >- give_warning = true; >+ give_warning = UNSAFE_OTHER; > } > else if (TREE_CODE (type) == REAL_TYPE) > { >@@ -2562,7 +2562,7 @@ unsafe_conversion_p (tree type, tree exp > { > 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. */ >@@ -2571,7 +2571,7 @@ unsafe_conversion_p (tree type, tree exp > { > REAL_VALUE_TYPE a = TREE_REAL_CST (expr); > if (!exact_real_truncate (TYPE_MODE (type), &a)) >- give_warning = true; >+ give_warning = UNSAFE_REAL; > } > } > } >@@ -2580,7 +2580,7 @@ unsafe_conversion_p (tree type, tree exp > /* 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) >@@ -2618,7 +2618,7 @@ unsafe_conversion_p (tree type, tree exp > && 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 >@@ -2627,12 +2627,12 @@ unsafe_conversion_p (tree type, tree exp > || (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. */ >@@ -2668,14 +2668,14 @@ unsafe_conversion_p (tree type, tree exp > > 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; >@@ -2689,8 +2689,9 @@ conversion_warning (tree type, tree expr > { > 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)) >@@ -2717,10 +2718,19 @@ conversion_warning (tree type, tree expr > > 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); >+ 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 if(conversion_kind) >+ { >+ warning_at (loc, OPT_Wconversion, >+ "conversion to %qT alters %qT constant value", >+ type, expr_type); >+ } > return; > > case COND_EXPR: >@@ -2736,10 +2746,19 @@ conversion_warning (tree type, tree expr > } > > 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); >+ 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 if(conversion_kind) >+ { >+ warning_at (loc, OPT_Wconversion, >+ "conversion to %qT from %qT may alter its value", >+ type, expr_type); >+ } > } > } > >Index: gcc/c-family/c-common.h >=================================================================== >--- gcc/c-family/c-common.h (revision 203112) >+++ gcc/c-family/c-common.h (working copy) >@@ -685,6 +685,16 @@ struct visibility_flags > unsigned inlines_hidden : 1; /* True when -finlineshidden in effect. */ > }; > >+/* These variables are possible types of unsafe conversions. >+ SAFE_CONVERSION The conversion is safe >+ UNSAFE_OTHER Another type of conversion with problems >+ UNSAFE_SIGN Conversion between signed and unsigned integers >+ which are all warned about immediately, so this is unused >+ UNSAFE_REAL Conversions that reduce the precision of reals >+ including conversions from reals to integers >+ */ >+enum conversion_safety { SAFE_CONVERSION = 0, UNSAFE_OTHER, UNSAFE_SIGN, UNSAFE_REAL }; >+ > /* Global visibility options. */ > extern struct visibility_flags visibility_options; > >@@ -738,7 +748,7 @@ extern tree c_common_signed_type (tree); > 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 enum conversion_safety 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); >Index: gcc/c-family/c.opt >=================================================================== >--- gcc/c-family/c.opt (revision 203112) >+++ gcc/c-family/c.opt (working copy) >@@ -387,6 +387,10 @@ Werror-implicit-function-declaration > 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++ ObjC++,Wconversion) >+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 >Index: gcc/doc/invoke.texi >=================================================================== >--- gcc/doc/invoke.texi (revision 203112) >+++ gcc/doc/invoke.texi (working copy) >@@ -263,7 +263,8 @@ Objective-C and Objective-C++ Dialects}. > -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 >@@ -4570,6 +4571,14 @@ value, like assigning a signed integer e > 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 >Index: gcc/testsuite/c-c++-common/Wconversion-real.c >=================================================================== >--- gcc/testsuite/c-c++-common/Wconversion-real.c (revision 203112) >+++ gcc/testsuite/c-c++-common/Wconversion-real.c (working copy) >@@ -2,8 +2,8 @@ > > /* { dg-do compile } */ > /* { dg-skip-if "doubles are floats" { "avr-*-*" } { "*" } { "" } } */ >-/* { dg-options "-std=c99 -Wconversion" { target c } } */ >-/* { dg-options "-Wconversion" { target c++ } } */ >+/* { dg-options "-std=c99 -Wfloat-conversion" { target c } } */ >+/* { dg-options "-Wfloat-conversion" { target c++ } } */ > /* { dg-require-effective-target large_double } */ > > float vfloat; >@@ -20,18 +20,18 @@ void h (void) > double d = 0; > long double ld = 0; > >- ffloat (3.1); /* { dg-warning "conversion" } */ >- vfloat = 3.1; /* { dg-warning "conversion" } */ >- ffloat (3.1L); /* { dg-warning "conversion" } */ >- vfloat = 3.1L; /* { dg-warning "conversion" } */ >- fdouble (3.1L); /* { dg-warning "conversion" "" { target large_long_double } } */ >- vdouble = 3.1L; /* { dg-warning "conversion" "" { target large_long_double } } */ >- ffloat (vdouble); /* { dg-warning "conversion" } */ >- vfloat = vdouble; /* { dg-warning "conversion" } */ >- ffloat (vlongdouble); /* { dg-warning "conversion" } */ >- vfloat = vlongdouble; /* { dg-warning "conversion" } */ >- fdouble (vlongdouble); /* { dg-warning "conversion" "" { target large_long_double } } */ >- vdouble = vlongdouble; /* { dg-warning "conversion" "" { target large_long_double } } */ >+ ffloat (3.1); /* { dg-warning "float-conversion" } */ >+ vfloat = 3.1; /* { dg-warning "float-conversion" } */ >+ ffloat (3.1L); /* { dg-warning "float-conversion" } */ >+ vfloat = 3.1L; /* { dg-warning "float-conversion" } */ >+ fdouble (3.1L); /* { dg-warning "float-conversion" "" { target large_long_double } } */ >+ vdouble = 3.1L; /* { dg-warning "float-conversion" "" { target large_long_double } } */ >+ ffloat (vdouble); /* { dg-warning "float-conversion" } */ >+ vfloat = vdouble; /* { dg-warning "float-conversion" } */ >+ ffloat (vlongdouble); /* { dg-warning "float-conversion" } */ >+ vfloat = vlongdouble; /* { dg-warning "float-conversion" } */ >+ fdouble (vlongdouble); /* { dg-warning "float-conversion" "" { target large_long_double } } */ >+ vdouble = vlongdouble; /* { dg-warning "float-conversion" "" { target large_long_double } } */ > > > ffloat ((float) 3.1);
You cannot view the attachment while viewing its details because your browser does not support IFRAMEs.
View the attachment on a separate page
.
View Attachment As Diff
View Attachment As Raw
Actions:
View
|
Diff
Attachments on
bug 53001
:
30870
|
30871
|
30873
|
30882
|
30899
|
30913
|
30937
|
30979
|
30980
|
30994
|
31014
|
31065
|
31097