projects / thirdparty / gcc.git / blame
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1 | ------------------------------------------------------------------------------ |
| 2 | -- -- | |
| 3 | -- GNAT RUN-TIME COMPONENTS -- | |
| 4 | -- -- | |
| 5 | -- S Y S T E M . V A L U E _ I -- | |
| 6 | -- -- | |
| 7 | -- S p e c -- | |
| 8 | -- -- | |
| cccef051 | 9 | -- Copyright (C) 1992-2023, Free Software Foundation, Inc. -- |
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10 | -- -- |
| 11 | -- GNAT is free software; you can redistribute it and/or modify it under -- | |
| 12 | -- terms of the GNU General Public License as published by the Free Soft- -- | |
| 13 | -- ware Foundation; either version 3, or (at your option) any later ver- -- | |
| 14 | -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- | |
| 15 | -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- | |
| 16 | -- or FITNESS FOR A PARTICULAR PURPOSE. -- | |
| 17 | -- -- | |
| 18 | -- As a special exception under Section 7 of GPL version 3, you are granted -- | |
| 19 | -- additional permissions described in the GCC Runtime Library Exception, -- | |
| 20 | -- version 3.1, as published by the Free Software Foundation. -- | |
| 21 | -- -- | |
| 22 | -- You should have received a copy of the GNU General Public License and -- | |
| 23 | -- a copy of the GCC Runtime Library Exception along with this program; -- | |
| 24 | -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- | |
| 25 | -- <http://www.gnu.org/licenses/>. -- | |
| 26 | -- -- | |
| 27 | -- GNAT was originally developed by the GNAT team at New York University. -- | |
| 28 | -- Extensive contributions were provided by Ada Core Technologies Inc. -- | |
| 29 | -- -- | |
| 30 | ------------------------------------------------------------------------------ | |
| 31 | ||
| 32 | -- This package contains routines for scanning signed integer values for use | |
| 33 | -- in Text_IO.Integer_IO, and the Value attribute. | |
| 34 | ||
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35 | pragma Assertion_Policy (Pre => Ignore, |
| 36 | Post => Ignore, | |
| 37 | Contract_Cases => Ignore, | |
| 38 | Ghost => Ignore, | |
| 39 | Subprogram_Variant => Ignore); | |
| 336ea8f2 | 40 | |
| 70bcf5c4 | 41 | with System.Val_Spec; use System.Val_Spec; |
| b3ae28dc | 42 | with System.Value_I_Spec; |
| 70bcf5c4 | 43 | with System.Value_U_Spec; |
| 336ea8f2 | 44 | |
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45 | generic |
| 46 | ||
| 47 | type Int is range <>; | |
| 48 | ||
| 49 | type Uns is mod <>; | |
| 50 | ||
| 649b3efa | 51 | with procedure Scan_Raw_Unsigned |
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52 | (Str : String; |
| 53 | Ptr : not null access Integer; | |
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54 | Max : Integer; |
| 55 | Res : out Uns); | |
| cb7584a4 | 56 | |
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57 | -- Additional parameters for ghost subprograms used inside contracts |
| 58 | ||
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59 | with package U_Spec is new System.Value_U_Spec (Uns => Uns) with Ghost; |
| 60 | with package Spec is new System.Value_I_Spec | |
| 61 | (Int => Int, Uns => Uns, U_Spec => U_Spec) | |
| b3ae28dc | 62 | with Ghost; |
| 336ea8f2 | 63 | |
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64 | package System.Value_I is |
| 65 | pragma Preelaborate; | |
| 91d68769 | 66 | |
| 649b3efa | 67 | procedure Scan_Integer |
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68 | (Str : String; |
| 69 | Ptr : not null access Integer; | |
| 649b3efa | 70 | Max : Integer; |
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71 | Res : out Int) |
| 72 | with | |
| cfcc5380 | 73 | Pre => Str'Last /= Positive'Last |
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74 | -- Ptr.all .. Max is either an empty range, or a valid range in Str |
| 75 | and then (Ptr.all > Max | |
| 76 | or else (Ptr.all >= Str'First and then Max <= Str'Last)) | |
| 77 | and then not Only_Space_Ghost (Str, Ptr.all, Max) | |
| 78 | and then | |
| 79 | (declare | |
| 80 | Non_Blank : constant Positive := First_Non_Space_Ghost | |
| 81 | (Str, Ptr.all, Max); | |
| 82 | Fst_Num : constant Positive := | |
| 83 | (if Str (Non_Blank) in '+' | '-' then Non_Blank + 1 | |
| 84 | else Non_Blank); | |
| 85 | begin | |
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86 | U_Spec.Is_Raw_Unsigned_Format_Ghost (Str (Fst_Num .. Max)) |
| 87 | and then U_Spec.Raw_Unsigned_No_Overflow_Ghost | |
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88 | (Str, Fst_Num, Max) |
| 89 | and then Spec.Uns_Is_Valid_Int | |
| cfcc5380 | 90 | (Minus => Str (Non_Blank) = '-', |
| 70bcf5c4 | 91 | Uval => U_Spec.Scan_Raw_Unsigned_Ghost |
| b3ae28dc | 92 | (Str, Fst_Num, Max))), |
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93 | Post => |
| 94 | (declare | |
| 95 | Non_Blank : constant Positive := First_Non_Space_Ghost | |
| 96 | (Str, Ptr.all'Old, Max); | |
| 97 | Fst_Num : constant Positive := | |
| 98 | (if Str (Non_Blank) in '+' | '-' then Non_Blank + 1 | |
| 99 | else Non_Blank); | |
| 100 | Uval : constant Uns := | |
| 70bcf5c4 | 101 | U_Spec.Scan_Raw_Unsigned_Ghost (Str, Fst_Num, Max); |
| 336ea8f2 | 102 | begin |
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103 | Spec.Is_Int_Of_Uns (Minus => Str (Non_Blank) = '-', |
| 104 | Uval => Uval, | |
| 105 | Val => Res) | |
| 70bcf5c4 | 106 | and then Ptr.all = U_Spec.Raw_Unsigned_Last_Ghost |
| b3ae28dc | 107 | (Str, Fst_Num, Max)); |
| 649b3efa | 108 | -- This procedure scans the string starting at Str (Ptr.all) for a valid |
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109 | -- integer according to the syntax described in (RM 3.5(43)). The substring |
| 110 | -- scanned extends no further than Str (Max). There are three cases for the | |
| 111 | -- return: | |
| 112 | -- | |
| 113 | -- If a valid integer is found after scanning past any initial spaces, then | |
| 114 | -- Ptr.all is updated past the last character of the integer (but trailing | |
| 115 | -- spaces are not scanned out). | |
| 116 | -- | |
| 117 | -- If no valid integer is found, then Ptr.all points either to an initial | |
| 118 | -- non-digit character, or to Max + 1 if the field is all spaces and the | |
| 119 | -- exception Constraint_Error is raised. | |
| 120 | -- | |
| 121 | -- If a syntactically valid integer is scanned, but the value is out of | |
| 122 | -- range, or, in the based case, the base value is out of range or there | |
| 123 | -- is an out of range digit, then Ptr.all points past the integer, and | |
| 124 | -- Constraint_Error is raised. | |
| 125 | -- | |
| 126 | -- Note: these rules correspond to the requirements for leaving the pointer | |
| 127 | -- positioned in Text_Io.Get | |
| 128 | -- | |
| 129 | -- Note: if Str is null, i.e. if Max is less than Ptr, then this is a | |
| 130 | -- special case of an all-blank string, and Ptr is unchanged, and hence | |
| 131 | -- is greater than Max as required in this case. | |
| 132 | ||
| 336ea8f2 | 133 | function Value_Integer (Str : String) return Int |
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134 | with |
| 135 | Pre => not Only_Space_Ghost (Str, Str'First, Str'Last) | |
| 136 | and then Str'Length /= Positive'Last | |
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137 | and then Spec.Is_Integer_Ghost (Spec.Slide_If_Necessary (Str)), |
| 138 | Post => Spec.Is_Value_Integer_Ghost | |
| 139 | (Spec.Slide_If_Necessary (Str), Value_Integer'Result), | |
| 336ea8f2 | 140 | Subprogram_Variant => (Decreases => Str'First); |
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141 | -- Used in computing X'Value (Str) where X is a signed integer type whose |
| 142 | -- base range does not exceed the base range of Integer. Str is the string | |
| 143 | -- argument of the attribute. Constraint_Error is raised if the string is | |
| 144 | -- malformed, or if the value is out of range. | |
| 145 | ||
| 146 | end System.Value_I; |