------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- P A R _ S C O -- -- -- -- S p e c -- -- -- -- Copyright (C) 2009, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package contains the routines used to deal with generation and output -- of Soure Coverage Obligations (SCO's) used for coverage analysis purposes. with Types; use Types; package Par_SCO is ---------------- -- SCO Format -- ---------------- -- Source coverage obligations are generated on a unit-by-unit basis in the -- ALI file, using lines that start with the identifying character C. These -- lines are generated if the -gnatC switch is set. -- Sloc Ranges -- In several places in the SCO lines, Sloc ranges appear. These are used -- to indicate the first and last Sloc of some construct in the tree and -- they have the form: -- line:col-line:col -- Note that SCO's are generated only for generic templates, not for -- generic instances (since only the first are part of the source). So -- we don't need generic instantiation stuff in these line:col items. -- SCO File headers -- The SCO information follows the cross-reference information, so it -- need not be read by tools like gnatbind, gnatmake etc. The SCO output -- is divided into sections, one section for each unit for which SCO's -- are generated. A SCO section has a header of the form: -- C dependency-number filename -- This header precedes SCO information for the unit identified by -- dependency number and file name. The dependency number is the -- index into the generated D lines and is ones origin (i.e. 2 = -- reference to second generated D line). -- Note that the filename here will reflect the original name if -- a Source_Reference pragma was encountered (since all line number -- references will be with respect to the original file). -- Statements -- For the purpose of SCO generation, the notion of statement includes -- simple statements and also the following declaration types: -- type_declaration -- subtype_declaration -- object_declaration -- renaming_declaration -- generic_instantiation -- Statement lines -- These lines correspond to a sequence of one or more statements which -- are always exeecuted in sequence, The first statement may be an entry -- point (e.g. statement after a label), and the last statement may be -- an exit point (e.g. an exit statement), but no other entry or exit -- points may occur within the sequence of statements. The idea is that -- the sequence can be treated as a single unit from a coverage point of -- view, if any of the code for the statement sequence is executed, this -- corresponds to coverage of the entire statement sequence. The form of -- a statement line in the ALI file is: -- CS sloc-range -- Exit points -- An exit point is a statement that causes transfer of control. Examples -- are exit statements, raise statements and return statements. The form -- of an exit point in the ALI file is: -- CT sloc-range -- Decisions -- Decisions represent the most significant section of the SCO lines -- Note: in the following description, logical operator includes the -- short circuited forms (so can be any of AND, OR, XOR, NOT, AND THEN, -- or OR ELSE). -- Decisions are either simple or complex. A simple decision is a boolean -- expresssion that occurs in the context of a control structure in the -- source program, including WHILE, IF, EXIT WHEN. Note that a boolean -- expression in any other context, e.g. on the right side of an -- assignment, is not considered to be a decision. -- A complex decision is an occurrence of a logical operator which is not -- itself an operand of some other logical operator. If any operand of -- the logical operator is itself a logical operator, this is not a -- separate decision, it is part of the same decision. -- So for example, if we have -- A, B, C, D : Boolean; -- function F (Arg : Boolean) return Boolean); -- ... -- A and then (B or else F (C and then D)) -- There are two (complex) decisions here: -- 1. X and then (Y or else Z) -- where X = A, Y = B, and Z = F (C and then D) -- 2. C and then D -- For each decision, a decision line is generated with the form: -- C* expression -- Here * is one of the following characters: -- I decision in IF statement or conditional expression -- E decision in EXIT WHEN statement -- W decision in WHILE iteration scheme -- X decision appearing in some other expression context -- The expression is a prefix polish form indicating the structure of -- the decision, including logical operators and short circuit forms. -- The following is a grammar showing the structure of expression: -- expression ::= term (if expr is not logical operator) -- expression ::= & term term (if expr is AND THEN) -- expression ::= | term term (if expr is OR ELSE) -- expression ::= !term (if expr is NOT) -- term ::= element -- term ::= expression -- element ::= outcome sloc-range -- outcome is one of the following letters: -- c condition -- t true condition -- f false condition -- where t/f are used to mark a condition that has been recognized by -- the compiler as always being true or false. -- & indicates either AND THEN connecting two conditions -- | indicates either OR ELSE connection two conditions -- ! indicates NOT applied to the expression ----------------- -- Subprograms -- ----------------- procedure Initialize; -- Initialize internal tables for a new compilation procedure SCO_Record (U : Unit_Number_Type); -- This procedure scans the tree for the unit identified by U, populating -- internal tables recording the SCO information. Note that this is done -- before any semantic analysis/expansion happens. procedure Set_SCO_Condition (First_Loc : Source_Ptr; Typ : Character); -- This procedure is called during semantic analysis to record a condition -- which has been identified as always True (Typ = 't') or always False -- (Typ = 'f') by the compiler. The condition is identified by the -- First_Sloc value in the original tree. procedure SCO_Output; -- Outputs SCO lines for all units, with appropriate section headers, for -- unit U in the ALI file, as recorded by previous calls to SCO_Record, -- possibly modified by calls to Set_SCO_Condition. procedure dsco; -- Debug routine to dump SCO table. This is a raw format dump showing -- exactly what the tables contain. procedure pscos; -- Debugging procedure to output contents of SCO binary tables in the -- format in which they appear in an ALI file. end Par_SCO;