diff options
Diffstat (limited to 'gcc/ada/gnat_rm.texi')
| -rw-r--r-- | gcc/ada/gnat_rm.texi | 81 |
1 files changed, 42 insertions, 39 deletions
diff --git a/gcc/ada/gnat_rm.texi b/gcc/ada/gnat_rm.texi index 81b6a1140bc..2ff9c117680 100644 --- a/gcc/ada/gnat_rm.texi +++ b/gcc/ada/gnat_rm.texi @@ -222,6 +222,7 @@ Implementation Defined Attributes * AST_Entry:: * Bit:: * Bit_Position:: +* Compiler_Version:: * Code_Address:: * Default_Bit_Order:: * Elaborated:: @@ -1502,7 +1503,7 @@ equality operators defined (such operations can be imported or declared as subprograms as required). Initialization is allowed only by constructor functions (see pragma @code{CPP_Constructor}). Such types are implicitly limited if not explicitly declared as limited or derived from a limited -type, and a warning is issued in that case. +type, and an error is issued in that case. Pragma @code{CPP_Class} is intended primarily for automatic generation using an automatic binding generator tool. @@ -1542,47 +1543,16 @@ must be of one of the following forms: @end itemize @noindent -where @var{T} is a tagged type to which the pragma @code{CPP_Class} applies. +where @var{T} is a tagged limited type imported from C++ with pragma +@code{Import} and @code{Convention} = @code{CPP}. The first form is the default constructor, used when an object of type -@var{T} is created on the Ada side with no explicit constructor. Other -constructors (including the copy constructor, which is simply a special -case of the second form in which the one and only argument is of type -@var{T}), can only appear in two contexts: - -@itemize @bullet -@item -On the right side of an initialization of an object of type @var{T}. -@item -In an extension aggregate for an object of a type derived from @var{T}. -@end itemize - -@noindent -Although the constructor is described as a function that returns a value -on the Ada side, it is typically a procedure with an extra implicit -argument (the object being initialized) at the implementation -level. GNAT issues the appropriate call, whatever it is, to get the -object properly initialized. - -In the case of derived objects, you may use one of two possible forms -for declaring and creating an object: - -@itemize @bullet -@item @code{New_Object : Derived_T} -@item @code{New_Object : Derived_T := (@var{constructor-call with} @dots{})} -@end itemize - -@noindent -In the first case the default constructor is called and extension fields -if any are initialized according to the default initialization -expressions in the Ada declaration. In the second case, the given -constructor is called and the extension aggregate indicates the explicit -values of the extension fields. +@var{T} is created on the Ada side with no explicit constructor. The +second form covers all the non-default constructors of the type. See +the GNAT users guide for details. If no constructors are imported, it is impossible to create any objects -on the Ada side. If no default constructor is imported, only the -initialization forms using an explicit call to a constructor are -permitted. +on the Ada side and the type is implicitly declared abstract. Pragma @code{CPP_Constructor} is intended primarily for automatic generation using an automatic binding generator tool. @@ -2440,7 +2410,8 @@ pragma Implicit_Packing; @noindent This is a configuration pragma that requests implicit packing for packed arrays for which a size clause is given but no explicit pragma Pack or -specification of Component_Size is present. Consider this example: +specification of Component_Size is present. It also applies to records +where no record representation clause is present. Consider this example: @smallexample @c ada type R is array (0 .. 7) of Boolean; @@ -2462,6 +2433,21 @@ specify the exact size that corresponds to the length of the array multiplied by the size in bits of the component type. @cindex Array packing +Similarly, the following example shows the use in the record case + +@smallexample @c ada +type r is record + a, b, c, d, e, f, g, h : boolean; + chr : character; +end record; +for r'size use 16; +@end smallexample + +@noindent +Without a pragma Pack, each Boolean field requires 8 bits, so the +minimum size is 72 bits, but with a pragma Pack, 16 bits would be +sufficient. The use of pragma Implciit_Packing allows this record +declaration to compile without an explicit pragma Pack. @node Pragma Import_Exception @unnumberedsec Pragma Import_Exception @cindex OpenVMS @@ -5162,6 +5148,8 @@ A turn off all optional warnings .A turn off warnings for failing assertions b turn on warnings for bad fixed value (not multiple of small) B* turn off warnings for bad fixed value (not multiple of small) +.b* turn on warnings for biased representation +.B turn off warnings for biased representation c turn on warnings for constant conditional C* turn off warnings for constant conditional .c turn on warnings for unrepped components @@ -5169,6 +5157,7 @@ C* turn off warnings for constant conditional d turn on warnings for implicit dereference D* turn off warnings for implicit dereference e treat all warnings as errors +.e turn on every optional warning f turn on warnings for unreferenced formal F* turn off warnings for unreferenced formal g* turn on warnings for unrecognized pragma @@ -5192,6 +5181,8 @@ O turn off warnings for address clause overlay .O* turn off warnings for out parameters assigned but not read p turn on warnings for ineffective pragma Inline in frontend P* turn off warnings for ineffective pragma Inline in frontend +.p turn on warnings for parameter ordering +.P* turn off warnings for parameter ordering q* turn on warnings for questionable missing parentheses Q turn off warnings for questionable missing parentheses r turn on warnings for redundant construct @@ -5207,6 +5198,8 @@ v* turn on warnings for unassigned variable V turn off warnings for unassigned variable w* turn on warnings for wrong low bound assumption W turn off warnings for wrong low bound assumption +.w turn on warnings for unnecessary Warnings Off pragmas +.W* turn off warnings for unnecessary Warnings Off pragmas x* turn on warnings for export/import X turn off warnings for export/import .x turn on warnings for non-local exceptions @@ -5360,6 +5353,7 @@ consideration, you should minimize the use of these attributes. * AST_Entry:: * Bit:: * Bit_Position:: +* Compiler_Version:: * Code_Address:: * Default_Bit_Order:: * Elaborated:: @@ -5512,6 +5506,15 @@ type @code{Universal_Integer}. The value depends only on the field @var{C} and is independent of the alignment of the containing record @var{R}. +@node Compiler_Version +@unnumberedsec Compiler_Version +@findex Compiler_Version +@noindent +@code{Standard'Compiler_Version} (@code{Standard} is the only allowed +prefix) yields a static string identifying the version of the compiler +being used to compile the unit containing the attribute reference. A +typical result would be something like "GNAT Pro 6.3.0w (20090221)". + @node Code_Address @unnumberedsec Code_Address @findex Code_Address |