diff options
Diffstat (limited to 'gcc/ada/gnat_ugn.texi')
| -rw-r--r-- | gcc/ada/gnat_ugn.texi | 135 |
1 files changed, 101 insertions, 34 deletions
diff --git a/gcc/ada/gnat_ugn.texi b/gcc/ada/gnat_ugn.texi index a39c2572be0..947506799a5 100644 --- a/gcc/ada/gnat_ugn.texi +++ b/gcc/ada/gnat_ugn.texi @@ -21,7 +21,7 @@ @copying @quotation -GNAT User's Guide for Native Platforms , Oct 09, 2017 +GNAT User's Guide for Native Platforms , Oct 20, 2017 AdaCore @@ -8809,19 +8809,6 @@ in the compiler sources for details in files @code{scos.ads} and @code{scos.adb}. @end table -@geindex -fdump-xref (gcc) - - -@table @asis - -@item @code{-fdump-xref} - -Generates cross reference information in GLI files for C and C++ sources. -The GLI files have the same syntax as the ALI files for Ada, and can be used -for source navigation in IDEs and on the command line using e.g. gnatxref -and the @code{--ext=gli} switch. -@end table - @geindex -flto (gcc) @@ -8830,8 +8817,9 @@ and the @code{--ext=gli} switch. @item @code{-flto[=@emph{n}]} Enables Link Time Optimization. This switch must be used in conjunction -with the traditional @code{-Ox} switches and instructs the compiler to -defer most optimizations until the link stage. The advantage of this +with the @code{-Ox} switches (but not with the @code{-gnatn} switch +since it is a full replacement for the latter) and instructs the compiler +to defer most optimizations until the link stage. The advantage of this approach is that the compiler can do a whole-program analysis and choose the best interprocedural optimization strategy based on a complete view of the program, instead of a fragmentary view with the usual approach. @@ -12474,8 +12462,8 @@ should not complain at you. This switch activates warnings for exception usage when pragma Restrictions (No_Exception_Propagation) is in effect. Warnings are given for implicit or explicit exception raises which are not covered by a local handler, and for -exception handlers which do not cover a local raise. The default is that these -warnings are not given. +exception handlers which do not cover a local raise. The default is that +these warnings are given for units that contain exception handlers. @item @code{-gnatw.X} @@ -17949,9 +17937,9 @@ Do not look for library files in the system default directory. @item @code{--ext=@emph{extension}} Specify an alternate ali file extension. The default is @code{ali} and other -extensions (e.g. @code{gli} for C/C++ sources when using @code{-fdump-xref}) -may be specified via this switch. Note that if this switch overrides the -default, which means that only the new extension will be considered. +extensions (e.g. @code{gli} for C/C++ sources) may be specified via this switch. +Note that if this switch overrides the default, which means that only the +new extension will be considered. @end table @geindex --RTS (gnatxref) @@ -22901,12 +22889,12 @@ combine a dimensioned and dimensionless value. Thus an expression such as @code{Acceleration}. The dimensionality checks for relationals use the same rules as -for "+" and "-"; thus +for "+" and "-", except when comparing to a literal; thus @quotation @example -acc > 10.0 +acc > len @end example @end quotation @@ -22915,12 +22903,21 @@ is equivalent to @quotation @example -acc-10.0 > 0.0 +acc-len > 0.0 +@end example +@end quotation + +and is thus illegal, but + +@quotation + +@example +acc > 10.0 @end example @end quotation -and is thus illegal. Analogously a conditional expression -requires the same dimension vector for each branch. +is accepted with a warning. Analogously a conditional expression requires the +same dimension vector for each branch (with no exception for literals). The dimension vector of a type conversion @code{T(@emph{expr})} is defined as follows, based on the nature of @code{T}: @@ -27187,8 +27184,62 @@ elaborated. The sequence by which the elaboration code of all units within a partition is -executed is referred to as @strong{elaboration order}. The elaboration order depends -on the following factors: +executed is referred to as @strong{elaboration order}. + +Within a single unit, elaboration code is executed in sequential order. + +@example +package body Client is + Result : ... := Server.Func; + + procedure Proc is + package Inst is new Server.Gen; + begin + Inst.Eval (Result); + end Proc; +begin + Proc; +end Client; +@end example + +In the example above, the elaboration order within package body @code{Client} is +as follows: + + +@enumerate + +@item +The object declaration of @code{Result} is elaborated. + + +@itemize * + +@item +Function @code{Server.Func} is invoked. +@end itemize + +@item +The subprogram body of @code{Proc} is elaborated. + +@item +Procedure @code{Proc} is invoked. + + +@itemize * + +@item +Generic unit @code{Server.Gen} is instantiated as @code{Inst}. + +@item +Instance @code{Inst} is elaborated. + +@item +Procedure @code{Inst.Eval} is invoked. +@end itemize +@end enumerate + +The elaboration order of all units within a partition depends on the following +factors: @itemize * @@ -27689,7 +27740,7 @@ dynamic model is in effect, GNAT assumes that all code within all units in a partition is elaboration code. GNAT performs very few diagnostics and generates run-time checks to verify the elaboration order of a program. This behavior is identical to that specified by the Ada Reference Manual. The -dynamic model is enabled with compilation switch @code{-gnatE}. +dynamic model is enabled with compiler switch @code{-gnatE}. @end itemize @geindex Static elaboration model @@ -28001,7 +28052,7 @@ elaborated prior to the body of @code{Static_Model}. The SPARK model is identical to the static model in its handling of internal targets. The SPARK model, however, requires explicit @code{Elaborate} or @code{Elaborate_All} pragmas to be present in the program when a target is -external, and emits hard errors instead of warnings: +external, and compiler switch @code{-gnatd.v} is in effect. @example 1. with Server; @@ -28146,7 +28197,7 @@ code. @emph{Switch to more permissive elaboration model} If the compilation was performed using the static model, enable the dynamic -model with compilation switch @code{-gnatE}. GNAT will no longer generate +model with compiler switch @code{-gnatE}. GNAT will no longer generate implicit @code{Elaborate} and @code{Elaborate_All} pragmas, resulting in a behavior identical to that specified by the Ada Reference Manual. The binder will generate an executable program that may or may not raise @code{Program_Error}, @@ -28711,6 +28762,22 @@ When this switch is in effect, GNAT will ignore @code{'Access} of an entry, operator, or subprogram when the static model is in effect. @end table +@geindex -gnatd.v (gnat) + + +@table @asis + +@item @code{-gnatd.v} + +Enforce SPARK elaboration rules in SPARK code + +When this switch is in effect, GNAT will enforce the SPARK rules of +elaboration as defined in the SPARK Reference Manual, section 7.7. As a +result, constructs which violate the SPARK elaboration rules are no longer +accepted, even if GNAT is able to statically ensure that these constructs +will not lead to ABE problems. +@end table + @geindex -gnatd.y (gnat) @@ -28785,7 +28852,7 @@ it will provide detailed traceback when an implicit @code{Elaborate} or @emph{SPARK model} GNAT will indicate how an elaboration requirement is met by the context of -a unit. +a unit. This diagnostic requires compiler switch @code{-gnatd.v}. @example 1. with Server; pragma Elaborate_All (Server); @@ -28846,8 +28913,8 @@ none of the binder or compiler switches. If the binder succeeds in finding an elaboration order, then apart from possible cases involing dispatching calls and access-to-subprogram types, the program is free of elaboration errors. If it is important for the program to be portable to compilers other than GNAT, -then the programmer should use compilation switch @code{-gnatel} and -consider the messages about missing or implicitly created @code{Elaborate} and +then the programmer should use compiler switch @code{-gnatel} and consider +the messages about missing or implicitly created @code{Elaborate} and @code{Elaborate_All} pragmas. If the binder reports an elaboration circularity, the programmer has several |