------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- G N A T 1 D R V -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2011, 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. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Back_End; use Back_End; with Comperr; with Csets; use Csets; with Debug; use Debug; with Elists; with Errout; use Errout; with Exp_CG; with Fmap; with Fname; use Fname; with Fname.UF; use Fname.UF; with Frontend; with Gnatvsn; use Gnatvsn; with Hostparm; with Inline; with Lib; use Lib; with Lib.Writ; use Lib.Writ; with Lib.Xref; with Namet; use Namet; with Nlists; with Opt; use Opt; with Osint; use Osint; with Output; use Output; with Par_SCO; with Prepcomp; with Repinfo; use Repinfo; with Restrict; with Rident; use Rident; with Rtsfind; with SCOs; with Sem; with Sem_Ch8; with Sem_Ch12; with Sem_Ch13; with Sem_Elim; with Sem_Eval; with Sem_Type; with Sinfo; use Sinfo; with Sinput.L; use Sinput.L; with Snames; with Sprint; use Sprint; with Stringt; with Stylesw; use Stylesw; with Targparm; use Targparm; with Tree_Gen; with Treepr; use Treepr; with Ttypes; with Types; use Types; with Uintp; use Uintp; with Uname; use Uname; with Urealp; with Usage; with Validsw; use Validsw; with System.Assertions; procedure Gnat1drv is Main_Unit_Node : Node_Id; -- Compilation unit node for main unit Main_Kind : Node_Kind; -- Kind of main compilation unit node Back_End_Mode : Back_End.Back_End_Mode_Type; -- Record back end mode procedure Adjust_Global_Switches; -- There are various interactions between front end switch settings, -- including debug switch settings and target dependent parameters. -- This procedure takes care of properly handling these interactions. -- We do it after scanning out all the switches, so that we are not -- depending on the order in which switches appear. procedure Check_Bad_Body; -- Called to check if the unit we are compiling has a bad body procedure Check_Rep_Info; -- Called when we are not generating code, to check if -gnatR was requested -- and if so, explain that we will not be honoring the request. procedure Check_Library_Items; -- For debugging -- checks the behavior of Walk_Library_Items pragma Warnings (Off, Check_Library_Items); -- In case the call below is commented out ---------------------------- -- Adjust_Global_Switches -- ---------------------------- procedure Adjust_Global_Switches is begin -- Debug flag -gnatd.I is a synonym for Generate_SCIL and requires code -- generation. if Debug_Flag_Dot_II and then Operating_Mode = Generate_Code then Generate_SCIL := True; end if; -- Disable CodePeer_Mode in Check_Syntax, since we need front-end -- expansion. if Operating_Mode = Check_Syntax then CodePeer_Mode := False; end if; -- Set ASIS mode if -gnatt and -gnatc are set if Operating_Mode = Check_Semantics and then Tree_Output then ASIS_Mode := True; -- Turn off inlining in ASIS mode, since ASIS cannot handle the extra -- information in the trees caused by inlining being active. -- More specifically, the tree seems to be malformed from the ASIS -- point of view if -gnatc and -gnatn appear together??? Inline_Active := False; -- Turn off SCIL generation and CodePeer mode in semantics mode, -- since SCIL requires front-end expansion. Generate_SCIL := False; CodePeer_Mode := False; end if; -- SCIL mode needs to disable front-end inlining since the generated -- trees (in particular order and consistency between specs compiled -- as part of a main unit or as part of a with-clause) are causing -- troubles. if Generate_SCIL then Front_End_Inlining := False; end if; -- Tune settings for optimal SCIL generation in CodePeer mode if CodePeer_Mode then -- Turn off inlining, confuses CodePeer output and gains nothing Front_End_Inlining := False; Inline_Active := False; -- Disable front-end optimizations, to keep the tree as close to the -- source code as possible, and also to avoid inconsistencies between -- trees when using different optimization switches. Optimization_Level := 0; -- Enable some restrictions systematically to simplify the generated -- code (and ease analysis). Note that restriction checks are also -- disabled in CodePeer mode, see Restrict.Check_Restriction, and -- user specified Restrictions pragmas are ignored, see -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings. Restrict.Restrictions.Set (No_Initialize_Scalars) := True; Restrict.Restrictions.Set (No_Task_Hierarchy) := True; Restrict.Restrictions.Set (No_Abort_Statements) := True; Restrict.Restrictions.Set (Max_Asynchronous_Select_Nesting) := True; Restrict.Restrictions.Value (Max_Asynchronous_Select_Nesting) := 0; -- Suppress overflow, division by zero and access checks since they -- are handled implicitly by CodePeer. -- Turn off dynamic elaboration checks: generates inconsistencies in -- trees between specs compiled as part of a main unit or as part of -- a with-clause. -- Turn off alignment checks: these cannot be proved statically by -- CodePeer and generate false positives. -- Enable all other language checks Suppress_Options := (Access_Check => True, Alignment_Check => True, Division_Check => True, Elaboration_Check => True, Overflow_Check => True, others => False); Enable_Overflow_Checks := False; Dynamic_Elaboration_Checks := False; -- Kill debug of generated code, since it messes up sloc values Debug_Generated_Code := False; -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD) -- Do we really need to spend time generating xref in CodePeer -- mode??? Consider setting Xref_Active to False. Xref_Active := True; -- Polling mode forced off, since it generates confusing junk Polling_Required := False; -- Set operating mode to Generate_Code to benefit from full front-end -- expansion (e.g. generics). Operating_Mode := Generate_Code; -- We need SCIL generation of course Generate_SCIL := True; -- Enable assertions and debug pragmas, since they give CodePeer -- valuable extra information. Assertions_Enabled := True; Debug_Pragmas_Enabled := True; -- Disable all simple value propagation. This is an optimization -- which is valuable for code optimization, and also for generation -- of compiler warnings, but these are being turned off by default, -- and CodePeer generates better messages (referencing original -- variables) this way. Debug_Flag_MM := True; -- Set normal RM validity checking, and checking of IN OUT parameters -- (this might give CodePeer more useful checks to analyze, to be -- confirmed???). All other validity checking is turned off, since -- this can generate very complex trees that only confuse CodePeer -- and do not bring enough useful info. Reset_Validity_Check_Options; Validity_Check_Default := True; Validity_Check_In_Out_Params := True; Validity_Check_In_Params := True; -- Turn off style check options since we are not interested in any -- front-end warnings when we are getting CodePeer output. Reset_Style_Check_Options; -- Always perform semantics and generate ali files in CodePeer mode, -- so that a gnatmake -c -k will proceed further when possible. Force_ALI_Tree_File := True; Try_Semantics := True; end if; -- Set Configurable_Run_Time mode if system.ads flag set if Targparm.Configurable_Run_Time_On_Target or Debug_Flag_YY then Configurable_Run_Time_Mode := True; end if; -- Set -gnatR3m mode if debug flag A set if Debug_Flag_AA then Back_Annotate_Rep_Info := True; List_Representation_Info := 1; List_Representation_Info_Mechanisms := True; end if; -- Force Target_Strict_Alignment true if debug flag -gnatd.a is set if Debug_Flag_Dot_A then Ttypes.Target_Strict_Alignment := True; end if; -- Disable static allocation of dispatch tables if -gnatd.t or if layout -- is enabled. The front end's layout phase currently treats types that -- have discriminant-dependent arrays as not being static even when a -- discriminant constraint on the type is static, and this leads to -- problems with subtypes of type Ada.Tags.Dispatch_Table_Wrapper. ??? if Debug_Flag_Dot_T or else Frontend_Layout_On_Target then Static_Dispatch_Tables := False; end if; -- Flip endian mode if -gnatd8 set if Debug_Flag_8 then Ttypes.Bytes_Big_Endian := not Ttypes.Bytes_Big_Endian; end if; -- Deal with forcing OpenVMS switches True if debug flag M is set, but -- record the setting of Targparm.Open_VMS_On_Target in True_VMS_Target -- before doing this, so we know if we are in real OpenVMS or not! Opt.True_VMS_Target := Targparm.OpenVMS_On_Target; if Debug_Flag_M then Targparm.OpenVMS_On_Target := True; Hostparm.OpenVMS := True; end if; -- Activate front end layout if debug flag -gnatdF is set if Debug_Flag_FF then Targparm.Frontend_Layout_On_Target := True; end if; -- Set and check exception mechanism if Targparm.ZCX_By_Default_On_Target then Exception_Mechanism := Back_End_Exceptions; end if; -- Set proper status for overflow checks. We turn on overflow checks if -- -gnatp was not specified, and either -gnato is set or the back-end -- takes care of overflow checks. Otherwise we suppress overflow checks -- by default (since front end checks are expensive). if not Opt.Suppress_Checks and then (Opt.Enable_Overflow_Checks or else (Targparm.Backend_Divide_Checks_On_Target and Targparm.Backend_Overflow_Checks_On_Target)) then Suppress_Options (Overflow_Check) := False; else Suppress_Options (Overflow_Check) := True; end if; -- Set switch indicating if we can use N_Expression_With_Actions -- Debug flag -gnatd.X decisively sets usage on if Debug_Flag_Dot_XX then Use_Expression_With_Actions := True; -- Debug flag -gnatd.Y decisively sets usage off elsif Debug_Flag_Dot_YY then Use_Expression_With_Actions := False; -- Otherwise this feature is implemented, so we allow its use else Use_Expression_With_Actions := True; end if; -- Set switch indicating if back end can handle limited types, and -- guarantee that no incorrect copies are made (e.g. in the context -- of a conditional expression). -- Debug flag -gnatd.L decisively sets usage on if Debug_Flag_Dot_LL then Back_End_Handles_Limited_Types := True; -- If no debug flag, usage off for AAMP, VM, SCIL cases elsif AAMP_On_Target or else VM_Target /= No_VM or else Generate_SCIL then Back_End_Handles_Limited_Types := False; -- Otherwise normal gcc back end, for now still turn flag off by -- default, since there are unresolved problems in the front end. else Back_End_Handles_Limited_Types := False; end if; -- Set switches for formal verification mode if Debug_Flag_Dot_FF then Alfa_Mode := True; -- Set strict standard interpretation of compiler permissions if Debug_Flag_Dot_DD then Strict_Alfa_Mode := True; end if; -- Turn off inlining, which would confuse formal verification output -- and gain nothing. Front_End_Inlining := False; Inline_Active := False; -- Disable front-end optimizations, to keep the tree as close to the -- source code as possible, and also to avoid inconsistencies between -- trees when using different optimization switches. Optimization_Level := 0; -- Enable some restrictions systematically to simplify the generated -- code (and ease analysis). Note that restriction checks are also -- disabled in Alfa mode, see Restrict.Check_Restriction, and user -- specified Restrictions pragmas are ignored, see -- Sem_Prag.Process_Restrictions_Or_Restriction_Warnings. Restrict.Restrictions.Set (No_Initialize_Scalars) := True; -- Suppress all language checks since they are handled implicitly by -- the formal verification backend. -- Turn off dynamic elaboration checks. -- Turn off alignment checks. -- Turn off validity checking. Suppress_Options := (others => True); Enable_Overflow_Checks := False; Dynamic_Elaboration_Checks := False; Reset_Validity_Check_Options; -- Kill debug of generated code, since it messes up sloc values Debug_Generated_Code := False; -- Turn cross-referencing on in case it was disabled (e.g. by -gnatD) -- as it is needed for computing effects of subprograms in the formal -- verification backend. Xref_Active := True; -- Polling mode forced off, since it generates confusing junk Polling_Required := False; -- Set operating mode to Generate_Code, but full front-end expansion -- is not desirable in Alfa mode, so a light expansion is performed -- instead. Operating_Mode := Generate_Code; -- Skip call to gigi Debug_Flag_HH := True; -- Disable Expressions_With_Actions nodes -- The gnat2why backend does not deal with Expressions_With_Actions -- in all places (in particular assertions). It is difficult to -- determine in the frontend which cases are allowed, so we disable -- Expressions_With_Actions entirely. Even in the cases where -- gnat2why deals with Expressions_With_Actions, it is easier to -- deal with the original constructs (quantified, conditional and -- case expressions) instead of the rewritten ones. Use_Expression_With_Actions := False; -- Enable assertions and debug pragmas, since they give valuable -- extra information for formal verification. Assertions_Enabled := True; Debug_Pragmas_Enabled := True; -- Turn off style check options since we are not interested in any -- front-end warnings when we are getting Alfa output. Reset_Style_Check_Options; -- Suppress compiler warnings, since what we are interested in here -- is what formal verification can find out. Warning_Mode := Suppress; -- Suppress the generation of name tables for enumerations, which are -- not needed for formal verification, and fall outside the Alfa -- subset (use of pointers). Global_Discard_Names := True; -- Suppress the expansion of tagged types and dispatching calls, -- which lead to the generation of non-Alfa code (use of pointers), -- which is more complex to formally verify than the original source. Tagged_Type_Expansion := False; end if; end Adjust_Global_Switches; -------------------- -- Check_Bad_Body -- -------------------- procedure Check_Bad_Body is Sname : Unit_Name_Type; Src_Ind : Source_File_Index; Fname : File_Name_Type; procedure Bad_Body_Error (Msg : String); -- Issue message for bad body found -------------------- -- Bad_Body_Error -- -------------------- procedure Bad_Body_Error (Msg : String) is begin Error_Msg_N (Msg, Main_Unit_Node); Error_Msg_File_1 := Fname; Error_Msg_N ("remove incorrect body in file{!", Main_Unit_Node); end Bad_Body_Error; -- Start of processing for Check_Bad_Body begin -- Nothing to do if we are only checking syntax, because we don't know -- enough to know if we require or forbid a body in this case. if Operating_Mode = Check_Syntax then return; end if; -- Check for body not allowed if (Main_Kind = N_Package_Declaration and then not Body_Required (Main_Unit_Node)) or else (Main_Kind = N_Generic_Package_Declaration and then not Body_Required (Main_Unit_Node)) or else Main_Kind = N_Package_Renaming_Declaration or else Main_Kind = N_Subprogram_Renaming_Declaration or else Nkind (Original_Node (Unit (Main_Unit_Node))) in N_Generic_Instantiation then Sname := Unit_Name (Main_Unit); -- If we do not already have a body name, then get the body name -- (but how can we have a body name here???) if not Is_Body_Name (Sname) then Sname := Get_Body_Name (Sname); end if; Fname := Get_File_Name (Sname, Subunit => False); Src_Ind := Load_Source_File (Fname); -- Case where body is present and it is not a subunit. Exclude the -- subunit case, because it has nothing to do with the package we are -- compiling. It is illegal for a child unit and a subunit with the -- same expanded name (RM 10.2(9)) to appear together in a partition, -- but there is nothing to stop a compilation environment from having -- both, and the test here simply allows that. If there is an attempt -- to include both in a partition, this is diagnosed at bind time. In -- Ada 83 mode this is not a warning case. -- Note: if weird file names are being used, we can have a situation -- where the file name that supposedly contains body in fact contains -- a spec, or we can't tell what it contains. Skip the error message -- in these cases. -- Also ignore body that is nothing but pragma No_Body; (that's the -- whole point of this pragma, to be used this way and to cause the -- body file to be ignored in this context). if Src_Ind /= No_Source_File and then Get_Expected_Unit_Type (Fname) = Expect_Body and then not Source_File_Is_Subunit (Src_Ind) and then not Source_File_Is_No_Body (Src_Ind) then Errout.Finalize (Last_Call => False); Error_Msg_Unit_1 := Sname; -- Ada 83 case of a package body being ignored. This is not an -- error as far as the Ada 83 RM is concerned, but it is almost -- certainly not what is wanted so output a warning. Give this -- message only if there were no errors, since otherwise it may -- be incorrect (we may have misinterpreted a junk spec as not -- needing a body when it really does). if Main_Kind = N_Package_Declaration and then Ada_Version = Ada_83 and then Operating_Mode = Generate_Code and then Distribution_Stub_Mode /= Generate_Caller_Stub_Body and then not Compilation_Errors then Error_Msg_N ("package $$ does not require a body?", Main_Unit_Node); Error_Msg_File_1 := Fname; Error_Msg_N ("body in file{? will be ignored", Main_Unit_Node); -- Ada 95 cases of a body file present when no body is -- permitted. This we consider to be an error. else -- For generic instantiations, we never allow a body if Nkind (Original_Node (Unit (Main_Unit_Node))) in N_Generic_Instantiation then Bad_Body_Error ("generic instantiation for $$ does not allow a body"); -- A library unit that is a renaming never allows a body elsif Main_Kind in N_Renaming_Declaration then Bad_Body_Error ("renaming declaration for $$ does not allow a body!"); -- Remaining cases are packages and generic packages. Here -- we only do the test if there are no previous errors, -- because if there are errors, they may lead us to -- incorrectly believe that a package does not allow a body -- when in fact it does. elsif not Compilation_Errors then if Main_Kind = N_Package_Declaration then Bad_Body_Error ("package $$ does not allow a body!"); elsif Main_Kind = N_Generic_Package_Declaration then Bad_Body_Error ("generic package $$ does not allow a body!"); end if; end if; end if; end if; end if; end Check_Bad_Body; ------------------------- -- Check_Library_Items -- ------------------------- -- Walk_Library_Items has plenty of assertions, so all we need to do is -- call it, just for these assertions, not actually doing anything else. procedure Check_Library_Items is procedure Action (Item : Node_Id); -- Action passed to Walk_Library_Items to do nothing ------------ -- Action -- ------------ procedure Action (Item : Node_Id) is begin null; end Action; procedure Walk is new Sem.Walk_Library_Items (Action); -- Start of processing for Check_Library_Items begin Walk; end Check_Library_Items; -------------------- -- Check_Rep_Info -- -------------------- procedure Check_Rep_Info is begin if List_Representation_Info /= 0 or else List_Representation_Info_Mechanisms then Set_Standard_Error; Write_Eol; Write_Str ("cannot generate representation information, no code generated"); Write_Eol; Write_Eol; Set_Standard_Output; end if; end Check_Rep_Info; -- Start of processing for Gnat1drv begin -- This inner block is set up to catch assertion errors and constraint -- errors. Since the code for handling these errors can cause another -- exception to be raised (namely Unrecoverable_Error), we need two -- nested blocks, so that the outer one handles unrecoverable error. begin -- Initialize all packages. For the most part, these initialization -- calls can be made in any order. Exceptions are as follows: -- Lib.Initialize need to be called before Scan_Compiler_Arguments, -- because it initializes a table filled by Scan_Compiler_Arguments. Osint.Initialize; Fmap.Reset_Tables; Lib.Initialize; Lib.Xref.Initialize; Scan_Compiler_Arguments; Osint.Add_Default_Search_Dirs; Nlists.Initialize; Sinput.Initialize; Sem.Initialize; Exp_CG.Initialize; Csets.Initialize; Uintp.Initialize; Urealp.Initialize; Errout.Initialize; SCOs.Initialize; Snames.Initialize; Stringt.Initialize; Inline.Initialize; Par_SCO.Initialize; Sem_Ch8.Initialize; Sem_Ch12.Initialize; Sem_Ch13.Initialize; Sem_Elim.Initialize; Sem_Eval.Initialize; Sem_Type.Init_Interp_Tables; -- Acquire target parameters from system.ads (source of package System) declare use Sinput; S : Source_File_Index; N : File_Name_Type; begin Name_Buffer (1 .. 10) := "system.ads"; Name_Len := 10; N := Name_Find; S := Load_Source_File (N); if S = No_Source_File then Write_Line ("fatal error, run-time library not installed correctly"); Write_Line ("cannot locate file system.ads"); raise Unrecoverable_Error; -- Remember source index of system.ads (which was read successfully) else System_Source_File_Index := S; end if; Targparm.Get_Target_Parameters (System_Text => Source_Text (S), Source_First => Source_First (S), Source_Last => Source_Last (S)); -- Acquire configuration pragma information from Targparm Restrict.Restrictions := Targparm.Restrictions_On_Target; end; Adjust_Global_Switches; -- Output copyright notice if full list mode unless we have a list -- file, in which case we defer this so that it is output in the file if (Verbose_Mode or else (Full_List and then Full_List_File_Name = null)) and then not Debug_Flag_7 then Write_Eol; Write_Str ("GNAT "); Write_Str (Gnat_Version_String); Write_Eol; Write_Str ("Copyright 1992-" & Current_Year & ", Free Software Foundation, Inc."); Write_Eol; end if; -- Check we do not have more than one source file, this happens only in -- the case where the driver is called directly, it cannot happen when -- gnat1 is invoked from gcc in the normal case. if Osint.Number_Of_Files /= 1 then Usage; Write_Eol; Osint.Fail ("you must provide one source file"); elsif Usage_Requested then Usage; end if; Original_Operating_Mode := Operating_Mode; Frontend; -- Exit with errors if the main source could not be parsed. Also, when -- -gnatd.H is present, the source file is not set. if Sinput.Main_Source_File = No_Source_File then -- Handle -gnatd.H debug mode if Debug_Flag_Dot_HH then -- For -gnatd.H, lock all the tables to keep the convention that -- the backend needs to unlock the tables it wants to touch. Atree.Lock; Elists.Lock; Fname.UF.Lock; Inline.Lock; Lib.Lock; Nlists.Lock; Sem.Lock; Sinput.Lock; Namet.Lock; Stringt.Lock; -- And all we need to do is to call the back end Back_End.Call_Back_End (Back_End.Generate_Object); end if; Errout.Finalize (Last_Call => True); Errout.Output_Messages; Exit_Program (E_Errors); end if; Main_Unit_Node := Cunit (Main_Unit); Main_Kind := Nkind (Unit (Main_Unit_Node)); Check_Bad_Body; -- In CodePeer mode we always delete old SCIL files before regenerating -- new ones, in case of e.g. errors, and also to remove obsolete scilx -- files generated by CodePeer itself. if CodePeer_Mode then Comperr.Delete_SCIL_Files; end if; -- Exit if compilation errors detected Errout.Finalize (Last_Call => False); if Compilation_Errors then Treepr.Tree_Dump; Sem_Ch13.Validate_Unchecked_Conversions; Sem_Ch13.Validate_Address_Clauses; Sem_Ch13.Validate_Independence; Errout.Output_Messages; Namet.Finalize; -- Generate ALI file if specially requested if Opt.Force_ALI_Tree_File then Write_ALI (Object => False); Tree_Gen; end if; Errout.Finalize (Last_Call => True); Exit_Program (E_Errors); end if; -- Set Generate_Code on main unit and its spec. We do this even if are -- not generating code, since Lib-Writ uses this to determine which -- units get written in the ali file. Set_Generate_Code (Main_Unit); -- If we have a corresponding spec, and it comes from source or it is -- not a generated spec for a child subprogram body, then we need object -- code for the spec unit as well. if Nkind (Unit (Main_Unit_Node)) in N_Unit_Body and then not Acts_As_Spec (Main_Unit_Node) then if Nkind (Unit (Main_Unit_Node)) = N_Subprogram_Body and then not Comes_From_Source (Library_Unit (Main_Unit_Node)) then null; else Set_Generate_Code (Get_Cunit_Unit_Number (Library_Unit (Main_Unit_Node))); end if; end if; -- Case of no code required to be generated, exit indicating no error if Original_Operating_Mode = Check_Syntax then Treepr.Tree_Dump; Errout.Finalize (Last_Call => True); Errout.Output_Messages; Tree_Gen; Namet.Finalize; Check_Rep_Info; -- Use a goto instead of calling Exit_Program so that finalization -- occurs normally. goto End_Of_Program; elsif Original_Operating_Mode = Check_Semantics then Back_End_Mode := Declarations_Only; -- All remaining cases are cases in which the user requested that code -- be generated (i.e. no -gnatc or -gnats switch was used). Check if we -- can in fact satisfy this request. -- Cannot generate code if someone has turned off code generation for -- any reason at all. We will try to figure out a reason below. elsif Operating_Mode /= Generate_Code then Back_End_Mode := Skip; -- We can generate code for a subprogram body unless there were missing -- subunits. Note that we always generate code for all generic units (a -- change from some previous versions of GNAT). elsif Main_Kind = N_Subprogram_Body and then not Subunits_Missing then Back_End_Mode := Generate_Object; -- We can generate code for a package body unless there are subunits -- missing (note that we always generate code for generic units, which -- is a change from some earlier versions of GNAT). elsif Main_Kind = N_Package_Body and then not Subunits_Missing then Back_End_Mode := Generate_Object; -- We can generate code for a package declaration or a subprogram -- declaration only if it does not required a body. elsif Nkind_In (Main_Kind, N_Package_Declaration, N_Subprogram_Declaration) and then (not Body_Required (Main_Unit_Node) or else Distribution_Stub_Mode = Generate_Caller_Stub_Body) then Back_End_Mode := Generate_Object; -- We can generate code for a generic package declaration of a generic -- subprogram declaration only if does not require a body. elsif Nkind_In (Main_Kind, N_Generic_Package_Declaration, N_Generic_Subprogram_Declaration) and then not Body_Required (Main_Unit_Node) then Back_End_Mode := Generate_Object; -- Compilation units that are renamings do not require bodies, so we can -- generate code for them. elsif Nkind_In (Main_Kind, N_Package_Renaming_Declaration, N_Subprogram_Renaming_Declaration) then Back_End_Mode := Generate_Object; -- Compilation units that are generic renamings do not require bodies -- so we can generate code for them. elsif Main_Kind in N_Generic_Renaming_Declaration then Back_End_Mode := Generate_Object; -- It's not an error to generate SCIL for e.g. a spec which has a body elsif CodePeer_Mode then Back_End_Mode := Generate_Object; -- In all other cases (specs which have bodies, generics, and bodies -- where subunits are missing), we cannot generate code and we generate -- a warning message. Note that generic instantiations are gone at this -- stage since they have been replaced by their instances. else Back_End_Mode := Skip; end if; -- At this stage Back_End_Mode is set to indicate if the backend should -- be called to generate code. If it is Skip, then code generation has -- been turned off, even though code was requested by the original -- command. This is not an error from the user point of view, but it is -- an error from the point of view of the gcc driver, so we must exit -- with an error status. -- We generate an informative message (from the gcc point of view, it -- is an error message, but from the users point of view this is not an -- error, just a consequence of compiling something that cannot -- generate code). if Back_End_Mode = Skip then Set_Standard_Error; Write_Str ("cannot generate code for "); Write_Str ("file "); Write_Name (Unit_File_Name (Main_Unit)); if Subunits_Missing then Write_Str (" (missing subunits)"); Write_Eol; -- Force generation of ALI file, for backward compatibility Opt.Force_ALI_Tree_File := True; elsif Main_Kind = N_Subunit then Write_Str (" (subunit)"); Write_Eol; -- Force generation of ALI file, for backward compatibility Opt.Force_ALI_Tree_File := True; elsif Main_Kind = N_Subprogram_Declaration then Write_Str (" (subprogram spec)"); Write_Eol; -- Generic package body in GNAT implementation mode elsif Main_Kind = N_Package_Body and then GNAT_Mode then Write_Str (" (predefined generic)"); Write_Eol; -- Force generation of ALI file, for backward compatibility Opt.Force_ALI_Tree_File := True; -- Only other case is a package spec else Write_Str (" (package spec)"); Write_Eol; end if; Set_Standard_Output; Sem_Ch13.Validate_Unchecked_Conversions; Sem_Ch13.Validate_Address_Clauses; Sem_Ch13.Validate_Independence; Errout.Finalize (Last_Call => True); Errout.Output_Messages; Treepr.Tree_Dump; Tree_Gen; -- Generate ALI file if specially requested, or for missing subunits, -- subunits or predefined generic. if Opt.Force_ALI_Tree_File then Write_ALI (Object => False); end if; Namet.Finalize; Check_Rep_Info; -- Exit program with error indication, to kill object file Exit_Program (E_No_Code); end if; -- In -gnatc mode, we only do annotation if -gnatt or -gnatR is also set -- as indicated by Back_Annotate_Rep_Info being set to True. -- We don't call for annotations on a subunit, because to process those -- the back-end requires that the parent(s) be properly compiled. -- Annotation is suppressed for targets where front-end layout is -- enabled, because the front end determines representations. -- Annotation is also suppressed in the case of compiling for a VM, -- since representations are largely symbolic there. if Back_End_Mode = Declarations_Only and then (not (Back_Annotate_Rep_Info or Generate_SCIL) or else Main_Kind = N_Subunit or else Targparm.Frontend_Layout_On_Target or else Targparm.VM_Target /= No_VM) then Sem_Ch13.Validate_Unchecked_Conversions; Sem_Ch13.Validate_Address_Clauses; Sem_Ch13.Validate_Independence; Errout.Finalize (Last_Call => True); Errout.Output_Messages; Write_ALI (Object => False); Tree_Dump; Tree_Gen; Namet.Finalize; Check_Rep_Info; return; end if; -- Ensure that we properly register a dependency on system.ads, since -- even if we do not semantically depend on this, Targparm has read -- system parameters from the system.ads file. Lib.Writ.Ensure_System_Dependency; -- Add dependencies, if any, on preprocessing data file and on -- preprocessing definition file(s). Prepcomp.Add_Dependencies; -- Back end needs to explicitly unlock tables it needs to touch Atree.Lock; Elists.Lock; Fname.UF.Lock; Inline.Lock; Lib.Lock; Nlists.Lock; Sem.Lock; Sinput.Lock; Namet.Lock; Stringt.Lock; -- ???Check_Library_Items under control of a debug flag, because it -- currently does not work if the -gnatn switch (back end inlining) is -- used. if Debug_Flag_Dot_WW then Check_Library_Items; end if; -- Here we call the back end to generate the output code Generating_Code := True; Back_End.Call_Back_End (Back_End_Mode); -- Once the backend is complete, we unlock the names table. This call -- allows a few extra entries, needed for example for the file name for -- the library file output. Namet.Unlock; -- Generate the call-graph output of dispatching calls Exp_CG.Generate_CG_Output; -- Validate unchecked conversions (using the values for size and -- alignment annotated by the backend where possible). Sem_Ch13.Validate_Unchecked_Conversions; -- Validate address clauses (again using alignment values annotated -- by the backend where possible). Sem_Ch13.Validate_Address_Clauses; -- Validate independence pragmas (again using values annotated by -- the back end for component layout etc.) Sem_Ch13.Validate_Independence; -- Now we complete output of errors, rep info and the tree info. These -- are delayed till now, since it is perfectly possible for gigi to -- generate errors, modify the tree (in particular by setting flags -- indicating that elaboration is required, and also to back annotate -- representation information for List_Rep_Info. Errout.Finalize (Last_Call => True); Errout.Output_Messages; List_Rep_Info; -- Only write the library if the backend did not generate any error -- messages. Otherwise signal errors to the driver program so that -- there will be no attempt to generate an object file. if Compilation_Errors then Treepr.Tree_Dump; Exit_Program (E_Errors); end if; Write_ALI (Object => (Back_End_Mode = Generate_Object)); if not Compilation_Errors then -- In case of ada backends, we need to make sure that the generated -- object file has a timestamp greater than the ALI file. We do this -- to make gnatmake happy when checking the ALI and obj timestamps, -- where it expects the object file being written after the ali file. -- Gnatmake's assumption is true for gcc platforms where the gcc -- wrapper needs to call the assembler after calling gnat1, but is -- not true for ada backends, where the object files are created -- directly by gnat1 (so are created before the ali file). Back_End.Gen_Or_Update_Object_File; end if; -- Generate ASIS tree after writing the ALI file, since in ASIS mode, -- Write_ALI may in fact result in further tree decoration from the -- original tree file. Note that we dump the tree just before generating -- it, so that the dump will exactly reflect what is written out. Treepr.Tree_Dump; Tree_Gen; -- Finalize name table and we are all done Namet.Finalize; exception -- Handle fatal internal compiler errors when Rtsfind.RE_Not_Available => Comperr.Compiler_Abort ("RE_Not_Available"); when System.Assertions.Assert_Failure => Comperr.Compiler_Abort ("Assert_Failure"); when Constraint_Error => Comperr.Compiler_Abort ("Constraint_Error"); when Program_Error => Comperr.Compiler_Abort ("Program_Error"); when Storage_Error => -- Assume this is a bug. If it is real, the message will in any case -- say Storage_Error, giving a strong hint! Comperr.Compiler_Abort ("Storage_Error"); end; <> null; -- The outer exception handles an unrecoverable error exception when Unrecoverable_Error => Errout.Finalize (Last_Call => True); Errout.Output_Messages; Set_Standard_Error; Write_Str ("compilation abandoned"); Write_Eol; Set_Standard_Output; Source_Dump; Tree_Dump; Exit_Program (E_Errors); end Gnat1drv;