Prior to this change, -fno-inline was stopping all the inlining unconditionally, even when requested with a pragma Inline_Always.
This was inconsistent with the behavior of the "always_inline" gcc attribute, and this change fixes this. It also removes an internal shortcircuit which was preventing consistency checks of the various inlining pragmas attached to a subprogram. For the following suprogram, the call to p1 must always be inlined regardless of -fno-inline, and the call to p2 must not be inlined in presence of -fno-inline: procedure Intra is x : integer; pragma Import (C, X); pragma Volatile (X); procedure p1; pragma Inline_Always (p1); procedure p2; pragma Inline (p2); procedure p1 is begin x := 1; end; procedure p2 is begin x := 2; end; begin p1; p2; end; And for the code below: procedure Bogus is x : integer; pragma Import (C, X); pragma Volatile (X); procedure p1; pragma Inline_Always (p1); pragma No_Inline (p1); procedure p2; pragma Inline (p2); pragma No_Inline (p2); procedure p1 is begin x := 1; end; procedure p2 is begin x := 2; end; begin p1; p2; end; The compiler must flag inconsistencies between No_Inline and Inline or Inline_Always with or without -fno-inline on the command line. Tested on x86_64-pc-linux-gnu, committed on trunk 2015-02-20 Olivier Hainque <hain...@adacore.com> * opt.ads: Replace Opt.Suppress_All_Inlining by two separate flags controlling the actual FE inlining out of pragma Inline and pragma Inline_Always. * adabkend.adb (Scan_Compiler_Arguments): Set both flags to True on -fno-inline, which disables all inlining in compilers with an Ada back-end and without back-end inlining support. * back_end.adb (Scan_Back_End_Switches): Set the Inline related flag to True on -fno-inline and leave Inline_Always alone for gcc back-ends. * back_end.ads (Scan_Compiler_Arguments): Adjust spec wrt the names of the Opt flags it sets. * gnat1drv.adb (Adjust_Global_Switches): Remove test on Opt.Suppress_All_Inlining in the Back_End_Inlining computation. * sem_prag.adb (Make_Inline): Remove early return conditioned on Opt.Suppress_All_Inlining. * sem_ch6.adb (Analyze_Subprogram_Body_Helper): Use the flags to disable the calls to Build_Body_To_Inline otherwise triggered by pragma Inline or Inline_Always. This will prevent actual front-end inlining of the subprogram on calls.
Index: sem_prag.adb =================================================================== --- sem_prag.adb (revision 220835) +++ sem_prag.adb (working copy) @@ -8204,12 +8204,6 @@ Applies := True; return; - -- Ignore if all inlining is suppressed - - elsif Suppress_All_Inlining then - Applies := True; - return; - -- If inlining is not possible, for now do not treat as an error elsif Status /= Suppressed Index: gnat1drv.adb =================================================================== --- gnat1drv.adb (revision 220835) +++ gnat1drv.adb (working copy) @@ -6,7 +6,7 @@ -- -- -- B o d y -- -- -- --- Copyright (C) 1992-2014, Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2015, 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- -- @@ -609,13 +609,9 @@ Back_End_Inlining := - -- No back end inlining if inlining is suppressed - - not Suppress_All_Inlining - -- No back end inlining available for VM targets - and then VM_Target = No_VM + VM_Target = No_VM -- No back end inlining available on AAMP Index: sem_ch6.adb =================================================================== --- sem_ch6.adb (revision 220835) +++ sem_ch6.adb (working copy) @@ -3739,8 +3739,11 @@ -- Legacy implementation (relying on frontend inlining) if not Back_End_Inlining then - if Has_Pragma_Inline_Always (Spec_Id) - or else (Has_Pragma_Inline (Spec_Id) and Front_End_Inlining) + if (Has_Pragma_Inline_Always (Spec_Id) + and then not Opt.Disable_FE_Inline_Always) + or else + (Has_Pragma_Inline (Spec_Id) and then Front_End_Inlining + and then not Opt.Disable_FE_Inline) then Build_Body_To_Inline (N, Spec_Id); end if; Index: back_end.adb =================================================================== --- back_end.adb (revision 220835) +++ back_end.adb (working copy) @@ -6,7 +6,7 @@ -- -- -- B o d y -- -- -- --- Copyright (C) 1992-2014, Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2015, 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- -- @@ -23,6 +23,8 @@ -- -- ------------------------------------------------------------------------------ +-- This is the version of the Back_End package for GCC back ends + with Atree; use Atree; with Debug; use Debug; with Elists; use Elists; @@ -251,11 +253,12 @@ else Store_Compilation_Switch (Switch_Chars); - -- Back end switch -fno-inline also sets the Suppress_All_Inlining - -- front end flag to entirely inhibit all inlining. + -- For gcc back ends, -fno-inline disables Inline pragmas only, + -- not Inline_Always to remain consistent with the always_inline + -- attribute behavior. if Switch_Chars (First .. Last) = "fno-inline" then - Opt.Suppress_All_Inlining := True; + Opt.Disable_FE_Inline := True; -- Back end switch -fpreserve-control-flow also sets the front end -- flag that inhibits improper control flow transformations. Index: back_end.ads =================================================================== --- back_end.ads (revision 220835) +++ back_end.ads (working copy) @@ -6,7 +6,7 @@ -- -- -- S p e c -- -- -- --- Copyright (C) 1992-2014, Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2015, 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- -- @@ -24,6 +24,7 @@ ------------------------------------------------------------------------------ -- Call the back end with all the information needed + -- Note: there are multiple bodies/variants of this package, so do not -- modify this spec without coordination. @@ -65,7 +66,8 @@ -- This routine is expected to set the following to True if necessary (the -- default for all of these in Opt is False). -- - -- Opt.Suppress_All_Inlining + -- Opt.Disable_FE_Inline + -- Opt.Disable_FE_Inline_Always -- Opt.Suppress_Control_Float_Optimizations -- Opt.Generate_SCO -- Opt.Generate_SCO_Instance_Table Index: opt.ads =================================================================== --- opt.ads (revision 220839) +++ opt.ads (working copy) @@ -1370,10 +1370,14 @@ -- with'ed indirectly. It is set True by use of either the -gnatg or -- -gnaty switches, but not by use of the Style_Checks pragma. - Suppress_All_Inlining : Boolean := False; + Disable_FE_Inline : Boolean := False; + Disable_FE_Inline_Always : Boolean := False; -- GNAT - -- Set by -fno-inline. Suppresses all inlining, both front end and back end - -- regardless of any other switches that are set. + -- Request to disable front end inlining from pragma Inline or pragma + -- Inline_Always out of the presence of the -fno-inline back end flag + -- on the command line, regardless of any other switches that are set. + -- It remains the back end's reponsibility to honor -fno-inline at the + -- back end level. Suppress_Control_Flow_Optimizations : Boolean := False; -- GNAT Index: adabkend.adb =================================================================== --- adabkend.adb (revision 220835) +++ adabkend.adb (working copy) @@ -6,7 +6,7 @@ -- -- -- B o d y -- -- -- --- Copyright (C) 2001-2014, AdaCore -- +-- Copyright (C) 2001-2015, AdaCore -- -- -- -- 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- -- @@ -178,12 +178,13 @@ return; -- Special check, the back end switch -fno-inline also sets the - -- front end flag to entirely inhibit all inlining. So we store it - -- and set the appropriate flag. + -- front end flags to entirely inhibit all inlining. So we store it + -- and set the appropriate flags. elsif Switch_Chars (First .. Last) = "fno-inline" then Lib.Store_Compilation_Switch (Switch_Chars); - Opt.Suppress_All_Inlining := True; + Opt.Disable_FE_Inline := True; + Opt.Disable_FE_Inline_Always := True; return; -- Similar processing for -fpreserve-control-flow