fbc: add "__thiscall" calling convention, -gen gcc only

- adds the keyword '__thiscall'
- emits '__thiscall' or __'attribute__((thiscall))' in -gen gcc
- emits x86_thiscallcc in -gen llvm (not tested)
- ignored in -gen gas, (i.e. no change in emitted code even if thiscall is present)
- must be explicitly specified in the procedure declaration
- default use of "thiscall" calling convention still platform dependant (e.g. win x86 32-bit) compared to default usage in g++
- recommend user to '#define thiscall __thiscall' depending on target platform

Author: jayrm

changelog.txt

@@ -67,6 +67,7 @@ Version 1.08.0
 - '-w suffix' or '-w pedantic' command line option enabled 'Suffix ignored' warning for built-in in string functions
 - __FB_UNIQUEID_PUSH__(), __FB_UNIQUEID__(), __FB_UNIQUEID_POP__(), __FB_ARG_LEFTOF__(), __FB_ARG_RIGHTOF__(), __FB_JOIN__() builtin macros
 - __FB_ARG_COUNT__() builtin macro
+- __thiscall keyword to specify the 'thiscall' calling convention (-gen gcc only)
 - __FB_QUOTE__(), __FB_UNQUOTE__(), __FB_EVAL__() builtin macros
 - rtlib: REDIM [PRESERVE] will generate run time error if attempting to resize static (fixed length) arrays.
 - gas64 emitter for x86_64 (SARG), added '-gen gas64' command line option to select

src/compiler/ast-node-call.bas

@@ -204,6 +204,7 @@ function astLoadCALL( byval n as ASTNODE ptr ) as IRVREG ptr
 
 		'' cdecl: pushed arguments must be popped by caller
 		'' pascal/stdcall: callee does it instead
+		'' thiscall: could be either depending on target !!! TODO !!!
 		argbytes = symbCalcArgLen( l->dtype, l->subtype, arg->arg.mode )
 		if( symbGetProcMode( proc ) = FB_FUNCMODE_CDECL ) then
 			bytestopop += argbytes

src/compiler/fbint.bi

@@ -346,6 +346,7 @@ enum FB_TOKEN
 	FB_TK_PASCAL
 	FB_TK_CDECL
 	FB_TK_STDCALL
+	FB_TK_THISCALL
 	FB_TK_ALIAS
 	FB_TK_LIB
 	FB_TK_OVERLOAD

src/compiler/ir-hlc.bas

@@ -555,6 +555,13 @@ private function hEmitProcHeader _
 				'' Linux GCC only accepts this
 				ln += " __attribute__((stdcall))"
 			end select
+		case FB_FUNCMODE_THISCALL
+			select case( env.clopt.target )
+			case FB_COMPTARGET_WIN32, FB_COMPTARGET_XBOX
+				ln += " __thiscall"
+			case else
+				ln += " __attribute__((thiscall))"
+			end select
 		end select
 	end if
 

src/compiler/ir-llvm.bas

@@ -367,6 +367,8 @@ private function hEmitProcCallConv( byval proc as FBSYMBOL ptr ) as string
 	select case as const( symbGetProcMode( proc ) )
 	case FB_FUNCMODE_STDCALL, FB_FUNCMODE_STDCALL_MS, FB_FUNCMODE_PASCAL
 		function = "x86_stdcallcc "
+	case FB_FUNCMODE_THISCALL
+		function = "x86_thiscall "
 	end select
 end function
 

src/compiler/parser-proc.bas

@@ -509,7 +509,7 @@ function cProcCallingConv( byval default as FB_FUNCMODE ) as FB_FUNCMODE
         default = env.target.fbcall
     end if
 
-	'' (CDECL|STDCALL|PASCAL)?
+	'' (CDECL|STDCALL|PASCAL|THISCALL)?
 	select case as const lexGetToken( )
 	case FB_TK_CDECL
 		function = FB_FUNCMODE_CDECL
@@ -525,6 +525,10 @@ function cProcCallingConv( byval default as FB_FUNCMODE ) as FB_FUNCMODE
 		function = FB_FUNCMODE_PASCAL
 		lexSkipToken( LEXCHECK_POST_SUFFIX )
 
+	case FB_TK_THISCALL
+		function = FB_FUNCMODE_THISCALL
+		lexSkipToken( )
+
 	case else
 		select case as const parser.mangling
 		case FB_MANGLING_BASIC, FB_MANGLING_RTLIB

src/compiler/symb-keyword.bas

@@ -108,6 +108,7 @@ dim shared kwdTb( 0 to FB_TOKENS-1 ) as SYMBKWD => _
 	( @"FUNCTION"   , FB_TK_FUNCTION    , FB_TKCLASS_KEYWORD ), _
 	( @"CDECL"      , FB_TK_CDECL       , FB_TKCLASS_KEYWORD ), _
 	( @"STDCALL"    , FB_TK_STDCALL     , FB_TKCLASS_KEYWORD ), _
+	( @"__THISCALL" , FB_TK_THISCALL    , FB_TKCLASS_KEYWORD ), _
 	( @"PASCAL"     , FB_TK_PASCAL      , FB_TKCLASS_KEYWORD ), _
 	( @"ALIAS"      , FB_TK_ALIAS       , FB_TKCLASS_KEYWORD ), _
 	( @"LIB"        , FB_TK_LIB         , FB_TKCLASS_KEYWORD ), _

src/compiler/symb-proc.bas

@@ -2928,6 +2928,8 @@ private sub hProcModeToStr( byref s as string, byval proc as FBSYMBOL ptr )
 		select case( symbGetProcMode( proc ) )
 		case FB_FUNCMODE_STDCALL, FB_FUNCMODE_STDCALL_MS
 			s += " stdcall"
+		case FB_FUNCMODE_THISCALL
+			s += " thiscall"
 		case FB_FUNCMODE_PASCAL
 			s += " pascal"
 		end select
@@ -2941,6 +2943,8 @@ private sub hProcModeToStr( byref s as string, byval proc as FBSYMBOL ptr )
 			case else
 				s += " stdcall"
 			end select
+		case FB_FUNCMODE_THISCALL
+			s += " thiscall"
 		case FB_FUNCMODE_PASCAL
 			if( env.target.fbcall <> FB_FUNCMODE_PASCAL ) then
 				s += " pascal"

src/compiler/symb.bas

@@ -2580,6 +2580,7 @@ function symbDumpToStr _
 		case FB_FUNCMODE_STDCALL_MS : s += " stdcallms"
 		case FB_FUNCMODE_PASCAL     : s += " pascal"
 		case FB_FUNCMODE_CDECL      : s += " cdecl"
+		case FB_FUNCMODE_THISCALL   : s += " thiscall"
 		end select
 
 		if( verbose ) then

src/compiler/symb.bi

@@ -217,6 +217,7 @@ enum FB_FUNCMODE
 	FB_FUNCMODE_STDCALL_MS						'' ms/vb-style: don't include the @n suffix
 	FB_FUNCMODE_CDECL
 	FB_FUNCMODE_PASCAL
+	FB_FUNCMODE_THISCALL
 
 	'' Symbolic constant to represent FBCALL, telling cProcCallingConv()
 	'' and the RTL procedure definitions to use env.target.fbcall which