X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=src%2Fcc65%2Ffunction.c;h=66777b189e624246bda42449db6ecb241992d70a;hb=d8338efc53e3be70bb17ab6c71f0dd95dff3db12;hp=8b4e92c741d4a0568d1a74ddc8233d8abb2abc4c;hpb=59bcc726b6ecf668aa1b8805cba84ec880bbf61e;p=cc65 diff --git a/src/cc65/function.c b/src/cc65/function.c index 8b4e92c74..66777b189 100644 --- a/src/cc65/function.c +++ b/src/cc65/function.c @@ -6,10 +6,10 @@ /* */ /* */ /* */ -/* (C) 2000 Ullrich von Bassewitz */ -/* Wacholderweg 14 */ -/* D-70597 Stuttgart */ -/* EMail: uz@musoftware.de */ +/* (C) 2000-2001 Ullrich von Bassewitz */ +/* Wacholderweg 14 */ +/* D-70597 Stuttgart */ +/* EMail: uz@cc65.org */ /* */ /* */ /* This software is provided 'as-is', without any expressed or implied */ @@ -47,6 +47,7 @@ #include "litpool.h" #include "locals.h" #include "scanner.h" +#include "segments.h" #include "stmt.h" #include "symtab.h" #include "function.h" @@ -62,11 +63,11 @@ /* Structure that holds all data needed for function activation */ struct Function { struct SymEntry* FuncEntry; /* Symbol table entry */ - type* ReturnType; /* Function return type */ + type* ReturnType; /* Function return type */ struct FuncDesc* Desc; /* Function descriptor */ - CodeMark EntryCode; /* Backpatch addr for entry code */ int Reserved; /* Reserved local space */ unsigned RetLab; /* Return code label */ + int TopLevelSP; /* SP at function top level */ }; /* Pointer to current function */ @@ -88,11 +89,11 @@ static Function* NewFunction (struct SymEntry* Sym) /* Initialize the fields */ F->FuncEntry = Sym; - F->ReturnType = Sym->Type + 1 + DECODE_SIZE; + F->ReturnType = GetFuncReturn (Sym->Type); F->Desc = (FuncDesc*) DecodePtr (Sym->Type + 1); - F->EntryCode = 0; F->Reserved = 0; - F->RetLab = GetLabel (); + F->RetLab = GetLocalLabel (); + F->TopLevelSP = 0; /* Return the new structure */ return F; @@ -108,7 +109,7 @@ static void FreeFunction (Function* F) -const char* GetFuncName (const Function* F) +const char* F_GetFuncName (const Function* F) /* Return the name of the current function */ { return F->FuncEntry->Name; @@ -116,7 +117,7 @@ const char* GetFuncName (const Function* F) -unsigned GetParamCount (const Function* F) +unsigned F_GetParamCount (const Function* F) /* Return the parameter count for the current function */ { return F->Desc->ParamCount; @@ -124,7 +125,7 @@ unsigned GetParamCount (const Function* F) -unsigned GetParamSize (const Function* F) +unsigned F_GetParamSize (const Function* F) /* Return the parameter size for the current function */ { return F->Desc->ParamSize; @@ -132,7 +133,7 @@ unsigned GetParamSize (const Function* F) -type* GetReturnType (Function* F) +type* F_GetReturnType (Function* F) /* Get the return type for the function */ { return F->ReturnType; @@ -140,7 +141,7 @@ type* GetReturnType (Function* F) -int HasVoidReturn (const Function* F) +int F_HasVoidReturn (const Function* F) /* Return true if the function does not have a return value */ { return IsTypeVoid (F->ReturnType); @@ -148,23 +149,31 @@ int HasVoidReturn (const Function* F) -int IsVariadic (const Function* F) +int F_IsVariadic (const Function* F) /* Return true if this is a variadic function */ { - return (F->Desc->Flags & FD_ELLIPSIS) != 0; + return (F->Desc->Flags & FD_VARIADIC) != 0; } -void RememberEntry (Function* F) -/* Remember the current output position for local space creation later */ +int F_IsOldStyle (const Function* F) +/* Return true if this is an old style (K&R) function */ { - F->EntryCode = GetCodePos (); + return (F->Desc->Flags & FD_OLDSTYLE) != 0; } -unsigned GetRetLab (const Function* F) +int F_HasOldStyleIntRet (const Function* F) +/* Return true if this is an old style (K&R) function with an implicit int return */ +{ + return (F->Desc->Flags & FD_OLDSTYLE_INTRET) != 0; +} + + + +unsigned F_GetRetLab (const Function* F) /* Return the return jump label */ { return F->RetLab; @@ -172,7 +181,15 @@ unsigned GetRetLab (const Function* F) -int ReserveLocalSpace (Function* F, unsigned Size) +int F_GetTopLevelSP (const Function* F) +/* Get the value of the stack pointer on function top level */ +{ + return F->TopLevelSP; +} + + + +int F_ReserveLocalSpace (Function* F, unsigned Size) /* Reserve (but don't allocate) the given local space and return the stack * offset. */ @@ -183,24 +200,21 @@ int ReserveLocalSpace (Function* F, unsigned Size) -void AllocLocalSpace (Function* F) +void F_AllocLocalSpace (Function* F) /* Allocate any local space previously reserved. The function will do * nothing if there is no reserved local space. */ { if (F->Reserved > 0) { - /* Switch to the code segment */ - g_usecode (); - - /* Create space on the stack */ - g_space (F->Reserved); + /* Create space on the stack */ + g_space (F->Reserved); - /* Correct the stack pointer */ - oursp -= F->Reserved; + /* Correct the stack pointer */ + oursp -= F->Reserved; - /* Nothing more reserved */ - F->Reserved = 0; + /* Nothing more reserved */ + F->Reserved = 0; } } @@ -215,11 +229,12 @@ void AllocLocalSpace (Function* F) void NewFunc (SymEntry* Func) /* Parse argument declarations and function body. */ { - int isbrk; - unsigned Flags; + int HadReturn; + int IsVoidFunc; + SymEntry* LastParam; /* Get the function descriptor from the function entry */ - FuncDesc* D = (FuncDesc*) DecodePtr (Func->Type+1); + FuncDesc* D = Func->V.F.Func; /* Allocate the function activation record for the function */ CurrentFunc = NewFunction (Func); @@ -227,49 +242,42 @@ void NewFunc (SymEntry* Func) /* Reenter the lexical level */ ReenterFunctionLevel (D); + /* Before adding more symbols, remember the last parameter for later */ + LastParam = D->SymTab->SymTail; + /* Declare two special functions symbols: __fixargs__ and __argsize__. * The latter is different depending on the type of the function (variadic * or not). */ - AddConstSym ("__fixargs__", type_uint, SC_DEF | SC_CONST, D->ParamSize); - if (D->Flags & FD_ELLIPSIS) { - /* Variadic function. The variable must be const. */ - static const type T [] = { T_UCHAR | T_QUAL_CONST, T_END }; - AddLocalSym ("__argsize__", T, SC_DEF | SC_REF | SC_AUTO, 0); + AddConstSym ("__fixargs__", type_uint, SC_DEF | SC_CONST, D->ParamSize); + if (D->Flags & FD_VARIADIC) { + /* Variadic function. The variable must be const. */ + static const type T [] = { T_UCHAR | T_QUAL_CONST, T_END }; + AddLocalSym ("__argsize__", T, SC_DEF | SC_REF | SC_AUTO, 0); } else { - /* Non variadic */ + /* Non variadic */ AddConstSym ("__argsize__", type_uchar, SC_DEF | SC_CONST, D->ParamSize); } /* Function body now defined */ Func->Flags |= SC_DEF; - /* Need a starting curly brace */ - if (curtok != TOK_LCURLY) { - Error ("`{' expected"); - } - /* Setup register variables */ InitRegVars (); - /* Switch to the code segment and define the function name label */ - g_usecode (); - g_defgloblabel (Func->Name); + /* Allocate code and data segments for this function */ + Func->V.F.Seg = PushSegments (Func); /* If this is a fastcall function, push the last parameter onto the stack */ if (IsFastCallFunc (Func->Type) && D->ParamCount > 0) { - SymEntry* LastParam; - unsigned Flags; + unsigned Flags; - /* Fastcall functions may never have an ellipsis or the compiler is buggy */ - CHECK ((D->Flags & FD_ELLIPSIS) == 0); + /* Fastcall functions may never have an ellipsis or the compiler is buggy */ + CHECK ((D->Flags & FD_VARIADIC) == 0); - /* Get a pointer to the last parameter entry */ - LastParam = D->SymTab->SymTail; - - /* Generate the push */ - if (IsTypeFunc (LastParam->Type)) { + /* Generate the push */ + if (IsTypeFunc (LastParam->Type)) { /* Pointer to function */ Flags = CF_PTR; } else { @@ -284,35 +292,57 @@ void NewFunc (SymEntry* Func) } /* Generate function entry code if needed */ - g_enter (TypeOf (Func->Type), GetParamSize (CurrentFunc)); - - /* Remember the current code position. This may be used later to create - * local variable space once we have created the function body itself. - * Currently this is not possible because the stack offsets of all locals - * have to be known in advance. - */ - RememberEntry (CurrentFunc); + g_enter (TypeOf (Func->Type), F_GetParamSize (CurrentFunc)); - /* Parse the function body */ + /* Setup the stack */ oursp = 0; - isbrk = compound (); - /* If the function did not end with an return statement, create exit code */ - if (!isbrk) { -#if 0 - /* If the function has a return type, flag an error */ - if (!voidfunc) { - Error ("Function `%s' must return a value", Func->Name); + /* Need a starting curly brace */ + ConsumeLCurly (); + + /* Parse local variable declarations if any */ + DeclareLocals (); + + /* Remember the current stack pointer. All variables allocated elsewhere + * must be dropped when doing a return from an inner block. + */ + CurrentFunc->TopLevelSP = oursp; + + /* Now process statements in this block */ + HadReturn = 0; + while (CurTok.Tok != TOK_RCURLY) { + if (CurTok.Tok != TOK_CEOF) { + HadReturn = Statement (0); + } else { + break; } -#endif - RestoreRegVars (0); + } - Flags = HasVoidReturn (CurrentFunc)? CF_NONE : CF_REG; - g_leave (Flags, 0); + /* If the function has a return type but no return statement, flag + * a warning + */ + IsVoidFunc = F_HasVoidReturn (CurrentFunc); +#if 0 + /* Does not work reliably */ + if (!F_IsVoidFunc && !HadReturn) { + Warning ("Function `%s' should return a value", Func->Name); } +#endif + + /* Output the function exit code label */ + g_defcodelabel (F_GetRetLab (CurrentFunc)); + + /* Restore the register variables */ + RestoreRegVars (!IsVoidFunc); - /* Dump literal data created by the function */ - DumpLiteralPool (); + /* Generate the exit code */ + g_leave (); + + /* Eat the closing brace */ + ConsumeRCurly (); + + /* Emit references to imports/exports */ + EmitExternals (); /* Cleanup register variables */ DoneRegVars (); @@ -320,6 +350,9 @@ void NewFunc (SymEntry* Func) /* Leave the lexical level */ LeaveFunctionLevel (); + /* Switch back to the old segments */ + PopSegments (); + /* Reset the current function pointer */ FreeFunction (CurrentFunc); CurrentFunc = 0; @@ -327,4 +360,3 @@ void NewFunc (SymEntry* Func) -