/* */
/* */
/* */
-/* (C) 2000-2008 Ullrich von Bassewitz */
-/* Roemerstrasse 52 */
-/* D-70794 Filderstadt */
-/* EMail: uz@cc65.org */
+/* (C) 2000-2011, Ullrich von Bassewitz */
+/* Roemerstrasse 52 */
+/* D-70794 Filderstadt */
+/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
#include "litpool.h"
#include "locals.h"
#include "scanner.h"
-#include "segments.h"
#include "stackptr.h"
#include "standard.h"
#include "stmt.h"
+/* Enumeration for function flags */
+typedef enum {
+ FF_NONE = 0x0000,
+ FF_HAS_RETURN = 0x0001, /* Function has a return statement */
+ FF_IS_MAIN = 0x0002, /* This is the main function */
+ FF_VOID_RETURN = 0x0004, /* Function returning void */
+} funcflags_t;
+
/* Structure that holds all data needed for function activation */
struct Function {
struct SymEntry* FuncEntry; /* Symbol table entry */
- Type* ReturnType; /* Function return type */
- struct FuncDesc* Desc; /* Function descriptor */
- int Reserved; /* Reserved local space */
- unsigned RetLab; /* Return code label */
- int TopLevelSP; /* SP at function top level */
+ Type* ReturnType; /* Function return type */
+ FuncDesc* Desc; /* Function descriptor */
+ int Reserved; /* Reserved local space */
+ unsigned RetLab; /* Return code label */
+ int TopLevelSP; /* SP at function top level */
unsigned RegOffs; /* Register variable space offset */
+ funcflags_t Flags; /* Function flags */
};
/* Pointer to current function */
/*****************************************************************************/
-/* Subroutines working with struct Function */
+/* Subroutines working with struct Function */
/*****************************************************************************/
F->RetLab = GetLocalLabel ();
F->TopLevelSP = 0;
F->RegOffs = RegisterSpace;
+ F->Flags = IsTypeVoid (F->ReturnType) ? FF_VOID_RETURN : FF_NONE;
/* Return the new structure */
return F;
int F_HasVoidReturn (const Function* F)
/* Return true if the function does not have a return value */
{
- return IsTypeVoid (F->ReturnType);
+ return (F->Flags & FF_VOID_RETURN) != 0;
+}
+
+
+
+void F_ReturnFound (Function* F)
+/* Mark the function as having a return statement */
+{
+ F->Flags |= FF_HAS_RETURN;
+}
+
+
+
+int F_HasReturn (const Function* F)
+/* Return true if the function contains a return statement*/
+{
+ return (F->Flags & FF_HAS_RETURN) != 0;
+}
+
+
+
+int F_IsMainFunc (const Function* F)
+/* Return true if this is the main function */
+{
+ return (F->Flags & FF_IS_MAIN) != 0;
}
+static void F_EmitDebugInfo (void)
+/* Emit debug infos for the current function */
+{
+ if (DebugInfo) {
+ /* Get the current fuction */
+ const SymEntry* Sym = CurrentFunc->FuncEntry;
+
+ /* Output info for the function itself */
+ AddTextLine ("\t.dbg\tfunc, \"%s\", \"00\", %s, \"%s\"",
+ Sym->Name,
+ (Sym->Flags & SC_EXTERN)? "extern" : "static",
+ Sym->AsmName);
+ }
+}
+
+
+
/*****************************************************************************/
-/* code */
+/* code */
/*****************************************************************************/
void NewFunc (SymEntry* Func)
/* Parse argument declarations and function body. */
{
- int HadReturn;
- SymEntry* Param;
+ int C99MainFunc = 0;/* Flag for C99 main function returning int */
+ SymEntry* Param;
/* Get the function descriptor from the function entry */
FuncDesc* D = Func->V.F.Func;
/* Reenter the lexical level */
ReenterFunctionLevel (D);
+ /* Check if the function header contains unnamed parameters. These are
+ * only allowed in cc65 mode.
+ */
+ if ((D->Flags & FD_UNNAMED_PARAMS) != 0 && (IS_Get (&Standard) != STD_CC65)) {
+ Error ("Parameter name omitted");
+ }
+
/* 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_VARIADIC) {
- /* Variadic function. The variable must be const. */
- static const Type T[] = { TYPE(T_UCHAR | T_QUAL_CONST), TYPE(T_END) };
- AddLocalSym ("__argsize__", T, SC_DEF | SC_REF | SC_AUTO, 0);
+ /* Variadic function. The variable must be const. */
+ static const Type T[] = { TYPE(T_UCHAR | T_QUAL_CONST), TYPE(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;
- /* Allocate code and data segments for this function */
- Func->V.F.Seg = PushSegments (Func);
-
/* Special handling for main() */
if (strcmp (Func->Name, "main") == 0) {
+
+ /* Mark this as the main function */
+ CurrentFunc->Flags |= FF_IS_MAIN;
+
/* Main cannot be a fastcall function */
if (IsQualFastcall (Func->Type)) {
Error ("`main' cannot be declared as __fastcall__");
if (D->ParamCount > 0 || (D->Flags & FD_VARIADIC) != 0) {
g_importmainargs ();
}
+
+ /* Determine if this is a main function in a C99 environment that
+ * returns an int.
+ */
+ if (IsTypeInt (F_GetReturnType (CurrentFunc)) &&
+ IS_Get (&Standard) == STD_C99) {
+ C99MainFunc = 1;
+ }
}
+ /* Allocate code and data segments for this function */
+ Func->V.F.Seg = PushSegments (Func);
+
+ /* Allocate a new literal pool */
+ PushLiteralPool (Func);
+
/* If this is a fastcall function, push the last parameter onto the stack */
if (IsQualFastcall (Func->Type) && D->ParamCount > 0) {
- unsigned Flags;
+ unsigned Flags;
- /* Fastcall functions may never have an ellipsis or the compiler is buggy */
- CHECK ((D->Flags & FD_VARIADIC) == 0);
+ /* Fastcall functions may never have an ellipsis or the compiler is buggy */
+ CHECK ((D->Flags & FD_VARIADIC) == 0);
- /* Generate the push */
- if (IsTypeFunc (D->LastParam->Type)) {
+ /* Generate the push */
+ if (IsTypeFunc (D->LastParam->Type)) {
/* Pointer to function */
Flags = CF_PTR;
} else {
/* Generate swap code */
g_swap_regvars (Param->V.R.SaveOffs, Reg, CheckedSizeOf (Param->Type));
-
}
}
CurrentFunc->TopLevelSP = StackPtr;
/* Now process statements in this block */
- HadReturn = 0;
- while (CurTok.Tok != TOK_RCURLY) {
- if (CurTok.Tok != TOK_CEOF) {
- HadReturn = Statement (0);
- } else {
- break;
- }
+ while (CurTok.Tok != TOK_RCURLY && CurTok.Tok != TOK_CEOF) {
+ Statement (0);
+ }
+
+ /* If this is not a void function, and not the main function in a C99
+ * environment returning int, output a warning if we didn't see a return
+ * statement.
+ */
+ if (!F_HasVoidReturn (CurrentFunc) && !F_HasReturn (CurrentFunc) && !C99MainFunc) {
+ Warning ("Control reaches end of non-void function");
+ }
+
+ /* If this is the main function in a C99 environment returning an int, let
+ * it always return zero. Note: Actual return statements jump to the return
+ * label defined below.
+ * The code is removed by the optimizer if unused.
+ */
+ if (C99MainFunc) {
+ g_getimmed (CF_INT | CF_CONST, 0, 0);
}
/* Output the function exit code label */
/* Emit references to imports/exports */
EmitExternals ();
+ /* Emit function debug info */
+ F_EmitDebugInfo ();
+ EmitDebugInfo ();
+
/* Leave the lexical level */
LeaveFunctionLevel ();
/* Eat the closing brace */
ConsumeRCurly ();
+ /* Restore the old literal pool, remembering the one for the function */
+ Func->V.F.LitPool = PopLiteralPool ();
+
/* Switch back to the old segments */
PopSegments ();
projects / cc65 / blobdiff