X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;ds=sidebyside;f=src%2Fcc65%2Fstmt.c;h=67742113cdda5532c7e9540d6d3a48042118702f;hb=57c2e0cc0bcda3d08692abc60f5c85510801801d;hp=0de58c6d2367ef951a54182c6488806f7b02174c;hpb=034a4b75e5553fc8d099c62caf91c0631f6ca36b;p=cc65 diff --git a/src/cc65/stmt.c b/src/cc65/stmt.c index 0de58c6d2..67742113c 100644 --- a/src/cc65/stmt.c +++ b/src/cc65/stmt.c @@ -1,10 +1,35 @@ -/* - * stmt.c - * - * Ullrich von Bassewitz, 06.08.1998 - * - * Original by John R. Dunning - see copyleft.jrd - */ +/*****************************************************************************/ +/* */ +/* stmt.c */ +/* */ +/* Parse a statement */ +/* */ +/* */ +/* */ +/* (C) 1998-2004 Ullrich von Bassewitz */ +/* Römerstraße 52 */ +/* D-70794 Filderstadt */ +/* EMail: uz@cc65.org */ +/* */ +/* */ +/* This software is provided 'as-is', without any expressed or implied */ +/* warranty. In no event will the authors be held liable for any damages */ +/* arising from the use of this software. */ +/* */ +/* Permission is granted to anyone to use this software for any purpose, */ +/* including commercial applications, and to alter it and redistribute it */ +/* freely, subject to the following restrictions: */ +/* */ +/* 1. The origin of this software must not be misrepresented; you must not */ +/* claim that you wrote the original software. If you use this software */ +/* in a product, an acknowledgment in the product documentation would be */ +/* appreciated but is not required. */ +/* 2. Altered source versions must be plainly marked as such, and must not */ +/* be misrepresented as being the original software. */ +/* 3. This notice may not be removed or altered from any source */ +/* distribution. */ +/* */ +/*****************************************************************************/ @@ -12,6 +37,7 @@ #include /* common */ +#include "coll.h" #include "xmalloc.h" /* cc65 */ @@ -25,23 +51,17 @@ #include "global.h" #include "goto.h" #include "litpool.h" +#include "loadexpr.h" #include "locals.h" #include "loop.h" #include "pragma.h" #include "scanner.h" +#include "stackptr.h" +#include "swstmt.h" #include "symtab.h" #include "stmt.h" - - - -/*****************************************************************************/ -/* Data */ -/*****************************************************************************/ - - - -/* Maximum count of cases */ -#define CASE_MAX 257 +#include "testexpr.h" +#include "typeconv.h" @@ -58,22 +78,40 @@ static void CheckTok (token_t Tok, const char* Msg, int* PendingToken) */ { if (CurTok.Tok != Tok) { - Error (Msg); + Error (Msg); } else if (PendingToken) { - *PendingToken = 1; + *PendingToken = 1; } else { - NextToken (); + NextToken (); } } static void CheckSemi (int* PendingToken) -/* Helper function for Statement. Will call CheckTok with the parameters - * for a semicolon. +/* Helper function for Statement. Will check for a semicolon and print an + * error message if not found (plus some error recovery). If PendingToken is + * NULL, it will the skip the token, otherwise it will store one to + * PendingToken. + * This function is a special version of CheckTok with the addition of the + * error recovery. */ { - CheckTok (TOK_SEMI, "`;' expected", PendingToken); + int HaveToken = (CurTok.Tok == TOK_SEMI); + if (!HaveToken) { + Error ("`;' expected"); + /* Try to be smart about errors */ + if (CurTok.Tok == TOK_COLON || CurTok.Tok == TOK_COMMA) { + HaveToken = 1; + } + } + if (HaveToken) { + if (PendingToken) { + *PendingToken = 1; + } else { + NextToken (); + } + } } @@ -81,7 +119,7 @@ static void CheckSemi (int* PendingToken) static void SkipPending (int PendingToken) /* Skip the pending token if we have one */ { - if (PendingToken) { + if (PendingToken) { NextToken (); } } @@ -98,6 +136,7 @@ static int IfStatement (void) /* Handle an 'if' statement */ { unsigned Label1; + unsigned TestResult; int GotBreak; /* Skip the if */ @@ -105,7 +144,7 @@ static int IfStatement (void) /* Generate a jump label and parse the condition */ Label1 = GetLocalLabel (); - test (Label1, 0); + TestResult = TestInParens (Label1, 0); /* Parse the if body */ GotBreak = Statement (0); @@ -122,21 +161,28 @@ static int IfStatement (void) } else { - /* Generate a jump around the else branch */ + /* Generate a jump around the else branch */ unsigned Label2 = GetLocalLabel (); - g_jump (Label2); + g_jump (Label2); - /* Skip the else */ + /* Skip the else */ NextToken (); - /* Define the target for the first test */ - g_defcodelabel (Label1); + /* If the if expression was always true, the code in the else branch + * is never executed. Output a warning if this is the case. + */ + if (TestResult == TESTEXPR_TRUE) { + Warning ("Unreachable code"); + } - /* Total break only if both branches had a break. */ + /* Define the target for the first test */ + g_defcodelabel (Label1); + + /* Total break only if both branches had a break. */ GotBreak &= Statement (0); /* Generate the label for the else clause */ - g_defcodelabel (Label2); + g_defcodelabel (Label2); /* Done */ return GotBreak; @@ -149,28 +195,32 @@ static void DoStatement (void) /* Handle the 'do' statement */ { /* Get the loop control labels */ - unsigned loop = GetLocalLabel (); - unsigned lab = GetLocalLabel (); + unsigned LoopLabel = GetLocalLabel (); + unsigned BreakLabel = GetLocalLabel (); + unsigned ContinueLabel = GetLocalLabel (); /* Skip the while token */ NextToken (); /* Add the loop to the loop stack */ - AddLoop (oursp, loop, lab, 0, 0); + AddLoop (BreakLabel, ContinueLabel); - /* Define the head label */ - g_defcodelabel (loop); + /* Define the loop label */ + g_defcodelabel (LoopLabel); /* Parse the loop body */ Statement (0); + /* Output the label for a continue */ + g_defcodelabel (ContinueLabel); + /* Parse the end condition */ Consume (TOK_WHILE, "`while' expected"); - test (loop, 1); + TestInParens (LoopLabel, 1); ConsumeSemi (); /* Define the break label */ - g_defcodelabel (lab); + g_defcodelabel (BreakLabel); /* Remove the loop from the loop stack */ DelLoop (); @@ -184,39 +234,36 @@ static void WhileStatement (void) int PendingToken; /* Get the loop control labels */ - unsigned loop = GetLocalLabel (); - unsigned lab = GetLocalLabel (); + unsigned LoopLabel = GetLocalLabel (); + unsigned BreakLabel = GetLocalLabel (); /* Skip the while token */ NextToken (); - /* Add the loop to the loop stack */ - AddLoop (oursp, loop, lab, 0, 0); + /* Add the loop to the loop stack. In case of a while loop, the loop head + * label is used for continue statements. + */ + AddLoop (BreakLabel, LoopLabel); /* Define the head label */ - g_defcodelabel (loop); + g_defcodelabel (LoopLabel); /* Test the loop condition */ - test (lab, 0); + TestInParens (BreakLabel, 0); + + /* Loop body */ + Statement (&PendingToken); + + /* Jump back to loop top */ + g_jump (LoopLabel); + + /* Exit label */ + g_defcodelabel (BreakLabel); - /* If the statement following the while loop is empty, that is, we have - * something like "while (1) ;", the test function ommitted the jump as - * an optimization. Since we know, the condition codes are set, we can - * do another small optimization here, and use a conditional jump - * instead an absolute one. + /* Eat remaining tokens that were delayed because of line info + * correctness */ - if (CurTok.Tok == TOK_SEMI) { - /* Use a conditional jump */ - g_truejump (CF_NONE, loop); - /* Shortcut */ - NextToken (); - } else { - /* There is code inside the while loop, parse the body */ - Statement (&PendingToken); - g_jump (loop); - g_defcodelabel (lab); - SkipPending (PendingToken); - } + SkipPending (PendingToken); /* Remove the loop from the loop stack */ DelLoop (); @@ -227,30 +274,38 @@ static void WhileStatement (void) static void ReturnStatement (void) /* Handle the 'return' statement */ { - struct expent lval; + ExprDesc Expr; NextToken (); if (CurTok.Tok != TOK_SEMI) { - if (HasVoidReturn (CurrentFunc)) { + + /* Check if the function has a return value declared */ + if (F_HasVoidReturn (CurrentFunc)) { Error ("Returning a value in function with return type void"); } - /* Evaluate the return expression. Result will be in primary */ - expression (&lval); + /* Evaluate the return expression */ + hie0 (&Expr); - /* Convert the return value to the type of the function result */ - if (!HasVoidReturn (CurrentFunc)) { - assignadjust (GetReturnType (CurrentFunc), &lval); + /* Ignore the return expression if the function returns void */ + if (!F_HasVoidReturn (CurrentFunc)) { + + /* Convert the return value to the type of the function result */ + TypeConversion (&Expr, F_GetReturnType (CurrentFunc)); + + /* Load the value into the primary */ + LoadExpr (CF_NONE, &Expr); } - } else if (!HasVoidReturn (CurrentFunc)) { - Error ("Function `%s' must return a value", GetFuncName (CurrentFunc)); + + } else if (!F_HasVoidReturn (CurrentFunc) && !F_HasOldStyleIntRet (CurrentFunc)) { + Error ("Function `%s' must return a value", F_GetFuncName (CurrentFunc)); } /* Cleanup the stack in case we're inside a block with locals */ - g_space (oursp - GetTopLevelSP (CurrentFunc)); + g_space (StackPtr - F_GetTopLevelSP (CurrentFunc)); /* Output a jump to the function exit code */ - g_jump (GetRetLab (CurrentFunc)); + g_jump (F_GetRetLab (CurrentFunc)); } @@ -268,16 +323,16 @@ static void BreakStatement (void) /* Check if we are inside a loop */ if (L == 0) { - /* Error: No current loop */ - Error ("`break' statement not within loop or switch"); - return; + /* Error: No current loop */ + Error ("`break' statement not within loop or switch"); + return; } /* Correct the stack pointer if needed */ - g_space (oursp - L->StackPtr); + g_space (StackPtr - L->StackPtr); /* Jump to the exit label of the loop */ - g_jump (L->Label); + g_jump (L->BreakLabel); } @@ -293,344 +348,26 @@ static void ContinueStatement (void) /* Get the current loop descriptor */ L = CurrentLoop (); if (L) { - /* Search for the correct loop */ - do { - if (L->Loop) { - break; - } - L = L->Next; - } while (L); + /* Search for a loop that has a continue label. */ + do { + if (L->ContinueLabel) { + break; + } + L = L->Next; + } while (L); } /* Did we find it? */ if (L == 0) { - Error ("`continue' statement not within a loop"); - return; + Error ("`continue' statement not within a loop"); + return; } /* Correct the stackpointer if needed */ - g_space (oursp - L->StackPtr); + g_space (StackPtr - L->StackPtr); - /* Output the loop code */ - if (L->linc) { - g_jump (L->linc); - } else { - g_jump (L->Loop); - } -} - - - -static void CascadeSwitch (struct expent* eval) -/* Handle a switch statement for chars with a cmp cascade for the selector */ -{ - unsigned ExitLab; /* Exit label */ - unsigned NextLab; /* Next case label */ - unsigned CodeLab; /* Label that starts the actual selector code */ - int HaveBreak; /* Remember if we exited with break */ - int HaveDefault; /* Remember if we had a default label */ - int lcount; /* Label count */ - unsigned Flags; /* Code generator flags */ - struct expent lval; /* Case label expression */ - long Val; /* Case label value */ - - - /* Create a loop so we may break out, init labels */ - ExitLab = GetLocalLabel (); - AddLoop (oursp, 0, ExitLab, 0, 0); - - /* Setup some variables needed in the loop below */ - Flags = TypeOf (eval->e_tptr) | CF_CONST | CF_FORCECHAR; - CodeLab = NextLab = 0; - HaveBreak = 1; - HaveDefault = 0; - - /* Parse the labels */ - lcount = 0; - while (CurTok.Tok != TOK_RCURLY) { - - if (CurTok.Tok == TOK_CASE || CurTok.Tok == TOK_DEFAULT) { - - /* If the code for the previous selector did not end with a - * break statement, we must jump over the next selector test. - */ - if (!HaveBreak) { - /* Define a label for the code */ - if (CodeLab == 0) { - CodeLab = GetLocalLabel (); - } - g_jump (CodeLab); - } - - /* If we have a cascade label, emit it */ - if (NextLab) { - g_defcodelabel (NextLab); - NextLab = 0; - } - - while (CurTok.Tok == TOK_CASE || CurTok.Tok == TOK_DEFAULT) { - - /* Parse the selector */ - if (CurTok.Tok == TOK_CASE) { - - /* Count labels */ - ++lcount; - - /* Skip the "case" token */ - NextToken (); - - /* Read the selector expression */ - constexpr (&lval); - if (!IsClassInt (lval.e_tptr)) { - Error ("Switch quantity not an integer"); - } - - /* Check the range of the expression */ - Val = lval.e_const; - switch (*eval->e_tptr) { - - case T_SCHAR: - /* Signed char */ - if (Val < -128 || Val > 127) { - Error ("Range error"); - } - break; - - case T_UCHAR: - if (Val < 0 || Val > 255) { - Error ("Range error"); - } - break; - - case T_INT: - if (Val < -32768 || Val > 32767) { - Error ("Range error"); - } - break; - - case T_UINT: - if (Val < 0 || Val > 65535) { - Error ("Range error"); - } - break; - - default: - Internal ("Invalid type: %02X", *eval->e_tptr & 0xFF); - } - - /* Emit a compare */ - g_cmp (Flags, Val); - - /* If another case follows, we will jump to the code if - * the condition is true. - */ - if (CurTok.Tok == TOK_CASE) { - /* Create a code label if needed */ - if (CodeLab == 0) { - CodeLab = GetLocalLabel (); - } - g_falsejump (CF_NONE, CodeLab); - } else if (CurTok.Tok != TOK_DEFAULT) { - /* No case follows, jump to next selector */ - if (NextLab == 0) { - NextLab = GetLocalLabel (); - } - g_truejump (CF_NONE, NextLab); - } - - /* Skip the colon */ - ConsumeColon (); - - } else { - - /* Default case */ - NextToken (); - - /* Handle the pathologic case: DEFAULT followed by CASE */ - if (CurTok.Tok == TOK_CASE) { - if (CodeLab == 0) { - CodeLab = GetLocalLabel (); - } - g_jump (CodeLab); - } - - /* Skip the colon */ - ConsumeColon (); - - /* Remember that we had a default label */ - HaveDefault = 1; - } - - } - - } - - /* Emit a code label if we have one */ - if (CodeLab) { - g_defcodelabel (CodeLab); - CodeLab = 0; - } - - /* Parse statements */ - if (CurTok.Tok != TOK_RCURLY) { - HaveBreak = Statement (0); - } - } - - /* Check if we have any labels */ - if (lcount == 0 && !HaveDefault) { - Warning ("No case labels"); - } - - /* Define the exit label and, if there's a next label left, create this - * one, too. - */ - if (NextLab) { - g_defcodelabel (NextLab); - } - g_defcodelabel (ExitLab); - - /* Eat the closing curly brace */ - NextToken (); - - /* End the loop */ - DelLoop (); -} - - - -static void TableSwitch (struct expent* eval) -/* Handle a switch statement via table based selector */ -{ - /* Entry for one case in a switch statement */ - struct swent { - long sw_const; /* selector value */ - unsigned sw_lab; /* label for this selector */ - }; - - int dlabel; /* for default */ - int lab; /* exit label */ - int label; /* label for case */ - int lcase; /* label for compares */ - int lcount; /* Label count */ - int HaveBreak; /* Last statement has a break */ - int HaveDefault; /* Remember if we had a default label */ - unsigned Flags; /* Code generator flags */ - struct expent lval; /* Case label expression */ - struct swent *p; - struct swent *swtab; - - /* Allocate memory for the switch table */ - swtab = xmalloc (CASE_MAX * sizeof (struct swent)); - - /* Create a look so we may break out, init labels */ - HaveBreak = 0; /* Keep gcc silent */ - HaveDefault = 0; /* No default case until now */ - dlabel = 0; /* init */ - lab = GetLocalLabel (); /* get exit */ - p = swtab; - AddLoop (oursp, 0, lab, 0, 0); - - /* Jump behind the code for the CASE labels */ - g_jump (lcase = GetLocalLabel ()); - lcount = 0; - while (CurTok.Tok != TOK_RCURLY) { - if (CurTok.Tok == TOK_CASE || CurTok.Tok == TOK_DEFAULT) { - if (lcount >= CASE_MAX) { - Fatal ("Too many case labels"); - } - label = GetLocalLabel (); - do { - if (CurTok.Tok == TOK_CASE) { - NextToken (); - constexpr (&lval); - if (!IsClassInt (lval.e_tptr)) { - Error ("Switch quantity not an integer"); - } - p->sw_const = lval.e_const; - p->sw_lab = label; - ++p; - ++lcount; - } else { - NextToken (); - dlabel = label; - HaveDefault = 1; - } - ConsumeColon (); - } while (CurTok.Tok == TOK_CASE || CurTok.Tok == TOK_DEFAULT); - g_defcodelabel (label); - HaveBreak = 0; - } - if (CurTok.Tok != TOK_RCURLY) { - HaveBreak = Statement (0); - } - } - - /* Check if we have any labels */ - if (lcount == 0 && !HaveDefault) { - Warning ("No case labels"); - } - - /* Eat the closing curly brace */ - NextToken (); - - /* If the last statement doesn't have a break or return, add one */ - if (!HaveBreak) { - g_jump (lab); - } - - /* Actual selector code goes here */ - g_defcodelabel (lcase); - - /* Create the call to the switch subroutine */ - Flags = TypeOf (eval->e_tptr); - g_switch (Flags); - - /* First entry is negative of label count */ - g_defdata (CF_INT | CF_CONST, -((int)lcount)-1, 0); - - /* Create the case selector table */ - p = swtab; - while (lcount) { - g_case (Flags, p->sw_lab, p->sw_const); /* Create one label */ - --lcount; - ++p; - } - - if (dlabel) { - g_jump (dlabel); - } - g_defcodelabel (lab); - DelLoop (); - - /* Free the allocated space for the labels */ - xfree (swtab); -} - - - -static void SwitchStatement (void) -/* Handle a 'switch' statement */ -{ - struct expent eval; /* Switch statement expression */ - - /* Eat the "switch" */ - NextToken (); - - /* Read the switch expression */ - ConsumeLParen (); - intexpr (&eval); - ConsumeRParen (); - - /* result of expr is in P */ - ConsumeLCurly (); - - /* Now decide which sort of switch we will create: */ - if (IsTypeChar (eval.e_tptr) || (CodeSizeFactor >= 200 && IsClassInt (eval.e_tptr))) { - CascadeSwitch (&eval); - } else { - TableSwitch (&eval); - } + /* Jump to next loop iteration */ + g_jump (L->ContinueLabel); } @@ -638,29 +375,33 @@ static void SwitchStatement (void) static void ForStatement (void) /* Handle a 'for' statement */ { - struct expent lval1; - struct expent lval2; - struct expent lval3; + ExprDesc lval1; + ExprDesc lval3; + int HaveIncExpr; + CodeMark IncExprStart; + CodeMark IncExprEnd; int PendingToken; /* Get several local labels needed later */ - unsigned TestLabel = GetLocalLabel (); - unsigned lab = GetLocalLabel (); - unsigned IncLabel = GetLocalLabel (); - unsigned lstat = GetLocalLabel (); + unsigned TestLabel = GetLocalLabel (); + unsigned BreakLabel = GetLocalLabel (); + unsigned IncLabel = GetLocalLabel (); + unsigned BodyLabel = GetLocalLabel (); /* Skip the FOR token */ NextToken (); - /* Add the loop to the loop stack */ - AddLoop (oursp, TestLabel, lab, IncLabel, lstat); + /* Add the loop to the loop stack. A continue jumps to the start of the + * the increment condition. + */ + AddLoop (BreakLabel, IncLabel); /* Skip the opening paren */ ConsumeLParen (); /* Parse the initializer expression */ if (CurTok.Tok != TOK_SEMI) { - expression (&lval1); + Expression0 (&lval1); } ConsumeSemi (); @@ -669,40 +410,56 @@ static void ForStatement (void) /* Parse the test expression */ if (CurTok.Tok != TOK_SEMI) { - boolexpr (&lval2); - g_truejump (CF_NONE, lstat); - g_jump (lab); + Test (BodyLabel, 1); + g_jump (BreakLabel); } else { - g_jump (lstat); + g_jump (BodyLabel); } ConsumeSemi (); + /* Remember the start of the increment expression */ + GetCodePos (&IncExprStart); + /* Label for the increment expression */ g_defcodelabel (IncLabel); /* Parse the increment expression */ - if (CurTok.Tok != TOK_RPAREN) { - expression (&lval3); + HaveIncExpr = (CurTok.Tok != TOK_RPAREN); + if (HaveIncExpr) { + Expression0 (&lval3); } /* Jump to the test */ g_jump (TestLabel); + /* Remember the end of the increment expression */ + GetCodePos (&IncExprEnd); + /* Skip the closing paren */ ConsumeRParen (); /* Loop body */ - g_defcodelabel (lstat); + g_defcodelabel (BodyLabel); Statement (&PendingToken); - /* Jump back to the increment expression */ - g_jump (IncLabel); - + /* If we had an increment expression, move the code to the bottom of + * the loop. In this case we don't need to jump there at the end of + * the loop body. + */ + if (HaveIncExpr) { + CodeMark Here; + GetCodePos (&Here); + MoveCode (&IncExprStart, &IncExprEnd, &Here); + } else { + /* Jump back to the increment expression */ + g_jump (IncLabel); + } + /* Skip a pending token if we have one */ SkipPending (PendingToken); /* Declare the break label */ - g_defcodelabel (lab); + g_defcodelabel (BreakLabel); /* Remove the loop from the loop stack */ DelLoop (); @@ -718,7 +475,7 @@ static int CompoundStatement (void) int GotBreak; /* Remember the stack at block entry */ - int OldStack = oursp; + int OldStack = StackPtr; /* Enter a new lexical level */ EnterBlockLevel (); @@ -738,9 +495,9 @@ static int CompoundStatement (void) /* Clean up the stack. */ if (!GotBreak) { - g_space (oursp - OldStack); + g_space (StackPtr - OldStack); } - oursp = OldStack; + StackPtr = OldStack; /* Emit references to imports/exports for this block */ EmitExternals (); @@ -763,8 +520,9 @@ int Statement (int* PendingToken) * NULL, the function will skip the token. */ { - struct expent lval; + ExprDesc Expr; int GotBreak; + CodeMark Start, End; /* Assume no pending token */ if (PendingToken) { @@ -828,16 +586,31 @@ int Statement (int* PendingToken) case TOK_SEMI: /* Ignore it */ - NextToken (); + CheckSemi (PendingToken); break; case TOK_PRAGMA: DoPragma (); - break; + break; default: + /* Remember the current code position */ + GetCodePos (&Start); /* Actual statement */ - expression (&lval); + ExprWithCheck (hie0, &Expr); + /* Load the result only if it is an lvalue and the type is + * marked as volatile. Otherwise the load is useless. + */ + if (ED_IsLVal (&Expr) && IsQualVolatile (Expr.Type)) { + LoadExpr (CF_NONE, &Expr); + } + /* If the statement didn't generate code, and is not of type + * void, emit a warning. + */ + GetCodePos (&End); + if (CodeRangeIsEmpty (&Start, &End) && !IsTypeVoid (Expr.Type)) { + Warning ("Statement has no effect"); + } CheckSemi (PendingToken); } } @@ -846,3 +619,4 @@ int Statement (int* PendingToken) +