From 5db55826f0592c542bee8d26b16d2052c1d95896 Mon Sep 17 00:00:00 2001 From: cuz Date: Fri, 7 Sep 2001 09:54:33 +0000 Subject: [PATCH] Removed an invalid data access. Check nested #ifs for overflow. Lots of cleanups and rewriting of code sections. Streamlined and extended #if stack handling. Added #elif preprocessor directive. git-svn-id: svn://svn.cc65.org/cc65/trunk@859 b7a2c559-68d2-44c3-8de9-860c34a00d81 --- src/cc65/preproc.c | 147 ++++++++++++++++++++++++++++++--------------- 1 file changed, 99 insertions(+), 48 deletions(-) diff --git a/src/cc65/preproc.c b/src/cc65/preproc.c index 9d441c30e..c95bbb92c 100644 --- a/src/cc65/preproc.c +++ b/src/cc65/preproc.c @@ -8,6 +8,7 @@ /* common */ #include "chartype.h" +#include "check.h" #include "print.h" #include "xmalloc.h" @@ -44,13 +45,17 @@ static int Pass1 (const char* From, char* To); -/* Set when the pp calls expr() recursively */ +/* Set when the preprocessor calls expr() recursively */ unsigned char Preprocessing = 0; /* Management data for #if */ -#define N_IFDEF 16 -static int i_ifdef = -1; -static char s_ifdef[N_IFDEF]; +#define MAX_IFS 64 +#define IFCOND_NONE 0x00U +#define IFCOND_SKIP 0x01U +#define IFCOND_ELSE 0x02U +#define IFCOND_NEEDTERM 0x04U +static unsigned char IfStack[MAX_IFS]; +static int IfIndex = -1; /* Buffer for macro expansion */ static char mlinebuf [LINESIZE]; @@ -71,6 +76,7 @@ static int ExpandMacros = 1; /* Types of preprocessor tokens */ typedef enum { PP_DEFINE, + PP_ELIF, PP_ELSE, PP_ENDIF, PP_ERROR, @@ -92,6 +98,7 @@ static const struct PPToken { pptoken_t Tok; /* Token */ } PPTokens[] = { { "define", PP_DEFINE }, + { "elif", PP_ELIF }, { "else", PP_ELSE }, { "endif", PP_ENDIF }, { "error", PP_ERROR }, @@ -135,10 +142,10 @@ static pptoken_t FindPPToken (const char* Ident) -static int keepch (char c) +static void keepch (char c) /* Put character c into translation buffer. */ { - return (*mptr++ = c); + *mptr++ = c; } @@ -146,9 +153,9 @@ static int keepch (char c) static void keepstr (const char* S) /* Put string str into translation buffer. */ { - while (*S) { - keepch (*S++); - } + unsigned Len = strlen (S); + memcpy (mptr, S, Len); + mptr += Len; } @@ -239,8 +246,8 @@ static char* CopyQuotedString (char* Target) static int MacName (char* Ident) -/* Get macro symbol name. If we have an error, print a diagnostic message - * and clear line. +/* Get a macro symbol name into Ident. If we have an error, print a + * diagnostic message and clear the line. */ { if (IsSym (Ident) == 0) { @@ -355,7 +362,7 @@ static int MacroCall (Macro* M) } /* Check for end of macro param list */ - if (CurC == ')') { + if (CurC == ')') { NextChar (); break; } @@ -503,7 +510,7 @@ static void DefineMacro (void) /*****************************************************************************/ - +/* Preprocessing */ /*****************************************************************************/ @@ -655,8 +662,8 @@ static void xlateline (void) -static void doundef (void) -/* Process #undef directive */ +static void DoUndef (void) +/* Process the #undef directive */ { ident Ident; @@ -668,21 +675,29 @@ static void doundef (void) -static int setmflag (int skip, int flag, int cond) -/* setmflag( skip, flag, cond ) */ +static int PushIf (int Skip, int Invert, int Cond) +/* Push a new if level onto the if stack */ { - if (skip) { - s_ifdef[++i_ifdef] = 3; - return (1); + /* Check for an overflow of the if stack */ + if (IfIndex >= MAX_IFS-1) { + PPError ("Too many nested #if clauses"); + return 1; + } + + /* Push the #if condition */ + ++IfIndex; + if (Skip) { + IfStack[IfIndex] = IFCOND_SKIP | IFCOND_NEEDTERM; + return 1; } else { - s_ifdef[++i_ifdef] = 6; - return (flag ^ cond); + IfStack[IfIndex] = IFCOND_NONE | IFCOND_NEEDTERM; + return (Invert ^ Cond); } } -static int doiff (int skip) +static int DoIf (int Skip) /* Process #if directive */ { ExprDesc lval; @@ -739,12 +754,12 @@ static int doiff (int skip) NextTok = sv2; /* Set the #if condition according to the expression result */ - return (setmflag (skip, 1, lval.ConstVal != 0)); + return PushIf (Skip, 1, lval.ConstVal != 0); } -static int doifdef (int skip, int flag) +static int DoIfDef (int skip, int flag) /* Process #ifdef if flag == 1, or #ifndef if flag == 0. */ { ident Ident; @@ -753,13 +768,13 @@ static int doifdef (int skip, int flag) if (MacName (Ident) == 0) { return 0; } else { - return setmflag (skip, flag, IsMacro(Ident)); + return PushIf (skip, flag, IsMacro(Ident)); } } -static void doinclude (void) +static void DoInclude (void) /* Open an include file. */ { char RTerm; @@ -819,7 +834,7 @@ Done: -static void doerror (void) +static void DoError (void) /* Print an error */ { SkipBlank (); @@ -829,7 +844,7 @@ static void doerror (void) PPError ("#error: %s", lptr); } - /* clear rest of line */ + /* Clear the rest of line */ ClearLine (); } @@ -868,20 +883,56 @@ void Preprocess (void) } break; + case PP_ELIF: + if (IfIndex >= 0) { + if ((IfStack[IfIndex] & IFCOND_ELSE) == 0) { + + /* Handle as #else/#if combination */ + if ((IfStack[IfIndex] & IFCOND_SKIP) == 0) { + Skip = !Skip; + } + IfStack[IfIndex] |= IFCOND_ELSE; + Skip = DoIf (Skip); + + /* #elif doesn't need a terminator */ + IfStack[IfIndex] &= ~IFCOND_NEEDTERM; + } else { + PPError ("Duplicate #else/#elif"); + } + } else { + PPError ("Unexpected #elif"); + } + break; + case PP_ELSE: - if (s_ifdef[i_ifdef] & 2) { - if (s_ifdef[i_ifdef] & 4) { - Skip = !Skip; - } - s_ifdef[i_ifdef] ^= 2; + if (IfIndex >= 0) { + if ((IfStack[IfIndex] & IFCOND_ELSE) == 0) { + if ((IfStack[IfIndex] & IFCOND_SKIP) == 0) { + Skip = !Skip; + } + IfStack[IfIndex] |= IFCOND_ELSE; + } else { + PPError ("Duplicate #else"); + } } else { PPError ("Unexpected `#else'"); } break; case PP_ENDIF: - if (i_ifdef >= 0) { - Skip = s_ifdef[i_ifdef--] & 1; + if (IfIndex >= 0) { + /* Remove any clauses on top of stack that do not + * need a terminating #endif. + */ + while (IfIndex >= 0 && (IfStack[IfIndex] & IFCOND_NEEDTERM) == 0) { + --IfIndex; + } + + /* Stack may not be empty here or something is wrong */ + CHECK (IfIndex >= 0); + + /* Remove the clause that needs a terminator */ + Skip = (IfStack[IfIndex--] & IFCOND_SKIP) != 0; } else { PPError ("Unexpected `#endif'"); } @@ -889,34 +940,34 @@ void Preprocess (void) case PP_ERROR: if (!Skip) { - doerror (); + DoError (); } break; case PP_IF: - Skip = doiff (Skip); + Skip = DoIf (Skip); break; case PP_IFDEF: - Skip = doifdef (Skip, 1); + Skip = DoIfDef (Skip, 1); break; case PP_IFNDEF: - Skip = doifdef (Skip, 0); + Skip = DoIfDef (Skip, 0); break; case PP_INCLUDE: if (!Skip) { - doinclude (); + DoInclude (); } break; case PP_LINE: - /* Not allowed in strict ANSI mode */ - if (ANSI) { - PPError ("Preprocessor directive expected"); - ClearLine (); - } + /* Not allowed in strict ANSI mode */ + if (!Skip && ANSI) { + PPError ("Preprocessor directive expected"); + ClearLine (); + } break; case PP_PRAGMA: @@ -930,7 +981,7 @@ void Preprocess (void) case PP_UNDEF: if (!Skip) { - doundef (); + DoUndef (); } break; @@ -942,7 +993,7 @@ void Preprocess (void) } if (NextLine () == 0) { - if (i_ifdef >= 0) { + if (IfIndex >= 0) { PPError ("`#endif' expected"); } return;