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cc65/src/cc65/preproc.c

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/*****************************************************************************/
/* */
/* preproc.c */
/* */
/* cc65 preprocessor */
/* */
/* */
/* */
/* (C) 1998-2010, Ullrich von Bassewitz */
/* Roemerstrasse 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. */
/* */
/*****************************************************************************/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
/* common */
#include "chartype.h"
#include "check.h"
#include "inline.h"
#include "print.h"
#include "xmalloc.h"
/* cc65 */
#include "codegen.h"
#include "error.h"
#include "expr.h"
#include "global.h"
#include "ident.h"
#include "incpath.h"
#include "input.h"
#include "lineinfo.h"
#include "macrotab.h"
#include "preproc.h"
#include "scanner.h"
#include "standard.h"
/*****************************************************************************/
/* Data */
/*****************************************************************************/
/* Set when the preprocessor calls expr() recursively */
unsigned char Preprocessing = 0;
/* Management data for #if */
#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 StrBuf* MLine;
/* Structure used when expanding macros */
typedef struct MacroExp MacroExp;
struct MacroExp {
Collection ActualArgs; /* Actual arguments */
StrBuf Replacement; /* Replacement with arguments substituted */
Macro* M; /* The macro we're handling */
};
/*****************************************************************************/
/* Forwards */
/*****************************************************************************/
static unsigned Pass1 (StrBuf* Source, StrBuf* Target);
/* Preprocessor pass 1. Remove whitespace. Handle old and new style comments
** and the "defined" operator.
*/
static void MacroReplacement (StrBuf* Source, StrBuf* Target);
/* Perform macro replacement. */
/*****************************************************************************/
/* Low level preprocessor token handling */
/*****************************************************************************/
/* Types of preprocessor tokens */
typedef enum {
PP_ILLEGAL = -1,
PP_DEFINE,
PP_ELIF,
PP_ELSE,
PP_ENDIF,
PP_ERROR,
PP_IF,
PP_IFDEF,
PP_IFNDEF,
PP_INCLUDE,
PP_LINE,
PP_PRAGMA,
PP_UNDEF,
PP_WARNING,
} pptoken_t;
/* Preprocessor keyword to token mapping table */
static const struct PPToken {
const char* Key; /* Keyword */
pptoken_t Tok; /* Token */
} PPTokens[] = {
{ "define", PP_DEFINE },
{ "elif", PP_ELIF },
{ "else", PP_ELSE },
{ "endif", PP_ENDIF },
{ "error", PP_ERROR },
{ "if", PP_IF },
{ "ifdef", PP_IFDEF },
{ "ifndef", PP_IFNDEF },
{ "include", PP_INCLUDE },
{ "line", PP_LINE },
{ "pragma", PP_PRAGMA },
{ "undef", PP_UNDEF },
{ "warning", PP_WARNING },
};
/* Number of preprocessor tokens */
#define PPTOKEN_COUNT (sizeof(PPTokens) / sizeof(PPTokens[0]))
static int CmpToken (const void* Key, const void* Elem)
/* Compare function for bsearch */
{
return strcmp ((const char*) Key, ((const struct PPToken*) Elem)->Key);
}
static pptoken_t FindPPToken (const char* Ident)
/* Find a preprocessor token and return it. Return PP_ILLEGAL if the identifier
** is not a valid preprocessor token.
*/
{
struct PPToken* P;
P = bsearch (Ident, PPTokens, PPTOKEN_COUNT, sizeof (PPTokens[0]), CmpToken);
return P? P->Tok : PP_ILLEGAL;
}
/*****************************************************************************/
/* struct MacroExp */
/*****************************************************************************/
static MacroExp* InitMacroExp (MacroExp* E, Macro* M)
/* Initialize a MacroExp structure */
{
InitCollection (&E->ActualArgs);
SB_Init (&E->Replacement);
E->M = M;
return E;
}
static void DoneMacroExp (MacroExp* E)
/* Cleanup after use of a MacroExp structure */
{
unsigned I;
/* Delete the list with actual arguments */
for (I = 0; I < CollCount (&E->ActualArgs); ++I) {
FreeStrBuf (CollAtUnchecked (&E->ActualArgs, I));
}
DoneCollection (&E->ActualArgs);
SB_Done (&E->Replacement);
}
static void ME_AppendActual (MacroExp* E, StrBuf* Arg)
/* Add a copy of Arg to the list of actual macro arguments.
** NOTE: This function will clear Arg!
*/
{
/* Create a new string buffer */
StrBuf* A = NewStrBuf ();
/* Move the contents of Arg to A */
SB_Move (A, Arg);
/* Add A to the actual arguments */
CollAppend (&E->ActualArgs, A);
}
static StrBuf* ME_GetActual (MacroExp* E, unsigned Index)
/* Return an actual macro argument with the given index */
{
return CollAt (&E->ActualArgs, Index);
}
static int ME_ArgIsVariadic (const MacroExp* E)
/* Return true if the next actual argument we will add is a variadic one */
{
return (E->M->Variadic &&
E->M->ArgCount == (int) CollCount (&E->ActualArgs) + 1);
}
/*****************************************************************************/
/* Code */
/*****************************************************************************/
static void Stringize (StrBuf* Source, StrBuf* Target)
/* Stringize the given string: Add double quotes at start and end and preceed
** each occurance of " and \ by a backslash.
*/
{
char C;
/* Add a starting quote */
SB_AppendChar (Target, '\"');
/* Replace any characters inside the string may not be part of a string
** unescaped.
*/
while ((C = SB_Get (Source)) != '\0') {
switch (C) {
case '\"':
case '\\':
SB_AppendChar (Target, '\\');
/* FALLTHROUGH */
default:
SB_AppendChar (Target, C);
break;
}
}
/* Add the closing quote */
SB_AppendChar (Target, '\"');
}
static void OldStyleComment (void)
/* Remove an old style C comment from line. */
{
/* Remember the current line number, so we can output better error
** messages if the comment is not terminated in the current file.
*/
unsigned StartingLine = GetCurrentLine();
/* Skip the start of comment chars */
NextChar ();
NextChar ();
/* Skip the comment */
while (CurC != '*' || NextC != '/') {
if (CurC == '\0') {
if (NextLine () == 0) {
PPError ("End-of-file reached in comment starting at line %u",
StartingLine);
return;
}
} else {
if (CurC == '/' && NextC == '*') {
PPWarning ("'/*' found inside a comment");
}
NextChar ();
}
}
/* Skip the end of comment chars */
NextChar ();
NextChar ();
}
static void NewStyleComment (void)
/* Remove a new style C comment from line. */
{
/* Beware: Because line continuation chars are handled when reading
** lines, we may only skip until the end of the source line, which
** may not be the same as the end of the input line. The end of the
** source line is denoted by a lf (\n) character.
*/
do {
NextChar ();
} while (CurC != '\n' && CurC != '\0');
if (CurC == '\n') {
NextChar ();
}
}
static int SkipWhitespace (int SkipLines)
/* Skip white space in the input stream. Do also skip newlines if SkipLines
** is true. Return zero if nothing was skipped, otherwise return a
** value != zero.
*/
{
int Skipped = 0;
while (1) {
if (IsSpace (CurC)) {
NextChar ();
Skipped = 1;
} else if (CurC == '\0' && SkipLines) {
/* End of line, read next */
if (NextLine () != 0) {
Skipped = 1;
} else {
/* End of input */
break;
}
} else {
/* No more white space */
break;
}
}
return Skipped;
}
static void CopyQuotedString (StrBuf* Target)
/* Copy a single or double quoted string from the input to Target. */
{
/* Remember the quote character, copy it to the target buffer and skip it */
char Quote = CurC;
SB_AppendChar (Target, CurC);
NextChar ();
/* Copy the characters inside the string */
while (CurC != '\0' && CurC != Quote) {
/* Keep an escaped char */
if (CurC == '\\') {
SB_AppendChar (Target, CurC);
NextChar ();
}
/* Copy the character */
SB_AppendChar (Target, CurC);
NextChar ();
}
/* If we had a terminating quote, copy it */
if (CurC != '\0') {
SB_AppendChar (Target, CurC);
NextChar ();
}
}
/*****************************************************************************/
/* Macro stuff */
/*****************************************************************************/
static int MacName (char* Ident)
/* Get a macro symbol name into Ident. If we have an error, print a
** diagnostic message and clear the line.
*/
{
if (IsSym (Ident) == 0) {
PPError ("Identifier expected");
ClearLine ();
return 0;
} else {
return 1;
}
}
static void ReadMacroArgs (MacroExp* E)
/* Identify the arguments to a macro call */
{
unsigned Parens; /* Number of open parenthesis */
StrBuf Arg = STATIC_STRBUF_INITIALIZER;
/* Read the actual macro arguments */
Parens = 0;
while (1) {
if (CurC == '(') {
/* Nested parenthesis */
SB_AppendChar (&Arg, CurC);
NextChar ();
++Parens;
} else if (IsQuote (CurC)) {
/* Quoted string - just copy */
CopyQuotedString (&Arg);
} else if (CurC == ',' || CurC == ')') {
if (Parens) {
/* Comma or right paren inside nested parenthesis */
if (CurC == ')') {
--Parens;
}
SB_AppendChar (&Arg, CurC);
NextChar ();
} else if (CurC == ',' && ME_ArgIsVariadic (E)) {
/* It's a comma, but we're inside a variadic macro argument, so
** just copy it and proceed.
*/
SB_AppendChar (&Arg, CurC);
NextChar ();
} else {
/* End of actual argument. Remove whitespace from the end. */
while (IsSpace (SB_LookAtLast (&Arg))) {
SB_Drop (&Arg, 1);
}
/* If this is not the single empty argument for a macro with
** an empty argument list, remember it.
*/
if (CurC != ')' || SB_NotEmpty (&Arg) || E->M->ArgCount > 0) {
ME_AppendActual (E, &Arg);
}
/* Check for end of macro param list */
if (CurC == ')') {
NextChar ();
break;
}
/* Start the next param */
NextChar ();
SB_Clear (&Arg);
}
} else if (SkipWhitespace (1)) {
/* Squeeze runs of blanks within an arg */
if (SB_NotEmpty (&Arg)) {
SB_AppendChar (&Arg, ' ');
}
} else if (CurC == '/' && NextC == '*') {
if (SB_NotEmpty (&Arg)) {
SB_AppendChar (&Arg, ' ');
}
OldStyleComment ();
} else if (IS_Get (&Standard) >= STD_C99 && CurC == '/' && NextC == '/') {
if (SB_NotEmpty (&Arg)) {
SB_AppendChar (&Arg, ' ');
}
NewStyleComment ();
} else if (CurC == '\0') {
/* End of input inside macro argument list */
PPError ("Unterminated argument list invoking macro '%s'", E->M->Name);
ClearLine ();
break;
} else {
/* Just copy the character */
SB_AppendChar (&Arg, CurC);
NextChar ();
}
}
/* Deallocate string buf resources */
SB_Done (&Arg);
}
static void MacroArgSubst (MacroExp* E)
/* Argument substitution according to ISO/IEC 9899:1999 (E), 6.10.3.1ff */
{
ident Ident;
int ArgIdx;
StrBuf* OldSource;
StrBuf* Arg;
int HaveSpace;
/* Remember the current input and switch to the macro replacement. */
int OldIndex = SB_GetIndex (&E->M->Replacement);
SB_Reset (&E->M->Replacement);
OldSource = InitLine (&E->M->Replacement);
/* Argument handling loop */
while (CurC != '\0') {
/* If we have an identifier, check if it's a macro */
if (IsSym (Ident)) {
/* Check if it's a macro argument */
if ((ArgIdx = FindMacroArg (E->M, Ident)) >= 0) {
/* A macro argument. Get the corresponding actual argument. */
Arg = ME_GetActual (E, ArgIdx);
/* Copy any following whitespace */
HaveSpace = SkipWhitespace (0);
/* If a ## operator follows, we have to insert the actual
** argument as is, otherwise it must be macro replaced.
*/
if (CurC == '#' && NextC == '#') {
/* ### Add placemarker if necessary */
SB_Append (&E->Replacement, Arg);
} else {
/* Replace the formal argument by a macro replaced copy
** of the actual.
*/
SB_Reset (Arg);
MacroReplacement (Arg, &E->Replacement);
/* If we skipped whitespace before, re-add it now */
if (HaveSpace) {
SB_AppendChar (&E->Replacement, ' ');
}
}
} else {
/* An identifier, keep it */
SB_AppendStr (&E->Replacement, Ident);
}
} else if (CurC == '#' && NextC == '#') {
/* ## operator. */
NextChar ();
NextChar ();
SkipWhitespace (0);
/* Since we need to concatenate the token sequences, remove
** any whitespace that was added to target, since it must come
** from the input.
*/
while (IsSpace (SB_LookAtLast (&E->Replacement))) {
SB_Drop (&E->Replacement, 1);
}
/* If the next token is an identifier which is a macro argument,
** replace it, otherwise do nothing.
*/
if (IsSym (Ident)) {
/* Check if it's a macro argument */
if ((ArgIdx = FindMacroArg (E->M, Ident)) >= 0) {
/* Get the corresponding actual argument and add it. */
SB_Append (&E->Replacement, ME_GetActual (E, ArgIdx));
} else {
/* Just an ordinary identifier - add as is */
SB_AppendStr (&E->Replacement, Ident);
}
}
} else if (CurC == '#' && E->M->ArgCount >= 0) {
/* A # operator within a macro expansion of a function like
** macro. Read the following identifier and check if it's a
** macro parameter.
*/
NextChar ();
SkipWhitespace (0);
if (!IsSym (Ident) || (ArgIdx = FindMacroArg (E->M, Ident)) < 0) {
PPError ("'#' is not followed by a macro parameter");
} else {
/* Make a valid string from Replacement */
Arg = ME_GetActual (E, ArgIdx);
SB_Reset (Arg);
Stringize (Arg, &E->Replacement);
}
} else if (IsQuote (CurC)) {
CopyQuotedString (&E->Replacement);
} else {
SB_AppendChar (&E->Replacement, CurC);
NextChar ();
}
}
#if 0
/* Remove whitespace from the end of the line */
while (IsSpace (SB_LookAtLast (&E->Replacement))) {
SB_Drop (&E->Replacement, 1);
}
#endif
/* Switch back the input */
InitLine (OldSource);
SB_SetIndex (&E->M->Replacement, OldIndex);
}
static void MacroCall (StrBuf* Target, Macro* M)
/* Process a function like macro */
{
MacroExp E;
/* Eat the left paren */
NextChar ();
/* Initialize our MacroExp structure */
InitMacroExp (&E, M);
/* Read the actual macro arguments */
ReadMacroArgs (&E);
/* Compare formal and actual argument count */
if (CollCount (&E.ActualArgs) != (unsigned) M->ArgCount) {
StrBuf Arg = STATIC_STRBUF_INITIALIZER;
/* Argument count mismatch */
PPError ("Macro argument count mismatch");
/* Be sure to make enough empty arguments available */
while (CollCount (&E.ActualArgs) < (unsigned) M->ArgCount) {
ME_AppendActual (&E, &Arg);
}
}
/* Replace macro arguments handling the # and ## operators */
MacroArgSubst (&E);
/* Do macro replacement on the macro that already has the parameters
** substituted.
*/
M->Expanding = 1;
MacroReplacement (&E.Replacement, Target);
M->Expanding = 0;
/* Free memory allocated for the macro expansion structure */
DoneMacroExp (&E);
}
static void ExpandMacro (StrBuf* Target, Macro* M)
/* Expand a macro into Target */
{
#if 0
static unsigned V = 0;
printf ("Expanding %s(%u)\n", M->Name, ++V);
#endif
/* Check if this is a function like macro */
if (M->ArgCount >= 0) {
int Whitespace = SkipWhitespace (1);
if (CurC != '(') {
/* Function like macro but no parameter list */
SB_AppendStr (Target, M->Name);
if (Whitespace) {
SB_AppendChar (Target, ' ');
}
} else {
/* Function like macro */
MacroCall (Target, M);
}
} else {
MacroExp E;
InitMacroExp (&E, M);
/* Handle # and ## operators for object like macros */
MacroArgSubst (&E);
/* Do macro replacement on the macro that already has the parameters
** substituted.
*/
M->Expanding = 1;
MacroReplacement (&E.Replacement, Target);
M->Expanding = 0;
/* Free memory allocated for the macro expansion structure */
DoneMacroExp (&E);
}
#if 0
printf ("Done with %s(%u)\n", M->Name, V--);
#endif
}
static void DefineMacro (void)
/* Handle a macro definition. */
{
ident Ident;
Macro* M;
Macro* Existing;
int C89;
/* Read the macro name */
SkipWhitespace (0);
if (!MacName (Ident)) {
return;
}
/* Remember if we're in C89 mode */
C89 = (IS_Get (&Standard) == STD_C89);
/* Get an existing macro definition with this name */
Existing = FindMacro (Ident);
/* Create a new macro definition */
M = NewMacro (Ident);
/* Check if this is a function like macro */
if (CurC == '(') {
/* Skip the left paren */
NextChar ();
/* Set the marker that this is a function like macro */
M->ArgCount = 0;
/* Read the formal parameter list */
while (1) {
/* Skip white space and check for end of parameter list */
SkipWhitespace (0);
if (CurC == ')') {
break;
}
/* The next token must be either an identifier, or - if not in
** C89 mode - the ellipsis.
*/
if (!C89 && CurC == '.') {
/* Ellipsis */
NextChar ();
if (CurC != '.' || NextC != '.') {
PPError ("'...' expected");
ClearLine ();
return;
}
NextChar ();
NextChar ();
/* Remember that the macro is variadic and use __VA_ARGS__ as
** the argument name.
*/
AddMacroArg (M, "__VA_ARGS__");
M->Variadic = 1;
} else {
/* Must be macro argument name */
if (MacName (Ident) == 0) {
return;
}
/* __VA_ARGS__ is only allowed in C89 mode */
if (!C89 && strcmp (Ident, "__VA_ARGS__") == 0) {
PPWarning ("'__VA_ARGS__' can only appear in the expansion "
"of a C99 variadic macro");
}
/* Add the macro argument */
AddMacroArg (M, Ident);
}
/* If we had an ellipsis, or the next char is not a comma, we've
** reached the end of the macro argument list.
*/
SkipWhitespace (0);
if (M->Variadic || CurC != ',') {
break;
}
NextChar ();
}
/* Check for a right paren and eat it if we find one */
if (CurC != ')') {
PPError ("')' expected");
ClearLine ();
return;
}
NextChar ();
}
/* Skip whitespace before the macro replacement */
SkipWhitespace (0);
/* Insert the macro into the macro table and allocate the ActualArgs array */
InsertMacro (M);
/* Remove whitespace and comments from the line, store the preprocessed
** line into the macro replacement buffer.
*/
Pass1 (Line, &M->Replacement);
/* Remove whitespace from the end of the line */
while (IsSpace (SB_LookAtLast (&M->Replacement))) {
SB_Drop (&M->Replacement, 1);
}
#if 0
printf ("%s: <%.*s>\n", M->Name, SB_GetLen (&M->Replacement), SB_GetConstBuf (&M->Replacement));
#endif
/* If we have an existing macro, check if the redefinition is identical.
** Print a diagnostic if not.
*/
if (Existing && MacroCmp (M, Existing) != 0) {
PPError ("Macro redefinition is not identical");
}
}
/*****************************************************************************/
/* Preprocessing */
/*****************************************************************************/
static unsigned Pass1 (StrBuf* Source, StrBuf* Target)
/* Preprocessor pass 1. Remove whitespace. Handle old and new style comments
** and the "defined" operator.
*/
{
unsigned IdentCount;
ident Ident;
int HaveParen;
/* Switch to the new input source */
StrBuf* OldSource = InitLine (Source);
/* Loop removing ws and comments */
IdentCount = 0;
while (CurC != '\0') {
if (SkipWhitespace (0)) {
/* Squeeze runs of blanks */
if (!IsSpace (SB_LookAtLast (Target))) {
SB_AppendChar (Target, ' ');
}
} else if (IsSym (Ident)) {
if (Preprocessing && strcmp (Ident, "defined") == 0) {
/* Handle the "defined" operator */
SkipWhitespace (0);
HaveParen = 0;
if (CurC == '(') {
HaveParen = 1;
NextChar ();
SkipWhitespace (0);
}
if (IsSym (Ident)) {
SB_AppendChar (Target, IsMacro (Ident)? '1' : '0');
if (HaveParen) {
SkipWhitespace (0);
if (CurC != ')') {
PPError ("')' expected");
} else {
NextChar ();
}
}
} else {
PPError ("Identifier expected");
SB_AppendChar (Target, '0');
}
} else {
++IdentCount;
SB_AppendStr (Target, Ident);
}
} else if (IsQuote (CurC)) {
CopyQuotedString (Target);
} else if (CurC == '/' && NextC == '*') {
if (!IsSpace (SB_LookAtLast (Target))) {
SB_AppendChar (Target, ' ');
}
OldStyleComment ();
} else if (IS_Get (&Standard) >= STD_C99 && CurC == '/' && NextC == '/') {
if (!IsSpace (SB_LookAtLast (Target))) {
SB_AppendChar (Target, ' ');
}
NewStyleComment ();
} else {
SB_AppendChar (Target, CurC);
NextChar ();
}
}
/* Switch back to the old source */
InitLine (OldSource);
/* Return the number of identifiers found in the line */
return IdentCount;
}
static void MacroReplacement (StrBuf* Source, StrBuf* Target)
/* Perform macro replacement. */
{
ident Ident;
Macro* M;
/* Remember the current input and switch to Source */
StrBuf* OldSource = InitLine (Source);
/* Loop substituting macros */
while (CurC != '\0') {
/* If we have an identifier, check if it's a macro */
if (IsSym (Ident)) {
/* Check if it's a macro */
if ((M = FindMacro (Ident)) != 0 && !M->Expanding) {
/* It's a macro, expand it */
ExpandMacro (Target, M);
} else {
/* An identifier, keep it */
SB_AppendStr (Target, Ident);
}
} else if (IsQuote (CurC)) {
CopyQuotedString (Target);
} else if (IsSpace (CurC)) {
if (!IsSpace (SB_LookAtLast (Target))) {
SB_AppendChar (Target, CurC);
}
NextChar ();
} else {
SB_AppendChar (Target, CurC);
NextChar ();
}
}
/* Switch back the input */
InitLine (OldSource);
}
static void PreprocessLine (void)
/* Translate one line. */
{
/* Trim whitespace and remove comments. The function returns the number of
** identifiers found. If there were any, we will have to check for macros.
*/
SB_Clear (MLine);
if (Pass1 (Line, MLine) > 0) {
MLine = InitLine (MLine);
SB_Reset (Line);
SB_Clear (MLine);
MacroReplacement (Line, MLine);
}
/* Read from the new line */
SB_Reset (MLine);
MLine = InitLine (MLine);
}
static int PushIf (int Skip, int Invert, int Cond)
/* Push a new if level onto the if stack */
{
/* 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 {
IfStack[IfIndex] = IFCOND_NONE | IFCOND_NEEDTERM;
return (Invert ^ Cond);
}
}
static void DoError (void)
/* Print an error */
{
SkipWhitespace (0);
if (CurC == '\0') {
PPError ("Invalid #error directive");
} else {
PPError ("#error: %s", SB_GetConstBuf (Line) + SB_GetIndex (Line));
}
/* Clear the rest of line */
ClearLine ();
}
static int DoIf (int Skip)
/* Process #if directive */
{
/* We're about to abuse the compiler expression parser to evaluate the
** #if expression. Save the current tokens to come back here later.
** NOTE: Yes, this is a hack, but it saves a complete separate expression
** evaluation for the preprocessor.
*/
Token SavedCurTok = CurTok;
Token SavedNextTok = NextTok;
/* Make sure the line infos for the tokens won't get removed */
if (SavedCurTok.LI) {
UseLineInfo (SavedCurTok.LI);
}
if (SavedNextTok.LI) {
UseLineInfo (SavedNextTok.LI);
}
/* Switch into special preprocessing mode */
Preprocessing = 1;
/* Expand macros in this line */
PreprocessLine ();
/* Add two semicolons as sentinels to the line, so the following
** expression evaluation will eat these two tokens but nothing from
** the following line.
*/
SB_AppendStr (Line, ";;");
SB_Terminate (Line);
/* Load CurTok and NextTok with tokens from the new input */
NextToken ();
NextToken ();
/* Call the expression parser */
ExprDesc Expr = NoCodeConstExpr (hie1);
/* End preprocessing mode */
Preprocessing = 0;
/* Reset the old tokens */
CurTok = SavedCurTok;
NextTok = SavedNextTok;
/* Set the #if condition according to the expression result */
return PushIf (Skip, 1, Expr.IVal != 0);
}
static int DoIfDef (int skip, int flag)
/* Process #ifdef if flag == 1, or #ifndef if flag == 0. */
{
ident Ident;
SkipWhitespace (0);
if (MacName (Ident) == 0) {
return 0;
} else {
return PushIf (skip, flag, IsMacro(Ident));
}
}
static void DoInclude (void)
/* Open an include file. */
{
char RTerm;
InputType IT;
StrBuf Filename = STATIC_STRBUF_INITIALIZER;
/* Preprocess the remainder of the line */
PreprocessLine ();
/* Skip blanks */
SkipWhitespace (0);
/* Get the next char and check for a valid file name terminator. Setup
** the include directory spec (SYS/USR) by looking at the terminator.
*/
switch (CurC) {
case '\"':
RTerm = '\"';
IT = IT_USRINC;
break;
case '<':
RTerm = '>';
IT = IT_SYSINC;
break;
default:
PPError ("'\"' or '<' expected");
goto Done;
}
NextChar ();
/* Get a copy of the filename */
while (CurC != '\0' && CurC != RTerm) {
SB_AppendChar (&Filename, CurC);
NextChar ();
}
SB_Terminate (&Filename);
/* Check if we got a terminator */
if (CurC == RTerm) {
/* Open the include file */
OpenIncludeFile (SB_GetConstBuf (&Filename), IT);
} else if (CurC == '\0') {
/* No terminator found */
PPError ("#include expects \"FILENAME\" or <FILENAME>");
}
Done:
/* Free the allocated filename data */
SB_Done (&Filename);
/* Clear the remaining line so the next input will come from the new
** file (if open)
*/
ClearLine ();
}
static void DoPragma (void)
/* Handle a #pragma line by converting the #pragma preprocessor directive into
** the _Pragma() compiler operator.
*/
{
/* Skip blanks following the #pragma directive */
SkipWhitespace (0);
/* Copy the remainder of the line into MLine removing comments and ws */
SB_Clear (MLine);
Pass1 (Line, MLine);
/* Convert the directive into the operator */
SB_CopyStr (Line, "_Pragma (");
SB_Reset (MLine);
Stringize (MLine, Line);
SB_AppendChar (Line, ')');
/* Initialize reading from line */
SB_Reset (Line);
InitLine (Line);
}
static void DoUndef (void)
/* Process the #undef directive */
{
ident Ident;
SkipWhitespace (0);
if (MacName (Ident)) {
UndefineMacro (Ident);
}
}
static void DoWarning (void)
/* Print a warning */
{
SkipWhitespace (0);
if (CurC == '\0') {
PPError ("Invalid #warning directive");
} else {
PPWarning ("#warning: %s", SB_GetConstBuf (Line) + SB_GetIndex (Line));
}
/* Clear the rest of line */
ClearLine ();
}
void Preprocess (void)
/* Preprocess a line */
{
int Skip;
ident Directive;
/* Create the output buffer if we don't already have one */
if (MLine == 0) {
MLine = NewStrBuf ();
}
/* Skip white space at the beginning of the line */
SkipWhitespace (0);
/* Check for stuff to skip */
Skip = 0;
while (CurC == '\0' || CurC == '#' || Skip) {
/* Check for preprocessor lines lines */
if (CurC == '#') {
NextChar ();
SkipWhitespace (0);
if (CurC == '\0') {
/* Ignore the empty preprocessor directive */
continue;
}
if (!IsSym (Directive)) {
PPError ("Preprocessor directive expected");
ClearLine ();
} else {
switch (FindPPToken (Directive)) {
case PP_DEFINE:
if (!Skip) {
DefineMacro ();
}
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 (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 (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'");
}
break;
case PP_ERROR:
if (!Skip) {
DoError ();
}
break;
case PP_IF:
Skip = DoIf (Skip);
break;
case PP_IFDEF:
Skip = DoIfDef (Skip, 1);
break;
case PP_IFNDEF:
Skip = DoIfDef (Skip, 0);
break;
case PP_INCLUDE:
if (!Skip) {
DoInclude ();
}
break;
case PP_LINE:
/* Should do something in C99 at least, but we ignore it */
if (!Skip) {
ClearLine ();
}
break;
case PP_PRAGMA:
if (!Skip) {
DoPragma ();
goto Done;
}
break;
case PP_UNDEF:
if (!Skip) {
DoUndef ();
}
break;
case PP_WARNING:
/* #warning is a non standard extension */
if (IS_Get (&Standard) > STD_C99) {
if (!Skip) {
DoWarning ();
}
} else {
if (!Skip) {
PPError ("Preprocessor directive expected");
}
ClearLine ();
}
break;
default:
if (!Skip) {
PPError ("Preprocessor directive expected");
}
ClearLine ();
}
}
}
if (NextLine () == 0) {
if (IfIndex >= 0) {
PPError ("'#endif' expected");
}
return;
}
SkipWhitespace (0);
}
PreprocessLine ();
Done:
if (Verbosity > 1 && SB_NotEmpty (Line)) {
printf ("%s:%u: %.*s\n", GetCurrentFile (), GetCurrentLine (),
(int) SB_GetLen (Line), SB_GetConstBuf (Line));
}
}
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