From 0c75182aabcc4d93a7216defede6e8cba5a46690 Mon Sep 17 00:00:00 2001
From: "Wolfgang (Blub) Bumiller" <blub@speed.at>
Date: Fri, 16 Nov 2012 19:01:44 +0100
Subject: [PATCH] Some #if parsing
---
ftepp.c | 164 ++++++++++++++++++++++++++++++++++++++++++++------------
1 file changed, 129 insertions(+), 35 deletions(-)
diff --git a/ftepp.c b/ftepp.c
index 769310b..c487058 100644
--- a/ftepp.c
+++ b/ftepp.c
@@ -32,6 +32,13 @@ typedef struct {
typedef struct {
int token;
char *value;
+ /* a copy from the lexer */
+ union {
+ vector v;
+ int i;
+ double f;
+ int t; /* type */
+ } constval;
} pptoken;
typedef struct {
@@ -42,7 +49,7 @@ typedef struct {
/* yes we need an extra flag since `#define FOO x` is not the same as `#define FOO() x` */
bool has_params;
- pptoken *output;
+ pptoken **output;
} ppmacro;
typedef struct {
@@ -134,45 +141,16 @@ static bool ftepp_skipspace(ftepp_t *ftepp)
if (ftepp->token != TOKEN_WHITE)
return true;
while (ftepp_next(ftepp) == TOKEN_WHITE) {}
- return (ftepp->token < TOKEN_EOF);
-}
-
-/* if/ifdef/define handlers */
-
-static bool ftepp_if(ftepp_t *ftepp, ppcondition *cond)
-{
- ftepp_error(ftepp, "TODO: #if");
- return false;
-}
-
-static bool ftepp_ifdef(ftepp_t *ftepp, ppcondition *cond)
-{
- ppmacro *macro;
- (void)ftepp_next(ftepp);
- if (!ftepp_skipspace(ftepp))
- return false;
-
- switch (ftepp->token) {
- case TOKEN_IDENT:
- case TOKEN_KEYWORD:
- macro = ftepp_macro_find(ftepp, ftepp_tokval(ftepp));
- break;
- default:
- ftepp_error(ftepp, "expected macro name");
- return false;
- }
-
- (void)ftepp_next(ftepp);
- if (!ftepp_skipspace(ftepp))
- return false;
- if (ftepp->token != TOKEN_EOL) {
- ftepp_error(ftepp, "stray tokens after #ifdef");
+ if (ftepp->token >= TOKEN_EOF) {
+ ftepp_error(ftepp, "unexpected end of preprocessor directive");
return false;
}
- cond->on = !!macro;
return true;
}
+/**
+ * The huge macro parsing code...
+ */
static bool ftepp_define(ftepp_t *ftepp)
{
ppmacro *macro;
@@ -182,6 +160,7 @@ static bool ftepp_define(ftepp_t *ftepp)
switch (ftepp->token) {
case TOKEN_IDENT:
+ case TOKEN_TYPENAME:
case TOKEN_KEYWORD:
macro = ppmacro_new(ftepp_ctx(ftepp), ftepp_tokval(ftepp));
break;
@@ -201,6 +180,120 @@ static bool ftepp_define(ftepp_t *ftepp)
return true;
}
+/**
+ * #if - the FTEQCC way:
+ * defined(FOO) => true if FOO was #defined regardless of parameters or contents
+ * <numbers> => True if the number is not 0
+ * !<factor> => True if the factor yields false
+ * <macro> => becomes the macro's FIRST token regardless of parameters
+ * <e> && <e> => True if both expressions are true
+ * <e> || <e> => True if either expression is true
+ * <string> => False
+ * <ident> => False (remember for macros the <macro> rule applies instead)
+ * Unary + and - are skipped
+ * parenthesis in expressions are allowed
+ * parameter lists on macros are errors
+ * No mathematical calculations are executed
+ */
+static bool ftepp_if_expr(ftepp_t *ftepp, bool *out)
+{
+ ppmacro *macro;
+ while (ftepp->token != TOKEN_EOL) {
+ switch (ftepp->token) {
+ case TOKEN_IDENT:
+ case TOKEN_TYPENAME:
+ case TOKEN_KEYWORD:
+ macro = ftepp_macro_find(ftepp, ftepp_tokval(ftepp));
+ if (!macro || !vec_size(macro->output)) {
+ *out = false;
+ } else {
+ /* This does not expand recursively! */
+ switch (macro->output[0]->token) {
+ case TOKEN_INTCONST:
+ *out = !!(macro->output[0]->constval.f);
+ break;
+ case TOKEN_FLOATCONST:
+ *out = !!(macro->output[0]->constval.f);
+ break;
+ default:
+ *out = false;
+ break;
+ }
+ }
+ break;
+ case TOKEN_STRINGCONST:
+ *out = false;
+ break;
+ case TOKEN_INTCONST:
+ *out = !!(ftepp->lex->tok.constval.i);
+ break;
+ case TOKEN_FLOATCONST:
+ *out = !!(ftepp->lex->tok.constval.f);
+ break;
+
+ default:
+ ftepp_error(ftepp, "junk in #if");
+ return false;
+ }
+ }
+ (void)ftepp_next(ftepp);
+ return true;
+}
+
+static bool ftepp_if(ftepp_t *ftepp, ppcondition *cond)
+{
+ bool result = false;
+
+ memset(cond, 0, sizeof(*cond));
+ (void)ftepp_next(ftepp);
+
+ if (!ftepp_skipspace(ftepp))
+ return false;
+ if (ftepp->token == TOKEN_EOL) {
+ ftepp_error(ftepp, "expected expression for #if-directive");
+ return false;
+ }
+
+ if (!ftepp_if_expr(ftepp, &result))
+ return false;
+
+ cond->on = result;
+ return true;
+}
+
+/**
+ * ifdef is rather simple
+ */
+static bool ftepp_ifdef(ftepp_t *ftepp, ppcondition *cond)
+{
+ ppmacro *macro;
+ memset(cond, 0, sizeof(*cond));
+ (void)ftepp_next(ftepp);
+ if (!ftepp_skipspace(ftepp))
+ return false;
+
+ switch (ftepp->token) {
+ case TOKEN_IDENT:
+ case TOKEN_TYPENAME:
+ case TOKEN_KEYWORD:
+ macro = ftepp_macro_find(ftepp, ftepp_tokval(ftepp));
+ break;
+ default:
+ ftepp_error(ftepp, "expected macro name");
+ return false;
+ }
+
+ (void)ftepp_next(ftepp);
+ if (!ftepp_skipspace(ftepp))
+ return false;
+ if (ftepp->token != TOKEN_EOL) {
+ ftepp_error(ftepp, "stray tokens after #ifdef");
+ return false;
+ }
+ cond->on = !!macro;
+ return true;
+}
+
/* Basic structure handlers */
static bool ftepp_else_allowed(ftepp_t *ftepp)
{
@@ -228,6 +321,7 @@ static bool ftepp_hash(ftepp_t *ftepp)
switch (ftepp->token) {
case TOKEN_KEYWORD:
case TOKEN_IDENT:
+ case TOKEN_TYPENAME:
if (!strcmp(ftepp_tokval(ftepp), "define")) {
return ftepp_define(ftepp);
}