scc

Simple C99 Compiler
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commit 84471603bc16659989db3fd5223b33772653b704
parent 15ef27b9b747e452e17642b36bfd996cfb5fe9ff
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Mon, 11 May 2015 15:51:03 +0200

Add support for macros with arguments

This patch builds an special string with all the information needed
to expand a macro.

Diffstat:
cc1/cpp.c | 136++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 131 insertions(+), 5 deletions(-)

diff --git a/cc1/cpp.c b/cc1/cpp.c @@ -10,6 +10,133 @@ #include "cc1.h" /* TODO: preprocessor error must not rise recover */ + +/* + * Parse an argument list (par0, par1, ...) and creates + * an array with pointers to all the arguments in the + * list + */ +static char * +parseargs(char *s, char *args[NR_MACROARG], int *nargs) +{ + unsigned n ; + size_t len; + char **bp, *endp, c; + + if (*s != '(') { + *nargs = -1; + return s; + } + if (*++s == ')') { + *nargs = 0; + return s+1; + } + + + for (bp = args, n = 1; n <= NR_MACROARG; ++bp, ++n) { + while (isspace(*s)) + ++s; + if (!isalnum(*s) && *s != '_') + error("macro arguments must be identifiers"); + for (endp = s; isalnum(*endp) || *endp == '_'; ++endp) + /* nothing */; + if ((len = endp - s) > IDENTSIZ) + error("macro argument too long"); + *bp = s; + for (s = endp; isspace(*s); ++s) + *s = '\0'; + c = *s; + *s++ = '\0'; + if (c == ')') + break; + if (c == ',') + continue; + else + error("macro parameters must be comma-separated"); + } + if (n > NR_MACROARG) + error("too much parameters in macro"); + *nargs = n; + return s; +} +/* + * Copy a define string, and substitute formal arguments of the + * macro into strings in the form @XX, where XX is the position + * of the argument in the argument list. + */ +static char * +copydefine(char *s, char *args[], char *buff, int bufsiz, int nargs) +{ + unsigned ncopy, n; + size_t len; + char arroba[5], *par, *endp, **bp; + + while (*s && bufsiz > 0) { + if (!isalnum(*s) && *s != '_') { + --bufsiz; + *buff++ = *s++; + continue; + } + /* + * found an identifier, is it one of the macro arguments? + */ + for (endp = s+1; isalnum(*endp) || *endp == '_'; ++endp) + /* nothing */; + len = endp - s; + for (bp =args, n = 0; n < nargs; ++bp, n++) { + if (strncmp(s, *bp, len)) + continue; + sprintf(arroba, "@%02d", n); + break; + } + if (n == nargs) + par = s, ncopy = len; + else + par = arroba, ncopy = 3; + + if ((bufsiz -= ncopy) < 0) + goto too_long; + memcpy(buff, par, ncopy); + buff += ncopy; + s = endp; + } + + if (*s == '\0') { + *buff = '\0'; + return s; + } + +too_long: + error("macro definition too long"); +} + +static char * +mkdefine(char *s, Symbol *sym) +{ + int nargs; + char *args[NR_MACROARG], buff[LINESIZ+1]; + char type; + + s = parseargs(s, args, &nargs); + if (nargs == -1) { + type = 'N'; + ++nargs; + } else { + type = 'P'; + } + + sprintf(buff, "%c%02d", type, nargs); + + while (isspace(*s)) + ++s; + + if (*s != '\0') + s = copydefine(s, args, buff+3, LINESIZ-3, nargs); + sym->u.s = xstrdup(buff); + + return s; +} + static char * define(char *s) { @@ -27,12 +154,11 @@ define(char *s) name[len] = '\0'; sym = install(name, NS_CPP); - while (isspace(*t)) - ++t; - for (s = t + strlen(t); isspace(*--s); *s = '\0') + for (s = t; isspace(*s); ++s) + /* nothing */; + for (t = s + strlen(s); isspace(*--t); *t = '\0') /* nothing */; - sym->u.s = xstrdup(t); - return s+1; + return mkdefine(s, sym); too_long: error("macro identifier too long");