~mcf/cproc

cproc/pp.c -rw-r--r-- 13.5 KiB View raw
3d91966bMichael Forney qbe: Omit unnecessary add to help QBE's memopt pass 7 days ago
                                                                                
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#include <assert.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "util.h"
#include "cc.h"

struct macroparam {
	char *name;
	enum {
		PARAMTOK = 1<<0,  /* the parameter is used normally */
		PARAMSTR = 1<<1,  /* the parameter is used with the '#' operator */
		PARAMVAR = 1<<2,  /* the parameter is __VA_ARGS__ */
	} flags;
};

struct macroarg {
	struct token *token;
	size_t ntoken;
	/* stringized argument */
	struct token str;
};

struct macro {
	enum {
		MACROOBJ,
		MACROFUNC,
	} kind;
	char *name;
	/* whether or not this macro is ineligible for expansion */
	bool hide;
	/* parameters of function-like macro */
	struct macroparam *param;
	size_t nparam;
	/* argument tokens of macro invocation */
	struct macroarg *arg;
	/* replacement list */
	struct token *token;
	size_t ntoken;
};

struct frame {
	struct token *token;
	size_t ntoken;
	struct macro *macro;
};

enum ppflags ppflags;

static struct array ctx;
static struct map *macros;
/* number of macros currently undergoing expansion */
static size_t macrodepth;

void
ppinit(void)
1 reference
{ macros = mkmap(64); next(); } /* check if two macro definitions are equal, as in C11 6.10.3p2 */ static bool macroequal(struct macro *m1, struct macro *m2)
1 reference
{ struct macroparam *p1, *p2; struct token *t1, *t2; if (m1->kind != m2->kind) return false; if (m1->kind == MACROFUNC) { if (m1->nparam != m2->nparam) return false; for (p1 = m1->param, p2 = m2->param; p1 < m1->param + m1->nparam; ++p1, ++p2) { if (strcmp(p1->name, p2->name) != 0 || p1->flags != p2->flags) return false; } } if (m1->ntoken != m2->ntoken) return false; for (t1 = m1->token, t2 = m2->token; t1 < m1->token + m1->ntoken; ++t1, ++t2) { if (t1->kind != t2->kind) return false; if (t1->lit && strcmp(t1->lit, t2->lit) != 0) return false; } return true; } /* find the index of a macro parameter with the given name */ static size_t macroparam(struct macro *m, struct token *t)
4 references
{ size_t i; if (t->kind == TIDENT) { for (i = 0; i < m->nparam; ++i) { if (strcmp(m->param[i].name, t->lit) == 0) return i; } } return -1; } /* lookup a macro by name */ static struct macro * macroget(char *name)
1 reference
{ struct mapkey k; mapkey(&k, name, strlen(name)); return mapget(macros, &k); } static void macrodone(struct macro *m)
1 reference
{ m->hide = false; if (m->kind == MACROFUNC && m->nparam > 0) { free(m->arg[0].token); free(m->arg); } --macrodepth; } static bool macrovarargs(struct macro *m)
1 reference
{ return m->kind == MACROFUNC && m->nparam > 0 && m->param[m->nparam - 1].flags & PARAMVAR; } static struct token * framenext(struct frame *f)
4 references
{ return f->ntoken--, f->token++; } /* push a new context frame */ static struct frame * ctxpush(struct token *t, size_t n, struct macro *m, bool space)
5 references
{ struct frame *f; f = arrayadd(&ctx, sizeof(*f)); f->token = t; f->ntoken = n; f->macro = m; if (n > 0) t[0].space = space; return f; } /* get the next token from the context */ static struct token * ctxnext(void)
2 references
{ struct frame *f; struct token *t; struct macro *m; bool space; size_t i; again: for (f = arraylast(&ctx, sizeof(*f)); ctx.len; --f, ctx.len -= sizeof(*f)) { if (f->ntoken) break; if (f->macro) macrodone(f->macro); } if (ctx.len == 0) return NULL; m = f->macro; if (m && m->kind == MACROFUNC) { /* try to expand macro parameter */ space = f->token->space; switch (f->token->kind) { case THASH: framenext(f); t = framenext(f); assert(t); i = macroparam(m, t); assert(i != -1); f = ctxpush(&m->arg[i].str, 1, NULL, space); break; case TIDENT: i = macroparam(m, f->token); if (i == -1) break; framenext(f); if (m->arg[i].ntoken == 0) goto again; f = ctxpush(m->arg[i].token, m->arg[i].ntoken, NULL, space); break; } /* XXX: token concatenation */ } return framenext(f); } static void define(void)
1 reference
{ struct token *t; enum tokenkind prev; struct macro *m; struct macroparam *p; struct array params = {0}, repl = {0}; struct mapkey k; void **entry; size_t i; m = xmalloc(sizeof(*m)); m->name = tokencheck(&tok, TIDENT, "after #define"); m->hide = false; t = arrayadd(&repl, sizeof(*t)); scan(t); if (t->kind == TLPAREN && !t->space) { m->kind = MACROFUNC; /* read macro parameter names */ while (scan(&tok), tok.kind != TRPAREN) { if (params.len) { if (p->flags & PARAMVAR) tokencheck(&tok, TRPAREN, "after '...'"); tokencheck(&tok, TCOMMA, "or ')' after macro parameter"); scan(&tok); } p = arrayadd(&params, sizeof(*p)); p->flags = 0; if (tok.kind == TELLIPSIS) { p->name = "__VA_ARGS__"; p->flags |= PARAMVAR; } else { p->name = tokencheck(&tok, TIDENT, "of macro parameter name or '...'"); } } scan(t); /* first token in replacement list */ } else { m->kind = MACROOBJ; } m->param = params.val; m->nparam = params.len / sizeof(m->param[0]); /* read macro body */ i = macroparam(m, t); while (t->kind != TNEWLINE && t->kind != TEOF) { if (t->kind == THASHHASH) error(&t->loc, "'##' operator is not yet implemented"); prev = t->kind; t = arrayadd(&repl, sizeof(*t)); scan(t); if (t->kind == TIDENT && strcmp(t->lit, "__VA_ARGS__") == 0 && !macrovarargs(m)) error(&t->loc, "__VA_ARGS__ can only be used in variadic function-like macros"); if (m->kind != MACROFUNC) continue; if (i != -1) m->param[i].flags |= PARAMTOK; i = macroparam(m, t); if (prev == THASH) { tokencheck(t, TIDENT, "after '#' operator"); if (i == -1) error(&t->loc, "'%s' is not a macro parameter name", t->lit); m->param[i].flags |= PARAMSTR; i = -1; } } m->token = repl.val; m->ntoken = repl.len / sizeof(*t) - 1; tok = *t; mapkey(&k, m->name, strlen(m->name)); entry = mapput(macros, &k); if (*entry && !macroequal(m, *entry)) error(&tok.loc, "redefinition of macro '%s'", m->name); *entry = m; } static void undef(void)
1 reference
{ char *name; struct mapkey k; void **entry; struct macro *m; name = tokencheck(&tok, TIDENT, "after #undef"); mapkey(&k, name, strlen(name)); entry = mapput(macros, &k); m = *entry; if (m) { free(name); free(m->param); free(m->token); *entry = NULL; } scan(&tok); } static void directive(void)
1 reference
{ enum ppflags oldflags; char *name; scan(&tok); if (tok.kind == TNEWLINE) return; /* empty directive */ oldflags = ppflags; ppflags |= PPNEWLINE; name = tokencheck(&tok, TIDENT, "or newline after '#'"); if (strcmp(name, "if") == 0) { error(&tok.loc, "#if directive is not implemented"); } else if (strcmp(name, "ifdef") == 0) { error(&tok.loc, "#ifdef directive is not implemented"); } else if (strcmp(name, "ifndef") == 0) { error(&tok.loc, "#ifndef directive is not implemented"); } else if (strcmp(name, "elif") == 0) { error(&tok.loc, "#elif directive is not implemented"); } else if (strcmp(name, "endif") == 0) { error(&tok.loc, "#endif directive is not implemented"); } else if (strcmp(name, "include") == 0) { error(&tok.loc, "#include directive is not implemented"); } else if (strcmp(name, "define") == 0) { scan(&tok); define(); } else if (strcmp(name, "undef") == 0) { scan(&tok); undef(); } else if (strcmp(name, "line") == 0) { error(&tok.loc, "#line directive is not implemented"); } else if (strcmp(name, "error") == 0) { error(&tok.loc, "#error directive is not implemented"); } else if (strcmp(name, "pragma") == 0) { error(&tok.loc, "#pragma directive is not implemented"); } else { error(&tok.loc, "invalid preprocessor directive #%s", name); } free(name); tokencheck(&tok, TNEWLINE, "after preprocessing directive"); ppflags = oldflags; } /* get the next token without expanding it */ static void nextinto(struct token *t)
2 references
{ static bool newline = true; for (;;) { scan(t); if (newline && t->kind == THASH) { directive(); } else { newline = tok.kind == TNEWLINE; break; } } } static struct token * rawnext(void)
4 references
{ struct token *t; t = ctxnext(); if (!t) { t = &tok; nextinto(t); } return t; } static bool peekparen(void)
1 reference
{ static struct array pending; struct token *t; struct frame *f; t = ctxnext(); if (t) { if (t->kind == TLPAREN) return true; f = arraylast(&ctx, sizeof(*f)); --f->token; ++f->ntoken; return false; } pending.len = 0; do t = arrayadd(&pending, sizeof(*t)), nextinto(t); while (t->kind == TNEWLINE); if (t->kind == TLPAREN) return true; t = pending.val; ctxpush(t, pending.len / sizeof(*t), NULL, t[0].space); return false; } static void stringize(struct array *buf, struct token *t)
1 reference
{ const char *lit; if ((t->space || t->kind == TNEWLINE) && buf->len > 1 && ((char *)buf->val)[buf->len - 1] != ' ') arrayaddbuf(buf, " ", 1); lit = t->lit ? t->lit : tokstr[t->kind]; if (t->kind == TSTRINGLIT || t->kind == TCHARCONST) { for (; *lit; ++lit) { if (*lit == '\\' || *lit == '"') arrayaddbuf(buf, "\\", 1); arrayaddbuf(buf, lit, 1); } } else if (lit) { arrayaddbuf(buf, lit, strlen(lit)); } } static bool expand(struct token *t) { struct macro *m; struct macroparam *p; struct macroarg *arg; struct array str, tok; size_t i, depth, paren; bool space; if (t->kind != TIDENT) return false; m = macroget(t->lit); if (!m || m->hide || t->hide) { t->hide = true; return false; } space = t->space; if (m->kind == MACROFUNC) { if (!peekparen()) return false; /* read macro arguments */ paren = 0; depth = macrodepth; tok = (struct array){0}; arg = xreallocarray(NULL, m->nparam, sizeof(*arg)); t = rawnext(); for (i = 0; i < m->nparam; ++i) { p = &m->param[i]; if (p->flags & PARAMSTR) { str = (struct array){0}; arrayaddbuf(&str, "\"", 1); } arg[i].ntoken = 0; for (;;) { if (t->kind == TEOF) error(&t->loc, "EOF when reading macro parameters"); if (macrodepth <= depth) { /* adjust current macro depth, in case it got shallower */ depth = macrodepth; if (paren == 0 && (t->kind == TRPAREN || t->kind == TCOMMA && !(p->flags & PARAMVAR))) break; switch (t->kind) { case TLPAREN: ++paren; break; case TRPAREN: --paren; break; } if (p->flags & PARAMSTR) stringize(&str, t); } if (p->flags & PARAMTOK && !expand(t)) { arrayaddbuf(&tok, t, sizeof(*t)); ++arg[i].ntoken; } t = rawnext(); } if (p->flags & PARAMSTR) { arrayaddbuf(&str, "\"", 2); arg[i].str = (struct token){ .kind = TSTRINGLIT, .lit = str.val, }; } if (t->kind == TRPAREN) break; t = rawnext(); } if (i + 1 < m->nparam) error(&t->loc, "not enough arguments for macro '%s'", m->name); if (t->kind != TRPAREN) error(&t->loc, "too many arguments for macro '%s'", m->name); for (i = 0, t = tok.val; i < m->nparam; ++i) { arg[i].token = t; t += arg[i].ntoken; } m->arg = arg; } ctxpush(m->token, m->ntoken, m, space); m->hide = true; ++macrodepth; return true; } static void keyword(struct token *tok)
1 reference
{ static const struct { const char *name; int value; } keywords[] = { {"_Alignas", T_ALIGNAS}, {"_Alignof", T_ALIGNOF}, {"_Atomic", T_ATOMIC}, {"_Bool", T_BOOL}, {"_Complex", T_COMPLEX}, {"_Generic", T_GENERIC}, {"_Imaginary", T_IMAGINARY}, {"_Noreturn", T_NORETURN}, {"_Static_assert", T_STATIC_ASSERT}, {"_Thread_local", T_THREAD_LOCAL}, {"__alignof__", T_ALIGNOF}, {"__asm", T__ASM__}, {"__asm__", T__ASM__}, {"__attribute__", T__ATTRIBUTE__}, {"__inline", TINLINE}, {"__inline__", TINLINE}, {"__signed", TSIGNED}, {"__signed__", TSIGNED}, {"__thread", T_THREAD_LOCAL}, {"__typeof", T__TYPEOF__}, {"__typeof__", T__TYPEOF__}, {"__volatile__", TVOLATILE}, {"auto", TAUTO}, {"break", TBREAK}, {"case", TCASE}, {"char", TCHAR}, {"const", TCONST}, {"continue", TCONTINUE}, {"default", TDEFAULT}, {"do", TDO}, {"double", TDOUBLE}, {"else", TELSE}, {"enum", TENUM}, {"extern", TEXTERN}, {"float", TFLOAT}, {"for", TFOR}, {"goto", TGOTO}, {"if", TIF}, {"inline", TINLINE}, {"int", TINT}, {"long", TLONG}, {"register", TREGISTER}, {"restrict", TRESTRICT}, {"return", TRETURN}, {"short", TSHORT}, {"signed", TSIGNED}, {"sizeof", TSIZEOF}, {"static", TSTATIC}, {"struct", TSTRUCT}, {"switch", TSWITCH}, {"typedef", TTYPEDEF}, {"union", TUNION}, {"unsigned", TUNSIGNED}, {"void", TVOID}, {"volatile", TVOLATILE}, {"while", TWHILE}, }; size_t low = 0, high = LEN(keywords), mid; int cmp; while (low < high) { mid = (low + high) / 2; cmp = strcmp(tok->lit, keywords[mid].name); if (cmp == 0) { free(tok->lit); tok->kind = keywords[mid].value; tok->lit = NULL; break; } if (cmp < 0) high = mid; else low = mid + 1; } } void next(void)
77 references
{ struct token *t; do t = rawnext(); while (expand(t) || t->kind == TNEWLINE && !(ppflags & PPNEWLINE)); tok = *t; if (tok.kind == TIDENT) keyword(&tok); } bool peek(int kind)
1 reference
{ static struct token pending; struct token old; old = tok; next(); if (tok.kind == kind) { next(); return true; } pending = tok; tok = old; ctxpush(&pending, 1, NULL, pending.space); return false; } char * expect(enum tokenkind kind, const char *msg)
66 references
{ char *lit; lit = tokencheck(&tok, kind, msg); next(); return lit; } bool consume(int kind)
22 references
{ if (tok.kind != kind) return false; next(); return true; }