commit 5029b379b8193ead69618b3e306c9dcd2e1ab296
parent d56911aa4feb7fb2f32fa38f53c0d74ecf7ea4d8
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date: Sat, 23 Jan 2016 11:09:20 +0100
[cc2] Add parser of IR
This is a totally incomplete parser, and it is in a state not thought to be shown,
but it is something to begin to talk.
Diffstat:
16 files changed, 914 insertions(+), 18 deletions(-)
diff --git a/cc2/Makefile b/cc2/Makefile
@@ -2,7 +2,8 @@
include ../config.mk
-OBJS = main.o parser.o code.o optm.o peep.o cgen.o
+OBJS = main.o parser.o code.o optm.o peep.o cgen.o \
+ symbol.o node.o arch/$(ARCH)/types.o
all: cc2
diff --git a/cc2/arch/amd64-sysv/arch.h b/cc2/arch/amd64-sysv/arch.h
@@ -0,0 +1,5 @@
+
+#define TINT long long
+#define TUINT unsigned long long
+#define TFLOAT double
+
diff --git a/cc2/arch/amd64-sysv/types.c b/cc2/arch/amd64-sysv/types.c
@@ -0,0 +1,89 @@
+
+#include "arch.h"
+#include "../../cc2.h"
+
+
+Type int8type = {
+ .flags = SIGNF | INTF,
+ .size = 1,
+ .align = 1
+};
+
+Type int16type = {
+ .flags = SIGNF | INTF,
+ .size = 2,
+ .align = 2
+};
+
+Type int32type = {
+ .flags = SIGNF | INTF,
+ .size = 4,
+ .align = 4
+};
+
+Type int64type = {
+ .flags = SIGNF | INTF,
+ .size = 8,
+ .align = 8
+};
+
+Type uint8type = {
+ .flags = INTF,
+ .size = 1,
+ .align = 1
+};
+
+Type uint16type = {
+ .flags = INTF,
+ .size = 2,
+ .align = 2
+};
+
+Type uint32type = {
+ .flags = INTF,
+ .size = 4,
+ .align = 2
+};
+
+Type uint64type = {
+ .flags = INTF,
+ .size = 8,
+ .align = 2
+};
+
+Type ptrtype = {
+ .flags = INTF,
+ .size = 8,
+ .align = 8
+};
+
+Type booltype = {
+ .flags = INTF,
+ .size = 1,
+ .align = 1
+};
+
+Type float32type = {
+ .size = 4,
+ .align = 4
+};
+
+Type float64type = {
+ .size = 8,
+ .align = 8
+};
+
+Type float80type = {
+ .size = 10,
+ .align = 12
+};
+
+Type voidtype = {
+ .size = 0,
+ .align = 0
+};
+
+Type elipsistype = {
+ .size = 0,
+ .align = 0
+};
diff --git a/cc2/arch/i386-sysv/arch.h b/cc2/arch/i386-sysv/arch.h
@@ -0,0 +1,5 @@
+
+#define TINT long long
+#define TUINT unsigned long long
+#define TFLOAT double
+
diff --git a/cc2/arch/i386-sysv/types.c b/cc2/arch/i386-sysv/types.c
@@ -0,0 +1,89 @@
+
+#include "arch.h"
+#include "../../cc2.h"
+
+
+Type int8type = {
+ .flags = SIGNF | INTF,
+ .size = 1,
+ .align = 1
+};
+
+Type int16type = {
+ .flags = SIGNF | INTF,
+ .size = 2,
+ .align = 2
+};
+
+Type int32type = {
+ .flags = SIGNF | INTF,
+ .size = 4,
+ .align = 4
+};
+
+Type int64type = {
+ .flags = SIGNF | INTF,
+ .size = 8,
+ .align = 8
+};
+
+Type uint8type = {
+ .flags = INTF,
+ .size = 1,
+ .align = 1
+};
+
+Type uint16type = {
+ .flags = INTF,
+ .size = 2,
+ .align = 2
+};
+
+Type uint32type = {
+ .flags = INTF,
+ .size = 4,
+ .align = 2
+};
+
+Type uint64type = {
+ .flags = INTF,
+ .size = 8,
+ .align = 2
+};
+
+Type ptrtype = {
+ .flags = INTF,
+ .size = 4,
+ .align = 4
+};
+
+Type booltype = {
+ .flags = INTF,
+ .size = 1,
+ .align = 1
+};
+
+Type float32type = {
+ .size = 4,
+ .align = 4
+};
+
+Type float64type = {
+ .size = 8,
+ .align = 8
+};
+
+Type float80type = {
+ .size = 10,
+ .align = 4
+};
+
+Type voidtype = {
+ .size = 0,
+ .align = 0
+};
+
+Type elipsistype = {
+ .size = 0,
+ .align = 0
+};
diff --git a/cc2/arch/z80/arch.h b/cc2/arch/z80/arch.h
@@ -0,0 +1,5 @@
+
+#define TINT long long
+#define TUINT unsigned long long
+#define TFLOAT double
+
diff --git a/cc2/arch/z80/types.c b/cc2/arch/z80/types.c
@@ -0,0 +1,89 @@
+
+#include "arch.h"
+#include "../../cc2.h"
+
+
+Type int8type = {
+ .flags = SIGNF | INTF,
+ .size = 1,
+ .align = 1
+};
+
+Type int16type = {
+ .flags = SIGNF | INTF,
+ .size = 2,
+ .align = 1
+};
+
+Type int32type = {
+ .flags = SIGNF | INTF,
+ .size = 4,
+ .align = 1
+};
+
+Type int64type = {
+ .flags = SIGNF | INTF,
+ .size = 8,
+ .align = 1
+};
+
+Type uint8type = {
+ .flags = INTF,
+ .size = 1,
+ .align = 1
+};
+
+Type uint16type = {
+ .flags = INTF,
+ .size = 2,
+ .align = 1
+};
+
+Type uint32type = {
+ .flags = INTF,
+ .size = 4,
+ .align = 1
+};
+
+Type uint64type = {
+ .flags = INTF,
+ .size = 8,
+ .align = 1
+};
+
+Type ptrtype = {
+ .flags = INTF,
+ .size = 2,
+ .align = 1
+};
+
+Type booltype = {
+ .flags = INTF,
+ .size = 1,
+ .align = 1
+};
+
+Type float32type = {
+ .size = 4,
+ .align = 1
+};
+
+Type float64type = {
+ .size = 4,
+ .align = 1
+};
+
+Type float80type = {
+ .size = 4,
+ .align = 1
+};
+
+Type voidtype = {
+ .size = 0,
+ .align = 0
+};
+
+Type elipsistype = {
+ .size = 0,
+ .align = 0
+};
diff --git a/cc2/cc2.h b/cc2/cc2.h
@@ -1,14 +1,136 @@
+enum tflags {
+ SIGNF = 1,
+ INTF = 2,
+ DEFTYP = 4,
+ STRUCTF = 8,
+ UNIONF = 16,
+ FUNCF = 32,
+ ARYF = 64
+};
+
+enum op {
+ /* types */
+ ELLIPSIS = 'E',
+ INT8 = 'C',
+ INT16 = 'I',
+ INT32 = 'W',
+ INT64 = 'Q',
+ UINT8 = 'K',
+ UINT16 = 'N',
+ UINT32 = 'Z',
+ UINT64 = 'O',
+ POINTER = 'P',
+ FUNCTION = 'F',
+ VECTOR = 'V',
+ UNION = 'U',
+ STRUCT = 'S',
+ BOOL = 'B',
+ FLOAT = 'J',
+ DOUBLE = 'D',
+ LDOUBLE = 'H',
+ VOID = '0',
+ ONAME = '"',
+ /* kind of operand */
+ NONE = 0,
+ MEM = 'M',
+ AUTO = 'A',
+ REG = 'R',
+ /* storage class */
+ GLOB = 'G',
+ EXTRN = 'X',
+ PRIVAT = 'Y',
+ LOCAL = 'T',
+ MEMBER = 'M',
+ LABEL = 'L',
+ /* operands */
+ OADD = '+',
+ OSUB = '-',
+ OMUL = '*',
+ OMOD = '%',
+ ODIV = '/',
+ OSHL = 'l',
+ OSHR = 'r',
+ OLT = '<',
+ OGT = '>',
+ OLE = '[',
+ OGE = ']',
+ OEQ = '=',
+ ONE = '!',
+ OBAND = '&',
+ OBOR = '|',
+ OBXOR = '^',
+ OCPL = '~',
+ OASSIG = ':',
+ ONEG = '_',
+ OCALL = 'c',
+ OPAR = 'p',
+ OFIELD = '.',
+ OCOMMA = ',',
+ OASK = '?',
+ OCOLON = ' ',
+ OADDR = '\'',
+ OAND = 'a',
+ OOR = 'b',
+ OPTR = '@',
+ OSYM = 'y',
+ OCAST = 'g',
+ OCONST = '#',
+ OSTRING = '"',
+ /*statements */
+ OJMP = 'j',
+ ORET = 'r',
+ OBLOOP = 'b',
+ OELOOP = 'e',
+ OCASE = 'v',
+ ODEFAULT = 'f',
+ OTABLE = 't',
+ OSWITCH = 's',
+ OEPARS = '\\',
+ OSTMT = '\t'
+};
+
enum nerrors {
+ EIDOVER, /* identifier overflow */
+ EOUTPAR, /* out pf params */
+ ESYNTAX, /* syntax error */
+ ESTACKA, /* stack unaligned */
+ ESTACKO, /* stack overflow */
+ ESTACKU, /* stack underflow */
ELNLINE, /* line too long */
EFERROR, /* error reading from file:%s*/
ENUMERR
};
typedef struct node Node;
+typedef struct type Type;
+typedef struct symbol Symbol;
+
+struct type {
+ unsigned short size;
+ unsigned short align;
+ unsigned short flags;
+};
+
+struct symbol {
+ unsigned short id;
+ char *name;
+ Type type;
+ char kind;
+ union {
+ TUINT i;
+ char *s;
+ } u;
+ Symbol *next;
+ Symbol *h_next;
+};
struct node {
- unsigned char op;
+ char op;
+ Type type;
+ Symbol *sym;
+ Node *left, *right;
+ Node *stmt;
};
/* main.c */
@@ -29,3 +151,14 @@ extern void peephole(void);
/* code.c */
extern void writeout(void);
+
+/* node.c */
+extern void cleannodes(void);
+extern void delnode(Node *np);
+extern Node *newnode(void);
+
+/* symbol.c */
+extern Symbol *getsym(int id);
+extern void popctx(void);
+extern void pushctx(void);
+extern void freesym(Symbol *sym);
diff --git a/cc2/cgen.c b/cc2/cgen.c
@@ -1,4 +1,5 @@
+#include "arch.h"
#include "cc2.h"
void
diff --git a/cc2/code.c b/cc2/code.c
@@ -1,4 +1,5 @@
+#include "arch.h"
#include "cc2.h"
void
diff --git a/cc2/main.c b/cc2/main.c
@@ -3,6 +3,7 @@
#include <stdio.h>
#include <stdlib.h>
+#include "arch.h"
#include "cc2.h"
#include "error.h"
diff --git a/cc2/node.c b/cc2/node.c
@@ -0,0 +1,64 @@
+
+#include <stdlib.h>
+
+#include "../inc/cc.h"
+
+#include "arch.h"
+#include "cc2.h"
+
+#define NSYMBOLS 32
+
+int inhome;
+
+struct arena {
+ Node *mem;
+ struct arena *next;
+};
+static struct arena *arena;
+static Node *freep;
+
+Node *
+newnode(void)
+{
+ struct arena *ap;
+ Node *np;
+
+ if (!freep) {
+ ap = xmalloc(sizeof(*ap));
+ ap->mem = xcalloc(NSYMBOLS, sizeof(Node));
+ ap->next = arena;
+ arena = ap;
+ for (np = ap->mem; np < &ap->mem[NSYMBOLS-1]; ++np)
+ np->left = np+1;
+ np->left = NULL;
+ freep = np;
+ }
+
+ np = freep;
+ freep = np->left;
+
+ np->right = NULL;
+ np->left = NULL;
+ np->sym = NULL;
+ np->stmt = NULL;
+ return np;
+}
+
+void
+delnode(Node *np)
+{
+ np->left = freep;
+ freep = np;
+}
+
+void
+cleannodes(void)
+{
+ struct arena *ap, *next;
+
+ for (ap = arena; ap; ap = next) {
+ next = ap;
+ free(ap->mem);
+ free(ap);
+ }
+}
diff --git a/cc2/optm.c b/cc2/optm.c
@@ -1,4 +1,5 @@
+#include "arch.h"
#include "cc2.h"
void
diff --git a/cc2/parser.c b/cc2/parser.c
@@ -1,60 +1,405 @@
#include <errno.h>
#include <stdio.h>
+#include <stdlib.h>
#include <string.h>
+#include "../inc/cc.h"
+#include "../inc/sizes.h"
+
+#include "arch.h"
#include "cc2.h"
-#define MAXLINE 200
+#define MAXLINE 200
+#define STACKSIZ 50
+
+extern Type int8type, int16type, int32type, int64type,
+ uint8type, uint16type, uint32type, uint64type,
+ float32type, float64type, float80type,
+ booltype,
+ ptrtype,
+ voidtype,
+ elipsistype;
+
+Type funtype = {
+ .flags = DEFTYP | FUNCF
+};
+
+Type arrtype = {
+ .flags = DEFTYP | ARYF
+};
+
+Type uniontype = {
+ .flags = DEFTYP | UNIONF
+};
+
+Type strtype = {
+ .flags = DEFTYP | STRUCTF
+};
+
+union tokenop {
+ void *arg;
+ int op;
+};
+
+typedef void parsefun(char *, union tokenop);
+static parsefun type, symbol, getname, unary, binary, ternary, call,
+ parameter, constant;
+
+typedef void evalfun(void);
+static evalfun vardecl, beginfun, endfun, endpars, stmt, begininit, endinit;
+
+static struct decoc {
+ void (*eval)(void);
+ void (*parse)(char *token, union tokenop);
+ union tokenop u;
+} optbl[] = {
+ [AUTO] = {vardecl, symbol, .u.op = AUTO},
+ [REG] = {vardecl, symbol, .u.op = REG},
+ [GLOB] = {vardecl, symbol, .u.op = MEM},
+ [EXTRN] = {vardecl, symbol, .u.op = MEM},
+ [PRIVAT] = {vardecl, symbol, .u.op = MEM},
+ [LOCAL] = {vardecl, symbol, .u.op = MEM},
+ [MEMBER] = {NULL, symbol},
+ [LABEL] = {NULL, symbol},
+
+ [INT8] = {NULL, type, .u.arg = &int8type},
+ [INT16] = {NULL, type, .u.arg = &int16type},
+ [INT32] = {NULL, type, .u.arg = &int32type},
+ [INT64] = {NULL, type, .u.arg = &int64type},
+ [UINT8] = {NULL, type, .u.arg = &uint8type},
+ [UINT16] = {NULL, type, .u.arg = &uint16type},
+ [UINT32] = {NULL, type, .u.arg = &uint32type},
+ [UINT64] = {NULL, type, .u.arg = &uint64type},
+ [FLOAT] = {NULL, type, .u.arg = &float32type},
+ [DOUBLE] = {NULL, type, .u.arg = &float64type},
+ [LDOUBLE] = {NULL, type, .u.arg = &float80type},
+ [VOID] = {NULL, type, .u.arg = &voidtype},
+ [BOOL] = {NULL, type, .u.arg = &booltype},
+ [POINTER] = {NULL, type, .u.arg = &ptrtype},
+ [ELLIPSIS] = {NULL, type, .u.arg = &elipsistype},
+
+ [FUNCTION] = {NULL, type, .u.arg = &funtype},
+ [VECTOR] = {NULL, NULL, .u.arg = &arrtype},
+ [UNION] = {NULL, NULL, .u.arg = &uniontype},
+ [STRUCT] = {NULL, NULL, .u.arg = &strtype},
+
+ [ONAME] = {NULL, getname},
+ ['{'] = {beginfun},
+ ['}'] = {endfun},
+ ['('] = {begininit},
+ [')'] = {endinit},
+ [OEPARS] = {endpars},
+ [OSTMT] = {stmt},
+
+ [OCPL] = {NULL, unary},
+ [ONEG] = {NULL, unary},
+ [OFIELD] = {NULL, unary},
+ [OADDR] = {NULL, unary},
+ [OAND] = {NULL, unary},
+ [OOR] = {NULL, unary},
+ [OPTR] = {NULL, unary},
+ [OCAST] = {NULL, unary},
+ [OPAR ] = {NULL, unary},
+
+ [OADD] = {NULL, binary},
+ [OSUB] = {NULL, binary},
+ [OMUL] = {NULL, binary},
+ [OMOD] = {NULL, binary},
+ [ODIV] = {NULL, binary},
+ [OSHL] = {NULL, binary},
+ [OSHR] = {NULL, binary},
+ [OLT] = {NULL, binary},
+ [OGT] = {NULL, binary},
+ [OLE] = {NULL, binary},
+ [OGE] = {NULL, binary},
+ [OEQ] = {NULL, binary},
+ [ONE] = {NULL, binary},
+ [OBAND] = {NULL, binary},
+ [OBOR] = {NULL, binary},
+ [OBXOR] = {NULL, binary},
+ [OASSIG] = {NULL, binary},
+ [OCOMMA] = {NULL, binary},
+
+ [OASK] = {NULL, ternary},
+ [OCALL] = {NULL, call},
+
+ [OCONST] = NULL, constant,
+
+ [OCASE] = NULL,
+ [ODEFAULT] = NULL,
+ [OTABLE] = NULL,
+ [OSWITCH] = NULL
+};
+
+static void *stack[STACKSIZ], **sp = stack;
+static Symbol *lastsym, *curfun;
+static Symbol *params[NR_FUNPARAM];
+static int funpars = -1, sclass, callpars, ininit;
+static Node *stmtp, *callp;
static void
-push(Node * np)
+push(void *elem)
{
+ if (sp == stack[STACKSIZ])
+ error(ESTACKO);
+ *sp++ = elem;
}
-static Node *
+static void *
pop(void)
{
+ if (sp == stack)
+ error(ESTACKU);
+ return *--sp;
+}
+
+static unsigned short
+newid(void)
+{
+ static unsigned short id;
+
+ if (++id == 0)
+ error(EIDOVER);
}
static void
-expr(char *tok)
+type(char *token, union tokenop u)
{
+ push(u.arg);
}
static void
-stmt(Node *np)
+getname(char *t, union tokenop u)
{
+ push((*++t) ? xstrdup(t) : NULL);
}
static void
-decl(char *tok)
+symbol(char *token, union tokenop u)
{
+ Node *np;
+
+ sclass = *token++;
+ np = newnode();
+ np->sym = getsym(atoi(token));
+ np->op = u.op;
+ push(np);
+}
+
+static Type *
+gettype(char *token)
+{
+ struct decoc *dp;
+
+ dp = &optbl[*token];
+ if (!dp->parse)
+ error(ESYNTAX);
+ (*dp->parse)(token, dp->u);
+ return pop();
+}
+
+static void
+constant(char *token, union tokenop u)
+{
+ static char letters[] = "0123456789ABCDEF";
+ Node *np = newnode();
+ Symbol *sym = getsym(0);
+ TUINT v;
+ unsigned c;
+
+ np->sym = sym;
+ ++token;
+ if (*token == OSTRING) {
+ np->op = OSYM;
+ np->type = ptrtype;
+ sym->id = newid();
+ sym->u.s = xstrdup(++token);
+ } else {
+ np->op = OCONST;
+ np->type = *gettype(token++);
+ for (v = 0; c = *token++; v += c) {
+ v <<= 4;
+ c = strchr(letters, c) - letters;
+ }
+ sym->u.i = v;
+ }
+}
+
+static void
+ternary(char *token, union tokenop u)
+{
+ Node *ask, *colon;
+ Type *tp;
+
+ tp = gettype(++token);
+
+ colon = newnode();
+ colon->op = OCOLON;
+ colon->right = pop();
+ colon->left = pop();
+
+ ask = newnode();
+ ask->op = OASK;
+ ask->type = *tp;
+ ask->left = pop();
+ ask->right = pop();
+ push(ask);
+}
+
+static void
+unary(char *token, union tokenop u)
+{
+ Node *np = newnode();
+
+ np->op = *token++;
+ np->type = *gettype(token);
+ np->left = pop();
+ np->right = NULL;
+ push(np);
+}
+
+static void
+call(char *token, union tokenop u)
+{
+ Node *np, *par, *fun;
+
+ for (par = NULL;; par = np) {
+ np = pop();
+ if (np->op != OPAR)
+ break;
+ np->right = par;
+ }
+ fun = newnode();
+ fun->op = OCALL;
+ fun->type = *gettype(token);
+ fun->left = np;
+ fun->right = par;
+ push(fun);
+}
+
+static void
+binary(char *token, union tokenop u)
+{
+ Node *np = newnode();
+
+ np->op = *token++;
+ np->type = *gettype(token);
+ np->right = pop();
+ np->left = pop();
+ push(np);
+}
+
+static void
+begininit(void)
+{
+ inint = 1;
+}
+
+static void
+endinit(void)
+{
+ ininit = 0;
+}
+
+static void
+beginfun(void)
+{
+ if (curfun)
+ error(ESYNTAX);
+ memset(params, 0, sizeof(params));
+ funpars = 0;
+ curfun = lastsym;
+ pushctx();
+}
+
+static void
+endfun(void)
+{
+ if (!curfun)
+ error(ESYNTAX);
+ popctx();
+ curfun = NULL;
+ funpars = -1;
+}
+
+static void
+endpars(void)
+{
+ if (!curfun || funpars == -1)
+ error(ESYNTAX);
+ funpars = -1;
+}
+
+static void
+vardecl(void)
+{
+ Type *tp;
+ Node *np;
+ Symbol *sym;
+ char *name;
+
+ name = pop();
+ tp = pop();
+ np = pop();
+
+ sym = np->sym;
+ sym->name = name;
+ sym->type = *tp;
+ sym->kind = sclass;
+ lastsym = sym;
+
+ if (funpars >= 0) {
+ if (funpars == NR_FUNPARAM)
+ error(EOUTPAR);
+ params[funpars++] = sym;
+ }
+ delnode(np);
+}
+
+static void
+stmt(void)
+{
+ static Node *lastp;
+ Node *np = pop();
+
+ if (!stmtp)
+ stmtp = np;
+ else
+ lastp->stmt = np;
+ lastp = np;
}
void
parse(void)
{
- char line[MAXLINE];
+ char line[MAXLINE], *t;
size_t len;
+ int c;
+ struct decoc *dp;
for (;;) {
- if (fgets(line, sizeof(line), stdin))
+ if (!fgets(line, sizeof(line), stdin))
break;
if ((len = strlen(line)) == 0 || line[0] == '\n')
continue;
if (line[len-1] != '\n')
error(ELNLINE);
line[len-1] = '\0';
- switch (*line) {
- case '\t':
- expr(strtok(line, "\t"));
- stmt(pop());
- break;
- default:
- decl(strtok(line, "\t"));
- break;
+
+ c = *line;
+ for (t = strtok(line, "\t\n"); t; t = strtok(NULL, "\t\n")) {
+ dp = &optbl[*t];
+ if (!dp->parse)
+ break;
+ (*dp->parse)(t, dp->u);
}
+
+ (*optbl[c].eval)();
+ if (sp != stack)
+ error(ESTACKA);
+ if (c == '}')
+ break;
}
if (ferror(stdin))
diff --git a/cc2/peep.c b/cc2/peep.c
@@ -1,4 +1,5 @@
+#include "arch.h"
#include "cc2.h"
void
diff --git a/cc2/symbol.c b/cc2/symbol.c
@@ -0,0 +1,66 @@
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "../inc/cc.h"
+
+#include "arch.h"
+#include "cc2.h"
+
+#define NR_SYMHASH 64
+
+static Symbol *symtab[NR_SYMHASH];
+static Symbol *locals;
+static int infunction;
+
+
+void
+freesym(Symbol *sym)
+{
+ free(sym->name);
+ free(sym);
+}
+
+void
+pushctx(void)
+{
+ infunction = 1;
+}
+
+void
+popctx(void)
+{
+ Symbol *sym, *next;
+
+ infunction = 0;
+ for (sym = locals; sym; sym = next) {
+ next = sym->next;
+ symtab[sym->id & NR_SYMHASH-1] = sym->h_next;
+ freesym(sym);
+ }
+}
+
+Symbol *
+getsym(int id)
+{
+ Symbol **htab, *sym;
+
+ htab = &symtab[id & NR_SYMHASH-1];
+ for (sym = *htab; sym; sym = sym->h_next) {
+ if (sym->id > 0 && sym->id != id)
+ break;
+ }
+ if (!sym) {
+ sym = xcalloc(1, sizeof(*sym));
+ sym->id = id;
+ if (!infunction) {
+ sym->next = NULL;
+ } else {
+ sym->next = locals;
+ locals = sym;
+ }
+ sym->h_next = *htab;
+ *htab = sym;
+ }
+ return sym;
+}
