scc

simple C compiler
git clone git://git.2f30.org/scc
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commit 7d416c42124594d23b5c26d6951b748a43b4de65
parent 33d48f1302e23a91f0835080c8b00372051026c4
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Tue, 26 Jan 2016 14:16:15 +0100

[cc2-i386] Add basic support for static variables

This code is similar to the code written by the z80 target,
but it uses the gas syntax (it is horrible).

Diffstat:
Mcc2/arch/i386-sysv/code.c | 159+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 159 insertions(+), 0 deletions(-)

diff --git a/cc2/arch/i386-sysv/code.c b/cc2/arch/i386-sysv/code.c @@ -1,20 +1,179 @@ +#include <stdio.h> +#include <stdlib.h> + #include "arch.h" #include "../../cc2.h" +#include "../../../inc/sizes.h" + +enum segment { + CODESEG, + DATASEG, + BSSSEG, + NOSEG +}; + +static int curseg = NOSEG; + +static void +segment(int seg) +{ + static char *txt[] = { + [CODESEG] = "\t.text\n", + [DATASEG] = "\t.data\n", + [BSSSEG] = "\t.bss\n", + }; + + if (seg == curseg) + return; + fputs(txt[seg], stdout); + curseg = seg; +} + +static char * +symname(Symbol *sym) +{ + static char name[IDENTSIZ+1]; + static unsigned short id; + + if (sym->name) { + switch (sym->kind) { + case EXTRN: + case GLOB: + case PRIVAT: + return sym->name; + } + } + + if (sym->numid == 0 && (sym->numid = ++id) == 0) + error(EIDOVER); + sprintf(name, ".%d", sym->numid); + + return name; +} + +static void +emitconst(Node *np) +{ + switch (np->type.size) { + case 1: + printf("%d", (int) np->u.i & 0xFF); + break; + case 2: + printf("%d", (int) np->u.i & 0xFFFF); + break; + case 4: + printf("%ld", (long) np->u.i & 0xFFFFFFFF); + break; + case 8: + printf("%lld", (long long) np->u.i & 0xFFFFFFFF); + break; + default: + abort(); + } +} + +static void +emittree(Node *np) +{ + if (!np) + return; + + switch (np->op) { + case OSTRING: + printf("\"%s\"", np->u.s); + free(np->u.s); + np->u.s = NULL; + break; + case OCONST: + emitconst(np); + break; + case OADDR: + emittree(np->left); + break; + case MEM: + fputs(symname(np->u.sym), stdout); + break; + default: + emittree(np->left); + printf(" %c ", np->op); + emittree(np->right); + break; + } +} +static void +size2asm(Type *tp) +{ + char *s; + + if (tp->align != 1) + printf("\t.align\t%d\n", tp->align); + + if (tp->flags & STRF) { + s = "\t.ascii\t"; + } else { + switch (tp->size) { + case 1: + s = "\t.byte\t"; + break; + case 2: + s = "\t.short\t"; + break; + case 4: + s = "\t.long\t"; + break; + case 8: + s = "\t.quad\t"; + break; + default: + s = "\t.space\t%llu"; + break; + } + } + printf(s, (unsigned long long) tp->size); +} void allocdata(Type *tp) { + size2asm(tp); + puts("0"); } void data(Node *np) { + size2asm(&np->type); + emittree(np); + putchar('\n'); } void label(Symbol *sym) { + int seg, flags = sym->type.flags; + char *name = symname(sym); + + putchar('\n'); + if (flags & FUNF) + seg = CODESEG; + else if (flags & INITF) + seg = DATASEG; + else + seg = BSSSEG; + segment(seg); + + switch (sym->kind) { + case LOCAL: + case EXTRN: + return; + case GLOB: + printf("\t.globl\t%s\n", name); + break; + } + + printf("%s:\n", name); + } void