[GNU] Treat labels-as-values as compile-time constant

This commit is contained in:
Rui Ueyama 2020-09-20 13:23:53 +09:00
parent 4f165ec60b
commit f0c98e0d59
4 changed files with 16 additions and 9 deletions

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@ -169,7 +169,7 @@ typedef struct Relocation Relocation;
struct Relocation { struct Relocation {
Relocation *next; Relocation *next;
int offset; int offset;
char *label; char **label;
long addend; long addend;
}; };

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@ -1338,7 +1338,7 @@ static void emit_data(Obj *prog) {
int pos = 0; int pos = 0;
while (pos < var->ty->size) { while (pos < var->ty->size) {
if (rel && rel->offset == pos) { if (rel && rel->offset == pos) {
println(" .quad %s%+ld", rel->label, rel->addend); println(" .quad %s%+ld", *rel->label, rel->addend);
rel = rel->next; rel = rel->next;
pos += 8; pos += 8;
} else { } else {

17
parse.c
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@ -136,8 +136,8 @@ static Node *stmt(Token **rest, Token *tok);
static Node *expr_stmt(Token **rest, Token *tok); static Node *expr_stmt(Token **rest, Token *tok);
static Node *expr(Token **rest, Token *tok); static Node *expr(Token **rest, Token *tok);
static int64_t eval(Node *node); static int64_t eval(Node *node);
static int64_t eval2(Node *node, char **label); static int64_t eval2(Node *node, char ***label);
static int64_t eval_rval(Node *node, char **label); static int64_t eval_rval(Node *node, char ***label);
static bool is_const_expr(Node *node); static bool is_const_expr(Node *node);
static Node *assign(Token **rest, Token *tok); static Node *assign(Token **rest, Token *tok);
static Node *logor(Token **rest, Token *tok); static Node *logor(Token **rest, Token *tok);
@ -1462,7 +1462,7 @@ write_gvar_data(Relocation *cur, Initializer *init, Type *ty, char *buf, int off
return cur; return cur;
} }
char *label = NULL; char **label = NULL;
uint64_t val = eval2(init->expr, &label); uint64_t val = eval2(init->expr, &label);
if (!label) { if (!label) {
@ -1830,7 +1830,7 @@ static int64_t eval(Node *node) {
// is a pointer to a global variable and n is a postiive/negative // is a pointer to a global variable and n is a postiive/negative
// number. The latter form is accepted only as an initialization // number. The latter form is accepted only as an initialization
// expression for a global variable. // expression for a global variable.
static int64_t eval2(Node *node, char **label) { static int64_t eval2(Node *node, char ***label) {
add_type(node); add_type(node);
if (is_flonum(node->ty)) if (is_flonum(node->ty))
@ -1902,6 +1902,9 @@ static int64_t eval2(Node *node, char **label) {
} }
case ND_ADDR: case ND_ADDR:
return eval_rval(node->lhs, label); return eval_rval(node->lhs, label);
case ND_LABEL_VAL:
*label = &node->unique_label;
return 0;
case ND_MEMBER: case ND_MEMBER:
if (!label) if (!label)
error_tok(node->tok, "not a compile-time constant"); error_tok(node->tok, "not a compile-time constant");
@ -1913,7 +1916,7 @@ static int64_t eval2(Node *node, char **label) {
error_tok(node->tok, "not a compile-time constant"); error_tok(node->tok, "not a compile-time constant");
if (node->var->ty->kind != TY_ARRAY && node->var->ty->kind != TY_FUNC) if (node->var->ty->kind != TY_ARRAY && node->var->ty->kind != TY_FUNC)
error_tok(node->tok, "invalid initializer"); error_tok(node->tok, "invalid initializer");
*label = node->var->name; *label = &node->var->name;
return 0; return 0;
case ND_NUM: case ND_NUM:
return node->val; return node->val;
@ -1922,12 +1925,12 @@ static int64_t eval2(Node *node, char **label) {
error_tok(node->tok, "not a compile-time constant"); error_tok(node->tok, "not a compile-time constant");
} }
static int64_t eval_rval(Node *node, char **label) { static int64_t eval_rval(Node *node, char ***label) {
switch (node->kind) { switch (node->kind) {
case ND_VAR: case ND_VAR:
if (node->var->is_local) if (node->var->is_local)
error_tok(node->tok, "not a compile-time constant"); error_tok(node->tok, "not a compile-time constant");
*label = node->var->name; *label = &node->var->name;
return 0; return 0;
case ND_DEREF: case ND_DEREF:
return eval2(node->lhs, label); return eval2(node->lhs, label);

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@ -91,6 +91,10 @@ int main() {
ASSERT(2, ({ void *p = &&v22; int i=0; goto *p; v21:i++; v22:i++; v23:i++; i; })); ASSERT(2, ({ void *p = &&v22; int i=0; goto *p; v21:i++; v22:i++; v23:i++; i; }));
ASSERT(1, ({ void *p = &&v33; int i=0; goto *p; v31:i++; v32:i++; v33:i++; i; })); ASSERT(1, ({ void *p = &&v33; int i=0; goto *p; v31:i++; v32:i++; v33:i++; i; }));
ASSERT(3, ({ static void *p[]={&&v41,&&v42,&&v43}; int i=0; goto *p[0]; v41:i++; v42:i++; v43:i++; i; }));
ASSERT(2, ({ static void *p[]={&&v52,&&v52,&&v53}; int i=0; goto *p[1]; v51:i++; v52:i++; v53:i++; i; }));
ASSERT(1, ({ static void *p[]={&&v62,&&v62,&&v63}; int i=0; goto *p[2]; v61:i++; v62:i++; v63:i++; i; }));
printf("OK\n"); printf("OK\n");
return 0; return 0;
} }