implement _Thread_local storage class

Implements: https://todo.sr.ht/~mcf/cproc/8

7 files changed, 48 insertions, 10 deletions

diff --git a/README.md b/README.md
index f1a1fd1..ea3a807 100644
--- a/README.md
+++ b/README.md
@@ -80,7 +80,6 @@ specified in `config.h`.
 - Digraph sequences ([6.4.6p3], will not be implemented).
 - Variable-length arrays ([#1]).
 - `volatile`-qualified types ([#7]).
-- `_Thread_local` storage-class specifier ([#5]).
 - `long double` type ([#3]).
 - Inline assembly ([#5]).
 - Preprocessor ([#6]).
diff --git a/cc.h b/cc.h
index fffee6f..d595eb8 100644
--- a/cc.h
+++ b/cc.h
@@ -541,7 +541,7 @@ void switchcase(struct switchcases *, unsigned long long, struct block *);
 
 struct block *mkblock(char *);
 
-struct value *mkglobal(char *, bool);
+struct value *mkglobal(char *, bool, bool);
 
 struct value *mkintconst(unsigned long long);
 unsigned long long intconstvalue(struct value *);
diff --git a/decl.c b/decl.c
index 6e7d360..8f35033 100644
--- a/decl.c
+++ b/decl.c
@@ -941,7 +941,7 @@ declcommon(struct scope *s, enum declkind kind, char *name, char *asmname, struc
 	if (kind == DECLFUNC || linkage != LINKNONE || sc & SCSTATIC) {
 		if (asmname)
 			name = asmname;
-		d->value = mkglobal(name, linkage == LINKNONE && !asmname);
+		d->value = mkglobal(name, linkage == LINKNONE && !asmname, sc & SCTHREADLOCAL);
 		d->asmname = asmname;
 	}
 	return d;
@@ -981,8 +981,6 @@ decl(struct scope *s, struct func *f)
 		if (sc & SCREGISTER)
 			error(&tok.loc, "external declaration must not contain 'register'");
 	}
-	if (sc & SCTHREADLOCAL)
-		error(&tok.loc, "'_Thread_local' is not yet supported");
 	if (consume(TSEMICOLON)) {
 		/* XXX 6.7p2 error unless in function parameter/struct/union, or tag/enum members are declared */
 		return true;
@@ -1029,7 +1027,7 @@ decl(struct scope *s, struct func *f)
 					error(&tok.loc, "object '%s' redefined", name);
 				init = parseinit(s, d->type);
 				hasinit = true;
-			} else if (d->linkage != LINKNONE) {
+			} else if (d->linkage != LINKNONE && (!(sc & SCTHREADLOCAL) || sc & SCEXTERN)) {
 				if (!(sc & SCEXTERN) && !d->defined && !d->tentative) {
 					d->tentative = true;
 					*tentativedefnsend = d;
@@ -1096,7 +1094,7 @@ stringdecl(struct expr *expr)
 	d = *entry;
 	if (!d) {
 		d = mkdecl(NULL, DECLOBJECT, expr->type, QUALNONE, LINKNONE);
-		d->value = mkglobal("string", true);
+		d->value = mkglobal("string", true, false);
 		emitdata(d, mkinit(0, expr->type->size, (struct bitfield){0}, expr));
 		*entry = d;
 	}
diff --git a/eval.c b/eval.c
index d6c70b1..2c5a84f 100644
--- a/eval.c
+++ b/eval.c
@@ -119,7 +119,7 @@ eval(struct expr *expr)
 		if (expr->u.compound.storage != SDSTATIC)
 			break;
 		d = mkdecl(NULL, DECLOBJECT, t, expr->qual, LINKNONE);
-		d->value = mkglobal(NULL, true);
+		d->value = mkglobal(NULL, true, false);
 		emitdata(d, expr->u.compound.init);
 		expr->kind = EXPRIDENT;
 		expr->u.ident.decl = d;
diff --git a/qbe.c b/qbe.c
index b01d2db..a5817f9 100644
--- a/qbe.c
+++ b/qbe.c
@@ -20,6 +20,7 @@ struct value {
 		VALUE_LABEL,
 	} kind;
 	unsigned id;
+	bool threadlocal;
 	union {
 		char *name;
 		unsigned long long i;
@@ -128,7 +129,7 @@ mkblock(char *name)
 }
 
 struct value *
-mkglobal(char *name, bool private)
+mkglobal(char *name, bool private, bool threadlocal)
 {
 	static unsigned id;
 	struct value *v;
@@ -137,6 +138,7 @@ mkglobal(char *name, bool private)
 	v->kind = VALUE_GLOBAL;
 	v->u.name = name;
 	v->id = private ? ++id : 0;
+	v->threadlocal = threadlocal;
 
 	return v;
 }
@@ -501,7 +503,7 @@ mkfunc(struct decl *decl, char *name, struct type *t, struct scope *s)
 
 	t = mkarraytype(&typechar, QUALCONST, strlen(name) + 1);
 	d = mkdecl("__func__", DECLOBJECT, t, QUALNONE, LINKNONE);
-	d->value = mkglobal(d->name, true);
+	d->value = mkglobal(d->name, true, false);
 	scopeputdecl(s, d);
 	f->namedecl = d;
 
@@ -1125,6 +1127,8 @@ emitinst(struct inst **instp, struct inst **instend)
 	}
 	fputs(instname[inst->kind], stdout);
 	putchar(' ');
+	if (inst->arg[0]->kind == VALUE_GLOBAL && inst->arg[0]->threadlocal)
+		fputs("thread ", stdout);
 	emitvalue(inst->arg[0]);
 	++instp;
 	op = inst->kind;
@@ -1152,6 +1156,8 @@ emitinst(struct inst **instp, struct inst **instend)
 	default:
 		if (inst->arg[1]) {
 			fputs(", ", stdout);
+			if (inst->arg[1]->kind == VALUE_GLOBAL && inst->arg[1]->threadlocal)
+				fputs("thread ", stdout);
 			emitvalue(inst->arg[1]);
 		}
 	}
@@ -1322,6 +1328,8 @@ emitdata(struct decl *d, struct init *init)
 	align = d->u.obj.align;
 	for (cur = init; cur; cur = cur->next)
 		cur->expr = eval(cur->expr);
+	if (d->value->threadlocal)
+		fputs("thread ", stdout);
 	if (d->linkage == LINKEXTERN)
 		fputs("export ", stdout);
 	fputs("data ", stdout);
diff --git a/test/thread-local.c b/test/thread-local.c
new file mode 100644
index 0000000..3086699
--- /dev/null
+++ b/test/thread-local.c
@@ -0,0 +1,10 @@
+thread_local int a = 1;
+static thread_local int b = 2;
+extern thread_local int c = 3;
+thread_local int d;
+static thread_local int e;
+extern thread_local int f;
+int main(void) {
+	static thread_local int x = 6;
+	return a + b + c + d + e - x;
+}
diff --git a/test/thread-local.qbe b/test/thread-local.qbe
new file mode 100644
index 0000000..0e9ba83
--- /dev/null
+++ b/test/thread-local.qbe
@@ -0,0 +1,23 @@
+thread export data $a = align 4 { w 1, }
+thread data $b = align 4 { w 2, }
+thread export data $c = align 4 { w 3, }
+thread export data $d = align 4 { z 4 }
+thread data $e = align 4 { z 4 }
+thread data $.Lx.2 = align 4 { w 6, }
+export
+function w $main() {
+@start.1
+@body.2
+	%.1 =w loadw thread $a
+	%.2 =w loadw thread $b
+	%.3 =w add %.1, %.2
+	%.4 =w loadw thread $c
+	%.5 =w add %.3, %.4
+	%.6 =w loadw thread $d
+	%.7 =w add %.5, %.6
+	%.8 =w loadw thread $e
+	%.9 =w add %.7, %.8
+	%.10 =w loadw thread $.Lx.2
+	%.11 =w sub %.9, %.10
+	ret %.11
+}