Add thread-local variable

Makefile

@@ -15,7 +15,7 @@ $(OBJS): chibicc.h
 
 test/%.exe: chibicc test/%.c
 	./chibicc -Iinclude -Itest -c -o test/$*.o test/$*.c
-	$(CC) -o $@ test/$*.o -xc test/common
+	$(CC) -pthread -o $@ test/$*.o -xc test/common
 
 test: $(TESTS)
 	for i in $^; do echo $$i; ./$$i || exit 1; echo; done
@@ -35,7 +35,7 @@ stage2/%.o: chibicc %.c
 stage2/test/%.exe: stage2/chibicc test/%.c
 	mkdir -p stage2/test
 	./stage2/chibicc -Iinclude -Itest -c -o stage2/test/$*.o test/$*.c
-	$(CC) -o $@ stage2/test/$*.o -xc test/common
+	$(CC) -pthread -o $@ stage2/test/$*.o -xc test/common
 
 test-stage2: $(TESTS:test/%=stage2/test/%)
 	for i in $^; do echo $$i; ./$$i || exit 1; echo; done

chibicc.h

@@ -141,6 +141,7 @@ struct Obj {
 
   // Global variable
   bool is_tentative;
+  bool is_tls;
   char *init_data;
   Relocation *rel;
 

codegen.c

@@ -67,6 +67,13 @@ static void gen_addr(Node *node) {
       return;
     }
 
+    // Thread-local variable
+    if (node->var->is_tls) {
+      println("  mov %%fs:0, %%rax");
+      println("  add $%s@tpoff, %%rax", node->var->name);
+      return;
+    }
+
     // Here, we generate an absolute address of a function or a global
     // variable. Even though they exist at a certain address at runtime,
     // their addresses are not known at link-time for the following
@@ -1136,13 +1143,19 @@ static void emit_data(Obj *prog) {
       ? MAX(16, var->align) : var->align;
     println("  .align %d", align);
 
+    // Common symbol
     if (opt_fcommon && var->is_tentative) {
       println("  .comm %s, %d, %d", var->name, var->ty->size, align);
       continue;
     }
 
+    // .data or .tdata
     if (var->init_data) {
-      println("  .data");
+      if (var->is_tls)
+        println("  .section .tdata,\"awT\",@progbits");
+      else
+        println("  .data");
+
       println("%s:", var->name);
 
       Relocation *rel = var->rel;
@@ -1159,7 +1172,12 @@ static void emit_data(Obj *prog) {
       continue;
     }
 
-    println("  .bss");
+    // .bss or .tbss
+    if (var->is_tls)
+      println("  .section .tbss,\"awT\",@nobits");
+    else
+      println("  .bss");
+
     println("%s:", var->name);
     println("  .zero %d", var->ty->size);
   }

parse.c

@@ -55,6 +55,7 @@ typedef struct {
   bool is_static;
   bool is_extern;
   bool is_inline;
+  bool is_tls;
   int align;
 } VarAttr;
 
@@ -365,6 +366,7 @@ static void push_tag_scope(Token *tok, Type *ty) {
 
 // declspec = ("void" | "_Bool" | "char" | "short" | "int" | "long"
 //             | "typedef" | "static" | "extern" | "inline"
+//             | "_Thread_local" | "__thread"
 //             | "signed" | "unsigned"
 //             | struct-decl | union-decl | typedef-name
 //             | enum-specifier | typeof-specifier
@@ -407,7 +409,7 @@ static Type *declspec(Token **rest, Token *tok, VarAttr *attr) {
   while (is_typename(tok)) {
     // Handle storage class specifiers.
     if (equal(tok, "typedef") || equal(tok, "static") || equal(tok, "extern") ||
-        equal(tok, "inline")) {
+        equal(tok, "inline") || equal(tok, "_Thread_local") || equal(tok, "__thread")) {
       if (!attr)
         error_tok(tok, "storage class specifier is not allowed in this context");
 
@@ -417,11 +419,15 @@ static Type *declspec(Token **rest, Token *tok, VarAttr *attr) {
         attr->is_static = true;
       else if (equal(tok, "extern"))
         attr->is_extern = true;
-      else
+      else if (equal(tok, "inline"))
         attr->is_inline = true;
+      else
+        attr->is_tls = true;
 
-      if (attr->is_typedef && attr->is_static + attr->is_extern + attr->is_inline > 1)
-        error_tok(tok, "typedef may not be used together with static, extern or inline");
+      if (attr->is_typedef &&
+          attr->is_static + attr->is_extern + attr->is_inline + attr->is_tls > 1)
+        error_tok(tok, "typedef may not be used together with static,"
+                  " extern, inline, __thread or _Thread_local");
       tok = tok->next;
       continue;
     }
@@ -1406,6 +1412,7 @@ static bool is_typename(Token *tok) {
     "typedef", "enum", "static", "extern", "_Alignas", "signed", "unsigned",
     "const", "volatile", "auto", "register", "restrict", "__restrict",
     "__restrict__", "_Noreturn", "float", "double", "typeof", "inline",
+    "_Thread_local", "__thread",
   };
 
   for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++)
@@ -2942,12 +2949,13 @@ static Token *global_variable(Token *tok, Type *basety, VarAttr *attr) {
     Obj *var = new_gvar(get_ident(ty->name), ty);
     var->is_definition = !attr->is_extern;
     var->is_static = attr->is_static;
+    var->is_tls = attr->is_tls;
     if (attr->align)
       var->align = attr->align;
 
     if (equal(tok, "="))
       gvar_initializer(&tok, tok->next, var);
-    else if (!attr->is_extern)
+    else if (!attr->is_extern && !attr->is_tls)
       var->is_tentative = true;
   }
   return tok;

preprocess.c

@@ -996,7 +996,6 @@ void init_macros(void) {
   define_macro("__STDC_HOSTED__", "1");
   define_macro("__STDC_NO_ATOMICS__", "1");
   define_macro("__STDC_NO_COMPLEX__", "1");
-  define_macro("__STDC_NO_THREADS__", "1");
   define_macro("__STDC_NO_VLA__", "1");
   define_macro("__STDC_UTF_16__", "1");
   define_macro("__STDC_UTF_32__", "1");

test/tls.c

@@ -0,0 +1,41 @@
+#include "test.h"
+#include <stdio.h>
+#include <pthread.h>
+
+_Thread_local int v1;
+_Thread_local int v2 = 5;
+int v3 = 7;
+
+int thread_main(void *unused) {
+  ASSERT(0, v1);
+  ASSERT(5, v2);
+  ASSERT(7, v3);
+
+  v1 = 1;
+  v2 = 2;
+  v3 = 3;
+
+  ASSERT(1, v1);
+  ASSERT(2, v2);
+  ASSERT(3, v3);
+
+  return 0;
+}
+
+int main() {
+  pthread_t thr;
+
+  ASSERT(0, v1);
+  ASSERT(5, v2);
+  ASSERT(7, v3);
+
+  ASSERT(0, pthread_create(&thr, NULL, thread_main, NULL));
+  ASSERT(0, pthread_join(thr, NULL));
+
+  ASSERT(0, v1);
+  ASSERT(5, v2);
+  ASSERT(3, v3);
+
+  printf("OK\n");
+  return 0;
+}

tokenize.c

@@ -163,7 +163,7 @@ static bool is_keyword(Token *tok) {
     "default", "extern", "_Alignof", "_Alignas", "do", "signed",
     "unsigned", "const", "volatile", "auto", "register", "restrict",
     "__restrict", "__restrict__", "_Noreturn", "float", "double",
-    "typeof", "asm",
+    "typeof", "asm", "_Thread_local", "__thread",
   };
 
   for (int i = 0; i < sizeof(kw) / sizeof(*kw); i++)