Merge branch 'feature/wasm-linker'

.gitignore

@@ -41,6 +41,7 @@ libsrc/_wasm/libc.c
 
 *.wasm
 /wcc
+/wcc-ld
 /cc.wasm
 /gen3cc.wasm
 /tests/*.wasm

Makefile

@@ -134,7 +134,7 @@ test-libs:	all
 clean:
 	rm -rf $(EXES) $(OBJ_DIR) a.out gen2* gen3* tmp.s \
 		dump_expr* dump_ir* dump_type* \
-		wcc cc.wasm a.wasm public release $(WCC_LIBS)
+		wcc wcc-ld cc.wasm a.wasm public release $(WCC_LIBS)
 	@$(MAKE) -C libsrc clean
 	@$(MAKE) -C tests clean
 
@@ -201,14 +201,23 @@ WCC_LIBS:=$(LIBSRC_DIR)/_wasm/crt0.c $(LIBSRC_DIR)/_wasm/libc.c
 wcc: $(PARENT_DEPS) $(WCC_OBJS) $(WCC_LIBS)
 	$(CC) -o $@ $(WCC_OBJS) $(LDFLAGS)
 
+WCCLD_SRCS:=$(DEBUG_DIR)/wcc-ld.c $(WCC_DIR)/wasm_linker.c \
+	$(WCC_DIR)/wcc_util.c $(WCC_DIR)/emit_wasm.c $(WCC_DIR)/traverse.c $(WCC_DIR)/traverse_setjmp.c \
+	$(wildcard $(CC1_FE_DIR)/*.c) \
+	$(UTIL_DIR)/util.c $(UTIL_DIR)/table.c
+WCCLD_OBJS:=$(addprefix $(WCC_OBJ_DIR)/,$(notdir $(WCCLD_SRCS:.c=.o)))
+
+wcc-ld: $(WCCLD_OBJS)
+	$(CC) -o $@ $(WCCLD_OBJS) $(LDFLAGS)
+
 -include $(WCC_OBJ_DIR)/*.d
 
 define DEFINE_WCCOBJ_TARGET
 $(WCC_OBJ_DIR)/%.o: $(1)/%.c $(PARENT_DEPS)
 	@mkdir -p $(WCC_OBJ_DIR)
 	$(CC) $(WCC_CFLAGS) -DXCC_TARGET_ARCH=XCC_ARCH_WASM -c -o $$@ $$<
 endef
-WCC_SRC_DIRS:=$(WCC_DIR) $(CC1_FE_DIR) $(CC1_BE_DIR) $(CC1_DIR) $(CPP_DIR) $(UTIL_DIR)
+WCC_SRC_DIRS:=$(WCC_DIR) $(DEBUG_DIR) $(CC1_FE_DIR) $(CC1_BE_DIR) $(CC1_DIR) $(CPP_DIR) $(UTIL_DIR)
 $(foreach D, $(WCC_SRC_DIRS), $(eval $(call DEFINE_WCCOBJ_TARGET,$(D))))
 
 WCC_CRT0_SRCS:=$(wildcard $(LIBSRC_DIR)/_wasm/crt0/*.c)

libsrc/_wasm/unistd/clock_gettime.c

@@ -1,7 +1,7 @@
 #include "time.h"
-
 #include "stddef.h"  // NULL
 #include "stdint.h"
+#include "../wasi.h"
 
 int clock_gettime(clockid_t clk_id, struct timespec *tp) {
   if (tp == NULL)

libsrc/_wasm/unistd/lseek.c

@@ -1,4 +1,5 @@
 #include "unistd.h"
+#include "../wasi.h"
 
 off_t lseek(int fd, off_t offset, int whence) {
   size_t size;

libsrc/_wasm/unistd/time.c

@@ -1,6 +1,7 @@
 #include "time.h"
 #include "stddef.h"  // NULL
 #include "stdint.h"
+#include "../wasi.h"
 
 time_t time(time_t *timer) {
   uint64_t t;

libsrc/_wasm/unistd/unlink.c

@@ -1,5 +1,6 @@
 #include "unistd.h"
 #include "errno.h"
+#include "string.h"
 #include "../wasi.h"
 
 extern int max_preopen_fd;

src/_debug/wcc-ld.c

@@ -0,0 +1,96 @@
+#include "../config.h"
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>  // atoi
+
+#include "../wcc/wasm.h"
+#include "../wcc/wasm_linker.h"
+#include "../wcc/wcc.h"
+#include "table.h"
+#include "util.h"
+
+static void init(void) {
+  out_type = OutExecutable;
+  functypes = new_vector();
+  tags = new_vector();
+  table_init(&indirect_function_table);
+}
+
+int main(int argc, char *argv[]) {
+  const char *ofn = "a.wasm";
+  const char *entry_point = "_start";
+  uint32_t stack_size = DEFAULT_STACK_SIZE;
+
+  init();
+
+  enum {
+    OPT_VERBOSE = 256,
+    OPT_ENTRY_POINT,
+    OPT_STACK_SIZE,
+  };
+  static const struct option options[] = {
+    {"o", required_argument},  // Specify output filename
+    {"-verbose", no_argument, OPT_VERBOSE},
+    {"-entry-point", required_argument, OPT_ENTRY_POINT},
+    {"-stack-size", required_argument, OPT_STACK_SIZE},
+
+    {NULL},
+  };
+
+  int opt;
+  while ((opt = optparse(argc, argv, options)) != -1) {
+    switch (opt) {
+    default: assert(false); break;
+    case 'o':
+      ofn = optarg;
+      break;
+    case OPT_VERBOSE:
+      verbose = true;
+      break;
+    case OPT_ENTRY_POINT:
+      entry_point = optarg;
+      break;
+    case OPT_STACK_SIZE:
+      {
+        int size = atoi(optarg);
+        if (size <= 0) {
+          error("stack-size must be positive");
+        }
+        stack_size = size;
+      }
+      break;
+    case '?':
+      fprintf(stderr, "Warning: unknown option: %s\n", argv[optind - 1]);
+      break;
+    }
+  }
+  int iarg = optind;
+
+  WasmLinker linker_body;
+  WasmLinker *linker = &linker_body;
+  linker_init(linker);
+
+  bool result = true;
+  for (int i = iarg; i < argc; ++i) {
+    const char *src = argv[i];
+    if (!read_wasm_obj(linker, src)) {
+      fprintf(stderr, "error: failed to read wasm object file: %s\n", src);
+      result = false;
+      break;
+    }
+  }
+  if (!result)
+    return 1;
+
+  Vector *exports = new_vector();
+  if (*entry_point != '\0')
+    vec_push(exports, alloc_name(entry_point, NULL, false));
+
+  if (!link_wasm_objs(linker, exports, stack_size) ||
+      !linker_emit_wasm(linker, ofn, exports))
+    return 1;
+
+  return 0;
+}

src/wcc/emit_wasm.c

@@ -310,14 +310,14 @@ static void emit_import_section(EmitWasm *ew) {
     const char *module_name = ew->import_module_name;
     size_t module_name_len = strlen(module_name);
 
-    for (int i = 0, len = global_scope->vars->len; i < len; ++i) {
-      VarInfo *varinfo = global_scope->vars->data[i];
-      if (varinfo->storage & VS_ENUM_MEMBER || varinfo->type->kind == TY_FUNC)
-        continue;
-      if (is_global_datsec_var(varinfo, global_scope))
+    const Name *name;
+    GVarInfo *info;
+    for (int it = 0; (it = table_iterate(&gvar_info_table, it, &name, (void**)&info)) != -1; ) {
+      if (!(info->flag & GVF_UNRESOLVED))
         continue;
-      GVarInfo *info = get_gvar_info_from_name(varinfo->name);
-      if (info == NULL || !(info->flag & GVF_UNRESOLVED))
+      VarInfo *varinfo = info->varinfo;
+      if (varinfo->storage & VS_ENUM_MEMBER || varinfo->type->kind == TY_FUNC ||
+          is_global_datsec_var(varinfo, global_scope))
         continue;
 
       const Name *name = varinfo->name;
@@ -729,10 +729,10 @@ static void emit_linking_section(EmitWasm *ew) {
   if (tags->len > 0) {  // Tag
     for (int i = 0, len = tags->len; i < len; ++i) {
       TagInfo *ti = tags->data[i];
-      int flags = 0;
+      int flags = WASM_SYM_BINDING_WEAK;
       data_push(&linking_section, SIK_SYMTAB_EVENT);  // kind
       data_uleb128(&linking_section, -1, flags);
-      data_uleb128(&linking_section, -1, i);
+      data_uleb128(&linking_section, -1, ti->typeindex);
       data_string(&linking_section, ti->name->chars, ti->name->bytes);
       ++count;
     }
@@ -790,7 +790,7 @@ static void emit_reloc_section(EmitWasm *ew, int section_index, Vector *relocs,
       case R_WASM_MEMORY_ADDR_I64:
       case R_WASM_FUNCTION_OFFSET_I32:
       case R_WASM_SECTION_OFFSET_I32:
-        data_uleb128(&ds, -1, reloc->addend);
+        data_leb128(&ds, -1, reloc->addend);
         break;
       default: break;
       }

src/wcc/gen_wasm.c

@@ -482,7 +482,7 @@ static void gen_ref_sub(Expr *expr) {
             RelocInfo *ri = calloc_or_die(sizeof(*ri));
             ri->type = R_WASM_TABLE_INDEX_SLEB;
             ri->offset = code->len;
-            ri->index = info->index;
+            ri->index = info->index;  // Assume that symtab index is same as function index.
             vec_push(extra->reloc_code, ri);
 
             ADD_VARUINT32(info->indirect_index);

src/wcc/traverse.c

@@ -579,9 +579,9 @@ static void traverse_vardecl(Stmt *stmt) {
           register_func_info(decl->ident, NULL, varinfo, 0);
         } else if (varinfo->storage & VS_EXTERN) {
           assert(!is_global_scope(curscope));
-          if (out_type < OutExecutable) {
+          if (out_type < OutExecutable && scope_find(global_scope, decl->ident, NULL) == NULL) {
             // Register into global to output linking information.
-            GVarInfo *info = register_gvar_info(decl->ident, varinfo);  // TODO: Confirm.
+            GVarInfo *info = register_gvar_info(decl->ident, varinfo);
             info->flag |= GVF_UNRESOLVED;
           }
         }