ir_visibility cleanup

This commit removes the strange differentiation between
ir_visibility_external and ir_visibility_default. We now only have
ir_visibility_external for all symbols visible across compilation units.
You may or may not attach graphs/initializers to them.

diff --git a/include/libfirm/typerep.h b/include/libfirm/typerep.h
index 55e4f8a..45db4bf 100644 (file)
--- a/include/libfirm/typerep.h
+++ b/include/libfirm/typerep.h
@@ -91,10 +91,12 @@
  */
 typedef enum {
        /**
-        * The entity is visible outside the compilation unit, but it is defined
-        * here.
+        * The entity is visible across compilation units. It might have an
+        * initializer/graph.
+        * Note that variables with visibility_external but not initializer are
+        * not "uninitialized" but considered to be in another compilation unit.
         */
-       ir_visibility_default,
+       ir_visibility_external,
        /**
         * The entity is local to the compilation unit.
         * A local entity is not visible in other compilation units.
@@ -103,18 +105,13 @@ typedef enum {
         */
        ir_visibility_local,
        /**
-        * The entity is defined outside the compilation unit but potentially used
-        * here.
-        */
-       ir_visibility_external,
-       /**
-        * This has the same semantic as visibility_local. Additionally the symbol is
-        * completely hidden from the linker (it only appears in the assembly).
+        * This has the same semantic as visibility_local. Additionally the symbol
+        * is completely hidden from the linker (it only appears in the assembly).
         * While visibility_local is probably still visible to debuggers,
         * visibility_private symbols aren't and probably won't appear in the object
         * files
         */
-       ir_visibility_private
+       ir_visibility_private,
 } ir_visibility;
 
 /**

diff --git a/ir/be/bedwarf.c b/ir/be/bedwarf.c
index c9f4e46..fe892e7 100644 (file)
--- a/ir/be/bedwarf.c
+++ b/ir/be/bedwarf.c
@@ -356,8 +356,7 @@ void be_dwarf_callframe_spilloffset(const arch_register_t *reg, int offset)
 static bool is_extern_entity(const ir_entity *entity)
 {
        ir_visited_t visibility = get_entity_visibility(entity);
-       return visibility == ir_visibility_default
-           || visibility == ir_visibility_external;
+       return visibility == ir_visibility_external;
 }
 
 static void emit_entity_label(const ir_entity *entity)

diff --git a/ir/be/begnuas.c b/ir/be/begnuas.c
index 02d3012..0904d64 100644 (file)
--- a/ir/be/begnuas.c
+++ b/ir/be/begnuas.c
@@ -421,15 +421,8 @@ static int entity_is_string_const(const ir_entity *ent)
 
 static bool entity_is_null(const ir_entity *entity)
 {
-       if (entity->initializer != NULL) {
-               return initializer_is_null(entity->initializer);
-       } else if (entity_has_compound_ent_values(entity)) {
-               /* I'm too lazy to implement this case as compound graph paths will be
-                * remove anyway in the future */
-               return false;
-       }
-       /* uninitialized, NULL is fine */
-       return true;
+       ir_initializer_t *initializer = get_entity_initializer(entity);
+       return initializer == NULL || initializer_is_null(initializer);
 }
 
 static bool is_comdat(const ir_entity *entity)
@@ -450,7 +443,7 @@ static be_gas_section_t determine_basic_section(const ir_entity *entity)
        if (linkage & IR_LINKAGE_CONSTANT) {
                /* mach-o is the only one with a cstring section */
                if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O
-                               && entity_is_string_const(entity))
+                   && entity_is_string_const(entity))
                        return GAS_SECTION_CSTRING;
 
                return GAS_SECTION_RODATA;
@@ -514,7 +507,8 @@ static void emit_visibility(const ir_entity *entity)
        if (get_entity_linkage(entity) & IR_LINKAGE_WEAK) {
                emit_weak(entity);
                /* Note: .weak seems to imply .globl so no need to output .globl */
-       } else if (get_entity_visibility(entity) == ir_visibility_default) {
+       } else if (get_entity_visibility(entity) == ir_visibility_external
+                  && entity_has_definition(entity)) {
                be_emit_cstring("\t.globl ");
                be_gas_emit_entity(entity);
                be_emit_char('\n');
@@ -1612,24 +1606,19 @@ static void emit_global(be_gas_decl_env_t *env, const ir_entity *entity)
                case ir_visibility_private:
                        emit_local_common(entity);
                        return;
-               case ir_visibility_default:
+               case ir_visibility_external:
                        if (linkage & IR_LINKAGE_MERGE) {
                                emit_common(entity);
                                return;
                        }
                        break;
-               case ir_visibility_external:
-                       if (linkage & IR_LINKAGE_MERGE)
-                               panic("merge link semantic not supported for extern entities");
-                       break;
                }
        }
 
        emit_visibility(entity);
-       if (visibility == ir_visibility_external) {
-               /* nothing to do for externally defined values */
+       /* nothing left to do without an initializer */
+       if (!entity_has_definition(entity))
                return;
-       }
 
        if (!is_po2(alignment))
                panic("alignment not a power of 2");
@@ -1665,6 +1654,7 @@ static void emit_global(be_gas_decl_env_t *env, const ir_entity *entity)
        }
 
        if (entity_is_null(entity)) {
+               /* we should use .space for stuff in the bss segment */
                unsigned size = get_type_size_bytes(type);
                if (size > 0) {
                        be_emit_irprintf("\t.space %u, 0\n", get_type_size_bytes(type));

diff --git a/ir/be/ia32/ia32_emitter.c b/ir/be/ia32/ia32_emitter.c
index d5c4e87..9449772 100644 (file)
--- a/ir/be/ia32/ia32_emitter.c
+++ b/ir/be/ia32/ia32_emitter.c
@@ -223,7 +223,7 @@ static void ia32_emit_entity(ir_entity *entity, int no_pic_adjust)
        be_gas_emit_entity(entity);
 
        if (get_entity_owner(entity) == get_tls_type()) {
-               if (get_entity_visibility(entity) == ir_visibility_external) {
+               if (!entity_has_definition(entity)) {
                        be_emit_cstring("@INDNTPOFF");
                } else {
                        be_emit_cstring("@NTPOFF");

diff --git a/ir/ir/irio.c b/ir/ir/irio.c
index 0f88eee..ea90cad 100644 (file)
--- a/ir/ir/irio.c
+++ b/ir/ir/irio.c
@@ -226,7 +226,6 @@ static void symtbl_init(void)
 
        INSERT(tt_visibility, "local", ir_visibility_local);
        INSERT(tt_visibility, "external", ir_visibility_external);
-       INSERT(tt_visibility, "default", ir_visibility_default);
        INSERT(tt_visibility, "private", ir_visibility_private);
 
        INSERT(tt_throws, "throw",   true);
@@ -324,7 +323,6 @@ static const char *get_visibility_name(ir_visibility visibility)
        switch (visibility) {
        case ir_visibility_local:    return "local";
        case ir_visibility_external: return "external";
-       case ir_visibility_default:  return "default";
        case ir_visibility_private:  return "private";
        }
        panic("INVALID_VISIBILITY");
@@ -1901,7 +1899,7 @@ static void read_entity(read_env_t *env, ir_entity_kind kind)
        long           entnr      = read_long(env);
        ident         *name       = NULL;
        ident         *ld_name    = NULL;
-       ir_visibility  visibility = ir_visibility_default;
+       ir_visibility  visibility = ir_visibility_external;
        ir_linkage     linkage    = IR_LINKAGE_DEFAULT;
        ir_type       *owner      = NULL;
        ir_entity     *entity     = NULL;

diff --git a/ir/opt/garbage_collect.c b/ir/opt/garbage_collect.c
index 963c4fc..7fc81ec 100644 (file)
--- a/ir/opt/garbage_collect.c
+++ b/ir/opt/garbage_collect.c
@@ -122,7 +122,7 @@ static void visit_segment(ir_type *segment)
 
        for (i = 0; i < n_entities; ++i) {
                ir_entity *entity = get_compound_member(segment, i);
-               if (get_entity_visibility(entity) != ir_visibility_default
+               if (get_entity_visibility(entity) != ir_visibility_external
                                && !(get_entity_linkage(entity) & IR_LINKAGE_HIDDEN_USER))
                        continue;
 

diff --git a/ir/tr/entity.c b/ir/tr/entity.c
index 4382d26..e8e0de7 100644 (file)
--- a/ir/tr/entity.c
+++ b/ir/tr/entity.c
@@ -72,7 +72,7 @@ static ir_entity *intern_new_entity(ir_type *owner, ir_entity_kind kind,
        res->aligned              = align_is_aligned;
        res->usage                = ir_usage_unknown;
        res->compiler_gen         = 0;
-       res->visibility           = ir_visibility_default;
+       res->visibility           = ir_visibility_external;
        res->offset               = -1;
        res->offset_bit_remainder = 0;
        res->alignment            = 0;