Add debug support to macos

lldb now works with this push. In tccmacho.c add S_ATTR_DEBUG to all debug sections. Add __DWARF section and rearange struct skinfo. In tccdbg.c The first filename in dwarf_line can not be used. Also had to fix structure/union/lexical_block/subroutine to allow empty childs. dwarfdump --verify complained about this.

herman ten brugge committed 3 years ago

Commit 62096261 parent ac0604a2 files · +107 −57Browse files

Unified · Split

2 files

tccdbg.c +71 −33
tccmacho.c +36 −24

tccdbg.c+71−33

 #define	DWARF_ABBREV_MEMBER			14
 #define	DWARF_ABBREV_MEMBER_BF			15
 #define	DWARF_ABBREV_STRUCTURE_TYPE		16
-#define	DWARF_ABBREV_UNION_TYPE			17
+#define	DWARF_ABBREV_STRUCTURE_EMPTY_TYPE	17
-#define	DWARF_ABBREV_SUBPROGRAM_EXTERNAL	18
+#define	DWARF_ABBREV_UNION_TYPE			18
-#define	DWARF_ABBREV_SUBPROGRAM_STATIC		19
+#define	DWARF_ABBREV_UNION_EMPTY_TYPE		19
-#define	DWARF_ABBREV_LEXICAL_BLOCK		20
+#define	DWARF_ABBREV_SUBPROGRAM_EXTERNAL	20
-#define	DWARF_ABBREV_SUBROUTINE_TYPE		21
+#define	DWARF_ABBREV_SUBPROGRAM_STATIC		21
-#define	DWARF_ABBREV_FORMAL_PARAMETER2		22
+#define	DWARF_ABBREV_LEXICAL_BLOCK		22
+#define	DWARF_ABBREV_LEXICAL_EMPTY_BLOCK	23
+#define	DWARF_ABBREV_SUBROUTINE_TYPE		24
+#define	DWARF_ABBREV_SUBROUTINE_EMPTY_TYPE	25
+#define	DWARF_ABBREV_FORMAL_PARAMETER2		26
 /* all entries should have been generated with dwarf_uleb128 except
    has_children. All values are currently below 128 so this currently
           DW_AT_decl_line, DW_FORM_udata,
           DW_AT_sibling, DW_FORM_ref4,
           0, 0,
+    DWARF_ABBREV_STRUCTURE_EMPTY_TYPE, DW_TAG_structure_type, 0,
+          DW_AT_name, DW_FORM_strp,
+          DW_AT_byte_size, DW_FORM_udata,
+          DW_AT_decl_file, DW_FORM_udata,
+          DW_AT_decl_line, DW_FORM_udata,
+          0, 0,
     DWARF_ABBREV_UNION_TYPE, DW_TAG_union_type, 1,
           DW_AT_name, DW_FORM_strp,
           DW_AT_byte_size, DW_FORM_udata,
           DW_AT_decl_line, DW_FORM_udata,
           DW_AT_sibling, DW_FORM_ref4,
           0, 0,
+    DWARF_ABBREV_UNION_EMPTY_TYPE, DW_TAG_union_type, 0,
+          DW_AT_name, DW_FORM_strp,
+          DW_AT_byte_size, DW_FORM_udata,
+          DW_AT_decl_file, DW_FORM_udata,
+          DW_AT_decl_line, DW_FORM_udata,
+          0, 0,
     DWARF_ABBREV_SUBPROGRAM_EXTERNAL, DW_TAG_subprogram, 1,
           DW_AT_external, DW_FORM_flag,
           DW_AT_name, DW_FORM_strp,
           DW_AT_high_pc, DW_FORM_data4,
 #else
           DW_AT_high_pc, DW_FORM_data8,
+#endif
+          0, 0,
+    DWARF_ABBREV_LEXICAL_EMPTY_BLOCK, DW_TAG_lexical_block, 0,
+          DW_AT_low_pc, DW_FORM_addr,
+#if PTR_SIZE == 4
+          DW_AT_high_pc, DW_FORM_data4,
+#else
+          DW_AT_high_pc, DW_FORM_data8,
 #endif
           0, 0,
     DWARF_ABBREV_SUBROUTINE_TYPE, DW_TAG_subroutine_type, 1,
           DW_AT_type, DW_FORM_ref4,
           DW_AT_sibling, DW_FORM_ref4,
           0, 0,
+    DWARF_ABBREV_SUBROUTINE_EMPTY_TYPE, DW_TAG_subroutine_type, 0,
+          DW_AT_type, DW_FORM_ref4,
+          0, 0,
     DWARF_ABBREV_FORMAL_PARAMETER2, DW_TAG_formal_parameter, 0,
           DW_AT_type, DW_FORM_ref4,
           0, 0,
     filename = strrchr(file->filename, '/');
     if (filename == NULL) {
-        for (i = 0; i < dwarf_line.filename_size; i++)
+        for (i = 1; i < dwarf_line.filename_size; i++)
             if (dwarf_line.filename_table[i].dir_entry == 0 &&
 		strcmp(dwarf_line.filename_table[i].name,
 		file->filename) == 0) {
     	        tcc_malloc(2*sizeof (struct dwarf_filename_struct));
             dwarf_line.filename_table[0].dir_entry = 0;
 	    if (undo) {
-                dwarf_line.filename_table[0].name = tcc_strdup(filename);
+                dwarf_line.filename_table[0].name = tcc_strdup(undo + 1);
                 dwarf_line.filename_table[1].dir_entry = 1;
                 dwarf_line.filename_table[1].name = tcc_strdup(undo + 1);
-		*undo = '/';
-                dwarf_line.filename_table[0].name = tcc_strdup(filename);
 	    }
 	    else {
                 dwarf_line.filename_table[0].name = tcc_strdup(filename);
 	    int pos = dwarf_info_section->data_offset;
 	    dwarf_data1(dwarf_info_section,
-                        IS_UNION (t->type.t) ? DWARF_ABBREV_UNION_TYPE
+                        IS_UNION (t->type.t) ? DWARF_ABBREV_UNION_EMPTY_TYPE
-                                             : DWARF_ABBREV_STRUCTURE_TYPE);
+                                             : DWARF_ABBREV_STRUCTURE_EMPTY_TYPE);
             dwarf_strp(dwarf_info_section,
                        (t->v & ~SYM_STRUCT) >= SYM_FIRST_ANOM
                        ? "" : get_tok_str(t->v & ~SYM_STRUCT, NULL));
             dwarf_uleb128(dwarf_info_section, 0);
             dwarf_uleb128(dwarf_info_section, dwarf_line.cur_file);
             dwarf_uleb128(dwarf_info_section, file->line_num);
-	    j = dwarf_info_section->data_offset + 5 - dwarf_info.start;
-	    dwarf_data4(dwarf_info_section, j);
-	    dwarf_data1(dwarf_info_section, 0);
 	    for (j = 0; j < debug_anon_hash[i].n_debug_type; j++)
 		write32le(dwarf_info_section->data +
 			  debug_anon_hash[i].debug_type[j],
 	    *undo = '/';
 	}
         if (strcmp(filename, "<command line>")) {
-	    for (j = 0; j < dwarf_line.filename_size; j++)
+	    for (j = 1; j < dwarf_line.filename_size; j++)
 	        if (dwarf_line.filename_table[j].dir_entry == i &&
 		    strcmp (dwarf_line.filename_table[j].name, filename) == 0)
 		    break;
         t = t->type.ref;
 	debug_type = tcc_debug_find(s1, t, 1);
 	if (debug_type == -1) {
-	    int pos_sib, i, *pos_type;
+	    int pos_sib = 0, i, *pos_type;
 	    debug_type = tcc_debug_add(s1, t, 1);
 	    e = t;
 	    }
 	    pos_type = (int *) tcc_malloc(i * sizeof(int));
 	    dwarf_data1(dwarf_info_section,
-			IS_UNION (t->type.t) ? DWARF_ABBREV_UNION_TYPE
+			IS_UNION (t->type.t)
-					     : DWARF_ABBREV_STRUCTURE_TYPE);
+		        ? t->next ? DWARF_ABBREV_UNION_TYPE
+				  : DWARF_ABBREV_UNION_EMPTY_TYPE
+		        : t->next ? DWARF_ABBREV_STRUCTURE_TYPE
+				  : DWARF_ABBREV_STRUCTURE_EMPTY_TYPE);
 	    dwarf_strp(dwarf_info_section,
                        (t->v & ~SYM_STRUCT) >= SYM_FIRST_ANOM
                        ? "" : get_tok_str(t->v & ~SYM_STRUCT, NULL));
 	    dwarf_uleb128(dwarf_info_section, t->c);
 	    dwarf_uleb128(dwarf_info_section, dwarf_line.cur_file);
 	    dwarf_uleb128(dwarf_info_section, file->line_num);
-	    pos_sib = dwarf_info_section->data_offset;
+	    if (t->next) {
-	    dwarf_data4(dwarf_info_section, 0);
+	        pos_sib = dwarf_info_section->data_offset;
+	        dwarf_data4(dwarf_info_section, 0);
+	    }
 	    e = t;
 	    i = 0;
             while (e->next) {
 		else
 		    dwarf_uleb128(dwarf_info_section, e->c);
 	    }
-	    dwarf_data1(dwarf_info_section, 0);
+	    if (t->next) {
-	    write32le(dwarf_info_section->data + pos_sib,
+	        dwarf_data1(dwarf_info_section, 0);
-		      dwarf_info_section->data_offset - dwarf_info.start);
+	        write32le(dwarf_info_section->data + pos_sib,
+		          dwarf_info_section->data_offset - dwarf_info.start);
+	    }
 	    e = t;
 	    i = 0;
 	    while (e->next) {
 		      dwarf_info_section->data_offset - dwarf_info.start);
 	}
         else if (type == VT_FUNC) {
-	    int sib_pos, *pos_type;
+	    int sib_pos = 0, *pos_type;
 	    Sym *f;
 	    i = dwarf_info_section->data_offset;
 	    debug_type = tcc_get_dwarf_info(s1, t->type.ref);
 	    if (retval == debug_type)
 		retval = i;
-	    dwarf_data1(dwarf_info_section, DWARF_ABBREV_SUBROUTINE_TYPE);
+	    dwarf_data1(dwarf_info_section,
+			t->type.ref->next ? DWARF_ABBREV_SUBROUTINE_TYPE
+					  : DWARF_ABBREV_SUBROUTINE_EMPTY_TYPE);
 	    if (last_pos != -1) {
 		tcc_debug_check_anon(s1, e, last_pos);
 		write32le(dwarf_info_section->data + last_pos,
 	    last_pos = dwarf_info_section->data_offset;
 	    e = t->type.ref;
 	    dwarf_data4(dwarf_info_section, 0);
-	    sib_pos = dwarf_info_section->data_offset;
+	    if (t->type.ref->next) {
-	    dwarf_data4(dwarf_info_section, 0);
+	        sib_pos = dwarf_info_section->data_offset;
+	        dwarf_data4(dwarf_info_section, 0);
+	    }
 	    f = t->type.ref;
 	    i = 0;
 	    while (f->next) {
 		pos_type[i++] = dwarf_info_section->data_offset;
 	        dwarf_data4(dwarf_info_section, 0);
 	    }
-	    dwarf_data1(dwarf_info_section, 0);
+	    if (t->type.ref->next) {
-	    write32le(dwarf_info_section->data + sib_pos,
+	        dwarf_data1(dwarf_info_section, 0);
-		      dwarf_info_section->data_offset - dwarf_info.start);
+	        write32le(dwarf_info_section->data + sib_pos,
+		          dwarf_info_section->data_offset - dwarf_info.start);
+	    }
 	    f = t->type.ref;
 	    i = 0;
 	    while (f->next) {
 		tcc_free (s->str);
             }
             tcc_free (cur->sym);
-            dwarf_data1(dwarf_info_section, DWARF_ABBREV_LEXICAL_BLOCK);
+            dwarf_data1(dwarf_info_section,
+			cur->child ? DWARF_ABBREV_LEXICAL_BLOCK
+			           : DWARF_ABBREV_LEXICAL_EMPTY_BLOCK);
             dwarf_reloc(dwarf_info_section, section_sym, R_DATA_PTR);
 #if PTR_SIZE == 4
             dwarf_data4(dwarf_info_section, func_ind + cur->start);
             dwarf_data8(dwarf_info_section, cur->end - cur->start);
 #endif
             tcc_debug_finish (s1, cur->child);
-            dwarf_data1(dwarf_info_section, 0);
+	    if (cur->child)
+                dwarf_data1(dwarf_info_section, 0);
         }
         else
         {

tccmacho.c+36−24

 #define S_ATTR_PURE_INSTRUCTIONS        0x80000000
 #define S_ATTR_SOME_INSTRUCTIONS        0x00000400
+#define S_ATTR_DEBUG             	0x02000000
 typedef uint32_t lc_str;
     sk_ro_data,
     sk_uw_info,
     sk_nl_ptr,  // non-lazy pointers, aka GOT
-    sk_la_ptr,  // lazy pointers
-    sk_init,
-    sk_fini,
-    sk_rw_data,
-    sk_stab,
-    sk_stab_str,
     sk_debug_info,
     sk_debug_abbrev,
     sk_debug_line,
     sk_debug_aranges,
     sk_debug_str,
     sk_debug_line_str,
+    sk_stab,
+    sk_stab_str,
+    sk_la_ptr,  // lazy pointers
+    sk_init,
+    sk_fini,
+    sk_rw_data,
     sk_bss,
     sk_linkedit,
     sk_last
 struct macho {
     struct mach_header_64 mh;
-    int seg2lc[5], nseg;
+    int seg2lc[6], nseg;
     struct load_command **lc;
     struct entry_point_command *ep;
     int nlc;
     /*[sk_ro_data] =*/        { 2, S_REGULAR, "__rodata" },
     /*[sk_uw_info] =*/        { 0 },
     /*[sk_nl_ptr] =*/         { 2, S_NON_LAZY_SYMBOL_POINTERS, "__got" },
-    /*[sk_la_ptr] =*/         { 3, S_LAZY_SYMBOL_POINTERS, "__la_symbol_ptr" },
+    /*[sk_debug_info] =*/     { 3, S_REGULAR | S_ATTR_DEBUG, "__debug_info" },
-    /*[sk_init] =*/           { 3, S_MOD_INIT_FUNC_POINTERS, "__mod_init_func" },
+    /*[sk_debug_abbrev] =*/   { 3, S_REGULAR | S_ATTR_DEBUG, "__debug_abbrev" },
-    /*[sk_fini] =*/           { 3, S_MOD_TERM_FUNC_POINTERS, "__mod_term_func" },
+    /*[sk_debug_line] =*/     { 3, S_REGULAR | S_ATTR_DEBUG, "__debug_line" },
-    /*[sk_rw_data] =*/        { 3, S_REGULAR, "__data" },
+    /*[sk_debug_aranges] =*/  { 3, S_REGULAR | S_ATTR_DEBUG, "__debug_aranges" },
-    /*[sk_stab] =*/           { 3, S_REGULAR, "__stab" },
+    /*[sk_debug_str] =*/      { 3, S_REGULAR | S_ATTR_DEBUG, "__debug_str" },
-    /*[sk_stab_str] =*/       { 3, S_REGULAR, "__stab_str" },
+    /*[sk_debug_line_str] =*/ { 3, S_REGULAR | S_ATTR_DEBUG, "__debug_line_str" },
-    /*[sk_debug_info] =*/     { 3, S_REGULAR, "__debug_info" },
+    /*[sk_stab] =*/           { 4, S_REGULAR, "__stab" },
-    /*[sk_debug_abbrev] =*/   { 3, S_REGULAR, "__debug_abbrev" },
+    /*[sk_stab_str] =*/       { 4, S_REGULAR, "__stab_str" },
-    /*[sk_debug_line] =*/     { 3, S_REGULAR, "__debug_line" },
+    /*[sk_la_ptr] =*/         { 4, S_LAZY_SYMBOL_POINTERS, "__la_symbol_ptr" },
-    /*[sk_debug_aranges] =*/  { 3, S_REGULAR, "__debug_aranges" },
+    /*[sk_init] =*/           { 4, S_MOD_INIT_FUNC_POINTERS, "__mod_init_func" },
-    /*[sk_debug_str] =*/      { 3, S_REGULAR, "__debug_str" },
+    /*[sk_fini] =*/           { 4, S_MOD_TERM_FUNC_POINTERS, "__mod_term_func" },
-    /*[sk_debug_line_str] =*/ { 3, S_REGULAR, "__debug_line_str" },
+    /*[sk_rw_data] =*/        { 4, S_REGULAR, "__data" },
-    /*[sk_bss] =*/            { 3, S_ZEROFILL, "__bss" },
+    /*[sk_bss] =*/            { 4, S_ZEROFILL, "__bss" },
-    /*[sk_linkedit] =*/       { 4, S_REGULAR, NULL },
+    /*[sk_linkedit] =*/       { 5, S_REGULAR, NULL },
 };
 #ifdef CONFIG_NEW_MACHO
 	*ptr++ = BIND_OPCODE_SET_DYLIB_SPECIAL_IMM |
 		 (BIND_SPECIAL_DYLIB_FLAT_LOOKUP & 0xf);
 	*ptr++ = BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM | 0;
-	strcpy(ptr, name);
+	strcpy((char *)ptr, name);
 	ptr += strlen(name) + 1;
 	*ptr++ = BIND_OPCODE_DO_BIND;
 	*ptr = BIND_OPCODE_DONE;
         *ptr++ = BIND_OPCODE_SET_DYLIB_SPECIAL_IMM |
 	         (BIND_SPECIAL_DYLIB_FLAT_LOOKUP & 0xf);
         *ptr++ = BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM | 0;
-        strcpy(ptr, name);
+        strcpy((char *)ptr, name);
         ptr += strlen(name) + 1;
         *ptr++ = BIND_OPCODE_SET_TYPE_IMM | BIND_TYPE_POINTER;
 	set_segment_and_offset(mo, s->sh_addr, ptr,
     seg->initprot = 3; // rw-
     seg->flags = SG_READ_ONLY;
+    seg = add_segment(mo, "__DWARF");
+    seg->vmaddr = -1;
+    seg->maxprot = 7;  // rwx
+    seg->initprot = 3; // rw-
     seg = add_segment(mo, "__DATA");
     seg->vmaddr = -1;
     seg->maxprot = 3;  // rw-
     seg->maxprot = 1;  // r--
     seg->initprot = 1; // r--
+    /* trick to avoid __DWARF vmaddr = -1 */
+    if (dwarf_info_section == NULL)
+	dwarf_info_section = new_section(s1, ".debug_info", SHT_PROGBITS, 0);
 #ifdef CONFIG_NEW_MACHO
     chained_fixups_lc = add_lc(mo, LC_DYLD_CHAINED_FIXUPS,
 			       sizeof(struct linkedit_data_command));
         type = s->sh_type;
         flags = s->sh_flags;
         sk = sk_unknown;
-        if (flags & SHF_ALLOC) {
+	/* debug sections have sometimes no SHF_ALLOC */
+        if ((flags & SHF_ALLOC) || !strncmp(s->name, ".debug_", 7)) {
             switch (type) {
             default:           sk = sk_unknown; break;
             case SHT_INIT_ARRAY: sk = sk_init; break;

Add debug support to macos

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