store offset instead of address of module string, for position independent code on 64 bit linux

2 files changed, 125 insertions, 1 deletions

diff --git a/cgaas.c b/cgaas.c
index adca535..1dfbdb5 100644
--- a/cgaas.c
+++ b/cgaas.c
@@ -681,6 +681,33 @@ static void store_relative_label_plus_offset_offset_in_code_section (struct labe
 }
 #endif
 
+#if defined (MACH_O64) || defined (LINUX)
+static void store_relative_label_plus_offset_in_data_section (struct label *label,int offset)
+{
+	struct relocation *new_relocation;
+
+# ifdef ELF_RELA
+	store_long_word_in_data_section (0);
+# else
+	store_long_word_in_data_section (offset);
+# endif
+
+	new_relocation=fast_memory_allocate_type (struct relocation);
+	++n_data_relocations;
+	
+	*last_data_relocation_l=new_relocation;
+	last_data_relocation_l=&new_relocation->next;
+	new_relocation->next=NULL;
+	
+	new_relocation->relocation_label=label;
+	new_relocation->relocation_offset=CURRENT_DATA_OFFSET-4;
+	new_relocation->relocation_kind=PC_RELATIVE_LONG_WORD_RELOCATION;
+# ifdef ELF_RELA
+	new_relocation->relocation_addend=offset;
+# endif
+}
+#endif
+
 static void store_label_plus_offset_in_data_section (LABEL *label,int offset)
 {
 	struct relocation *new_relocation;
@@ -2268,6 +2295,13 @@ void store_label_in_data_section (LABEL *label)
 	store_label_plus_offset_in_data_section (label,0);
 }
 
+#if defined (MACH_O64) || defined (LINUX)
+void store_label_offset_in_data_section (LABEL *label)
+{
+	store_relative_label_plus_offset_in_data_section (label,0);
+}
+#endif
+
 void store_descriptor_in_data_section (LABEL *label)
 {
 	store_label_plus_offset_in_data_section (label,2);
@@ -6598,6 +6632,23 @@ static void relocate_data (void)
 				relocation->relocation_addend += v;
 			}
 		}
+#ifdef LINUX
+		else if (relocation->relocation_kind==PC_RELATIVE_LONG_WORD_RELOCATION){
+			if (label->label_id==TEXT_LABEL_ID || (label->label_id==DATA_LABEL_ID
+# if defined (RELOCATIONS_RELATIVE_TO_EXPORTED_DATA_LABEL) && defined (FUNCTION_LEVEL_LINKING)
+				&& !((label->label_flags & EXPORT_LABEL) && label->label_object_label->object_label_kind==EXPORTED_DATA_LABEL)
+# endif
+				))
+			{
+				v = label->label_offset;
+				v -= 4;
+# ifdef FUNCTION_LEVEL_LINKING
+				v -= label->label_object_label->object_label_offset;
+# endif
+				relocation->relocation_addend += v;
+			}
+		}
+#endif
 	}
 #else
 	struct relocation *relocation;
@@ -7240,6 +7291,43 @@ static void write_data_relocations (void)
 #endif
 				break;				
 			}
+#ifdef LINUX
+			case PC_RELATIVE_LONG_WORD_RELOCATION:
+			{
+				struct label *label;
+		
+				label=relocation->relocation_label;
+# ifdef FUNCTION_LEVEL_LINKING
+				if (label->label_id==-1)
+# else
+				if (label->label_id<0)
+# endif
+					internal_error_in_function ("write_data_relocations");
+
+# ifdef ELF
+				write_q (relocation->relocation_offset);
+				write_l (R_X86_64_PC32);
+#  ifdef FUNCTION_LEVEL_LINKING
+				write_l (elf_label_number (label));
+#  else
+				write_l (label->label_id);
+#  endif
+#  ifdef ELF_RELA
+				write_q (relocation->relocation_addend);
+#  endif
+# else
+				write_l (relocation->relocation_offset);
+#  ifdef FUNCTION_LEVEL_LINKING
+				if (label->label_id==TEXT_LABEL_ID || label->label_id==DATA_LABEL_ID)
+					write_l (label->label_object_label->object_label_number);
+				else
+#  endif
+				write_l (label->label_id);
+				write_w (R_REL32);
+# endif
+				break;				
+			}
+#endif
 			default:
 				internal_error_in_function ("write_data_relocations");
 		}
diff --git a/cgcode.c b/cgcode.c
index 64fed62..857aa3f 100644
--- a/cgcode.c
+++ b/cgcode.c
@@ -8920,7 +8920,16 @@ static void code_new_descriptor (int arity,int lazy_record_flag)
 
 	if (module_info_flag && module_label){
 # ifdef GEN_OBJ
+#  ifdef MACH_O64
+		store_label_offset_in_data_section (module_label);
+#  else
+#   ifdef LINUX
+		if (pic_flag)
+			store_label_offset_in_data_section (module_label);
+		else
+#   endif
 		store_label_in_data_section (module_label);
+#  endif
 # endif
 		if (assembly_flag)
 # ifdef MACH_O64
@@ -9236,7 +9245,16 @@ void code_record (char record_label_name[],char type[],int a_size,int b_size,cha
 	/* not for 68k to maintain long word alignment */
 	if (module_info_flag && module_label){
 # ifdef GEN_OBJ
+#  ifdef MACH_O64
+		store_label_offset_in_data_section (module_label);
+#  else
+#   ifdef LINUX
+		if (pic_flag)
+			store_label_offset_in_data_section (module_label);
+		else
+#   endif
 		store_label_in_data_section (module_label);
+#  endif
 # endif
 		if (assembly_flag)
 # ifdef MACH_O64
@@ -9464,7 +9482,16 @@ void code_pb (char string[],int string_length)
 #if TIME_PROFILE_WITH_MODULE_NAMES
 	if (module_label!=NULL){
 # ifdef GEN_OBJ
+#  ifdef MACH_O64
+		store_label_offset_in_data_section (module_label);
+#  else
+#   ifdef LINUX
+		if (pic_flag)
+			store_label_offset_in_data_section (module_label);
+		else
+#   endif
 		store_label_in_data_section (module_label);
+#  endif
 # endif
 	}
 #endif
@@ -9531,7 +9558,16 @@ void write_profile_table (void)
 #if TIME_PROFILE_WITH_MODULE_NAMES
 		if (module_label!=NULL){
 # ifdef GEN_OBJ
+#  ifdef MACH_O64
+			store_label_offset_in_data_section (module_label);
+#  else
+#   ifdef LINUX
+			if (pic_flag)
+				store_label_offset_in_data_section (module_label);
+			else
+#   endif
 			store_label_in_data_section (module_label);
+#  endif
 # endif
 		}
 #endif
@@ -9896,7 +9932,7 @@ void show_imports_and_exports (VOID)
 
 void initialize_coding (VOID)
 {
-	register int n;
+	int n;
 	
 	last_INT_descriptor_block=NULL;
 	last_BOOL_descriptor_block=NULL;