initial implementation of GOT entries and initial support of PE visibility

for the midipix targets.

signed-off by Z. Gilboa; see copying.midipix (9cd0746c) for additional information.

3 files changed, 160 insertions, 49 deletions

diff --git a/gcc/config/i386/midipix.c b/gcc/config/i386/midipix.c
index bb05cc105..f9b6d4190 100644
--- a/gcc/config/i386/midipix.c
+++ b/gcc/config/i386/midipix.c
@@ -31,12 +31,17 @@
 #include "target.h"
 #include "i386-protos.h"
 #include "function.h"
+#include "cgraph.h"
 
 /* common specs */
 const int TARGET_NOP_FUN_DLLIMPORT	= 0;
 const int use_pe_aligned_common		= 1;
 const int flag_writable_rel_rdata	= 0;
 
+/* pointer annotation */
+static const char winnt_ptrsize_long[] 	= ".long";
+static const char winnt_ptrsize_quad[] 	= ".quad";
+
 /* target SEH providers */
 #define TARGET_SEH_WINNT			(TARGET_SEH && TARGET_NT64)
 #define TARGET_SEH_MIDIPIX			(TARGET_SEH && TARGET_NT32)
@@ -124,6 +129,83 @@ void midipix_asm_generate_internal_label (
 }
 
 
+static void midipix_pe_create_got_entry(FILE * stream, const char * name, tree decl)
+{
+	const char * ptrsize = TARGET_64BIT
+		? winnt_ptrsize_quad
+		: winnt_ptrsize_long;
+
+	fputs("\n",stream);
+	fputs(GAS_SECTION,stream);
+
+	switch (decl->decl_with_vis.visibility) {
+		case VISIBILITY_HIDDEN:
+			fputs(HIDDEN_SECTION_NAME,stream);
+			break;
+
+		case VISIBILITY_INTERNAL:
+			fputs(INTERNAL_SECTION_NAME,stream);
+			break;
+
+		default:
+			fputs(GOT_SECTION_NAME,stream);
+			break;
+	}
+
+	fputs("$",stream);
+	assemble_name(stream,name);
+	fputs(GOT_SECTION_ATTR,stream);
+
+	if (decl->decl_with_vis.weak_flag)
+		fputs("\n\t.global __imp_",stream);
+	else
+		fputs("\n\t.global __imp_",stream);
+
+	assemble_name(stream,name);
+	fputs("\n__imp_",stream);
+	assemble_name(stream,name);
+	fputs(":\n\t",stream);
+	fputs(ptrsize,stream);
+	fputs("\t",stream);
+	assemble_name(stream,name);
+	fputs("\n",stream);
+	fputs("\t.linkonce discard\n\n",stream);
+}
+
+
+void midipix_asm_output_got_entry(
+	FILE * 		asmout,
+	const char * 	name,
+	tree 		decl,
+	section * 	sect)
+{
+	if (!decl->base.public_flag)
+		return;
+
+	/* .got entry */
+	midipix_pe_create_got_entry(asmout,name,decl);
+
+	/* re-establish generic named section */
+	if (in_section && in_section->common.flags & (SECTION_STYLE_MASK == SECTION_NAMED))
+		targetm.asm_out.named_section(
+			in_section->named.name,
+			in_section->named.common.flags,
+			in_section->named.decl);
+
+	/* re-establish .bss section */
+	else if (sect == bss_noswitch_section)
+		fputs("\t.bss\n",asmout);
+
+	/* re-establish .data section */
+	else if (sect == data_section)
+		fputs("\t.data\n",asmout);
+
+	/* re-establish .text section (default) */
+	else
+		fputs("\t.text\n",asmout);
+}
+
+
 void midipix_asm_declare_object_name(FILE * gas_exhaled, const char * name, tree decl)
 {
 	extern void assemble_name (FILE *, const char *);
@@ -159,7 +241,7 @@ void midipix_asm_output_external(
 	tree		decl,
 	const char *	name)
 {
-	if (TREE_CODE(decl) == FUNCTION_DECL)
+	if (decl->base.code == FUNCTION_DECL)
 		i386_pe_record_external_function(
 			decl,name);
 }
@@ -181,22 +263,22 @@ void midipix_asm_output_def_from_decls(
 {
 	const char * sym;
 
-	sym = IDENTIFIER_POINTER(
-		DECL_ASSEMBLER_NAME(decl));
+	sym = (const char *)decl->decl_with_vis.assembler_name->identifier.id.str;
 
 	i386_pe_maybe_record_exported_symbol(
 		decl,sym,false);
 
-	if (TREE_CODE(decl) == FUNCTION_DECL)
+	if (decl->base.code == FUNCTION_DECL)
 		i386_pe_declare_function_type(
-			asmout,
-			sym,
-			TREE_PUBLIC(decl));
+			asmout,sym,decl->base.public_flag);
 
 	ASM_OUTPUT_DEF(
 		asmout,
 		sym,
 		IDENTIFIER_POINTER(target));
+
+	if (!decl->decl_with_vis.weak_flag)
+		midipix_asm_output_got_entry(asmout,sym,decl,0);
 }
 
 
@@ -205,14 +287,10 @@ void midipix_i386_pe_assemble_visibility (
 	tree	decl	__attribute__((unused)),
 	int	visible __attribute__((unused)))
 {
-	/* todo: add the symbol to a special section (.hidden),
-	   and teach the linker to not export symbols that are
-	   listed under that section. */
+	/* cf. midipix_pe_create_got_entry */
 }
 
 
-
-
 /* seh hook selectors */
 void midipix_seh_hook__pe_seh_init(FILE * f)
 {
@@ -334,21 +412,16 @@ section * midipix_i386_pe_function_section (
 		bool			exit);
 
 	const char *	fname;
-	char *		secname;
-	size_t		size;
-
 	bool		weak;
 	section *	asm_section;
+	char *		secname;
+	size_t		size;
 
-	weak = (decl && DECL_WEAK (decl));
-
-	if (weak && DECL_ATTRIBUTES(decl) && lookup_attribute (
-			"weak_import",
-			DECL_ATTRIBUTES(decl)))
-		weak = 0;
-
-	fname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
+	/* .got entry */
+	fname = (const char *)decl->decl_with_vis.assembler_name->identifier.id.str;
+	weak  = (decl->decl_with_vis.dllimport_flag && decl->decl_with_vis.weak_flag);
 
+	/* section entry */
 	#ifdef MIDIPIX_TARGET_DEBUG
 	fputs ("\t# <", asm_out_file);
 	assemble_name (asm_out_file, fname);
@@ -389,6 +462,18 @@ section * midipix_i386_pe_function_section (
 }
 
 
+void midipix_i386_pe_asm_output_aligned_decl_common(
+	FILE *		stream,
+	tree 		decl,
+	const char *	name,
+	HOST_WIDE_INT 	size,
+	HOST_WIDE_INT 	align)
+{
+	i386_pe_asm_output_aligned_decl_common(
+		stream,decl,name,size,align);
+}
+
+
 void midipix_i386_pe_start_function (FILE * gas_exhaled, const char *name, tree decl)
 {
 	#ifdef MIDIPIX_TARGET_DEBUG
@@ -403,16 +488,15 @@ void midipix_i386_pe_start_function (FILE * gas_exhaled, const char *name, tree
 
 void midipix_i386_pe_end_function (FILE * gas_exhaled, const char * name, tree decl)
 {
-	if ((!TARGET_SEH) || (cfun->is_thunk))
+	if (cfun->is_thunk)
 		return;
 
-	fputs ("\t.seh_endproc\n", gas_exhaled);
+	if (TARGET_SEH)
+		fputs ("\t.seh_endproc\n", gas_exhaled);
 
-	#ifdef MIDIPIX_TARGET_DEBUG
-	fputs ("\t# </", gas_exhaled);
-	assemble_name (gas_exhaled, name);
-	fputs (">\n\n\n", gas_exhaled);
-	#endif
+	/* avoid duplicate GOT entries */
+	if (decl && !decl->decl_with_vis.weak_flag)
+		midipix_asm_output_got_entry(gas_exhaled,name,decl,0);
 }
 
 
@@ -422,24 +506,11 @@ void midipix_i386_pe_asm_weaken_decl(
 	const char *	name,
 	const char *	alias __attribute__((unused)))
 {
-	if ((decl) && DECL_EXTERNAL(decl)) {
-		#ifdef MIDIPIX_TARGET_DEBUG
-		fputs ("\t# (external weak symbol label)\n", gas_exhaled);
-		#endif
-
-		fputs ("\t.weak\t", gas_exhaled);
-		assemble_name (gas_exhaled, name);
-		fputs ("\n", gas_exhaled);
-	} else {
-		#ifdef MIDIPIX_TARGET_DEBUG
-		fputs("\t# (normal weak symbol label)\n", gas_exhaled);
-		#endif
+	midipix_asm_output_got_entry(gas_exhaled,name,decl,0);
 
-		/* write a patch for ld so that we can use .globl instead */
-		fputs("\t.weak\t", gas_exhaled);
-		assemble_name (gas_exhaled, name);
-		fputs ("\n", gas_exhaled);
-	}
+	fputs ("\t.weak\t", gas_exhaled);
+	assemble_name (gas_exhaled, name);
+	fputs ("\n", gas_exhaled);
 }
 
 
@@ -451,3 +522,12 @@ void midipix_i386_pe_asm_weaken_label(FILE * gas_exhaled, const char * name)
 		name,
 		(const char *)0);
 }
+
+int midipix_symbol_ref_dllimport_p(rtx symbol)
+{
+	tree decl = SYMBOL_REF_DECL(symbol);
+
+	return decl && decl->base.public_flag &&
+		(!decl->decl_with_vis.visibility_specified
+			|| (decl->decl_with_vis.visibility == VISIBILITY_DEFAULT));
+}
diff --git a/gcc/config/i386/midipix.h b/gcc/config/i386/midipix.h
index 3502ba618..2354cf2ce 100644
--- a/gcc/config/i386/midipix.h
+++ b/gcc/config/i386/midipix.h
@@ -68,6 +68,8 @@
 						? MS_ABI       \
 						: SYSV_ABI
 
+#undef  SYMBOL_REF_DLLIMPORT_P
+#define SYMBOL_REF_DLLIMPORT_P			midipix_symbol_ref_dllimport_p
 
 #undef  MULTIPLE_SYMBOL_SPACES
 #define MULTIPLE_SYMBOL_SPACES			(1)
@@ -161,6 +163,21 @@
 #undef  RODATA_SECTION_NAME
 #define RODATA_SECTION_NAME			".rdata,\"r\""
 
+#undef  GOT_SECTION_NAME
+#define GOT_SECTION_NAME			".got"
+
+#undef  PROTECTED_SECTION_NAME
+#define PROTECTED_SECTION_NAME			GOT_SECTION_NAME
+
+#undef  HIDDEN_SECTION_NAME
+#define HIDDEN_SECTION_NAME			".hidden"
+
+#undef  INTERNAL_SECTION_NAME
+#define INTERNAL_SECTION_NAME			".intern"
+
+#undef  GOT_SECTION_ATTR
+#define GOT_SECTION_ATTR			",\"r\""
+
 #undef  GAS_PE_ASM_SET_OP
 #define GAS_PE_ASM_SET_OP			"\t.set\t"
 
@@ -205,6 +222,9 @@
 #undef  ASM_OUTPUT_DWARF_OFFSET
 #define ASM_OUTPUT_DWARF_OFFSET			midipix_asm_output_dwarf_offset
 
+#undef  ASM_OUTPUT_GOT_ENTRY
+#define ASM_OUTPUT_GOT_ENTRY			midipix_asm_output_got_entry
+
 /* assembler labels */
 #undef  USER_LABEL_PREFIX
 #define USER_LABEL_PREFIX			(TARGET_NT64 ? ""   : "_")
@@ -260,7 +280,7 @@
 #define ASM_OUTPUT_ALIGNED_BSS			asm_output_aligned_bss
 
 #undef  ASM_OUTPUT_ALIGNED_DECL_COMMON
-#define ASM_OUTPUT_ALIGNED_DECL_COMMON		i386_pe_asm_output_aligned_decl_common
+#define ASM_OUTPUT_ALIGNED_DECL_COMMON		midipix_i386_pe_asm_output_aligned_decl_common
 
 #undef  TARGET_ASM_UNIQUE_SECTION
 #define TARGET_ASM_UNIQUE_SECTION		i386_pe_unique_section
@@ -348,6 +368,7 @@ extern void midipix_asm_output_external		(FILE * asmout, tree decl, const char *
 extern void midipix_asm_output_def_from_decls	(FILE * asmout, tree decl, tree target);
 extern void midipix_asm_output_external_libcall (FILE * asmout, rtx fn);
 
+extern void midipix_asm_output_got_entry	(FILE * asmout, const char * name, tree decl, section * sect);
 extern void midipix_asm_declare_object_name	(FILE * asmout, const char * name, tree decl);
 extern void midipix_i386_pe_start_function	(FILE * asmout, const char * name, tree decl);
 extern void midipix_i386_pe_end_function	(FILE * asmout, const char * name, tree decl);
@@ -366,6 +387,14 @@ extern section * midipix_i386_pe_function_section(
 	bool			startup,
 	bool			exit);
 
+extern void midipix_i386_pe_asm_output_aligned_decl_common(
+	FILE *		stream,
+	tree 		decl,
+	const char *	name,
+	HOST_WIDE_INT 	size,
+	HOST_WIDE_INT 	align);
+
+extern int midipix_symbol_ref_dllimport_p(rtx symbol);
 
 /* inlined functions */
 static inline void midipix_extra_os_cpp_builtins(void)
@@ -379,6 +408,7 @@ static inline void midipix_extra_os_cpp_builtins(void)
 static inline void midipix_target_os_cpp_builtins(void)
 {
 	builtin_define_std("__PE__");
+	builtin_define_std("__PE_VISIBILITY__");
 	builtin_define_std("__midipix__");
 	midipix_extra_os_cpp_builtins();
 }
@@ -389,3 +419,4 @@ static inline int midipix_i386_pe_reloc_rw_mask	(void)
 }
 
 #endif
+
diff --git a/gcc/config/i386/winnt.c b/gcc/config/i386/winnt.c
index 169832fd3..0712c6956 100644
--- a/gcc/config/i386/winnt.c
+++ b/gcc/config/i386/winnt.c
@@ -357,7 +357,7 @@ i386_pe_binds_local_p (const_tree exp)
       && DECL_WEAK (exp))
     return false;
 
-  return true;
+  return default_binds_local_p_1(exp,0);
 }
 
 /* Also strip the fastcall prefix and stdcall suffix.  */