Using helper callbacks to write assembly instructions

include/Asm/arch.h

@@ -176,13 +176,14 @@ typedef struct _ArchPluginHelper
 {
 	Arch * arch;
 
-	/* variables */
-	char const * filename;
-	FILE * fp;
-
 	/* callbacks */
+	/* accessors */
+	char const * (*get_filename)(Arch * arch);
 	ArchRegister * (*get_register_by_name_size)(Arch * arch,
 			char const * name, uint32_t size);
+
+	/* assembly */
+	ssize_t (*write)(Arch * arch, void const * buf, size_t size);
 } ArchPluginHelper;
 
 typedef struct _ArchPlugin ArchPlugin;

src/arch.c

@@ -19,7 +19,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-#include <assert.h>
+#include <errno.h>
 #include "Asm/arch.h"
 #include "Asm/asm.h"
 #include "arch.h"
@@ -41,6 +41,10 @@ struct _Arch
 	ArchPlugin * plugin;
 	size_t instructions_cnt;
 	size_t registers_cnt;
+
+	/* internal */
+	char const * filename;
+	FILE * fp;
 };
 
 
@@ -50,6 +54,12 @@ struct _Arch
 		((ai->op3 & AOM_TYPE) ? 1 : 0))
 
 
+/* prototypes */
+/* callbacks */
+static char const * _arch_get_filename(Arch * arch);
+static ssize_t _arch_write(Arch * arch, void const * buf, size_t size);
+
+
 /* public */
 /* functions */
 /* arch_new */
@@ -413,6 +423,8 @@ ArchRegister * arch_get_register_by_name_size(Arch * arch, char const * name,
 /* arch_exit */
 int arch_exit(Arch * arch)
 {
+	arch->filename = NULL;
+	arch->fp = NULL;
 	memset(&arch->helper, 0, sizeof(arch->helper));
 	return 0;
 }
@@ -425,10 +437,12 @@ int arch_init(Arch * arch, char const * filename, FILE * fp)
 	fprintf(stderr, "DEBUG: %s(\"%s\", %p)\n", __func__, filename,
 			(void *)fp);
 #endif
+	arch->filename = filename;
+	arch->fp = fp;
 	arch->helper.arch = arch;
-	arch->helper.filename = filename;
+	arch->helper.get_filename = _arch_get_filename;
-	arch->helper.fp = fp;
 	arch->helper.get_register_by_name_size = arch_get_register_by_name_size;
+	arch->helper.write = _arch_write;
 	arch->plugin->helper = &arch->helper;
 	return 0;
 }
@@ -443,3 +457,27 @@ int arch_write(Arch * arch, ArchInstruction * instruction,
 #endif
 	return arch->plugin->write(arch->plugin, instruction, call);
 }
+
+
+/* private */
+/* callbacks */
+/* arch_get_filename */
+static char const * _arch_get_filename(Arch * arch)
+{
+	return arch->filename;
+}
+
+
+/* arch_write */
+static ssize_t _arch_write(Arch * arch, void const * buf, size_t size)
+{
+	if(fwrite(buf, size, 1, arch->fp) == 1)
+		return size;
+	if(ferror(arch->fp))
+		return -error_set_code(1, "%s: %s", arch->filename,
+				strerror(errno));
+	if(feof(arch->fp))
+		return -error_set_code(1, "%s: %s", arch->filename,
+				"End of file reached");
+	return -error_set_code(1, "%s: %s", arch->filename, "Write error");
+}

src/arch/dalvik.c

@@ -111,10 +111,11 @@ static int _dalvik_write(ArchPlugin * plugin, ArchInstruction * instruction,
 			break;
 		default:
 			/* FIXME should not happen */
-			return -error_set_code(1, "%s: %s", helper->filename,
+			return -error_set_code(1, "%s: %s",
+					helper->get_filename(helper->arch),
 					"Invalid size for opcode");
 	}
-	if(fwrite(buf, size, 1, helper->fp) != 1)
+	if(helper->write(helper->arch, buf, size) != size)
-		return -1; /* XXX report error */
+		return -1;
 	return 0;
 }

src/arch/i386.h

@@ -158,36 +158,40 @@ static int _write_immediate(ArchPlugin * plugin,
 
 static int _write_immediate8(ArchPlugin * plugin, uint8_t value)
 {
-	if(fwrite(&value, sizeof(value), 1, plugin->helper->fp) != 1)
+	ArchPluginHelper * helper = plugin->helper;
-		return -error_set_code(1, "%s: %s", plugin->helper->filename,
+
-				strerror(errno));
+	if(helper->write(helper->arch, &value, sizeof(value)) != sizeof(value))
+		return -1;
 	return 0;
 }
 
 static int _write_immediate16(ArchPlugin * plugin, uint16_t value)
 {
+	ArchPluginHelper * helper = plugin->helper;
+
 	value = _htol16(value);
-	if(fwrite(&value, sizeof(value), 1, plugin->helper->fp) != 1)
+	if(helper->write(helper->arch, &value, sizeof(value)) != sizeof(value))
-		return -error_set_code(1, "%s: %s", plugin->helper->filename,
+		return -1;
-				strerror(errno));
 	return 0;
 }
 
 static int _write_immediate24(ArchPlugin * plugin, uint32_t value)
 {
+	ArchPluginHelper * helper = plugin->helper;
+
 	value = _htol32(value) >> 8;
-	if(fwrite(&value, 3, 1, plugin->helper->fp) != 1)
+	if(helper->write(helper->arch, &value, 3) != 3)
-		return -error_set_code(1, "%s: %s", plugin->helper->filename,
+		return -1;
-				strerror(errno));
 	return 0;
 }
 
 static int _write_immediate32(ArchPlugin * plugin, uint32_t value)
 {
+	ArchPluginHelper * helper = plugin->helper;
+
 	value = _htol32(value);
-	if(fwrite(&value, sizeof(value), 1, plugin->helper->fp) != 1)
+	if(helper->write(helper->arch, &value, sizeof(value)) != sizeof(value))
-		return -error_set_code(1, "%s: %s", plugin->helper->filename,
+		return -1;
-				strerror(errno));
 	return 0;
 }
 

src/arch/java.c

@@ -275,7 +275,6 @@ static int _java_write(ArchPlugin * plugin, ArchInstruction * instruction,
 	ArchPluginHelper * helper = plugin->helper;
 
 	/* FIXME really implement */
-	return (fwrite(&instruction->opcode, sizeof(char), 1, helper->fp) == 1)
+	return (helper->write(helper->arch, &instruction->opcode, 1) == 1)
-		? 0 : -error_set_code(1, "%s: %s", helper->filename,
+		? 0 : -1;
-				strerror(errno));
 }

src/arch/sparc.h

@@ -41,6 +41,7 @@ static int _write_sethi(ArchPlugin * plugin, ArchInstruction * instruction,
 static int _sparc_write(ArchPlugin * plugin, ArchInstruction * instruction,
 		ArchInstructionCall * call)
 {
+	ArchPluginHelper * helper = plugin->helper;
 	uint32_t opcode = instruction->opcode;
 
 	if((opcode & 0xc0000000) == 0xc0000000)
@@ -66,7 +67,8 @@ static int _sparc_write(ArchPlugin * plugin, ArchInstruction * instruction,
 	else
 		return -1;
 	opcode = _htob32(opcode);
-	if(fwrite(&opcode, sizeof(opcode), 1, plugin->helper->fp) != 1)
+	if(helper->write(helper->arch, &opcode, sizeof(opcode))
+			!= sizeof(opcode))
 		return -1;
 	return 0;
 }