[SYSCSE]: System Call Sign Extender

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

CMakeLists.txt

@@ -24,6 +24,7 @@ if (NOT CMAKE_BUILD_TYPE)
 endif (NOT CMAKE_BUILD_TYPE)
 
 find_package(DWARF REQUIRED)
+find_package(Sqlite REQUIRED)
 
 _set_fancy(LIB_INSTALL_DIR "${EXEC_INSTALL_PREFIX}${CMAKE_INSTALL_PREFIX}/${__LIB}" "libdir")
 
@@ -74,8 +75,12 @@ set(prefcnt_SRCS prefcnt.c)
 add_executable(prefcnt ${prefcnt_SRCS})
 target_link_libraries(prefcnt dwarves)
 
+set(syscse_SRCS syscse.c)
+add_executable(syscse ${syscse_SRCS})
+target_link_libraries(syscse dwarves)
+
 install(TARGETS codiff ctracer dtagnames pahole pdwtags
-		pfunct pglobal prefcnt RUNTIME DESTINATION
+		pfunct pglobal prefcnt syscse RUNTIME DESTINATION
 		${CMAKE_INSTALL_PREFIX}/bin)
 install(TARGETS dwarves LIBRARY DESTINATION ${LIB_INSTALL_DIR})
 install(TARGETS dwarves dwarves_emit dwarves_reorganize LIBRARY DESTINATION ${LIB_INSTALL_DIR})

MANIFEST

@@ -16,6 +16,7 @@ pdwtags.c
 pfunct.c
 pglobal.c
 prefcnt.c
+syscse.c
 NEWS
 README
 README.ctracer

rpm/SPECS/dwarves.spec

@@ -73,6 +73,7 @@ rm -rf %{buildroot}
 %{_bindir}/pfunct
 %{_bindir}/pglobal
 %{_bindir}/prefcnt
+%{_bindir}/syscse
 %{_bindir}/ostra-cg
 %dir %{_datadir}/dwarves/runtime/
 %dir %{_datadir}/dwarves/runtime/python/

syscse.c

@@ -0,0 +1,153 @@
+/* 
+  Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
+
+  System call sign extender
+
+  This program is free software; you can redistribute it and/or modify it
+  under the terms of version 2 of the GNU General Public License as
+  published by the Free Software Foundation.
+*/
+
+#define _GNU_SOURCE
+#include <argp.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "dwarves.h"
+
+static const char *prefix = "sys_";
+static size_t prefix_len = 4;
+
+static struct tag *filter(struct tag *self, struct cu *cu,
+			  void *cookie __unused)
+{
+	if (self->tag == DW_TAG_subprogram) {
+		struct function *f = tag__function(self);
+
+		if (f->proto.nr_parms != 0) {
+			const char *name = function__name(f, cu);
+
+			if (strlen(name) > prefix_len &&
+			    memcmp(name, prefix, prefix_len) == 0)
+				return self;
+		}
+	}
+	return NULL;
+}
+
+static void zero_extend(const int regparm, const struct base_type *bt,
+			const char *parm)
+{
+	const char *instr = "INVALID";
+
+	switch (bt->size) {
+	case 4: /* 32 bits */
+		instr = "sll";
+		break;
+	case 2: /* 16 bits */
+		instr = "slw";
+		break;
+	case 1: /* 8 bits */
+		instr = "slb";
+		break;
+	}
+
+	printf("\t%s\t$a%d, $a%d, 0"
+	       "\t/* zero extend $a%d(%s %s) from %d to 64-bit */\n",
+	       instr, regparm, regparm, regparm, bt->name, parm, bt->size * 8);
+}
+
+static int emit_wrapper(struct tag *self, struct cu *cu, void *cookie __unused)
+{
+	struct parameter *parm;
+	struct function *f = tag__function(self);
+	const char *name = function__name(f, cu);
+	int regparm = 0, needs_wrapper = 0;
+
+	function__for_each_parameter(f, parm) {
+		const Dwarf_Off type_id = parameter__type(parm, cu);
+		struct tag *type = cu__find_tag_by_id(cu, type_id);
+
+		assert(type != NULL);
+		if (type->tag == DW_TAG_base_type) {
+			struct base_type *bt = tag__base_type(type);
+
+			if (bt->size < 8 &&
+			    strncmp(bt->name, "unsigned", 8) == 0) {
+				if (!needs_wrapper) {
+					printf("wrap_%s:\n", name);
+					needs_wrapper = 1;
+				}
+				zero_extend(regparm, bt,
+					    parameter__name(parm, cu));
+			}
+		}
+		++regparm;
+	}
+
+	if (needs_wrapper)
+		printf("\tj\t%s\n\n", name);
+
+
+	return 0;
+}
+
+static int cu__emit_wrapper(struct cu *self, void *cookie __unused)
+{
+	return cu__for_each_tag(self, emit_wrapper, NULL, filter);
+}
+
+static void cus__emit_wrapper(struct cus *self)
+{
+	cus__for_each_cu(self, cu__emit_wrapper, NULL, NULL);
+}
+
+static const struct argp_option options[] = {
+	{
+		.key  = 'p',
+		.name = "prefix",
+		.arg  = "PREFIX",
+		.doc  = "function prefix",
+	},
+	{
+		.name = NULL,
+	}
+};
+
+static error_t options_parser(int key, char *arg, struct argp_state *state)
+{
+	switch (key) {
+	case ARGP_KEY_INIT: state->child_inputs[0] = state->input; break;
+	case 'p': prefix = arg;	break;
+	default:  return ARGP_ERR_UNKNOWN;
+	}
+	return 0;
+}
+
+static const char args_doc[] = "[FILE]";
+
+static struct argp argp = {
+	.options  = options,
+	.parser	  = options_parser,
+	.args_doc = args_doc,
+};
+
+int main(int argc, char *argv[])
+{
+	int err;
+	struct cus *cus = cus__new(NULL, NULL);
+
+	if (cus == NULL) {
+		fprintf(stderr, "%s: insufficient memory\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	err = cus__loadfl(cus, &argp, argc, argv);
+	if (err != 0)
+		return EXIT_FAILURE;
+
+	cus__emit_wrapper(cus);
+	return EXIT_SUCCESS;
+}