Merge remote-tracking branch 'lucas/unwind_integration'
[nit.git] / src / abstract_compiler.nit
index 395f7a1..0f71dff 100644 (file)
@@ -20,6 +20,7 @@ module abstract_compiler
 import literal
 import typing
 import auto_super_init
+import frontend
 
 # Add compiling options
 redef class ToolContext
@@ -31,6 +32,8 @@ redef class ToolContext
        var opt_cc_path: OptionArray = new OptionArray("Set include path for C header files (may be used more than once)", "--cc-path")
        # --make-flags
        var opt_make_flags: OptionString = new OptionString("Additional options to make", "--make-flags")
+       # --compile-dir
+       var opt_compile_dir: OptionString = new OptionString("Directory used to generate temporary files", "--compile-dir")
        # --hardening
        var opt_hardening: OptionBool = new OptionBool("Generate contracts in the C code against bugs in the compiler", "--hardening")
        # --no-shortcut-range
@@ -51,7 +54,7 @@ redef class ToolContext
        redef init
        do
                super
-               self.option_context.add_option(self.opt_output, self.opt_no_cc, self.opt_make_flags, self.opt_hardening, self.opt_no_shortcut_range)
+               self.option_context.add_option(self.opt_output, self.opt_no_cc, self.opt_make_flags, self.opt_compile_dir, self.opt_hardening, self.opt_no_shortcut_range)
                self.option_context.add_option(self.opt_no_check_covariance, self.opt_no_check_initialization, self.opt_no_check_assert, self.opt_no_check_autocast, self.opt_no_check_other)
                self.option_context.add_option(self.opt_typing_test_metrics)
        end
@@ -70,6 +73,20 @@ redef class ModelBuilder
        do
                super
 
+               # Look for the the Nit clib path
+               var path_env = "NIT_DIR".environ
+               if not path_env.is_empty then
+                       var libname = "{path_env}/clib"
+                       if libname.file_exists then cc_paths.add(libname)
+               end
+
+               var libname = "{sys.program_name.dirname}/../clib"
+               if libname.file_exists then cc_paths.add(libname.simplify_path)
+
+               if cc_paths.is_empty then
+                       toolcontext.error(null, "Cannot determine the nit clib path. define envvar NIT_DIR.")
+               end
+
                # Add user defined cc_paths
                cc_paths.append(toolcontext.opt_cc_path.value)
 
@@ -88,16 +105,22 @@ redef class ModelBuilder
                # A single C file regroups many compiled rumtime functions
                # Note that we do not try to be clever an a small change in a Nit source file may change the content of all the generated .c files
                var time0 = get_time
+               self.toolcontext.info("*** WRITING C ***", 1)
 
-               ".nit_compile".mkdir
+               var compile_dir = toolcontext.opt_compile_dir.value
+               if compile_dir == null then compile_dir = ".nit_compile"
+
+               compile_dir.mkdir
+               var orig_dir=".." # FIXME only works if `compile_dir` is a subdirectory of cwd
 
                var outname = self.toolcontext.opt_output.value
                if outname == null then
-                       outname = "{mainmodule.name}.bin"
+                       outname = "{mainmodule.name}"
                end
+               var outpath = orig_dir.join_path(outname).simplify_path
 
                var hfilename = compiler.header.file.name + ".h"
-               var hfilepath = ".nit_compile/{hfilename}"
+               var hfilepath = "{compile_dir}/{hfilename}"
                var h = new OFStream.open(hfilepath)
                for l in compiler.header.decl_lines do
                        h.write l
@@ -115,8 +138,9 @@ redef class ModelBuilder
                        var i = 0
                        var hfile: nullable OFStream = null
                        var count = 0
-                       var cfilename = ".nit_compile/{f.name}.0.h"
-                       hfile = new OFStream.open(cfilename)
+                       var cfilename = "{f.name}.0.h"
+                       var cfilepath = "{compile_dir}/{cfilename}"
+                       hfile = new OFStream.open(cfilepath)
                        hfile.write "#include \"{hfilename}\"\n"
                        for key in f.required_declarations do
                                if not compiler.provided_declarations.has_key(key) then
@@ -136,10 +160,11 @@ redef class ModelBuilder
                                if file == null or count > 10000  then
                                        i += 1
                                        if file != null then file.close
-                                       cfilename = ".nit_compile/{f.name}.{i}.c"
-                                       self.toolcontext.info("new C source files to compile: {cfilename}", 3)
+                                       cfilename = "{f.name}.{i}.c"
+                                       cfilepath = "{compile_dir}/{cfilename}"
+                                       self.toolcontext.info("new C source files to compile: {cfilepath}", 3)
                                        cfiles.add(cfilename)
-                                       file = new OFStream.open(cfilename)
+                                       file = new OFStream.open(cfilepath)
                                        file.write "#include \"{f.name}.0.h\"\n"
                                        count = total_lines
                                end
@@ -159,41 +184,48 @@ redef class ModelBuilder
 
                # Generate the Makefile
 
-               var makename = ".nit_compile/{mainmodule.name}.mk"
-               var makefile = new OFStream.open(makename)
+               var makename = "{mainmodule.name}.mk"
+               var makepath = "{compile_dir}/{makename}"
+               var makefile = new OFStream.open(makepath)
 
                var cc_includes = ""
                for p in cc_paths do
-                       #p = "..".join_path(p)
+                       p = orig_dir.join_path(p).simplify_path
                        cc_includes += " -I \"" + p + "\""
                end
-               makefile.write("CC = ccache cc\nCFLAGS = -g -O2{cc_includes}\nLDFLAGS ?= \nLDLIBS  ?= -lm -lgc\n\n")
-               makefile.write("all: {outname}\n\n")
+               makefile.write("CC = ccache cc\nCFLAGS = -g -O2\nCINCL = {cc_includes}\nLDFLAGS ?= \nLDLIBS  ?= -lunwind -lm -lgc\n\n")
+               makefile.write("all: {outpath}\n\n")
 
                var ofiles = new Array[String]
                # Compile each generated file
                for f in cfiles do
                        var o = f.strip_extension(".c") + ".o"
-                       makefile.write("{o}: {f}\n\t$(CC) $(CFLAGS) -D NONITCNI -c -o {o} {f}\n\n")
+                       makefile.write("{o}: {f}\n\t$(CC) $(CFLAGS) $(CINCL) -D NONITCNI -c -o {o} {f}\n\n")
                        ofiles.add(o)
                end
+
+               # Add gc_choser.h to aditionnal bodies
+               var gc_chooser = new ExternCFile("{cc_paths.first}/gc_chooser.c", "-DWITH_LIBGC")
+               compiler.extern_bodies.add(gc_chooser)
+
                # Compile each required extern body into a specific .o
                for f in compiler.extern_bodies do
                        var basename = f.filename.basename(".c")
-                       var o = ".nit_compile/{basename}.extern.o"
-                       makefile.write("{o}: {f.filename}\n\t$(CC) $(CFLAGS) -D NONITCNI {f.cflags} -c -o {o} {f.filename}\n\n")
+                       var o = "{basename}.extern.o"
+                       var ff = orig_dir.join_path(f.filename).simplify_path
+                       makefile.write("{o}: {ff}\n\t$(CC) $(CFLAGS) -D NONITCNI {f.cflags} -c -o {o} {ff}\n\n")
                        ofiles.add(o)
                end
 
                # Link edition
-               makefile.write("{outname}: {ofiles.join(" ")}\n\t$(CC) $(LDFLAGS) -o {outname} {ofiles.join(" ")} $(LDLIBS)\n\n")
+               makefile.write("{outpath}: {ofiles.join(" ")}\n\t$(CC) $(LDFLAGS) -o {outpath} {ofiles.join(" ")} $(LDLIBS)\n\n")
                # Clean
                makefile.write("clean:\n\trm {ofiles.join(" ")} 2>/dev/null\n\n")
                makefile.close
-               self.toolcontext.info("Generated makefile: {makename}", 2)
+               self.toolcontext.info("Generated makefile: {makepath}", 2)
 
                var time1 = get_time
-               self.toolcontext.info("*** END COMPILING TO C: {time1-time0} ***", 2)
+               self.toolcontext.info("*** END WRITING C: {time1-time0} ***", 2)
 
                # Execute the Makefile
 
@@ -203,13 +235,13 @@ redef class ModelBuilder
                self.toolcontext.info("*** COMPILING C ***", 1)
                var makeflags = self.toolcontext.opt_make_flags.value
                if makeflags == null then makeflags = ""
-               self.toolcontext.info("make -B -f {makename} -j 4 {makeflags}", 2)
+               self.toolcontext.info("make -B -C {compile_dir} -f {makename} -j 4 {makeflags}", 2)
 
                var res
                if self.toolcontext.verbose_level >= 3 then
-                       res = sys.system("make -B -f {makename} -j 4 {makeflags} 2>&1")
+                       res = sys.system("make -B -C {compile_dir} -f {makename} -j 4 {makeflags} 2>&1")
                else
-                       res = sys.system("make -B -f {makename} -j 4 {makeflags} 2>&1 >/dev/null")
+                       res = sys.system("make -B -C {compile_dir} -f {makename} -j 4 {makeflags} 2>&1 >/dev/null")
                end
                if res != 0 then
                        toolcontext.error(null, "make failed! Error code: {res}.")
@@ -224,8 +256,12 @@ end
 abstract class AbstractCompiler
        type VISITOR: AbstractCompilerVisitor
 
-       # The main module of the program
-       var mainmodule: MModule protected writable
+       # The main module of the program currently compiled
+       # Is assigned during the separate compilation
+       var mainmodule: MModule writable
+
+       # The real main module of the program
+       var realmainmodule: MModule
 
        # The modeulbuilder used to know the model and the AST
        var modelbuilder: ModelBuilder protected writable
@@ -236,6 +272,7 @@ abstract class AbstractCompiler
        init(mainmodule: MModule, modelbuilder: ModelBuilder)
        do
                self.mainmodule = mainmodule
+               self.realmainmodule = mainmodule
                self.modelbuilder = modelbuilder
        end
 
@@ -273,22 +310,19 @@ abstract class AbstractCompiler
        # This method call compile_header_strucs method that has to be refined
        fun compile_header do
                var v = self.header
+               self.header.add_decl("#define UNW_LOCAL_ONLY")
                self.header.add_decl("#include <stdlib.h>")
                self.header.add_decl("#include <stdio.h>")
                self.header.add_decl("#include <string.h>")
-               self.header.add_decl("#ifndef NOBOEHM")
-               self.header.add_decl("#include <gc/gc.h>")
-               self.header.add_decl("#ifdef NOBOEHM_ATOMIC")
-               self.header.add_decl("#undef GC_MALLOC_ATOMIC")
-               self.header.add_decl("#define GC_MALLOC_ATOMIC(x) GC_MALLOC(x)")
-               self.header.add_decl("#endif /*NOBOEHM_ATOMIC*/")
-               self.header.add_decl("#else /*NOBOEHM*/")
-               self.header.add_decl("#define GC_MALLOC(x) calloc(1, (x))")
-               self.header.add_decl("#define GC_MALLOC_ATOMIC(x) calloc(1, (x))")
-               self.header.add_decl("#endif /*NOBOEHM*/")
+               self.header.add_decl("#include <libunwind.h>")
+               self.header.add_decl("#include <signal.h>")
+               self.header.add_decl("#include <gc_chooser.h>")
 
                compile_header_structs
 
+               # Signal handler function prototype
+               self.header.add_decl("void show_backtrace(int);")
+
                # Global variable used by the legacy native interface
                self.header.add_decl("extern int glob_argc;")
                self.header.add_decl("extern char **glob_argv;")
@@ -320,18 +354,50 @@ abstract class AbstractCompiler
                                v.compiler.header.add_decl("extern long count_type_test_skipped_{tag};")
                        end
                end
+
+               v.add_decl("void show_backtrace (int signo) \{")
+               v.add_decl("char* opt = getenv(\"NIT_NO_STACK\");")
+               v.add_decl("unw_cursor_t cursor;")
+               v.add_decl("if(opt==NULL)\{")
+               v.add_decl("unw_context_t uc;")
+               v.add_decl("unw_word_t ip;")
+               v.add_decl("char* procname = malloc(sizeof(char) * 100);")
+               v.add_decl("unw_getcontext(&uc);")
+               v.add_decl("unw_init_local(&cursor, &uc);")
+               v.add_decl("printf(\"-------------------------------------------------\\n\");")
+               v.add_decl("printf(\"-- C Stack Trace   ------------------------------\\n\");")
+               v.add_decl("printf(\"-------------------------------------------------\\n\");")
+               v.add_decl("while (unw_step(&cursor) > 0) \{")
+               v.add_decl("    unw_get_proc_name(&cursor, procname, 100, &ip);")
+               v.add_decl("    printf(\"` %s \\n\",procname);")
+               v.add_decl("\}")
+               v.add_decl("printf(\"-------------------------------------------------\\n\");")
+               v.add_decl("free(procname);")
+               v.add_decl("\}")
+               v.add_decl("exit(signo);")
+               v.add_decl("\}")
+
                v.add_decl("int main(int argc, char** argv) \{")
+
+               v.add("signal(SIGABRT, show_backtrace);")
+               v.add("signal(SIGFPE, show_backtrace);")
+               v.add("signal(SIGILL, show_backtrace);")
+               v.add("signal(SIGINT, show_backtrace);")
+               v.add("signal(SIGTERM, show_backtrace);")
+               v.add("signal(SIGSEGV, show_backtrace);")
+
                v.add("glob_argc = argc; glob_argv = argv;")
+               v.add("initialize_gc_option();")
                var main_type = mainmodule.sys_type
                if main_type != null then
                        var mainmodule = v.compiler.mainmodule
                        var glob_sys = v.init_instance(main_type)
                        v.add("glob_sys = {glob_sys};")
-                       var main_init = mainmodule.try_get_primitive_method("init", main_type)
+                       var main_init = mainmodule.try_get_primitive_method("init", main_type.mclass)
                        if main_init != null then
                                v.send(main_init, [glob_sys])
                        end
-                       var main_method = mainmodule.try_get_primitive_method("main", main_type)
+                       var main_method = mainmodule.try_get_primitive_method("main", main_type.mclass)
                        if main_method != null then
                                v.send(main_method, [glob_sys])
                        end
@@ -362,6 +428,7 @@ abstract class AbstractCompiler
                                v.add("printf(\"\\t%ld (%.2f%%)\\n\", count_type_test_total_{tag}, 100.0*count_type_test_total_{tag}/count_type_test_total_total);")
                        end
                end
+
                v.add("return 0;")
                v.add("\}")
        end
@@ -423,8 +490,8 @@ abstract class AbstractCompiler
 
        # Display stats about compilation process
        # Metrics used:
-       #       * type tests against resolved types (x isa Collection[Animal])
-       #       * type tests against unresolved types (x isa Collection[E])
+       #       * type tests against resolved types (`x isa Collection[Animal]`)
+       #       * type tests against unresolved types (`x isa Collection[E]`)
        #       * type tests skipped
        #       * type tests total
        #       *
@@ -507,7 +574,7 @@ abstract class AbstractCompilerVisitor
        # The current visited AST node
        var current_node: nullable ANode writable = null
 
-       # The current Frame
+       # The current `Frame`
        var frame: nullable Frame writable
 
        # Alias for self.compiler.mainmodule.object_type
@@ -524,13 +591,14 @@ abstract class AbstractCompilerVisitor
                self.writer = new CodeWriter(compiler.files.last)
        end
 
-       # Force to get the primitive class named `name' or abort
+       # Force to get the primitive class named `name` or abort
        fun get_class(name: String): MClass do return self.compiler.mainmodule.get_primitive_class(name)
 
-       # Force to get the primitive property named `name' in the instance `recv' or abort
+       # Force to get the primitive property named `name` in the instance `recv` or abort
        fun get_property(name: String, recv: MType): MMethod
        do
-               return self.compiler.modelbuilder.force_get_primitive_method(self.current_node.as(not null), name, recv, self.compiler.mainmodule)
+               assert recv isa MClassType
+               return self.compiler.modelbuilder.force_get_primitive_method(self.current_node.as(not null), name, recv.mclass, self.compiler.mainmodule)
        end
 
        fun compile_callsite(callsite: CallSite, args: Array[RuntimeVariable]): nullable RuntimeVariable
@@ -542,7 +610,7 @@ abstract class AbstractCompilerVisitor
 
        fun native_array_def(pname: String, ret_type: nullable MType, arguments: Array[RuntimeVariable]) is abstract
 
-       # Transform varargs, in raw arguments, into a single argument of type Array
+       # Transform varargs, in raw arguments, into a single argument of type `Array`
        # Note: this method modify the given `args`
        # If there is no vararg, then `args` is not modified.
        fun varargize(mpropdef: MPropDef, msignature: MSignature, args: Array[RuntimeVariable])
@@ -594,8 +662,8 @@ abstract class AbstractCompilerVisitor
 
        # Unsafely cast a value to a new type
        # ie the result share the same C variable but my have a different mcasttype
-       # NOTE: if the adaptation is useless then `value' is returned as it.
-       # ENSURE: return.name == value.name
+       # NOTE: if the adaptation is useless then `value` is returned as it.
+       # ENSURE: `result.name == value.name`
        fun autoadapt(value: RuntimeVariable, mtype: MType): RuntimeVariable
        do
                mtype = self.anchor(mtype)
@@ -619,7 +687,7 @@ abstract class AbstractCompilerVisitor
        fun adapt_signature(m: MMethodDef, args: Array[RuntimeVariable]) is abstract
 
        # Box or unbox a value to another type iff a C type conversion is needed
-       # ENSURE: result.mtype.ctype == mtype.ctype
+       # ENSURE: `result.mtype.ctype == mtype.ctype`
        fun autobox(value: RuntimeVariable, mtype: MType): RuntimeVariable is abstract
 
        #  Generate a polymorphic subtype test
@@ -636,10 +704,10 @@ abstract class AbstractCompilerVisitor
        #  Generate a static call on a method definition
        fun call(m: MMethodDef, recvtype: MClassType, args: Array[RuntimeVariable]): nullable RuntimeVariable is abstract
 
-       #  Generate a polymorphic send for the method `m' and the arguments `args'
+       #  Generate a polymorphic send for the method `m` and the arguments `args`
        fun send(m: MMethod, args: Array[RuntimeVariable]): nullable RuntimeVariable is abstract
 
-       # Generate a monomorphic send for the method `m', the type `t' and the arguments `args'
+       # Generate a monomorphic send for the method `m`, the type `t` and the arguments `args`
        fun monomorphic_send(m: MMethod, t: MType, args: Array[RuntimeVariable]): nullable RuntimeVariable
        do
                assert t isa MClassType
@@ -647,6 +715,14 @@ abstract class AbstractCompilerVisitor
                return self.call(propdef, t, args)
        end
 
+       # Generate a monomorphic super send from the method `m`, the type `t` and the arguments `args`
+       fun monomorphic_super_send(m: MMethodDef, t: MType, args: Array[RuntimeVariable]): nullable RuntimeVariable
+       do
+               assert t isa MClassType
+               m = m.lookup_next_definition(self.compiler.mainmodule, t)
+               return self.call(m, t, args)
+       end
+
        # Attributes handling
 
        # Generate a polymorphic attribute is_set test
@@ -681,7 +757,7 @@ abstract class AbstractCompilerVisitor
        private var names: HashSet[String] = new HashSet[String]
        private var last: Int = 0
 
-       # Return a new name based on `s' and unique in the visitor
+       # Return a new name based on `s` and unique in the visitor
        fun get_name(s: String): String
        do
                if not self.names.has(s) then
@@ -715,7 +791,7 @@ abstract class AbstractCompilerVisitor
        private var escapemark_names = new HashMap[EscapeMark, String]
 
        # Return a "const char*" variable associated to the classname of the dynamic type of an object
-       # NOTE: we do not return a RuntimeVariable "NativeString" as the class may not exist in the module/program
+       # NOTE: we do not return a `RuntimeVariable` "NativeString" as the class may not exist in the module/program
        fun class_name_string(value: RuntimeVariable): String is abstract
 
        # Variables handling
@@ -788,13 +864,11 @@ abstract class AbstractCompilerVisitor
                self.add("if ({name}) \{")
                self.add("{res} = {name};")
                self.add("\} else \{")
-               var nat = self.new_var(self.get_class("NativeString").mclass_type)
+               var native_mtype = self.get_class("NativeString").mclass_type
+               var nat = self.new_var(native_mtype)
                self.add("{nat} = \"{string.escape_to_c}\";")
-               var res2 = self.init_instance(mtype)
-               self.add("{res} = {res2};")
                var length = self.int_instance(string.length)
-               self.send(self.get_property("with_native", mtype), [res, nat, length])
-               self.check_init_instance(res, mtype)
+               self.add("{res} = {self.send(self.get_property("to_s_with_length", native_mtype), [nat, length]).as(not null)};")
                self.add("{name} = {res};")
                self.add("\}")
                return res
@@ -830,7 +904,7 @@ abstract class AbstractCompilerVisitor
        end
 
        # look for a needed .h and .c file for a given .nit source-file
-       # FIXME: bad API, parameter should be a MModule, not its source-file
+       # FIXME: bad API, parameter should be a `MModule`, not its source-file
        fun add_extern(file: String)
        do
                file = file.strip_extension(".nit")
@@ -854,7 +928,7 @@ abstract class AbstractCompilerVisitor
                self.compiler.extern_bodies.add(f)
        end
 
-       # Return a new local runtime_variable initialized with the C expression `cexpr'.
+       # Return a new local runtime_variable initialized with the C expression `cexpr`.
        fun new_expr(cexpr: String, mtype: MType): RuntimeVariable
        do
                var res = new_var(mtype)
@@ -866,15 +940,32 @@ abstract class AbstractCompilerVisitor
        # used by aborts, asserts, casts, etc.
        fun add_abort(message: String)
        do
+               self.add("fprintf(stderr, \"Runtime error: %s\", \"{message.escape_to_c}\");")
+               add_raw_abort
+       end
+
+       fun add_raw_abort
+       do
                if self.current_node != null and self.current_node.location.file != null then
-                       self.add("fprintf(stderr, \"Runtime error: %s (%s:%d)\\n\", \"{message.escape_to_c}\", \"{self.current_node.location.file.filename.escape_to_c}\", {current_node.location.line_start});")
+                       self.add("fprintf(stderr, \" (%s:%d)\\n\", \"{self.current_node.location.file.filename.escape_to_c}\", {current_node.location.line_start});")
                else
-                       self.add("fprintf(stderr, \"Runtime error: %s\\n\", \"{message.escape_to_c}\");")
+                       self.add("fprintf(stderr, \"\\n\");")
                end
-               self.add("exit(1);")
+               self.add("show_backtrace(1);")
        end
 
-       # Generate a return with the value `s'
+       # Add a dynamic cast
+       fun add_cast(value: RuntimeVariable, mtype: MType, tag: String)
+       do
+               var res = self.type_test(value, mtype, tag)
+               self.add("if (!{res}) \{")
+               var cn = self.class_name_string(value)
+               self.add("fprintf(stderr, \"Runtime error: Cast failed. Expected `%s`, got `%s`\", \"{mtype.to_s.escape_to_c}\", {cn});")
+               self.add_raw_abort
+               self.add("\}")
+       end
+
+       # Generate a return with the value `s`
        fun ret(s: RuntimeVariable)
        do
                self.assign(self.frame.returnvar.as(not null), s)
@@ -905,17 +996,14 @@ abstract class AbstractCompilerVisitor
                res = autoadapt(res, nexpr.mtype.as(not null))
                var implicit_cast_to = nexpr.implicit_cast_to
                if implicit_cast_to != null and not self.compiler.modelbuilder.toolcontext.opt_no_check_autocast.value then
-                       var castres = self.type_test(res, implicit_cast_to, "auto")
-                       self.add("if (!{castres}) \{")
-                       self.add_abort("Cast failed")
-                       self.add("\}")
+                       add_cast(res, implicit_cast_to, "auto")
                        res = autoadapt(res, implicit_cast_to)
                end
                self.current_node = old
                return res
        end
 
-       # Alias for `self.expr(nexpr, self.bool_type)'
+       # Alias for `self.expr(nexpr, self.bool_type)`
        fun expr_bool(nexpr: AExpr): RuntimeVariable do return expr(nexpr, bool_type)
 
        # Safely show a debug message on the current node and repeat the message in the C code as a comment
@@ -961,7 +1049,7 @@ abstract class AbstractRuntimeFunction
        # May inline the body or generate a C function call
        fun call(v: VISITOR, arguments: Array[RuntimeVariable]): nullable RuntimeVariable is abstract
 
-       # Generate the code for the RuntimeFunction
+       # Generate the code for the `AbstractRuntimeFunction`
        # Warning: compile more than once compilation makes CC unhappy
        fun compile_to_c(compiler: COMPILER) is abstract
 end
@@ -969,7 +1057,7 @@ end
 # A runtime variable hold a runtime value in C.
 # Runtime variables are associated to Nit local variables and intermediate results in Nit expressions.
 #
-# The tricky point is that a single C variable can be associated to more than one RuntimeVariable because the static knowledge of the type of an expression can vary in the C code.
+# The tricky point is that a single C variable can be associated to more than one `RuntimeVariable` because the static knowledge of the type of an expression can vary in the C code.
 class RuntimeVariable
        # The name of the variable in the C code
        var name: String
@@ -1013,7 +1101,7 @@ class RuntimeVariable
        end
 end
 
-# A frame correspond to a visited property in a GlobalCompilerVisitor
+# A frame correspond to a visited property in a `GlobalCompilerVisitor`
 class Frame
 
        type VISITOR: AbstractCompilerVisitor
@@ -1046,63 +1134,6 @@ class ExternCFile
        var cflags: String
 end
 
-redef class String
-       # Mangle a string to be a unique valid C identifier
-       fun to_cmangle: String
-       do
-               var res = new Buffer
-               var underscore = false
-               for c in self do
-                       if (c >= 'a' and c <= 'z') or (c >='A' and c <= 'Z') then
-                               res.add(c)
-                               underscore = false
-                               continue
-                       end
-                       if underscore then
-                               res.append('_'.ascii.to_s)
-                               res.add('d')
-                       end
-                       if c >= '0' and c <= '9' then
-                               res.add(c)
-                               underscore = false
-                       else if c == '_' then
-                               res.add(c)
-                               underscore = true
-                       else
-                               res.add('_')
-                               res.append(c.ascii.to_s)
-                               res.add('d')
-                               underscore = false
-                       end
-               end
-               return res.to_s
-       end
-
-       # Escape " \ ' and non printable characters for literal C strings or characters
-       fun escape_to_c: String
-       do
-               var b = new Buffer
-               for c in self do
-                       if c == '\n' then
-                               b.append("\\n")
-                       else if c == '\0' then
-                               b.append("\\0")
-                       else if c == '"' then
-                               b.append("\\\"")
-                       else if c == '\'' then
-                               b.append("\\\'")
-                       else if c == '\\' then
-                               b.append("\\\\")
-                       else if c.ascii < 32 then
-                               b.append("\\{c.ascii.to_base(8, false)}")
-                       else
-                               b.add(c)
-                       end
-               end
-               return b.to_s
-       end
-end
-
 redef class MType
        # Return the C type associated to a given Nit static type
        fun ctype: String do return "val*"
@@ -1313,10 +1344,7 @@ redef class MMethodDef
                        # generate the cast
                        # note that v decides if and how to implements the cast
                        v.add("/* Covariant cast for argument {i} ({self.msignature.mparameters[i].name}) {arguments[i+1].inspect} isa {mtype} */")
-                       var cond = v.type_test(arguments[i+1], mtype, "covariance")
-                       v.add("if (!{cond}) \{")
-                       v.add_abort("Cast failed")
-                       v.add("\}")
+                       v.add_cast(arguments[i+1], mtype, "covariance")
                end
        end
 end
@@ -1446,7 +1474,7 @@ redef class AInternMethPropdef
                                v.add("printf(\"%c\", {arguments.first});")
                                return
                        else if pname == "object_id" then
-                               v.ret(arguments.first)
+                               v.ret(v.new_expr("(long){arguments.first}", ret.as(not null)))
                                return
                        else if pname == "+" then
                                v.ret(v.new_expr("{arguments[0]} + {arguments[1]}", ret.as(not null)))
@@ -1491,7 +1519,7 @@ redef class AInternMethPropdef
                                v.add("printf({arguments.first}?\"true\\n\":\"false\\n\");")
                                return
                        else if pname == "object_id" then
-                               v.ret(arguments.first)
+                               v.ret(v.new_expr("(long){arguments.first}", ret.as(not null)))
                                return
                        else if pname == "==" then
                                v.ret(v.equal_test(arguments[0], arguments[1]))
@@ -1552,24 +1580,6 @@ redef class AInternMethPropdef
                                v.ret(v.new_expr("(long){arguments[0]}", ret.as(not null)))
                                return
                        end
-               else if cname == "Char" then
-                       if pname == "output" then
-                               v.add("printf(\"%c\", {arguments.first});")
-                               return
-                       else if pname == "object_id" then
-                               v.ret(arguments.first)
-                               return
-                       else if pname == "==" then
-                               v.ret(v.equal_test(arguments[0], arguments[1]))
-                               return
-                       else if pname == "!=" then
-                               var res = v.equal_test(arguments[0], arguments[1])
-                               v.ret(v.new_expr("!{res}", ret.as(not null)))
-                               return
-                       else if pname == "ascii" then
-                               v.ret(v.new_expr("{arguments[0]}", ret.as(not null)))
-                               return
-                       end
                else if cname == "NativeString" then
                        if pname == "[]" then
                                v.ret(v.new_expr("{arguments[0]}[{arguments[1]}]", ret.as(not null)))
@@ -1589,13 +1599,13 @@ redef class AInternMethPropdef
                        return
                end
                if pname == "exit" then
-                       v.add("exit({arguments[1]});")
+                       v.add("show_backtrace({arguments[1]});")
                        return
                else if pname == "sys" then
                        v.ret(v.new_expr("glob_sys", ret.as(not null)))
                        return
                else if pname == "calloc_string" then
-                       v.ret(v.new_expr("(char*)GC_MALLOC_ATOMIC({arguments[1]})", ret.as(not null)))
+                       v.ret(v.new_expr("(char*)nit_alloc({arguments[1]})", ret.as(not null)))
                        return
                else if pname == "calloc_array" then
                        v.calloc_array(ret.as(not null), arguments)
@@ -1606,6 +1616,9 @@ redef class AInternMethPropdef
                else if pname == "is_same_type" then
                        v.ret(v.is_same_type_test(arguments[0], arguments[1]))
                        return
+               else if pname == "is_same_instance" then
+                       v.ret(v.equal_test(arguments[0], arguments[1]))
+                       return
                else if pname == "output_class_name" then
                        var nat = v.class_name_string(arguments.first)
                        v.add("printf(\"%s\\n\", {nat});")
@@ -1615,7 +1628,13 @@ redef class AInternMethPropdef
                        v.ret(v.new_expr("(char*){nat}", ret.as(not null)))
                        return
                else if pname == "force_garbage_collection" then
-                       v.add("GC_gcollect();")
+                       v.add("nit_gcollect();")
+                       return
+               else if pname == "native_argc" then
+                       v.ret(v.new_expr("glob_argc", ret.as(not null)))
+                       return
+               else if pname == "native_argv" then
+                       v.ret(v.new_expr("glob_argv[{arguments[1]}]", ret.as(not null)))
                        return
                end
                v.add("printf(\"NOT YET IMPLEMENTED {class_name}:{mpropdef} at {location.to_s}\\n\");")
@@ -1630,7 +1649,7 @@ redef class AExternMethPropdef
                var nextern = self.n_extern
                if nextern == null then
                        v.add("fprintf(stderr, \"NOT YET IMPLEMENTED nitni for {mpropdef} at {location.to_s}\\n\");")
-                       v.add("exit(1);")
+                       v.add("show_backtrace(1);")
                        return
                end
                externname = nextern.text.substring(1, nextern.text.length-2)
@@ -1662,7 +1681,7 @@ redef class AExternInitPropdef
                var nextern = self.n_extern
                if nextern == null then
                        v.add("printf(\"NOT YET IMPLEMENTED nitni for {mpropdef} at {location.to_s}\\n\");")
-                       v.add("exit(1);")
+                       v.add("show_backtrace(1);")
                        return
                end
                externname = nextern.text.substring(1, nextern.text.length-2)
@@ -1753,13 +1772,17 @@ redef class AClassdef
 end
 
 redef class ADeferredMethPropdef
-       redef fun compile_to_c(v, mpropdef, arguments) do v.add_abort("Deferred method called")
+       redef fun compile_to_c(v, mpropdef, arguments) do
+               var cn = v.class_name_string(arguments.first)
+               v.add("fprintf(stderr, \"Runtime error: Abstract method `%s` called on `%s`\", \"{mpropdef.mproperty.name.escape_to_c}\", {cn});")
+               v.add_raw_abort
+       end
        redef fun can_inline do return true
 end
 
 redef class AExpr
        # Try to compile self as an expression
-       # Do not call this method directly, use `v.expr' instead
+       # Do not call this method directly, use `v.expr` instead
        private fun expr(v: AbstractCompilerVisitor): nullable RuntimeVariable
        do
                v.add("printf(\"NOT YET IMPLEMENTED {class_name}:{location.to_s}\\n\");")
@@ -1774,7 +1797,7 @@ redef class AExpr
        end
 
        # Try to compile self as a statement
-       # Do not call this method directly, use `v.stmt' instead
+       # Do not call this method directly, use `v.stmt` instead
        private fun stmt(v: AbstractCompilerVisitor)
        do
                var res = expr(v)
@@ -1787,6 +1810,15 @@ redef class ABlockExpr
        do
                for e in self.n_expr do v.stmt(e)
        end
+       redef fun expr(v)
+       do
+               var last = self.n_expr.last
+               for e in self.n_expr do
+                       if e == last then break
+                       v.stmt(e)
+               end
+               return v.expr(last, null)
+       end
 end
 
 redef class AVardeclExpr
@@ -1817,6 +1849,13 @@ redef class AVarAssignExpr
                var i = v.expr(self.n_value, variable.declared_type)
                v.assign(v.variable(variable), i)
        end
+       redef fun expr(v)
+       do
+               var variable = self.variable.as(not null)
+               var i = v.expr(self.n_value, variable.declared_type)
+               v.assign(v.variable(variable), i)
+               return i
+       end
 end
 
 redef class AVarReassignExpr
@@ -1870,6 +1909,18 @@ redef class AIfExpr
                v.stmt(self.n_else)
                v.add("\}")
        end
+
+       redef fun expr(v)
+       do
+               var res = v.new_var(self.mtype.as(not null))
+               var cond = v.expr_bool(self.n_expr)
+               v.add("if ({cond})\{")
+               v.assign(res, v.expr(self.n_then.as(not null), null))
+               v.add("\} else \{")
+               v.assign(res, v.expr(self.n_else.as(not null), null))
+               v.add("\}")
+               return res
+       end
 end
 
 redef class AIfexprExpr
@@ -2024,6 +2075,21 @@ redef class AOrExpr
        end
 end
 
+redef class AImpliesExpr
+       redef fun expr(v)
+       do
+               var res = v.new_var(self.mtype.as(not null))
+               var i1 = v.expr_bool(self.n_expr)
+               v.add("if (!{i1}) \{")
+               v.add("{res} = 1;")
+               v.add("\} else \{")
+               var i2 = v.expr_bool(self.n_expr2)
+               v.add("{res} = {i2};")
+               v.add("\}")
+               return res
+       end
+end
+
 redef class AAndExpr
        redef fun expr(v)
        do
@@ -2062,25 +2128,16 @@ redef class AOrElseExpr
        end
 end
 
-redef class AEeExpr
-       redef fun expr(v)
-       do
-               var value1 = v.expr(self.n_expr, null)
-               var value2 = v.expr(self.n_expr2, null)
-               return v.equal_test(value1, value2)
-       end
-end
-
 redef class AIntExpr
-       redef fun expr(v) do return v.new_expr("{self.n_number.text}", self.mtype.as(not null))
+       redef fun expr(v) do return v.new_expr("{self.value.to_s}", self.mtype.as(not null))
 end
 
 redef class AFloatExpr
-       redef fun expr(v) do return v.new_expr("{self.n_float.text}", self.mtype.as(not null))
+       redef fun expr(v) do return v.new_expr("{self.n_float.text}", self.mtype.as(not null)) # FIXME use value, not n_float
 end
 
 redef class ACharExpr
-       redef fun expr(v) do return v.new_expr("{self.n_char.text}", self.mtype.as(not null))
+       redef fun expr(v) do return v.new_expr("'{self.value.to_s.escape_to_c}'", self.mtype.as(not null))
 end
 
 redef class AArrayExpr
@@ -2167,10 +2224,7 @@ redef class AAsCastExpr
                var i = v.expr(self.n_expr, null)
                if v.compiler.modelbuilder.toolcontext.opt_no_check_assert.value then return i
 
-               var cond = v.type_test(i, self.mtype.as(not null), "as")
-               v.add("if (!{cond}) \{")
-               v.add_abort("Cast failed")
-               v.add("\}")
+               v.add_cast(i, self.mtype.as(not null), "as")
                return i
        end
 end
@@ -2351,20 +2405,8 @@ end
 
 # Utils
 
-redef class HashSet[E]
-       init from(elements: Collection[E]) do
-               init
-               self.add_all(elements)
-       end
-end
-
 redef class Array[E]
-       init from(elements: Collection[E]) do
-               init
-               self.add_all(elements)
-       end
-
-       # Return a new Array with the elements only contened in 'self' and not in 'o'
+       # Return a new `Array` with the elements only contened in self and not in `o`
        fun -(o: Array[E]): Array[E] do
                var res = new Array[E]
                for e in self do if not o.has(e) then res.add(e)
@@ -2373,208 +2415,25 @@ redef class Array[E]
 end
 
 redef class MModule
-
-       # Return a linearization of a set of mtypes
-       fun linearize_mtypes(mtypes: Set[MType]): Array[MType] do
-               var lin = new Array[MType].from(mtypes)
-               var sorter = new TypeSorter(self)
-               sorter.sort(lin)
-               return lin
-       end
-
-       # Return a reverse linearization of a set of mtypes
-       fun reverse_linearize_mtypes(mtypes: Set[MType]): Array[MType] do
-               var lin = new Array[MType].from(mtypes)
-               var sorter = new ReverseTypeSorter(self)
-               sorter.sort(lin)
-               return lin
-       end
-
-       # Return super types of a `mtype` in `self`
-       fun super_mtypes(mtype: MType, mtypes: Set[MType]): Set[MType] do
-               if not self.super_mtypes_cache.has_key(mtype) then
-                       var supers = new HashSet[MType]
-                       for otype in mtypes do
-                               if otype == mtype then continue
-                               if mtype.is_subtype(self, null, otype) then
-                                       supers.add(otype)
-                               end
-                       end
-                       self.super_mtypes_cache[mtype] = supers
-               end
-               return self.super_mtypes_cache[mtype]
-       end
-
-       private var super_mtypes_cache: Map[MType, Set[MType]] = new HashMap[MType, Set[MType]]
-
-       # Return all sub mtypes (directs and indirects) of a `mtype` in `self`
-       fun sub_mtypes(mtype: MType, mtypes: Set[MType]): Set[MType] do
-               if not self.sub_mtypes_cache.has_key(mtype) then
-                       var subs = new HashSet[MType]
-                       for otype in mtypes do
-                               if otype == mtype then continue
-                               if otype.is_subtype(self, null, mtype) then
-                                       subs.add(otype)
-                               end
-                       end
-                       self.sub_mtypes_cache[mtype] = subs
-               end
-               return self.sub_mtypes_cache[mtype]
-       end
-
-       private var sub_mtypes_cache: Map[MType, Set[MType]] = new HashMap[MType, Set[MType]]
-
-       # Return a linearization of a set of mclasses
-       fun linearize_mclasses_2(mclasses: Set[MClass]): Array[MClass] do
-               var lin = new Array[MClass].from(mclasses)
-               var sorter = new ClassSorter(self)
-               sorter.sort(lin)
-               return lin
-       end
-
-       # Return a reverse linearization of a set of mtypes
-       fun reverse_linearize_mclasses(mclasses: Set[MClass]): Array[MClass] do
-               var lin = new Array[MClass].from(mclasses)
-               var sorter = new ReverseClassSorter(self)
-               sorter.sort(lin)
-               return lin
-       end
-
-       # Return all super mclasses (directs and indirects) of a `mclass` in `self`
-       fun super_mclasses(mclass: MClass): Set[MClass] do
-               if not self.super_mclasses_cache.has_key(mclass) then
-                       var supers = new HashSet[MClass]
-                       if self.flatten_mclass_hierarchy.has(mclass) then
-                               for sup in self.flatten_mclass_hierarchy[mclass].greaters do
-                                       if sup == mclass then continue
-                                       supers.add(sup)
-                               end
-                       end
-                       self.super_mclasses_cache[mclass] = supers
-               end
-               return self.super_mclasses_cache[mclass]
-       end
-
-       private var super_mclasses_cache: Map[MClass, Set[MClass]] = new HashMap[MClass, Set[MClass]]
-
-       # Return all parents of a `mclass` in `self`
-       fun parent_mclasses(mclass: MClass): Set[MClass] do
-               if not self.parent_mclasses_cache.has_key(mclass) then
-                       var parents = new HashSet[MClass]
-                       if self.flatten_mclass_hierarchy.has(mclass) then
-                               for sup in self.flatten_mclass_hierarchy[mclass].direct_greaters do
-                                       if sup == mclass then continue
-                                       parents.add(sup)
-                               end
-                       end
-                       self.parent_mclasses_cache[mclass] = parents
-               end
-               return self.parent_mclasses_cache[mclass]
-       end
-
-       private var parent_mclasses_cache: Map[MClass, Set[MClass]] = new HashMap[MClass, Set[MClass]]
-
-       # Return all sub mclasses (directs and indirects) of a `mclass` in `self`
-       fun sub_mclasses(mclass: MClass): Set[MClass] do
-               if not self.sub_mclasses_cache.has_key(mclass) then
-                       var subs = new HashSet[MClass]
-                       if self.flatten_mclass_hierarchy.has(mclass) then
-                               for sub in self.flatten_mclass_hierarchy[mclass].smallers do
-                                       if sub == mclass then continue
-                                       subs.add(sub)
-                               end
-                       end
-                       self.sub_mclasses_cache[mclass] = subs
-               end
-               return self.sub_mclasses_cache[mclass]
-       end
-
-       private var sub_mclasses_cache: Map[MClass, Set[MClass]] = new HashMap[MClass, Set[MClass]]
-
-       # All 'mproperties' associated to all 'mclassdefs' of `mclass`
+       # All `MProperty` associated to all `MClassDef` of `mclass`
        fun properties(mclass: MClass): Set[MProperty] do
                if not self.properties_cache.has_key(mclass) then
                        var properties = new HashSet[MProperty]
-                       var parents = self.super_mclasses(mclass)
+                       var parents = new Array[MClass]
+                       if self.flatten_mclass_hierarchy.has(mclass) then
+                               parents.add_all(mclass.in_hierarchy(self).direct_greaters)
+                       end
                        for parent in parents do
                                properties.add_all(self.properties(parent))
                        end
-
                        for mclassdef in mclass.mclassdefs do
-                               for mpropdef in mclassdef.mpropdefs do
-                                       properties.add(mpropdef.mproperty)
+                               for mprop in mclassdef.intro_mproperties do
+                                       properties.add(mprop)
                                end
                        end
                        self.properties_cache[mclass] = properties
                end
                return properties_cache[mclass]
        end
-
        private var properties_cache: Map[MClass, Set[MProperty]] = new HashMap[MClass, Set[MProperty]]
 end
-
-# A sorter for linearize list of types
-private class TypeSorter
-       super AbstractSorter[MType]
-
-       private var mmodule: MModule
-
-       init(mmodule: MModule) do self.mmodule = mmodule
-
-       redef fun compare(a, b) do
-               if a == b then
-                       return 0
-               else if a.is_subtype(self.mmodule, null, b) then
-                       return -1
-               end
-               return 1
-       end
-end
-
-# A sorter for reverse linearization
-private class ReverseTypeSorter
-       super TypeSorter
-
-       init(mmodule: MModule) do end
-
-       redef fun compare(a, b) do
-               if a == b then
-                       return 0
-               else if a.is_subtype(self.mmodule, null, b) then
-                       return 1
-               end
-               return -1
-       end
-end
-
-# A sorter for linearize list of classes
-private class ClassSorter
-       super AbstractSorter[MClass]
-
-       var mmodule: MModule
-
-       redef fun compare(a, b) do
-               if a == b then
-                       return 0
-               else if self.mmodule.flatten_mclass_hierarchy.has(a) and self.mmodule.flatten_mclass_hierarchy[a].greaters.has(b) then
-                       return -1
-               end
-               return 1
-       end
-end
-
-# A sorter for reverse linearization
-private class ReverseClassSorter
-       super AbstractSorter[MClass]
-
-       var mmodule: MModule
-
-       redef fun compare(a, b) do
-               if a == b then
-                       return 0
-               else if self.mmodule.flatten_mclass_hierarchy.has(a) and self.mmodule.flatten_mclass_hierarchy[a].greaters.has(b) then
-                       return 1
-               end
-               return -1
-       end
-end