--- /dev/null
+/* Most of this is Copyright Dima Kogan <dima@secretsauce.net>
+ *
+ * Pieces of this were taken from dwarf_prototypes.c in the dwarves project.
+ * Those are Copyright (C) 2008 Arnaldo Carvalho de Melo <acme@redhat.com>.
+ *
+ * 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.
+ *
+ */
+#include <stdio.h>
+#include <elfutils/libdwfl.h>
+#include <dwarf.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+
+#include "config.h"
+#include "prototype.h"
+#include "type.h"
+#include "param.h"
+#include "dict.h"
+#include "lens.h"
+#include "lens_enum.h"
+#include "value.h"
+#include "expr.h"
+#include "library.h"
+#include "options.h"
+#include "filter.h"
+
+#if 0
+#define complain( die, format, ... ) \
+ fprintf(stderr, "%s() die '%s' @ 0x%lx: " format "\n", \
+ __func__, dwarf_diename(die), dwarf_dieoffset(die), \
+ ##__VA_ARGS__ )
+#else
+#define complain( die, format, ... )
+#endif
+
+// A map from DIE addresses (Dwarf_Off) to type structures (struct
+// arg_type_info*). This is created and filled in at the start of each import,
+// and deleted when the import is complete
+static struct dict type_hash;
+
+
+static bool getType( struct arg_type_info** info, Dwarf_Die* type_die);
+
+
+#if 0
+static bool _dump_dwarf_tree(Dwarf_Die* die, int indent)
+{
+ while(1)
+ {
+ printf("%*sprocessing unit: 0x%02x/'%s'\n", indent*4, "",
+ dwarf_tag(die), dwarf_diename(die) );
+
+ Dwarf_Die child;
+ if (dwarf_child(die, &child) == 0)
+ {
+ if( !_dump_dwarf_tree(&child, indent+1) )
+ return false;
+ }
+
+ int res = dwarf_siblingof(die, die);
+ if( res == 0 ) continue; // sibling exists
+ if( res < 0 ) return false; // error
+ break; // no sibling exists
+ }
+
+ return true;
+}
+
+static bool dump_dwarf_tree(Dwarf_Die* die)
+{
+ return _dump_dwarf_tree( die, 0 );
+}
+
+static bool _dump_ltrace_tree( const struct arg_type_info* info, int indent )
+{
+ if( indent > 7 )
+ {
+ printf("%*s%p ...\n", indent*4, "", (void*)info);
+ return true;
+ }
+
+ if( info == NULL )
+ {
+ printf("%*s%p NULL\n", indent*4, "", (void*)info);
+ return true;
+ }
+
+ switch(info->type)
+ {
+ case ARGTYPE_VOID:
+ printf("%*s%p void\n", indent*4, "", (void*)info);
+ break;
+
+ case ARGTYPE_INT:
+ case ARGTYPE_UINT:
+ case ARGTYPE_LONG:
+ case ARGTYPE_ULONG:
+ case ARGTYPE_CHAR:
+ case ARGTYPE_SHORT:
+ case ARGTYPE_USHORT:
+ case ARGTYPE_FLOAT:
+ case ARGTYPE_DOUBLE:
+ printf("%*s%p base\n", indent*4, "", (void*)info);
+ break;
+
+ case ARGTYPE_ARRAY:
+ printf("%*s%p array. elements not printed\n", indent*4, "", (void*)info);
+ break;
+
+ case ARGTYPE_POINTER:
+ printf("%*s%p pointer to...\n", indent*4, "", (void*)info);
+ _dump_ltrace_tree( info->u.ptr_info.info, indent+1 );
+ break;
+
+ case ARGTYPE_STRUCT:
+ printf("%*s%p struct...\n", indent*4, "", (void*)info);
+ struct struct_field
+ {
+ struct arg_type_info *info;
+ int own_info;
+ }* elements = (struct struct_field*)info->u.entries.data;
+ unsigned int i;
+ for(i=0; i<info->u.entries.size; i++)
+ _dump_ltrace_tree( elements[i].info, indent+1 );
+ break;
+
+ default:
+ printf("%*s%p unknown type\n", indent*4, "", (void*)info);
+ return false;;
+ }
+
+ return true;
+}
+
+static bool dump_ltrace_tree( const struct arg_type_info* info )
+{
+ return _dump_ltrace_tree( info, 0 );
+}
+#endif
+
+
+
+static uint64_t attr_numeric(Dwarf_Die *die, uint32_t name)
+{
+ Dwarf_Attribute attr;
+ uint32_t form;
+
+ if (dwarf_attr(die, name, &attr) == NULL)
+ return 0;
+
+ form = dwarf_whatform(&attr);
+
+ switch (form) {
+ case DW_FORM_addr: {
+ Dwarf_Addr addr;
+ if (dwarf_formaddr(&attr, &addr) == 0)
+ return addr;
+ }
+ break;
+ case DW_FORM_data1:
+ case DW_FORM_data2:
+ case DW_FORM_data4:
+ case DW_FORM_data8:
+ case DW_FORM_sdata:
+ case DW_FORM_udata: {
+ Dwarf_Word value;
+ if (dwarf_formudata(&attr, &value) == 0)
+ return value;
+ }
+ break;
+ case DW_FORM_flag:
+ case DW_FORM_flag_present: {
+ bool value;
+ if (dwarf_formflag(&attr, &value) == 0)
+ return value;
+ }
+ break;
+ default:
+ complain(die, "DW_AT_<0x%x>=0x%x", name, form);
+ break;
+ }
+
+ return 0;
+}
+
+static enum arg_type getBaseType( Dwarf_Die* die )
+{
+ int encoding = attr_numeric(die, DW_AT_encoding);
+
+ if( encoding == DW_ATE_void )
+ return ARGTYPE_VOID;
+
+ if( encoding == DW_ATE_signed_char || encoding == DW_ATE_unsigned_char )
+ return ARGTYPE_CHAR;
+
+ if( encoding == DW_ATE_signed ||
+ encoding == DW_ATE_unsigned )
+ {
+ bool is_signed = (encoding == DW_ATE_signed);
+ switch( attr_numeric(die, DW_AT_byte_size) )
+ {
+ case sizeof(char):
+ return ARGTYPE_CHAR;
+
+ case sizeof(short):
+ return is_signed ? ARGTYPE_SHORT : ARGTYPE_USHORT;
+
+ case sizeof(int):
+ return is_signed ? ARGTYPE_INT : ARGTYPE_UINT;
+
+ case sizeof(long):
+ return is_signed ? ARGTYPE_LONG : ARGTYPE_ULONG;
+
+ default:
+ complain(die, "");
+ exit(1);
+ }
+ }
+
+ if( encoding == DW_ATE_float )
+ {
+ switch( attr_numeric(die, DW_AT_byte_size) )
+ {
+ case sizeof(float):
+ return ARGTYPE_FLOAT;
+
+ case sizeof(double):
+ return ARGTYPE_DOUBLE;
+
+ default:
+ complain(die, "");
+ exit(1);
+ }
+ }
+
+ complain(die, "");
+ exit(1);
+ return ARGTYPE_VOID;
+}
+
+static bool getTypeDie( Dwarf_Die* type_die, Dwarf_Die* die )
+{
+ Dwarf_Attribute attr;
+ return
+ dwarf_attr(die, DW_AT_type, &attr) != NULL &&
+ dwarf_formref_die(&attr, type_die) != NULL;
+}
+
+static size_t dwarf_die_hash(const void* x)
+{
+ return *(const Dwarf_Off*)x;
+}
+static int dwarf_die_eq(const void* a, const void* b)
+{
+ return *(const Dwarf_Off*)a == *(const Dwarf_Off*)b;
+}
+
+static bool getEnum(struct arg_type_info* enum_info, Dwarf_Die* parent)
+{
+ enum_info->type = ARGTYPE_INT;
+
+ struct enum_lens *lens = calloc(1, sizeof(struct enum_lens));
+ if (lens == NULL)
+ {
+ complain(parent, "alloc error");
+ return false;
+ }
+ lens_init_enum(lens);
+ enum_info->lens = &lens->super;
+
+ Dwarf_Die die;
+ if( dwarf_child(parent, &die) != 0 )
+ {
+ // empty enum. we're done
+ return true;
+ }
+
+ while(1) {
+ complain(&die, "enum element: 0x%02x/'%s'", dwarf_tag(&die), dwarf_diename(&die) );
+
+ if( dwarf_tag(&die) != DW_TAG_enumerator )
+ {
+ complain(&die, "Enums can have ONLY DW_TAG_enumerator elements");
+ return false;
+ }
+
+ if( !dwarf_hasattr(&die, DW_AT_const_value) )
+ {
+ complain(&die, "Enums MUST have DW_AT_const_value values");
+ return false;
+ }
+
+ const char* key = dwarf_diename(&die);
+ if( key == NULL )
+ {
+ complain(&die, "Enums must have a DW_AT_name key");
+ return false;
+ }
+ const char* dupkey = strdup(key);
+ if( dupkey == NULL )
+ {
+ complain(&die, "Couldn't duplicate enum key");
+ return false;
+ }
+
+ struct value* value = calloc( 1, sizeof(struct value) );
+ if( value == NULL )
+ {
+ complain(&die, "Couldn't alloc enum value");
+ return false;
+ }
+
+ value_init_detached(value, NULL, type_get_simple( ARGTYPE_INT ), 0);
+ value_set_word(value, attr_numeric(&die, DW_AT_const_value) );
+
+ if( lens_enum_add( lens, dupkey, 0, value, 0 ) )
+ {
+ complain(&die, "Couldn't add enum element");
+ return false;
+ }
+
+ int res = dwarf_siblingof(&die, &die);
+ if( res == 0 ) continue; /* sibling exists */
+ if( res < 0 ) return false; /* error */
+ break; /* no sibling exists */
+ }
+
+ return true;
+}
+
+static bool getArray(struct arg_type_info* array_info, Dwarf_Die* parent)
+{
+ Dwarf_Die type_die;
+ if( !getTypeDie( &type_die, parent ) )
+ {
+ complain( parent, "Array has unknown type" );
+ return false;
+ }
+
+ struct arg_type_info* info;
+ if( !getType( &info, &type_die ) )
+ {
+ complain( parent, "Couldn't figure out array's type" );
+ return false;
+ }
+
+ Dwarf_Die subrange;
+ if( dwarf_child(parent, &subrange) != 0 )
+ {
+ complain( parent, "Array must have a DW_TAG_subrange_type child, but has none" );
+ return false;
+ }
+
+ Dwarf_Die next_subrange;
+ if( dwarf_siblingof(&subrange, &next_subrange) <= 0 )
+ {
+ complain( parent, "Array must have exactly one DW_TAG_subrange_type child" );
+ return false;
+ }
+
+ if( !dwarf_hasattr(&subrange, DW_AT_upper_bound) )
+ {
+ complain( parent, "Array subrange must have a DW_AT_upper_bound");
+ return false;
+ }
+
+ if( dwarf_hasattr(&subrange, DW_AT_lower_bound) )
+ {
+ if( attr_numeric(&subrange, DW_AT_lower_bound) != 0 )
+ {
+ complain( parent, "Array subrange has a nonzero lower bound. Don't know what to do");
+ return false;
+ }
+ }
+
+ // I'm not checking the subrange type. It should be some sort of integer,
+ // and I don't know what it would mean for it to be something else
+
+ struct value* value = calloc( 1, sizeof(struct value) );
+ if( value == NULL )
+ {
+ complain(&subrange, "Couldn't alloc length value");
+ return false;
+ }
+ value_init_detached(value, NULL, type_get_simple( ARGTYPE_INT ), 0);
+ value_set_word(value, attr_numeric(&subrange, DW_AT_upper_bound)+1 );
+
+ struct expr_node* length = calloc( 1, sizeof(struct expr_node) );
+ if( length == NULL )
+ {
+ complain(&subrange, "Couldn't alloc length expr");
+ return false;
+ }
+ expr_init_const(length, value);
+
+ type_init_array(array_info, info, 0, length, 0 );
+
+ return true;
+}
+
+static bool getStructure(struct arg_type_info* struct_info, Dwarf_Die* parent)
+{
+ type_init_struct(struct_info);
+
+ Dwarf_Die die;
+ if( dwarf_child(parent, &die) != 0 )
+ {
+ // no elements; we're done
+ return true;
+ }
+
+ while(1) {
+ fprintf(stderr, "member: 0x%02x/'%s'\n", dwarf_tag(&die), dwarf_diename(&die) );
+
+ if( dwarf_tag(&die) != DW_TAG_member )
+ {
+ complain(&die, "Structure can have ONLY DW_TAG_member");
+ return false;
+ }
+
+ Dwarf_Die type_die;
+ if( !getTypeDie( &type_die, &die ) )
+ {
+ complain( &die, "Couldn't get type of element");
+ return false;
+ }
+
+ struct arg_type_info* member_info = NULL;
+ if( !getType( &member_info, &type_die ) )
+ {
+ complain(&die, "Couldn't parse type from DWARF data");
+ return false;
+ }
+ type_struct_add( struct_info, member_info, 0 );
+
+ int res = dwarf_siblingof(&die, &die);
+ if( res == 0 ) continue; /* sibling exists */
+ if( res < 0 ) return false; /* error */
+ break; /* no sibling exists */
+ }
+
+ return true;
+}
+
+// Reads the type in the die into the given structure
+// Returns true on sucess
+static bool getType( struct arg_type_info** info, Dwarf_Die* type_die)
+{
+ Dwarf_Off die_offset = dwarf_dieoffset(type_die);
+ struct arg_type_info** found_type = dict_find(&type_hash, &die_offset );
+ if(found_type != NULL)
+ {
+ *info = *found_type;
+ complain(type_die, "Read pre-computed type: %p", *info);
+ return true;
+ }
+
+ Dwarf_Die next_die;
+
+ switch( dwarf_tag(type_die) )
+ {
+ case DW_TAG_base_type:
+ *info = type_get_simple( getBaseType( type_die ) );
+ complain(type_die, "Storing base type: %p", *info);
+ dict_insert( &type_hash, &die_offset, info );
+ return true;
+
+ case DW_TAG_subroutine_type:
+ case DW_TAG_inlined_subroutine:
+ // function pointers are stored as void*. If ltrace tries to dereference
+ // these, it'll get a segfault
+ *info = type_get_simple( ARGTYPE_VOID );
+ complain(type_die, "Storing subroutine type: %p", *info);
+ dict_insert( &type_hash, &die_offset, info );
+ return true;
+
+ case DW_TAG_pointer_type:
+
+ if( !getTypeDie(&next_die, type_die ) )
+ {
+ // the pointed-to type isn't defined, so I report a void*
+ *info = type_get_simple( ARGTYPE_VOID );
+ complain(type_die, "Storing void-pointer type: %p", *info);
+ dict_insert( &type_hash, &die_offset, info );
+ return true;
+ }
+
+ *info = calloc( 1, sizeof(struct arg_type_info) );
+ if( *info == NULL )
+ {
+ complain(type_die, "alloc error");
+ return false;
+ }
+ type_init_pointer(*info, NULL, 0);
+
+ complain(type_die, "Storing pointer type: %p", *info);
+ dict_insert( &type_hash, &die_offset, info );
+ return getType( &(*info)->u.ptr_info.info, &next_die );
+
+ case DW_TAG_structure_type:
+ *info = calloc( 1, sizeof(struct arg_type_info) );
+ if( *info == NULL )
+ {
+ complain(type_die, "alloc error");
+ return false;
+ }
+
+ complain(type_die, "Storing struct type: %p", *info);
+ dict_insert( &type_hash, &die_offset, info );
+ return getStructure( *info, type_die );
+
+
+ case DW_TAG_typedef: ;
+ case DW_TAG_const_type: ;
+ case DW_TAG_volatile_type: ;
+ // Various tags are simply pass-through, so I just keep going
+ bool res = true;
+ if( getTypeDie(&next_die, type_die ) )
+ {
+ complain(type_die, "Storing const/typedef type: %p", *info);
+ res = getType( info, &next_die );
+ }
+ else
+ {
+ // no type. Use 'void'. Normally I'd think this is bogus, but stdio
+ // typedefs something to void
+ *info = type_get_simple( ARGTYPE_VOID );
+ complain(type_die, "Storing void type: %p", *info);
+ }
+ if( res )
+ dict_insert( &type_hash, &die_offset, info );
+ return res;
+
+ case DW_TAG_enumeration_type:
+ // We have an enumeration. This has type "int", but has a particular
+ // lens to handle the enum
+ *info = calloc( 1, sizeof(struct arg_type_info) );
+ if( *info == NULL )
+ {
+ complain(type_die, "alloc error");
+ return false;
+ }
+
+ complain(type_die, "Storing enum int: %p", *info);
+ dict_insert( &type_hash, &die_offset, info );
+ return getEnum( *info, type_die );
+
+ case DW_TAG_array_type:
+ *info = calloc( 1, sizeof(struct arg_type_info) );
+ if( *info == NULL )
+ {
+ complain(type_die, "alloc error");
+ return false;
+ }
+
+ complain(type_die, "Storing array: %p", *info);
+ dict_insert( &type_hash, &die_offset, info );
+ return getArray( *info, type_die );
+
+ default:
+ complain(type_die, "Unknown type tag 0x%x", dwarf_tag(type_die));
+ break;
+ }
+
+ return false;
+}
+
+static bool getPrototype(struct prototype* proto, Dwarf_Die* subroutine)
+{
+ // First, look at the return type. This is stored in a DW_AT_type tag in the
+ // subroutine DIE. If there is no such tag, this function returns void
+ Dwarf_Die return_type_die;
+ if( !getTypeDie(&return_type_die, subroutine ) )
+ {
+ proto->return_info = type_get_simple( ARGTYPE_VOID );
+ proto->own_return_info = 0;
+ }
+ else
+ {
+ proto->return_info = calloc( 1, sizeof( struct arg_type_info ) );
+ if( proto->return_info == NULL )
+ {
+ complain(subroutine, "Couldn't alloc return type");
+ return false;
+ }
+ proto->own_return_info = 0;
+
+ if( !getType( &proto->return_info, &return_type_die ) )
+ {
+ complain(subroutine, "Couldn't get return type");
+ return false;
+ }
+ }
+
+
+ // Now look at the arguments
+ Dwarf_Die arg_die;
+ if( dwarf_child(subroutine, &arg_die) != 0 )
+ {
+ // no args. We're done
+ return true;
+ }
+
+ while(1) {
+ if( dwarf_tag(&arg_die) != DW_TAG_formal_parameter )
+ goto next_prototype_argument;
+
+ complain(&arg_die, "arg: 0x%02x", dwarf_tag(&arg_die));
+
+ Dwarf_Die type_die;
+ if( !getTypeDie(&type_die, &arg_die ) )
+ {
+ complain(&arg_die, "Couldn't get the argument type die");
+ return false;
+ }
+
+ struct arg_type_info* arg_type_info = NULL;
+ if( !getType( &arg_type_info, &type_die ) )
+ {
+ complain(&arg_die, "Couldn't parse arg type from DWARF data");
+ return false;
+ }
+
+ struct param param;
+ param_init_type(¶m, arg_type_info, 0);
+ if( prototype_push_param(proto, ¶m) <0 )
+ {
+ complain(&arg_die, "couldn't add argument to the prototype");
+ return false;
+ }
+
+ next_prototype_argument: ;
+ int res = dwarf_siblingof(&arg_die, &arg_die);
+ if( res == 0 ) continue; /* sibling exists */
+ if( res < 0 ) return false; /* error */
+ break; /* no sibling exists */
+ }
+
+ return true;
+}
+
+static bool process_die_compileunit(struct protolib* plib, struct library* lib, Dwarf_Die* parent)
+{
+ Dwarf_Die die;
+ if( dwarf_child(parent, &die) != 0 )
+ return false;
+
+ while(1)
+ {
+ if( dwarf_tag(&die) == DW_TAG_subprogram )
+ {
+ const char* function_name = dwarf_diename(&die);
+
+ complain(&die, "subroutine_type: 0x%02x; function '%s'", dwarf_tag(&die), function_name);
+
+ struct prototype* proto =
+ protolib_lookup_prototype(plib, function_name, true );
+
+ if( proto != NULL )
+ {
+ complain(&die, "Prototype already exists. Skipping");
+ goto next_prototype;
+ }
+
+ if( !filter_matches_symbol(options.plt_filter, function_name, lib) &&
+ !filter_matches_symbol(options.static_filter, function_name, lib) &&
+ !filter_matches_symbol(options.export_filter, function_name, lib) )
+ {
+ complain(&die, "Prototype not requested by any filter");
+ goto next_prototype;
+ }
+
+ proto = malloc(sizeof(struct prototype));
+ if( proto == NULL )
+ {
+ complain(&die, "couldn't alloc prototype");
+ return false;
+ }
+ prototype_init( proto );
+
+ if( !getPrototype(proto, &die ) )
+ {
+ complain(&die, "couldn't get prototype");
+ return false;
+ }
+
+ protolib_add_prototype(plib, function_name, 0, proto);
+ }
+
+ next_prototype:;
+ int res = dwarf_siblingof(&die, &die);
+ if( res == 0 ) continue; /* sibling exists */
+ if( res < 0 ) return false; /* error */
+ break; /* no sibling exists */
+ }
+
+ return true;
+}
+
+static bool import( struct protolib* plib, struct library* lib, Dwfl* dwfl )
+{
+ dict_init(&type_hash, sizeof(Dwarf_Off), sizeof(struct arg_type_info*),
+ dwarf_die_hash, dwarf_die_eq, NULL );
+
+ Dwarf_Addr bias;
+ Dwarf_Die* die = NULL;
+ while( (die = dwfl_nextcu(dwfl, die, &bias)) != NULL )
+ {
+ if( dwarf_tag(die) == DW_TAG_compile_unit )
+ {
+ if( !process_die_compileunit(plib, lib, die) )
+ {
+ complain(die, "Error reading compile unit");
+ exit(1);
+ return false;
+ }
+ }
+ else
+ {
+ complain(die, "DW_TAG_compile_unit expected");
+ exit(1);
+ return false;
+ }
+ }
+
+ dict_destroy( &type_hash, NULL, NULL, NULL );
+ return true;
+}
+
+bool import_DWARF_prototypes( struct protolib* plib, struct library* lib,
+ Dwfl *dwfl )
+{
+ if( plib == NULL )
+ {
+ plib = protolib_cache_default(&g_protocache, lib->soname, 0);
+ if (plib == NULL)
+ {
+ fprintf(stderr, "Error loading protolib %s: %s.\n",
+ lib->soname, strerror(errno));
+ }
+ }
+
+ return import(plib, lib, dwfl);
+}
+
+/*
+- I handle static functions now. Should I? Those do not have DW_AT_external==1
+
+- should process existing prototypes to make sure they match
+
+- what do function pointers look like? I'm doing void*
+
+- unions
+
+- all my *allocs leak
+
+- protolib_lookup_prototype should look for imports?
+
+*/
projects / platform / upstream / ltrace.git / commitdiff