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Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/tree-mudflap.c')
| -rw-r--r-- | gcc-4.2.1-5666.3/gcc/tree-mudflap.c | 1345 |
1 files changed, 1345 insertions, 0 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/tree-mudflap.c b/gcc-4.2.1-5666.3/gcc/tree-mudflap.c new file mode 100644 index 000000000..54cedb844 --- /dev/null +++ b/gcc-4.2.1-5666.3/gcc/tree-mudflap.c @@ -0,0 +1,1345 @@ +/* Mudflap: narrow-pointer bounds-checking by tree rewriting. + Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc. + Contributed by Frank Ch. Eigler <fche@redhat.com> + and Graydon Hoare <graydon@redhat.com> + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING. If not, write to the Free +Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301, USA. */ + + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "hard-reg-set.h" +#include "rtl.h" +#include "tree.h" +#include "tm_p.h" +#include "basic-block.h" +#include "flags.h" +#include "function.h" +#include "tree-inline.h" +#include "tree-gimple.h" +#include "tree-flow.h" +#include "tree-mudflap.h" +#include "tree-dump.h" +#include "tree-pass.h" +#include "hashtab.h" +#include "diagnostic.h" +#include <demangle.h> +#include "langhooks.h" +#include "ggc.h" +#include "cgraph.h" +#include "toplev.h" + +/* Internal function decls */ + + +/* Options. */ +#define flag_mudflap_threads (flag_mudflap == 2) + +/* Helpers. */ +static tree mf_build_string (const char *string); +static tree mf_varname_tree (tree); +static tree mf_file_function_line_tree (location_t); + +/* Indirection-related instrumentation. */ +static void mf_decl_cache_locals (void); +static void mf_decl_clear_locals (void); +static void mf_xform_derefs (void); +static unsigned int execute_mudflap_function_ops (void); + +/* Addressable variables instrumentation. */ +static void mf_xform_decls (tree, tree); +static tree mx_xfn_xform_decls (tree *, int *, void *); +static void mx_register_decls (tree, tree *); +static unsigned int execute_mudflap_function_decls (void); + + +/* ------------------------------------------------------------------------ */ +/* Some generally helpful functions for mudflap instrumentation. */ + +/* Build a reference to a literal string. */ +static tree +mf_build_string (const char *string) +{ + size_t len = strlen (string); + tree result = mf_mark (build_string (len + 1, string)); + + TREE_TYPE (result) = build_array_type + (char_type_node, build_index_type (build_int_cst (NULL_TREE, len))); + TREE_CONSTANT (result) = 1; + TREE_INVARIANT (result) = 1; + TREE_READONLY (result) = 1; + TREE_STATIC (result) = 1; + + result = build1 (ADDR_EXPR, build_pointer_type (char_type_node), result); + + return mf_mark (result); +} + +/* Create a properly typed STRING_CST node that describes the given + declaration. It will be used as an argument for __mf_register(). + Try to construct a helpful string, including file/function/variable + name. */ + +static tree +mf_varname_tree (tree decl) +{ + static pretty_printer buf_rec; + static int initialized = 0; + pretty_printer *buf = & buf_rec; + const char *buf_contents; + tree result; + + gcc_assert (decl); + + if (!initialized) + { + pp_construct (buf, /* prefix */ NULL, /* line-width */ 0); + initialized = 1; + } + pp_clear_output_area (buf); + + /* Add FILENAME[:LINENUMBER[:COLUMNNUMBER]]. */ + { + expanded_location xloc = expand_location (DECL_SOURCE_LOCATION (decl)); + const char *sourcefile; + unsigned sourceline = xloc.line; + unsigned sourcecolumn = 0; +#ifdef USE_MAPPED_LOCATION + sourcecolumn = xloc.column; +#endif + sourcefile = xloc.file; + if (sourcefile == NULL && current_function_decl != NULL_TREE) + sourcefile = DECL_SOURCE_FILE (current_function_decl); + if (sourcefile == NULL) + sourcefile = "<unknown file>"; + + pp_string (buf, sourcefile); + + if (sourceline != 0) + { + pp_string (buf, ":"); + pp_decimal_int (buf, sourceline); + + if (sourcecolumn != 0) + { + pp_string (buf, ":"); + pp_decimal_int (buf, sourcecolumn); + } + } + } + + if (current_function_decl != NULL_TREE) + { + /* Add (FUNCTION) */ + pp_string (buf, " ("); + { + const char *funcname = NULL; + if (DECL_NAME (current_function_decl)) + funcname = lang_hooks.decl_printable_name (current_function_decl, 1); + if (funcname == NULL) + funcname = "anonymous fn"; + + pp_string (buf, funcname); + } + pp_string (buf, ") "); + } + else + pp_string (buf, " "); + + /* Add <variable-declaration>, possibly demangled. */ + { + const char *declname = NULL; + + if (DECL_NAME (decl) != NULL) + { + if (strcmp ("GNU C++", lang_hooks.name) == 0) + { + /* The gcc/cp decl_printable_name hook doesn't do as good a job as + the libiberty demangler. */ + declname = cplus_demangle (IDENTIFIER_POINTER (DECL_NAME (decl)), + DMGL_AUTO | DMGL_VERBOSE); + } + if (declname == NULL) + declname = lang_hooks.decl_printable_name (decl, 3); + } + if (declname == NULL) + declname = "<unnamed variable>"; + + pp_string (buf, declname); + } + + /* Return the lot as a new STRING_CST. */ + buf_contents = pp_base_formatted_text (buf); + result = mf_build_string (buf_contents); + pp_clear_output_area (buf); + + return result; +} + + +/* And another friend, for producing a simpler message. */ + +static tree +mf_file_function_line_tree (location_t location) +{ + expanded_location xloc = expand_location (location); + const char *file = NULL, *colon, *line, *op, *name, *cp; + char linecolbuf[30]; /* Enough for two decimal numbers plus a colon. */ + char *string; + tree result; + + /* Add FILENAME[:LINENUMBER[:COLUMNNUMBER]]. */ + file = xloc.file; + if (file == NULL && current_function_decl != NULL_TREE) + file = DECL_SOURCE_FILE (current_function_decl); + if (file == NULL) + file = "<unknown file>"; + + if (xloc.line > 0) + { +#ifdef USE_MAPPED_LOCATION + if (xloc.column > 0) + sprintf (linecolbuf, "%d:%d", xloc.line, xloc.column); + else +#endif + sprintf (linecolbuf, "%d", xloc.line); + colon = ":"; + line = linecolbuf; + } + else + colon = line = ""; + + /* Add (FUNCTION). */ + name = lang_hooks.decl_printable_name (current_function_decl, 1); + if (name) + { + op = " ("; + cp = ")"; + } + else + op = name = cp = ""; + + string = concat (file, colon, line, op, name, cp, NULL); + result = mf_build_string (string); + free (string); + + return result; +} + + +/* global tree nodes */ + +/* Global tree objects for global variables and functions exported by + mudflap runtime library. mf_init_extern_trees must be called + before using these. */ + +/* uintptr_t (usually "unsigned long") */ +static GTY (()) tree mf_uintptr_type; + +/* struct __mf_cache { uintptr_t low; uintptr_t high; }; */ +static GTY (()) tree mf_cache_struct_type; + +/* struct __mf_cache * const */ +static GTY (()) tree mf_cache_structptr_type; + +/* extern struct __mf_cache __mf_lookup_cache []; */ +static GTY (()) tree mf_cache_array_decl; + +/* extern unsigned char __mf_lc_shift; */ +static GTY (()) tree mf_cache_shift_decl; + +/* extern uintptr_t __mf_lc_mask; */ +static GTY (()) tree mf_cache_mask_decl; + +/* Their function-scope local shadows, used in single-threaded mode only. */ + +/* auto const unsigned char __mf_lc_shift_l; */ +static GTY (()) tree mf_cache_shift_decl_l; + +/* auto const uintptr_t __mf_lc_mask_l; */ +static GTY (()) tree mf_cache_mask_decl_l; + +/* extern void __mf_check (void *ptr, size_t sz, int type, const char *); */ +static GTY (()) tree mf_check_fndecl; + +/* extern void __mf_register (void *ptr, size_t sz, int type, const char *); */ +static GTY (()) tree mf_register_fndecl; + +/* extern void __mf_unregister (void *ptr, size_t sz, int type); */ +static GTY (()) tree mf_unregister_fndecl; + +/* extern void __mf_init (); */ +static GTY (()) tree mf_init_fndecl; + +/* extern int __mf_set_options (const char*); */ +static GTY (()) tree mf_set_options_fndecl; + + +/* Helper for mudflap_init: construct a decl with the given category, + name, and type, mark it an external reference, and pushdecl it. */ +static inline tree +mf_make_builtin (enum tree_code category, const char *name, tree type) +{ + tree decl = mf_mark (build_decl (category, get_identifier (name), type)); + TREE_PUBLIC (decl) = 1; + DECL_EXTERNAL (decl) = 1; + lang_hooks.decls.pushdecl (decl); + return decl; +} + +/* Helper for mudflap_init: construct a tree corresponding to the type + struct __mf_cache { uintptr_t low; uintptr_t high; }; + where uintptr_t is the FIELD_TYPE argument. */ +static inline tree +mf_make_mf_cache_struct_type (tree field_type) +{ + /* There is, abominably, no language-independent way to construct a + RECORD_TYPE. So we have to call the basic type construction + primitives by hand. */ + tree fieldlo = build_decl (FIELD_DECL, get_identifier ("low"), field_type); + tree fieldhi = build_decl (FIELD_DECL, get_identifier ("high"), field_type); + + tree struct_type = make_node (RECORD_TYPE); + DECL_CONTEXT (fieldlo) = struct_type; + DECL_CONTEXT (fieldhi) = struct_type; + TREE_CHAIN (fieldlo) = fieldhi; + TYPE_FIELDS (struct_type) = fieldlo; + TYPE_NAME (struct_type) = get_identifier ("__mf_cache"); + layout_type (struct_type); + + return struct_type; +} + +#define build_function_type_0(rtype) \ + build_function_type (rtype, void_list_node) +#define build_function_type_1(rtype, arg1) \ + build_function_type (rtype, tree_cons (0, arg1, void_list_node)) +#define build_function_type_3(rtype, arg1, arg2, arg3) \ + build_function_type (rtype, tree_cons (0, arg1, tree_cons (0, arg2, \ + tree_cons (0, arg3, void_list_node)))) +#define build_function_type_4(rtype, arg1, arg2, arg3, arg4) \ + build_function_type (rtype, tree_cons (0, arg1, tree_cons (0, arg2, \ + tree_cons (0, arg3, tree_cons (0, arg4, \ + void_list_node))))) + +/* Initialize the global tree nodes that correspond to mf-runtime.h + declarations. */ +void +mudflap_init (void) +{ + static bool done = false; + tree mf_const_string_type; + tree mf_cache_array_type; + tree mf_check_register_fntype; + tree mf_unregister_fntype; + tree mf_init_fntype; + tree mf_set_options_fntype; + + if (done) + return; + done = true; + + mf_uintptr_type = lang_hooks.types.type_for_mode (ptr_mode, + /*unsignedp=*/true); + mf_const_string_type + = build_pointer_type (build_qualified_type + (char_type_node, TYPE_QUAL_CONST)); + + mf_cache_struct_type = mf_make_mf_cache_struct_type (mf_uintptr_type); + mf_cache_structptr_type = build_pointer_type (mf_cache_struct_type); + mf_cache_array_type = build_array_type (mf_cache_struct_type, 0); + mf_check_register_fntype = + build_function_type_4 (void_type_node, ptr_type_node, size_type_node, + integer_type_node, mf_const_string_type); + mf_unregister_fntype = + build_function_type_3 (void_type_node, ptr_type_node, size_type_node, + integer_type_node); + mf_init_fntype = + build_function_type_0 (void_type_node); + mf_set_options_fntype = + build_function_type_1 (integer_type_node, mf_const_string_type); + + mf_cache_array_decl = mf_make_builtin (VAR_DECL, "__mf_lookup_cache", + mf_cache_array_type); + mf_cache_shift_decl = mf_make_builtin (VAR_DECL, "__mf_lc_shift", + unsigned_char_type_node); + mf_cache_mask_decl = mf_make_builtin (VAR_DECL, "__mf_lc_mask", + mf_uintptr_type); + /* Don't process these in mudflap_enqueue_decl, should they come by + there for some reason. */ + mf_mark (mf_cache_array_decl); + mf_mark (mf_cache_shift_decl); + mf_mark (mf_cache_mask_decl); + mf_check_fndecl = mf_make_builtin (FUNCTION_DECL, "__mf_check", + mf_check_register_fntype); + mf_register_fndecl = mf_make_builtin (FUNCTION_DECL, "__mf_register", + mf_check_register_fntype); + mf_unregister_fndecl = mf_make_builtin (FUNCTION_DECL, "__mf_unregister", + mf_unregister_fntype); + mf_init_fndecl = mf_make_builtin (FUNCTION_DECL, "__mf_init", + mf_init_fntype); + mf_set_options_fndecl = mf_make_builtin (FUNCTION_DECL, "__mf_set_options", + mf_set_options_fntype); +} +#undef build_function_type_4 +#undef build_function_type_3 +#undef build_function_type_1 +#undef build_function_type_0 + + +/* ------------------------------------------------------------------------ */ +/* Memory reference transforms. Perform the mudflap indirection-related + tree transforms on the current function. + + This is the second part of the mudflap instrumentation. It works on + low-level GIMPLE using the CFG, because we want to run this pass after + tree optimizations have been performed, but we have to preserve the CFG + for expansion from trees to RTL. */ + +static unsigned int +execute_mudflap_function_ops (void) +{ + /* Don't instrument functions such as the synthetic constructor + built during mudflap_finish_file. */ + if (mf_marked_p (current_function_decl) || + DECL_ARTIFICIAL (current_function_decl)) + return 0; + + push_gimplify_context (); + + /* In multithreaded mode, don't cache the lookup cache parameters. */ + if (! flag_mudflap_threads) + mf_decl_cache_locals (); + + mf_xform_derefs (); + + if (! flag_mudflap_threads) + mf_decl_clear_locals (); + + pop_gimplify_context (NULL); + return 0; +} + +/* Create and initialize local shadow variables for the lookup cache + globals. Put their decls in the *_l globals for use by + mf_build_check_statement_for. */ + +static void +mf_decl_cache_locals (void) +{ + tree t, shift_init_stmts, mask_init_stmts; + tree_stmt_iterator tsi; + + /* Build the cache vars. */ + mf_cache_shift_decl_l + = mf_mark (create_tmp_var (TREE_TYPE (mf_cache_shift_decl), + "__mf_lookup_shift_l")); + + mf_cache_mask_decl_l + = mf_mark (create_tmp_var (TREE_TYPE (mf_cache_mask_decl), + "__mf_lookup_mask_l")); + + /* Build initialization nodes for the cache vars. We just load the + globals into the cache variables. */ + t = build2 (MODIFY_EXPR, TREE_TYPE (mf_cache_shift_decl_l), + mf_cache_shift_decl_l, mf_cache_shift_decl); + SET_EXPR_LOCATION (t, DECL_SOURCE_LOCATION (current_function_decl)); + gimplify_to_stmt_list (&t); + shift_init_stmts = t; + + t = build2 (MODIFY_EXPR, TREE_TYPE (mf_cache_mask_decl_l), + mf_cache_mask_decl_l, mf_cache_mask_decl); + SET_EXPR_LOCATION (t, DECL_SOURCE_LOCATION (current_function_decl)); + gimplify_to_stmt_list (&t); + mask_init_stmts = t; + + /* Anticipating multiple entry points, we insert the cache vars + initializers in each successor of the ENTRY_BLOCK_PTR. */ + for (tsi = tsi_start (shift_init_stmts); + ! tsi_end_p (tsi); + tsi_next (&tsi)) + insert_edge_copies (tsi_stmt (tsi), ENTRY_BLOCK_PTR); + + for (tsi = tsi_start (mask_init_stmts); + ! tsi_end_p (tsi); + tsi_next (&tsi)) + insert_edge_copies (tsi_stmt (tsi), ENTRY_BLOCK_PTR); + bsi_commit_edge_inserts (); +} + + +static void +mf_decl_clear_locals (void) +{ + /* Unset local shadows. */ + mf_cache_shift_decl_l = NULL_TREE; + mf_cache_mask_decl_l = NULL_TREE; +} + +static void +mf_build_check_statement_for (tree base, tree limit, + block_stmt_iterator *instr_bsi, + location_t *locus, tree dirflag) +{ + tree_stmt_iterator head, tsi; + block_stmt_iterator bsi; + basic_block cond_bb, then_bb, join_bb; + edge e; + tree cond, t, u, v; + tree mf_base; + tree mf_elem; + tree mf_limit; + + /* We first need to split the current basic block, and start altering + the CFG. This allows us to insert the statements we're about to + construct into the right basic blocks. */ + + cond_bb = bb_for_stmt (bsi_stmt (*instr_bsi)); + bsi = *instr_bsi; + bsi_prev (&bsi); + if (! bsi_end_p (bsi)) + e = split_block (cond_bb, bsi_stmt (bsi)); + else + e = split_block_after_labels (cond_bb); + cond_bb = e->src; + join_bb = e->dest; + + /* A recap at this point: join_bb is the basic block at whose head + is the gimple statement for which this check expression is being + built. cond_bb is the (possibly new, synthetic) basic block the + end of which will contain the cache-lookup code, and a + conditional that jumps to the cache-miss code or, much more + likely, over to join_bb. */ + + /* Create the bb that contains the cache-miss fallback block (mf_check). */ + then_bb = create_empty_bb (cond_bb); + make_edge (cond_bb, then_bb, EDGE_TRUE_VALUE); + make_single_succ_edge (then_bb, join_bb, EDGE_FALLTHRU); + + /* Mark the pseudo-fallthrough edge from cond_bb to join_bb. */ + e = find_edge (cond_bb, join_bb); + e->flags = EDGE_FALSE_VALUE; + e->count = cond_bb->count; + e->probability = REG_BR_PROB_BASE; + + /* Update dominance info. Note that bb_join's data was + updated by split_block. */ + if (dom_info_available_p (CDI_DOMINATORS)) + { + set_immediate_dominator (CDI_DOMINATORS, then_bb, cond_bb); + set_immediate_dominator (CDI_DOMINATORS, join_bb, cond_bb); + } + + /* Build our local variables. */ + mf_elem = create_tmp_var (mf_cache_structptr_type, "__mf_elem"); + mf_base = create_tmp_var (mf_uintptr_type, "__mf_base"); + mf_limit = create_tmp_var (mf_uintptr_type, "__mf_limit"); + + /* Build: __mf_base = (uintptr_t) <base address expression>. */ + t = build2 (MODIFY_EXPR, void_type_node, mf_base, + convert (mf_uintptr_type, unshare_expr (base))); + SET_EXPR_LOCUS (t, locus); + gimplify_to_stmt_list (&t); + head = tsi_start (t); + tsi = tsi_last (t); + + /* Build: __mf_limit = (uintptr_t) <limit address expression>. */ + t = build2 (MODIFY_EXPR, void_type_node, mf_limit, + convert (mf_uintptr_type, unshare_expr (limit))); + SET_EXPR_LOCUS (t, locus); + gimplify_to_stmt_list (&t); + tsi_link_after (&tsi, t, TSI_CONTINUE_LINKING); + + /* Build: __mf_elem = &__mf_lookup_cache [(__mf_base >> __mf_shift) + & __mf_mask]. */ + t = build2 (RSHIFT_EXPR, mf_uintptr_type, mf_base, + (flag_mudflap_threads ? mf_cache_shift_decl : mf_cache_shift_decl_l)); + t = build2 (BIT_AND_EXPR, mf_uintptr_type, t, + (flag_mudflap_threads ? mf_cache_mask_decl : mf_cache_mask_decl_l)); + t = build4 (ARRAY_REF, + TREE_TYPE (TREE_TYPE (mf_cache_array_decl)), + mf_cache_array_decl, t, NULL_TREE, NULL_TREE); + t = build1 (ADDR_EXPR, mf_cache_structptr_type, t); + t = build2 (MODIFY_EXPR, void_type_node, mf_elem, t); + SET_EXPR_LOCUS (t, locus); + gimplify_to_stmt_list (&t); + tsi_link_after (&tsi, t, TSI_CONTINUE_LINKING); + + /* Quick validity check. + + if (__mf_elem->low > __mf_base + || (__mf_elem_high < __mf_limit)) + { + __mf_check (); + ... and only if single-threaded: + __mf_lookup_shift_1 = f...; + __mf_lookup_mask_l = ...; + } + + It is expected that this body of code is rarely executed so we mark + the edge to the THEN clause of the conditional jump as unlikely. */ + + /* Construct t <-- '__mf_elem->low > __mf_base'. */ + t = build3 (COMPONENT_REF, mf_uintptr_type, + build1 (INDIRECT_REF, mf_cache_struct_type, mf_elem), + TYPE_FIELDS (mf_cache_struct_type), NULL_TREE); + t = build2 (GT_EXPR, boolean_type_node, t, mf_base); + + /* Construct '__mf_elem->high < __mf_limit'. + + First build: + 1) u <-- '__mf_elem->high' + 2) v <-- '__mf_limit'. + + Then build 'u <-- (u < v). */ + + u = build3 (COMPONENT_REF, mf_uintptr_type, + build1 (INDIRECT_REF, mf_cache_struct_type, mf_elem), + TREE_CHAIN (TYPE_FIELDS (mf_cache_struct_type)), NULL_TREE); + + v = mf_limit; + + u = build2 (LT_EXPR, boolean_type_node, u, v); + + /* Build the composed conditional: t <-- 't || u'. Then store the + result of the evaluation of 't' in a temporary variable which we + can use as the condition for the conditional jump. */ + t = build2 (TRUTH_OR_EXPR, boolean_type_node, t, u); + cond = create_tmp_var (boolean_type_node, "__mf_unlikely_cond"); + t = build2 (MODIFY_EXPR, boolean_type_node, cond, t); + gimplify_to_stmt_list (&t); + tsi_link_after (&tsi, t, TSI_CONTINUE_LINKING); + + /* Build the conditional jump. 'cond' is just a temporary so we can + simply build a void COND_EXPR. We do need labels in both arms though. */ + t = build3 (COND_EXPR, void_type_node, cond, + build1 (GOTO_EXPR, void_type_node, tree_block_label (then_bb)), + build1 (GOTO_EXPR, void_type_node, tree_block_label (join_bb))); + SET_EXPR_LOCUS (t, locus); + tsi_link_after (&tsi, t, TSI_CONTINUE_LINKING); + + /* At this point, after so much hard work, we have only constructed + the conditional jump, + + if (__mf_elem->low > __mf_base + || (__mf_elem_high < __mf_limit)) + + The lowered GIMPLE tree representing this code is in the statement + list starting at 'head'. + + We can insert this now in the current basic block, i.e. the one that + the statement we're instrumenting was originally in. */ + bsi = bsi_last (cond_bb); + for (tsi = head; ! tsi_end_p (tsi); tsi_next (&tsi)) + bsi_insert_after (&bsi, tsi_stmt (tsi), BSI_CONTINUE_LINKING); + + /* Now build up the body of the cache-miss handling: + + __mf_check(); + refresh *_l vars. + + This is the body of the conditional. */ + + u = tree_cons (NULL_TREE, + mf_file_function_line_tree (locus == NULL ? UNKNOWN_LOCATION + : *locus), + NULL_TREE); + u = tree_cons (NULL_TREE, dirflag, u); + /* NB: we pass the overall [base..limit] range to mf_check. */ + u = tree_cons (NULL_TREE, + fold_build2 (PLUS_EXPR, integer_type_node, + fold_build2 (MINUS_EXPR, mf_uintptr_type, mf_limit, mf_base), + integer_one_node), + u); + u = tree_cons (NULL_TREE, mf_base, u); + t = build_function_call_expr (mf_check_fndecl, u); + gimplify_to_stmt_list (&t); + head = tsi_start (t); + tsi = tsi_last (t); + + if (! flag_mudflap_threads) + { + t = build2 (MODIFY_EXPR, void_type_node, + mf_cache_shift_decl_l, mf_cache_shift_decl); + tsi_link_after (&tsi, t, TSI_CONTINUE_LINKING); + + t = build2 (MODIFY_EXPR, void_type_node, + mf_cache_mask_decl_l, mf_cache_mask_decl); + tsi_link_after (&tsi, t, TSI_CONTINUE_LINKING); + } + + /* Insert the check code in the THEN block. */ + bsi = bsi_start (then_bb); + for (tsi = head; ! tsi_end_p (tsi); tsi_next (&tsi)) + bsi_insert_after (&bsi, tsi_stmt (tsi), BSI_CONTINUE_LINKING); + + *instr_bsi = bsi_start (join_bb); + bsi_next (instr_bsi); +} + + +/* Check whether the given decl, generally a VAR_DECL or PARM_DECL, is + eligible for instrumentation. For the mudflap1 pass, this implies + that it should be registered with the libmudflap runtime. For the + mudflap2 pass this means instrumenting an indirection operation with + respect to the object. +*/ +static int +mf_decl_eligible_p (tree decl) +{ + return ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL) + /* The decl must have its address taken. In the case of + arrays, this flag is also set if the indexes are not + compile-time known valid constants. */ + && TREE_ADDRESSABLE (decl) /* XXX: not sufficient: return-by-value structs! */ + /* The type of the variable must be complete. */ + && COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (decl)) + /* The decl hasn't been decomposed somehow. */ + && !DECL_HAS_VALUE_EXPR_P (decl)); +} + + +static void +mf_xform_derefs_1 (block_stmt_iterator *iter, tree *tp, + location_t *locus, tree dirflag) +{ + tree type, base, limit, addr, size, t; + + /* Don't instrument read operations. */ + if (dirflag == integer_zero_node && flag_mudflap_ignore_reads) + return; + + /* Don't instrument marked nodes. */ + if (mf_marked_p (*tp)) + return; + + t = *tp; + type = TREE_TYPE (t); + + if (type == error_mark_node) + return; + + size = TYPE_SIZE_UNIT (type); + + switch (TREE_CODE (t)) + { + case ARRAY_REF: + case COMPONENT_REF: + { + /* This is trickier than it may first appear. The reason is + that we are looking at expressions from the "inside out" at + this point. We may have a complex nested aggregate/array + expression (e.g. "a.b[i].c"), maybe with an indirection as + the leftmost operator ("p->a.b.d"), where instrumentation + is necessary. Or we may have an innocent "a.b.c" + expression that must not be instrumented. We need to + recurse all the way down the nesting structure to figure it + out: looking just at the outer node is not enough. */ + tree var; + int component_ref_only = (TREE_CODE (t) == COMPONENT_REF); + /* If we have a bitfield component reference, we must note the + innermost addressable object in ELT, from which we will + construct the byte-addressable bounds of the bitfield. */ + tree elt = NULL_TREE; + int bitfield_ref_p = (TREE_CODE (t) == COMPONENT_REF + && DECL_BIT_FIELD_TYPE (TREE_OPERAND (t, 1))); + + /* Iterate to the top of the ARRAY_REF/COMPONENT_REF + containment hierarchy to find the outermost VAR_DECL. */ + var = TREE_OPERAND (t, 0); + while (1) + { + if (bitfield_ref_p && elt == NULL_TREE + && (TREE_CODE (var) == ARRAY_REF || TREE_CODE (var) == COMPONENT_REF)) + elt = var; + + if (TREE_CODE (var) == ARRAY_REF) + { + component_ref_only = 0; + var = TREE_OPERAND (var, 0); + } + else if (TREE_CODE (var) == COMPONENT_REF) + var = TREE_OPERAND (var, 0); + else if (INDIRECT_REF_P (var)) + { + base = TREE_OPERAND (var, 0); + break; + } + else + { + gcc_assert (TREE_CODE (var) == VAR_DECL + || TREE_CODE (var) == PARM_DECL + || TREE_CODE (var) == RESULT_DECL + || TREE_CODE (var) == STRING_CST); + /* Don't instrument this access if the underlying + variable is not "eligible". This test matches + those arrays that have only known-valid indexes, + and thus are not labeled TREE_ADDRESSABLE. */ + if (! mf_decl_eligible_p (var) || component_ref_only) + return; + else + { + base = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (var)), var); + break; + } + } + } + + /* Handle the case of ordinary non-indirection structure + accesses. These have only nested COMPONENT_REF nodes (no + INDIRECT_REF), but pass through the above filter loop. + Note that it's possible for such a struct variable to match + the eligible_p test because someone else might take its + address sometime. */ + + /* We need special processing for bitfield components, because + their addresses cannot be taken. */ + if (bitfield_ref_p) + { + tree field = TREE_OPERAND (t, 1); + + if (TREE_CODE (DECL_SIZE_UNIT (field)) == INTEGER_CST) + size = DECL_SIZE_UNIT (field); + + if (elt) + elt = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (elt)), elt); + addr = fold_convert (ptr_type_node, elt ? elt : base); + addr = fold_build2 (PLUS_EXPR, ptr_type_node, + addr, fold_convert (ptr_type_node, + byte_position (field))); + } + else + addr = build1 (ADDR_EXPR, build_pointer_type (type), t); + + limit = fold_build2 (MINUS_EXPR, mf_uintptr_type, + fold_build2 (PLUS_EXPR, mf_uintptr_type, + convert (mf_uintptr_type, addr), + size), + integer_one_node); + } + break; + + case INDIRECT_REF: + addr = TREE_OPERAND (t, 0); + base = addr; + limit = fold_build2 (MINUS_EXPR, ptr_type_node, + fold_build2 (PLUS_EXPR, ptr_type_node, base, size), + integer_one_node); + break; + + case TARGET_MEM_REF: + addr = tree_mem_ref_addr (ptr_type_node, t); + base = addr; + limit = fold_build2 (MINUS_EXPR, ptr_type_node, + fold_build2 (PLUS_EXPR, ptr_type_node, base, size), + build_int_cst (ptr_type_node, 1)); + break; + + case ARRAY_RANGE_REF: + warning (0, "mudflap checking not yet implemented for ARRAY_RANGE_REF"); + return; + + case BIT_FIELD_REF: + /* ??? merge with COMPONENT_REF code above? */ + { + tree ofs, rem, bpu; + + /* If we're not dereferencing something, then the access + must be ok. */ + if (TREE_CODE (TREE_OPERAND (t, 0)) != INDIRECT_REF) + return; + + bpu = bitsize_int (BITS_PER_UNIT); + ofs = convert (bitsizetype, TREE_OPERAND (t, 2)); + rem = size_binop (TRUNC_MOD_EXPR, ofs, bpu); + ofs = size_binop (TRUNC_DIV_EXPR, ofs, bpu); + + size = convert (bitsizetype, TREE_OPERAND (t, 1)); + size = size_binop (PLUS_EXPR, size, rem); + size = size_binop (CEIL_DIV_EXPR, size, bpu); + size = convert (sizetype, size); + + addr = TREE_OPERAND (TREE_OPERAND (t, 0), 0); + addr = convert (ptr_type_node, addr); + addr = fold_build2 (PLUS_EXPR, ptr_type_node, addr, ofs); + + base = addr; + limit = fold_build2 (MINUS_EXPR, ptr_type_node, + fold_build2 (PLUS_EXPR, ptr_type_node, base, size), + integer_one_node); + } + break; + + default: + return; + } + + mf_build_check_statement_for (base, limit, iter, locus, dirflag); +} + +static void +mf_xform_derefs (void) +{ + basic_block bb, next; + block_stmt_iterator i; + int saved_last_basic_block = last_basic_block; + + bb = ENTRY_BLOCK_PTR ->next_bb; + do + { + next = bb->next_bb; + for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i)) + { + tree s = bsi_stmt (i); + + /* Only a few GIMPLE statements can reference memory. */ + switch (TREE_CODE (s)) + { + case MODIFY_EXPR: + mf_xform_derefs_1 (&i, &TREE_OPERAND (s, 0), EXPR_LOCUS (s), + integer_one_node); + mf_xform_derefs_1 (&i, &TREE_OPERAND (s, 1), EXPR_LOCUS (s), + integer_zero_node); + break; + + case RETURN_EXPR: + if (TREE_OPERAND (s, 0) != NULL_TREE) + { + if (TREE_CODE (TREE_OPERAND (s, 0)) == MODIFY_EXPR) + mf_xform_derefs_1 (&i, &TREE_OPERAND (TREE_OPERAND (s, 0), 1), + EXPR_LOCUS (s), integer_zero_node); + else + mf_xform_derefs_1 (&i, &TREE_OPERAND (s, 0), EXPR_LOCUS (s), + integer_zero_node); + } + break; + + default: + ; + } + } + bb = next; + } + while (bb && bb->index <= saved_last_basic_block); +} + +/* ------------------------------------------------------------------------ */ +/* ADDR_EXPR transforms. Perform the declaration-related mudflap tree + transforms on the current function. + + This is the first part of the mudflap instrumentation. It works on + high-level GIMPLE because after lowering, all variables are moved out + of their BIND_EXPR binding context, and we lose liveness information + for the declarations we wish to instrument. */ + +static unsigned int +execute_mudflap_function_decls (void) +{ + /* Don't instrument functions such as the synthetic constructor + built during mudflap_finish_file. */ + if (mf_marked_p (current_function_decl) || + DECL_ARTIFICIAL (current_function_decl)) + return 0; + + push_gimplify_context (); + + mf_xform_decls (DECL_SAVED_TREE (current_function_decl), + DECL_ARGUMENTS (current_function_decl)); + + pop_gimplify_context (NULL); + return 0; +} + +/* This struct is passed between mf_xform_decls to store state needed + during the traversal searching for objects that have their + addresses taken. */ +struct mf_xform_decls_data +{ + tree param_decls; +}; + + +/* Synthesize a CALL_EXPR and a TRY_FINALLY_EXPR, for this chain of + _DECLs if appropriate. Arrange to call the __mf_register function + now, and the __mf_unregister function later for each. */ +static void +mx_register_decls (tree decl, tree *stmt_list) +{ + tree finally_stmts = NULL_TREE; + tree_stmt_iterator initially_stmts = tsi_start (*stmt_list); + + while (decl != NULL_TREE) + { + if (mf_decl_eligible_p (decl) + /* Not already processed. */ + && ! mf_marked_p (decl) + /* Automatic variable. */ + && ! DECL_EXTERNAL (decl) + && ! TREE_STATIC (decl)) + { + tree size = NULL_TREE, variable_name; + tree unregister_fncall, unregister_fncall_params; + tree register_fncall, register_fncall_params; + + size = convert (size_type_node, TYPE_SIZE_UNIT (TREE_TYPE (decl))); + + /* (& VARIABLE, sizeof (VARIABLE), __MF_TYPE_STACK) */ + unregister_fncall_params = + tree_cons (NULL_TREE, + convert (ptr_type_node, + mf_mark (build1 (ADDR_EXPR, + build_pointer_type (TREE_TYPE (decl)), + decl))), + tree_cons (NULL_TREE, + size, + tree_cons (NULL_TREE, + /* __MF_TYPE_STACK */ + build_int_cst (NULL_TREE, 3), + NULL_TREE))); + /* __mf_unregister (...) */ + unregister_fncall = build_function_call_expr (mf_unregister_fndecl, + unregister_fncall_params); + + /* (& VARIABLE, sizeof (VARIABLE), __MF_TYPE_STACK, "name") */ + variable_name = mf_varname_tree (decl); + register_fncall_params = + tree_cons (NULL_TREE, + convert (ptr_type_node, + mf_mark (build1 (ADDR_EXPR, + build_pointer_type (TREE_TYPE (decl)), + decl))), + tree_cons (NULL_TREE, + size, + tree_cons (NULL_TREE, + /* __MF_TYPE_STACK */ + build_int_cst (NULL_TREE, 3), + tree_cons (NULL_TREE, + variable_name, + NULL_TREE)))); + + /* __mf_register (...) */ + register_fncall = build_function_call_expr (mf_register_fndecl, + register_fncall_params); + + /* Accumulate the two calls. */ + /* ??? Set EXPR_LOCATION. */ + gimplify_stmt (®ister_fncall); + gimplify_stmt (&unregister_fncall); + + /* Add the __mf_register call at the current appending point. */ + if (tsi_end_p (initially_stmts)) + warning (0, "mudflap cannot track %qs in stub function", + IDENTIFIER_POINTER (DECL_NAME (decl))); + else + { + tsi_link_before (&initially_stmts, register_fncall, TSI_SAME_STMT); + + /* Accumulate the FINALLY piece. */ + append_to_statement_list (unregister_fncall, &finally_stmts); + } + mf_mark (decl); + } + + decl = TREE_CHAIN (decl); + } + + /* Actually, (initially_stmts!=NULL) <=> (finally_stmts!=NULL) */ + if (finally_stmts != NULL_TREE) + { + tree t = build2 (TRY_FINALLY_EXPR, void_type_node, + *stmt_list, finally_stmts); + *stmt_list = NULL; + append_to_statement_list (t, stmt_list); + } +} + + +/* Process every variable mentioned in BIND_EXPRs. */ +static tree +mx_xfn_xform_decls (tree *t, int *continue_p, void *data) +{ + struct mf_xform_decls_data* d = (struct mf_xform_decls_data*) data; + + if (*t == NULL_TREE || *t == error_mark_node) + { + *continue_p = 0; + return NULL_TREE; + } + + *continue_p = 1; + + switch (TREE_CODE (*t)) + { + case BIND_EXPR: + { + /* Process function parameters now (but only once). */ + mx_register_decls (d->param_decls, &BIND_EXPR_BODY (*t)); + d->param_decls = NULL_TREE; + + mx_register_decls (BIND_EXPR_VARS (*t), &BIND_EXPR_BODY (*t)); + } + break; + + default: + break; + } + + return NULL_TREE; +} + +/* Perform the object lifetime tracking mudflap transform on the given function + tree. The tree is mutated in place, with possibly copied subtree nodes. + + For every auto variable declared, if its address is ever taken + within the function, then supply its lifetime to the mudflap + runtime with the __mf_register and __mf_unregister calls. +*/ + +static void +mf_xform_decls (tree fnbody, tree fnparams) +{ + struct mf_xform_decls_data d; + d.param_decls = fnparams; + walk_tree_without_duplicates (&fnbody, mx_xfn_xform_decls, &d); +} + + +/* ------------------------------------------------------------------------ */ +/* Externally visible mudflap functions. */ + + +/* Mark and return the given tree node to prevent further mudflap + transforms. */ +static GTY ((param_is (union tree_node))) htab_t marked_trees = NULL; + +tree +mf_mark (tree t) +{ + void **slot; + + if (marked_trees == NULL) + marked_trees = htab_create_ggc (31, htab_hash_pointer, htab_eq_pointer, NULL); + + slot = htab_find_slot (marked_trees, t, INSERT); + *slot = t; + return t; +} + +int +mf_marked_p (tree t) +{ + void *entry; + + if (marked_trees == NULL) + return 0; + + entry = htab_find (marked_trees, t); + return (entry != NULL); +} + +/* Remember given node as a static of some kind: global data, + function-scope static, or an anonymous constant. Its assembler + label is given. */ + +/* A list of globals whose incomplete declarations we encountered. + Instead of emitting the __mf_register call for them here, it's + delayed until program finish time. If they're still incomplete by + then, warnings are emitted. */ + +static GTY (()) VEC(tree,gc) *deferred_static_decls; + +/* A list of statements for calling __mf_register() at startup time. */ +static GTY (()) tree enqueued_call_stmt_chain; + +static void +mudflap_register_call (tree obj, tree object_size, tree varname) +{ + tree arg, args, call_stmt; + + args = tree_cons (NULL_TREE, varname, NULL_TREE); + + arg = build_int_cst (NULL_TREE, 4); /* __MF_TYPE_STATIC */ + args = tree_cons (NULL_TREE, arg, args); + + arg = convert (size_type_node, object_size); + args = tree_cons (NULL_TREE, arg, args); + + arg = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (obj)), obj); + arg = convert (ptr_type_node, arg); + args = tree_cons (NULL_TREE, arg, args); + + call_stmt = build_function_call_expr (mf_register_fndecl, args); + + append_to_statement_list (call_stmt, &enqueued_call_stmt_chain); +} + +void +mudflap_enqueue_decl (tree obj) +{ + if (mf_marked_p (obj)) + return; + + /* We don't need to process variable decls that are internally + generated extern. If we did, we'd end up with warnings for them + during mudflap_finish_file (). That would confuse the user, + since the text would refer to variables that don't show up in the + user's source code. */ + if (DECL_P (obj) && DECL_EXTERNAL (obj) && DECL_ARTIFICIAL (obj)) + return; + + VEC_safe_push (tree, gc, deferred_static_decls, obj); +} + + +void +mudflap_enqueue_constant (tree obj) +{ + tree object_size, varname; + + if (mf_marked_p (obj)) + return; + + if (TREE_CODE (obj) == STRING_CST) + object_size = build_int_cst (NULL_TREE, TREE_STRING_LENGTH (obj)); + else + object_size = size_in_bytes (TREE_TYPE (obj)); + + if (TREE_CODE (obj) == STRING_CST) + varname = mf_build_string ("string literal"); + else + varname = mf_build_string ("constant"); + + mudflap_register_call (obj, object_size, varname); +} + + +/* Emit any file-wide instrumentation. */ +void +mudflap_finish_file (void) +{ + tree ctor_statements = NULL_TREE; + + /* No need to continue when there were errors. */ + if (errorcount != 0 || sorrycount != 0) + return; + + /* Insert a call to __mf_init. */ + { + tree call2_stmt = build_function_call_expr (mf_init_fndecl, NULL_TREE); + append_to_statement_list (call2_stmt, &ctor_statements); + } + + /* If appropriate, call __mf_set_options to pass along read-ignore mode. */ + if (flag_mudflap_ignore_reads) + { + tree arg = tree_cons (NULL_TREE, + mf_build_string ("-ignore-reads"), NULL_TREE); + tree call_stmt = build_function_call_expr (mf_set_options_fndecl, arg); + append_to_statement_list (call_stmt, &ctor_statements); + } + + /* Process all enqueued object decls. */ + if (deferred_static_decls) + { + size_t i; + tree obj; + for (i = 0; VEC_iterate (tree, deferred_static_decls, i, obj); i++) + { + gcc_assert (DECL_P (obj)); + + if (mf_marked_p (obj)) + continue; + + /* Omit registration for static unaddressed objects. NB: + Perform registration for non-static objects regardless of + TREE_USED or TREE_ADDRESSABLE, because they may be used + from other compilation units. */ + if (! TREE_PUBLIC (obj) && ! TREE_ADDRESSABLE (obj)) + continue; + + if (! COMPLETE_TYPE_P (TREE_TYPE (obj))) + { + warning (0, "mudflap cannot track unknown size extern %qs", + IDENTIFIER_POINTER (DECL_NAME (obj))); + continue; + } + + mudflap_register_call (obj, + size_in_bytes (TREE_TYPE (obj)), + mf_varname_tree (obj)); + } + + VEC_truncate (tree, deferred_static_decls, 0); + } + + /* Append all the enqueued registration calls. */ + if (enqueued_call_stmt_chain) + { + append_to_statement_list (enqueued_call_stmt_chain, &ctor_statements); + enqueued_call_stmt_chain = NULL_TREE; + } + + cgraph_build_static_cdtor ('I', ctor_statements, + MAX_RESERVED_INIT_PRIORITY-1); +} + + +static bool +gate_mudflap (void) +{ + return flag_mudflap != 0; +} + +struct tree_opt_pass pass_mudflap_1 = +{ + "mudflap1", /* name */ + gate_mudflap, /* gate */ + execute_mudflap_function_decls, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + 0, /* tv_id */ + PROP_gimple_any, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_dump_func, /* todo_flags_finish */ + 0 /* letter */ +}; + +struct tree_opt_pass pass_mudflap_2 = +{ + "mudflap2", /* name */ + gate_mudflap, /* gate */ + execute_mudflap_function_ops, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + 0, /* tv_id */ + PROP_gimple_leh, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_verify_flow | TODO_verify_stmts + | TODO_dump_func, /* todo_flags_finish */ + 0 /* letter */ +}; + +#include "gt-tree-mudflap.h" |