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Diffstat (limited to 'gcc/gimple-low.c')
| -rw-r--r-- | gcc/gimple-low.c | 811 |
1 files changed, 811 insertions, 0 deletions
diff --git a/gcc/gimple-low.c b/gcc/gimple-low.c new file mode 100644 index 0000000..c6a0312 --- /dev/null +++ b/gcc/gimple-low.c @@ -0,0 +1,811 @@ +/* Tree lowering pass. Lowers GIMPLE into unstructured form. + + Copyright (C) 2003, 2005 Free Software Foundation, Inc. + +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 "tree.h" +#include "rtl.h" +#include "varray.h" +#include "tree-gimple.h" +#include "tree-inline.h" +#include "diagnostic.h" +#include "langhooks.h" +#include "langhooks-def.h" +#include "tree-flow.h" +#include "timevar.h" +#include "except.h" +#include "hashtab.h" +#include "flags.h" +#include "function.h" +#include "expr.h" +#include "toplev.h" +#include "tree-pass.h" + +struct lower_data +{ + /* Block the current statement belongs to. */ + tree block; + + /* A TREE_LIST of label and return statements to be moved to the end + of the function. */ + tree return_statements; + + /* True if the function calls __builtin_setjmp. */ + bool calls_builtin_setjmp; +}; + +static void lower_stmt (tree_stmt_iterator *, struct lower_data *); +static void lower_bind_expr (tree_stmt_iterator *, struct lower_data *); +static void lower_cond_expr (tree_stmt_iterator *, struct lower_data *); +static void lower_return_expr (tree_stmt_iterator *, struct lower_data *); +static void lower_builtin_setjmp (tree_stmt_iterator *); + +/* Lower the body of current_function_decl. */ + +static unsigned int +lower_function_body (void) +{ + struct lower_data data; + tree *body_p = &DECL_SAVED_TREE (current_function_decl); + tree bind = *body_p; + tree_stmt_iterator i; + tree t, x; + + gcc_assert (TREE_CODE (bind) == BIND_EXPR); + + memset (&data, 0, sizeof (data)); + data.block = DECL_INITIAL (current_function_decl); + BLOCK_SUBBLOCKS (data.block) = NULL_TREE; + BLOCK_CHAIN (data.block) = NULL_TREE; + TREE_ASM_WRITTEN (data.block) = 1; + + *body_p = alloc_stmt_list (); + i = tsi_start (*body_p); + tsi_link_after (&i, bind, TSI_NEW_STMT); + lower_bind_expr (&i, &data); + + i = tsi_last (*body_p); + + /* If the function falls off the end, we need a null return statement. + If we've already got one in the return_statements list, we don't + need to do anything special. Otherwise build one by hand. */ + if (block_may_fallthru (*body_p) + && (data.return_statements == NULL + || TREE_OPERAND (TREE_VALUE (data.return_statements), 0) != NULL)) + { + x = build1 (RETURN_EXPR, void_type_node, NULL); + SET_EXPR_LOCATION (x, cfun->function_end_locus); + tsi_link_after (&i, x, TSI_CONTINUE_LINKING); + } + + /* If we lowered any return statements, emit the representative + at the end of the function. */ + for (t = data.return_statements ; t ; t = TREE_CHAIN (t)) + { + x = build1 (LABEL_EXPR, void_type_node, TREE_PURPOSE (t)); + tsi_link_after (&i, x, TSI_CONTINUE_LINKING); + + /* Remove the line number from the representative return statement. + It now fills in for many such returns. Failure to remove this + will result in incorrect results for coverage analysis. */ + x = TREE_VALUE (t); +#ifdef USE_MAPPED_LOCATION + SET_EXPR_LOCATION (x, UNKNOWN_LOCATION); +#else + SET_EXPR_LOCUS (x, NULL); +#endif + tsi_link_after (&i, x, TSI_CONTINUE_LINKING); + } + + /* If the function calls __builtin_setjmp, we need to emit the computed + goto that will serve as the unique dispatcher for all the receivers. */ + if (data.calls_builtin_setjmp) + { + tree disp_label, disp_var, arg; + + /* Build 'DISP_LABEL:' and insert. */ + disp_label = create_artificial_label (); + /* This mark will create forward edges from every call site. */ + DECL_NONLOCAL (disp_label) = 1; + current_function_has_nonlocal_label = 1; + x = build1 (LABEL_EXPR, void_type_node, disp_label); + tsi_link_after (&i, x, TSI_CONTINUE_LINKING); + + /* Build 'DISP_VAR = __builtin_setjmp_dispatcher (DISP_LABEL);' + and insert. */ + disp_var = create_tmp_var (ptr_type_node, "setjmpvar"); + t = build_addr (disp_label, current_function_decl); + arg = tree_cons (NULL, t, NULL); + t = implicit_built_in_decls[BUILT_IN_SETJMP_DISPATCHER]; + t = build_function_call_expr (t,arg); + x = build2 (MODIFY_EXPR, void_type_node, disp_var, t); + + /* Build 'goto DISP_VAR;' and insert. */ + tsi_link_after (&i, x, TSI_CONTINUE_LINKING); + x = build1 (GOTO_EXPR, void_type_node, disp_var); + tsi_link_after (&i, x, TSI_CONTINUE_LINKING); + } + + gcc_assert (data.block == DECL_INITIAL (current_function_decl)); + BLOCK_SUBBLOCKS (data.block) + = blocks_nreverse (BLOCK_SUBBLOCKS (data.block)); + + clear_block_marks (data.block); + return 0; +} + +struct tree_opt_pass pass_lower_cf = +{ + "lower", /* name */ + NULL, /* gate */ + lower_function_body, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + 0, /* tv_id */ + PROP_gimple_any, /* properties_required */ + PROP_gimple_lcf, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_dump_func, /* todo_flags_finish */ + 0 /* letter */ +}; + + +/* Lower the EXPR. Unlike gimplification the statements are not relowered + when they are changed -- if this has to be done, the lowering routine must + do it explicitly. DATA is passed through the recursion. */ + +static void +lower_stmt_body (tree expr, struct lower_data *data) +{ + tree_stmt_iterator tsi; + + for (tsi = tsi_start (expr); !tsi_end_p (tsi); ) + lower_stmt (&tsi, data); +} + + +/* Lower the OpenMP directive statement pointed by TSI. DATA is + passed through the recursion. */ + +static void +lower_omp_directive (tree_stmt_iterator *tsi, struct lower_data *data) +{ + tree stmt; + + stmt = tsi_stmt (*tsi); + + lower_stmt_body (OMP_BODY (stmt), data); + tsi_link_before (tsi, stmt, TSI_SAME_STMT); + tsi_link_before (tsi, OMP_BODY (stmt), TSI_SAME_STMT); + OMP_BODY (stmt) = NULL_TREE; + tsi_delink (tsi); +} + + +/* Lower statement TSI. DATA is passed through the recursion. */ + +static void +lower_stmt (tree_stmt_iterator *tsi, struct lower_data *data) +{ + tree stmt = tsi_stmt (*tsi); + + if (EXPR_HAS_LOCATION (stmt) && data) + TREE_BLOCK (stmt) = data->block; + + switch (TREE_CODE (stmt)) + { + case BIND_EXPR: + lower_bind_expr (tsi, data); + return; + case COND_EXPR: + lower_cond_expr (tsi, data); + return; + case RETURN_EXPR: + lower_return_expr (tsi, data); + return; + + case TRY_FINALLY_EXPR: + case TRY_CATCH_EXPR: + lower_stmt_body (TREE_OPERAND (stmt, 0), data); + lower_stmt_body (TREE_OPERAND (stmt, 1), data); + break; + case CATCH_EXPR: + lower_stmt_body (CATCH_BODY (stmt), data); + break; + case EH_FILTER_EXPR: + lower_stmt_body (EH_FILTER_FAILURE (stmt), data); + break; + + case NOP_EXPR: + case ASM_EXPR: + case GOTO_EXPR: + case LABEL_EXPR: + case SWITCH_EXPR: + case OMP_FOR: + case OMP_SECTIONS: + case OMP_SECTION: + case OMP_SINGLE: + case OMP_MASTER: + case OMP_ORDERED: + case OMP_CRITICAL: + case OMP_RETURN: + case OMP_CONTINUE: + break; + + case MODIFY_EXPR: + if (TREE_CODE (TREE_OPERAND (stmt, 1)) == CALL_EXPR) + stmt = TREE_OPERAND (stmt, 1); + else + break; + /* FALLTHRU */ + + case CALL_EXPR: + { + tree decl = get_callee_fndecl (stmt); + if (decl + && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL + && DECL_FUNCTION_CODE (decl) == BUILT_IN_SETJMP) + { + data->calls_builtin_setjmp = true; + lower_builtin_setjmp (tsi); + return; + } + } + break; + + case OMP_PARALLEL: + lower_omp_directive (tsi, data); + return; + + default: + gcc_unreachable (); + } + + tsi_next (tsi); +} + +/* Lower a bind_expr TSI. DATA is passed through the recursion. */ + +static void +lower_bind_expr (tree_stmt_iterator *tsi, struct lower_data *data) +{ + tree old_block = data->block; + tree stmt = tsi_stmt (*tsi); + tree new_block = BIND_EXPR_BLOCK (stmt); + + if (new_block) + { + if (new_block == old_block) + { + /* The outermost block of the original function may not be the + outermost statement chain of the gimplified function. So we + may see the outermost block just inside the function. */ + gcc_assert (new_block == DECL_INITIAL (current_function_decl)); + new_block = NULL; + } + else + { + /* We do not expect to handle duplicate blocks. */ + gcc_assert (!TREE_ASM_WRITTEN (new_block)); + TREE_ASM_WRITTEN (new_block) = 1; + + /* Block tree may get clobbered by inlining. Normally this would + be fixed in rest_of_decl_compilation using block notes, but + since we are not going to emit them, it is up to us. */ + BLOCK_CHAIN (new_block) = BLOCK_SUBBLOCKS (old_block); + BLOCK_SUBBLOCKS (old_block) = new_block; + BLOCK_SUBBLOCKS (new_block) = NULL_TREE; + BLOCK_SUPERCONTEXT (new_block) = old_block; + + data->block = new_block; + } + } + + record_vars (BIND_EXPR_VARS (stmt)); + lower_stmt_body (BIND_EXPR_BODY (stmt), data); + + if (new_block) + { + gcc_assert (data->block == new_block); + + BLOCK_SUBBLOCKS (new_block) + = blocks_nreverse (BLOCK_SUBBLOCKS (new_block)); + data->block = old_block; + } + + /* The BIND_EXPR no longer carries any useful information -- kill it. */ + tsi_link_before (tsi, BIND_EXPR_BODY (stmt), TSI_SAME_STMT); + tsi_delink (tsi); +} + +/* Try to determine whether a TRY_CATCH expression can fall through. + This is a subroutine of block_may_fallthru. */ + +static bool +try_catch_may_fallthru (tree stmt) +{ + tree_stmt_iterator i; + + /* If the TRY block can fall through, the whole TRY_CATCH can + fall through. */ + if (block_may_fallthru (TREE_OPERAND (stmt, 0))) + return true; + + i = tsi_start (TREE_OPERAND (stmt, 1)); + switch (TREE_CODE (tsi_stmt (i))) + { + case CATCH_EXPR: + /* We expect to see a sequence of CATCH_EXPR trees, each with a + catch expression and a body. The whole TRY_CATCH may fall + through iff any of the catch bodies falls through. */ + for (; !tsi_end_p (i); tsi_next (&i)) + { + if (block_may_fallthru (CATCH_BODY (tsi_stmt (i)))) + return true; + } + return false; + + case EH_FILTER_EXPR: + /* The exception filter expression only matters if there is an + exception. If the exception does not match EH_FILTER_TYPES, + we will execute EH_FILTER_FAILURE, and we will fall through + if that falls through. If the exception does match + EH_FILTER_TYPES, the stack unwinder will continue up the + stack, so we will not fall through. We don't know whether we + will throw an exception which matches EH_FILTER_TYPES or not, + so we just ignore EH_FILTER_TYPES and assume that we might + throw an exception which doesn't match. */ + return block_may_fallthru (EH_FILTER_FAILURE (tsi_stmt (i))); + + default: + /* This case represents statements to be executed when an + exception occurs. Those statements are implicitly followed + by a RESX_EXPR to resume execution after the exception. So + in this case the TRY_CATCH never falls through. */ + return false; + } +} + +/* Try to determine if we can fall out of the bottom of BLOCK. This guess + need not be 100% accurate; simply be conservative and return true if we + don't know. This is used only to avoid stupidly generating extra code. + If we're wrong, we'll just delete the extra code later. */ + +bool +block_may_fallthru (tree block) +{ + tree stmt = expr_last (block); + + switch (stmt ? TREE_CODE (stmt) : ERROR_MARK) + { + case GOTO_EXPR: + case RETURN_EXPR: + case RESX_EXPR: + /* Easy cases. If the last statement of the block implies + control transfer, then we can't fall through. */ + return false; + + case SWITCH_EXPR: + /* If SWITCH_LABELS is set, this is lowered, and represents a + branch to a selected label and hence can not fall through. + Otherwise SWITCH_BODY is set, and the switch can fall + through. */ + return SWITCH_LABELS (stmt) == NULL_TREE; + + case COND_EXPR: + if (block_may_fallthru (COND_EXPR_THEN (stmt))) + return true; + return block_may_fallthru (COND_EXPR_ELSE (stmt)); + + case BIND_EXPR: + return block_may_fallthru (BIND_EXPR_BODY (stmt)); + + case TRY_CATCH_EXPR: + return try_catch_may_fallthru (stmt); + + case TRY_FINALLY_EXPR: + /* The finally clause is always executed after the try clause, + so if it does not fall through, then the try-finally will not + fall through. Otherwise, if the try clause does not fall + through, then when the finally clause falls through it will + resume execution wherever the try clause was going. So the + whole try-finally will only fall through if both the try + clause and the finally clause fall through. */ + return (block_may_fallthru (TREE_OPERAND (stmt, 0)) + && block_may_fallthru (TREE_OPERAND (stmt, 1))); + + case MODIFY_EXPR: + if (TREE_CODE (TREE_OPERAND (stmt, 1)) == CALL_EXPR) + stmt = TREE_OPERAND (stmt, 1); + else + return true; + /* FALLTHRU */ + + case CALL_EXPR: + /* Functions that do not return do not fall through. */ + return (call_expr_flags (stmt) & ECF_NORETURN) == 0; + + case CLEANUP_POINT_EXPR: + return block_may_fallthru (TREE_OPERAND (stmt, 0)); + + default: + return true; + } +} + +/* Lower a cond_expr TSI. DATA is passed through the recursion. */ + +static void +lower_cond_expr (tree_stmt_iterator *tsi, struct lower_data *data) +{ + tree stmt = tsi_stmt (*tsi); + bool then_is_goto, else_is_goto; + tree then_branch, else_branch; + tree then_goto, else_goto; + + then_branch = COND_EXPR_THEN (stmt); + else_branch = COND_EXPR_ELSE (stmt); + + lower_stmt_body (then_branch, data); + lower_stmt_body (else_branch, data); + + then_goto = expr_only (then_branch); + then_is_goto = then_goto && simple_goto_p (then_goto); + + else_goto = expr_only (else_branch); + else_is_goto = else_goto && simple_goto_p (else_goto); + + if (!then_is_goto || !else_is_goto) + { + tree then_label, else_label, end_label, t; + + then_label = NULL_TREE; + else_label = NULL_TREE; + end_label = NULL_TREE; + + /* Replace the cond_expr with explicit gotos. */ + if (!then_is_goto) + { + t = build1 (LABEL_EXPR, void_type_node, NULL_TREE); + if (TREE_SIDE_EFFECTS (then_branch)) + then_label = t; + else + end_label = t; + then_goto = build_and_jump (&LABEL_EXPR_LABEL (t)); + } + + if (!else_is_goto) + { + t = build1 (LABEL_EXPR, void_type_node, NULL_TREE); + if (TREE_SIDE_EFFECTS (else_branch)) + else_label = t; + else + { + /* Both THEN and ELSE can be no-ops if one or both contained an + empty BIND_EXPR that was associated with the toplevel block + of an inlined function. In that case remove_useless_stmts + can't have cleaned things up for us; kill the whole + conditional now. */ + if (end_label) + { + tsi_delink (tsi); + return; + } + else + end_label = t; + } + else_goto = build_and_jump (&LABEL_EXPR_LABEL (t)); + } + + if (then_label) + { + bool may_fallthru = block_may_fallthru (then_branch); + + tsi_link_after (tsi, then_label, TSI_CONTINUE_LINKING); + tsi_link_after (tsi, then_branch, TSI_CONTINUE_LINKING); + + if (else_label && may_fallthru) + { + end_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE); + t = build_and_jump (&LABEL_EXPR_LABEL (end_label)); + tsi_link_after (tsi, t, TSI_CONTINUE_LINKING); + } + } + + if (else_label) + { + tsi_link_after (tsi, else_label, TSI_CONTINUE_LINKING); + tsi_link_after (tsi, else_branch, TSI_CONTINUE_LINKING); + } + + if (end_label) + tsi_link_after (tsi, end_label, TSI_CONTINUE_LINKING); + } + + COND_EXPR_THEN (stmt) = then_goto; + COND_EXPR_ELSE (stmt) = else_goto; + + tsi_next (tsi); +} + +/* Lower a return_expr TSI. DATA is passed through the recursion. */ + +static void +lower_return_expr (tree_stmt_iterator *tsi, struct lower_data *data) +{ + tree stmt = tsi_stmt (*tsi); + tree value, t, label; + + /* Extract the value being returned. */ + value = TREE_OPERAND (stmt, 0); + if (value && TREE_CODE (value) == MODIFY_EXPR) + value = TREE_OPERAND (value, 1); + + /* Match this up with an existing return statement that's been created. */ + for (t = data->return_statements; t ; t = TREE_CHAIN (t)) + { + tree tvalue = TREE_OPERAND (TREE_VALUE (t), 0); + if (tvalue && TREE_CODE (tvalue) == MODIFY_EXPR) + tvalue = TREE_OPERAND (tvalue, 1); + + if (value == tvalue) + { + label = TREE_PURPOSE (t); + goto found; + } + } + + /* Not found. Create a new label and record the return statement. */ + label = create_artificial_label (); + data->return_statements = tree_cons (label, stmt, data->return_statements); + + /* Generate a goto statement and remove the return statement. */ + found: + t = build1 (GOTO_EXPR, void_type_node, label); + SET_EXPR_LOCUS (t, EXPR_LOCUS (stmt)); + tsi_link_before (tsi, t, TSI_SAME_STMT); + tsi_delink (tsi); +} + +/* Lower a __builtin_setjmp TSI. + + __builtin_setjmp is passed a pointer to an array of five words (not + all will be used on all machines). It operates similarly to the C + library function of the same name, but is more efficient. + + It is lowered into 3 other builtins, namely __builtin_setjmp_setup, + __builtin_setjmp_dispatcher and __builtin_setjmp_receiver, but with + __builtin_setjmp_dispatcher shared among all the instances; that's + why it is only emitted at the end by lower_function_body. + + After full lowering, the body of the function should look like: + + { + void * setjmpvar.0; + int D.1844; + int D.2844; + + [...] + + __builtin_setjmp_setup (&buf, &<D1847>); + D.1844 = 0; + goto <D1846>; + <D1847>:; + __builtin_setjmp_receiver (&<D1847>); + D.1844 = 1; + <D1846>:; + if (D.1844 == 0) goto <D1848>; else goto <D1849>; + + [...] + + __builtin_setjmp_setup (&buf, &<D2847>); + D.2844 = 0; + goto <D2846>; + <D2847>:; + __builtin_setjmp_receiver (&<D2847>); + D.2844 = 1; + <D2846>:; + if (D.2844 == 0) goto <D2848>; else goto <D2849>; + + [...] + + <D3850>:; + return; + <D3853>: [non-local]; + setjmpvar.0 = __builtin_setjmp_dispatcher (&<D3853>); + goto setjmpvar.0; + } + + The dispatcher block will be both the unique destination of all the + abnormal call edges and the unique source of all the abnormal edges + to the receivers, thus keeping the complexity explosion localized. */ + +static void +lower_builtin_setjmp (tree_stmt_iterator *tsi) +{ + tree stmt = tsi_stmt (*tsi); + tree cont_label = create_artificial_label (); + tree next_label = create_artificial_label (); + tree dest, t, arg; + + /* NEXT_LABEL is the label __builtin_longjmp will jump to. Its address is + passed to both __builtin_setjmp_setup and __builtin_setjmp_receiver. */ + FORCED_LABEL (next_label) = 1; + + if (TREE_CODE (stmt) == MODIFY_EXPR) + { + dest = TREE_OPERAND (stmt, 0); + stmt = TREE_OPERAND (stmt, 1); + } + else + dest = NULL_TREE; + + /* Build '__builtin_setjmp_setup (BUF, NEXT_LABEL)' and insert. */ + t = build_addr (next_label, current_function_decl); + arg = tree_cons (NULL, t, NULL); + t = TREE_VALUE (TREE_OPERAND (stmt, 1)); + arg = tree_cons (NULL, t, arg); + t = implicit_built_in_decls[BUILT_IN_SETJMP_SETUP]; + t = build_function_call_expr (t, arg); + SET_EXPR_LOCUS (t, EXPR_LOCUS (stmt)); + tsi_link_before (tsi, t, TSI_SAME_STMT); + + /* Build 'DEST = 0' and insert. */ + if (dest) + { + t = build2 (MODIFY_EXPR, void_type_node, dest, integer_zero_node); + SET_EXPR_LOCUS (t, EXPR_LOCUS (stmt)); + tsi_link_before (tsi, t, TSI_SAME_STMT); + } + + /* Build 'goto CONT_LABEL' and insert. */ + t = build1 (GOTO_EXPR, void_type_node, cont_label); + tsi_link_before (tsi, t, TSI_SAME_STMT); + + /* Build 'NEXT_LABEL:' and insert. */ + t = build1 (LABEL_EXPR, void_type_node, next_label); + tsi_link_before (tsi, t, TSI_SAME_STMT); + + /* Build '__builtin_setjmp_receiver (NEXT_LABEL)' and insert. */ + t = build_addr (next_label, current_function_decl); + arg = tree_cons (NULL, t, NULL); + t = implicit_built_in_decls[BUILT_IN_SETJMP_RECEIVER]; + t = build_function_call_expr (t, arg); + SET_EXPR_LOCUS (t, EXPR_LOCUS (stmt)); + tsi_link_before (tsi, t, TSI_SAME_STMT); + + /* Build 'DEST = 1' and insert. */ + if (dest) + { + t = build2 (MODIFY_EXPR, void_type_node, dest, integer_one_node); + SET_EXPR_LOCUS (t, EXPR_LOCUS (stmt)); + tsi_link_before (tsi, t, TSI_SAME_STMT); + } + + /* Build 'CONT_LABEL:' and insert. */ + t = build1 (LABEL_EXPR, void_type_node, cont_label); + tsi_link_before (tsi, t, TSI_SAME_STMT); + + /* Remove the call to __builtin_setjmp. */ + tsi_delink (tsi); +} + + +/* Record the variables in VARS into function FN. */ + +void +record_vars_into (tree vars, tree fn) +{ + struct function *saved_cfun = cfun; + + if (fn != current_function_decl) + cfun = DECL_STRUCT_FUNCTION (fn); + + for (; vars; vars = TREE_CHAIN (vars)) + { + tree var = vars; + + /* BIND_EXPRs contains also function/type/constant declarations + we don't need to care about. */ + if (TREE_CODE (var) != VAR_DECL) + continue; + + /* Nothing to do in this case. */ + if (DECL_EXTERNAL (var)) + continue; + + /* Record the variable. */ + cfun->unexpanded_var_list = tree_cons (NULL_TREE, var, + cfun->unexpanded_var_list); + } + + if (fn != current_function_decl) + cfun = saved_cfun; +} + + +/* Record the variables in VARS into current_function_decl. */ + +void +record_vars (tree vars) +{ + record_vars_into (vars, current_function_decl); +} + + +/* Mark BLOCK used if it has a used variable in it, then recurse over its + subblocks. */ + +static void +mark_blocks_with_used_vars (tree block) +{ + tree var; + tree subblock; + + if (!TREE_USED (block)) + { + for (var = BLOCK_VARS (block); + var; + var = TREE_CHAIN (var)) + { + if (TREE_USED (var)) + { + TREE_USED (block) = true; + break; + } + } + } + for (subblock = BLOCK_SUBBLOCKS (block); + subblock; + subblock = BLOCK_CHAIN (subblock)) + mark_blocks_with_used_vars (subblock); +} + +/* Mark the used attribute on blocks correctly. */ + +static unsigned int +mark_used_blocks (void) +{ + mark_blocks_with_used_vars (DECL_INITIAL (current_function_decl)); + return 0; +} + + +struct tree_opt_pass pass_mark_used_blocks = +{ + "blocks", /* name */ + NULL, /* gate */ + mark_used_blocks, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + 0, /* tv_id */ + 0, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_dump_func, /* todo_flags_finish */ + 0 /* letter */ +}; |
