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rtl.h (force_line_numbers, [...]): Declare. 

* rtl.h (force_line_numbers, restore_line_number_status): Declare.
	* emit-rtl.c (force_line_numbers, restore_line_number_status):
	New functions.
	* stmt.c (struct nesting): Replace seenlabel with line_number_status.
	(expand_start_case): Adjust to this change.
	(check_seenlabel): New function.
	(pushcase, pushcase_range, expand_endcase): Use it.

From-SVN: r18031
This commit is contained in:
Joern Rennecke 1998-02-17 10:26:44 +00:00
parent 93f83bd58d
commit a11759a38c
3 changed files with 72 additions and 60 deletions
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22
gcc/emit-rtl.c
View File

@ -3457,3 +3457,25 @@ init_emit_once (line_numbers)
pic_offset_table_rtx = gen_rtx_REG (Pmode, PIC_OFFSET_TABLE_REGNUM);
#endif
}
/* Query and clear/ restore no_line_numbers. This is used by the
switch / case handling in stmt.c to give proper line numbers in
warnings about unreachable code. */
int
force_line_numbers ()
{
int old = no_line_numbers;
no_line_numbers = 0;
if (old)
force_next_line_note ();
return old;
}
void
restore_line_number_status (old_value)
int old_value;
{
no_line_numbers = old_value;
}

5
gcc/rtl.h
View File

@ -1147,6 +1147,11 @@ extern void reorder_insns_with_line_notes PROTO ((rtx, rtx, rtx));
extern void emit_insn_after_with_line_notes PROTO ((rtx, rtx, rtx));
extern enum rtx_code classify_insn PROTO ((rtx));
extern rtx emit PROTO ((rtx));
/* Query and clear/ restore no_line_numbers. This is used by the
switch / case handling in stmt.c to give proper line numbers in
warnings about unreachable code. */
int force_line_numbers PROTO((void));
void restore_line_number_status PROTO((int old_value));
/* In insn-emit.c */
extern void add_clobbers PROTO ((rtx, int));

105
gcc/stmt.c
View File

@ -316,8 +316,10 @@ struct nesting
int num_ranges;
/* Name of this kind of statement, for warnings. */
char *printname;
/* Nonzero if a case label has been seen in this case stmt. */
char seenlabel;
/* Used to save no_line_numbers till we see the first case label.
We set this to -1 when we see the first case label in this
case statement. */
int line_number_status;
} case_stmt;
} data;
};
@ -3759,7 +3761,7 @@ expand_start_case (exit_flag, expr, type, printname)
thiscase->data.case_stmt.default_label = 0;
thiscase->data.case_stmt.num_ranges = 0;
thiscase->data.case_stmt.printname = printname;
thiscase->data.case_stmt.seenlabel = 0;
thiscase->data.case_stmt.line_number_status = force_line_numbers ();
case_stack = thiscase;
nesting_stack = thiscase;
@ -3822,6 +3824,41 @@ case_index_expr_type ()
return 0;
}
static void
check_seenlabel ()
{
/* If this is the first label, warn if any insns have been emitted. */
if (case_stack->data.case_stmt.line_number_status >= 0)
{
rtx insn;
restore_line_number_status
(case_stack->data.case_stmt.line_number_status);
case_stack->data.case_stmt.line_number_status = -1;
for (insn = case_stack->data.case_stmt.start;
insn;
insn = NEXT_INSN (insn))
{
if (GET_CODE (insn) == CODE_LABEL)
break;
if (GET_CODE (insn) != NOTE
&& (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
{
do
insn = PREV_INSN (insn);
while (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0);
warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
NOTE_LINE_NUMBER(insn),
"unreachable code at beginning of %s",
case_stack->data.case_stmt.printname);
break;
}
}
}
}
/* Accumulate one case or default label inside a case or switch statement.
VALUE is the value of the case (a null pointer, for a default label).
The function CONVERTER, when applied to arguments T and V,
@ -3858,6 +3895,8 @@ pushcase (value, converter, label, duplicate)
index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
nominal_type = case_stack->data.case_stmt.nominal_type;
check_seenlabel ();
/* If the index is erroneous, avoid more problems: pretend to succeed. */
if (index_type == error_mark_node)
return 0;
@ -3866,27 +3905,6 @@ pushcase (value, converter, label, duplicate)
if (value != 0)
value = (*converter) (nominal_type, value);
/* If this is the first label, warn if any insns have been emitted. */
if (case_stack->data.case_stmt.seenlabel == 0)
{
rtx insn;
for (insn = case_stack->data.case_stmt.start;
insn;
insn = NEXT_INSN (insn))
{
if (GET_CODE (insn) == CODE_LABEL)
break;
if (GET_CODE (insn) != NOTE
&& (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
{
warning ("unreachable code at beginning of %s",
case_stack->data.case_stmt.printname);
break;
}
}
}
case_stack->data.case_stmt.seenlabel = 1;
/* Fail if this value is out of range for the actual type of the index
(which may be narrower than NOMINAL_TYPE). */
if (value != 0 && ! int_fits_type_p (value, index_type))
@ -3943,26 +3961,7 @@ pushcase_range (value1, value2, converter, label, duplicate)
if (index_type == error_mark_node)
return 0;
/* If this is the first label, warn if any insns have been emitted. */
if (case_stack->data.case_stmt.seenlabel == 0)
{
rtx insn;
for (insn = case_stack->data.case_stmt.start;
insn;
insn = NEXT_INSN (insn))
{
if (GET_CODE (insn) == CODE_LABEL)
break;
if (GET_CODE (insn) != NOTE
&& (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
{
warning ("unreachable code at beginning of %s",
case_stack->data.case_stmt.printname);
break;
}
}
}
case_stack->data.case_stmt.seenlabel = 1;
check_seenlabel ();
/* Convert VALUEs to type in which the comparisons are nominally done
and replace any unspecified value with the corresponding bound. */
@ -4613,6 +4612,8 @@ expand_end_case (orig_index)
do_pending_stack_adjust ();
check_seenlabel ();
/* An ERROR_MARK occurs for various reasons including invalid data type. */
if (index_type != error_mark_node)
{
@ -4625,22 +4626,6 @@ expand_end_case (orig_index)
&& TREE_CODE (index_expr) != INTEGER_CST)
check_for_full_enumeration_handling (TREE_TYPE (orig_index));
/* If this is the first label, warn if any insns have been emitted. */
if (thiscase->data.case_stmt.seenlabel == 0)
{
rtx insn;
for (insn = get_last_insn ();
insn != case_stack->data.case_stmt.start;
insn = PREV_INSN (insn))
if (GET_CODE (insn) != NOTE
&& (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
{
warning ("unreachable code at beginning of %s",
case_stack->data.case_stmt.printname);
break;
}
}
/* If we don't have a default-label, create one here,
after the body of the switch. */
if (thiscase->data.case_stmt.default_label == 0)