Author: pfg
Date: Wed Nov 13 04:31:27 2013
New Revision: 258081
URL: http://svnweb.freebsd.org/changeset/base/258081
Log:
gcc: Backport fixes for -W parentheses in C++
This fixes GCC 19564:
http://gcc.gnu.org/ml/gcc-patches/2006-12/msg00868.html
http://gcc.gnu.org/ml/gcc-patches/2006-12/msg01772.html
http://gcc.gnu.org/ml/gcc-patches/2007-01/msg00545.html
The patch and its fixes are used by Google in their enhanced gcc-4.2.1
port and predates the license switch in GCC so they are still under
GPLv2.
MFC after: 3 weeks
Modified:
head/contrib/gcc/ChangeLog.gcc43
head/contrib/gcc/c-common.c
head/contrib/gcc/c-common.h
head/contrib/gcc/c-typeck.c
head/contrib/gcc/cp/cp-tree.h
head/contrib/gcc/cp/parser.c
head/contrib/gcc/cp/pt.c
head/contrib/gcc/cp/semantics.c
head/contrib/gcc/cp/typeck.c
head/contrib/gcc/doc/invoke.texi
Modified: head/contrib/gcc/ChangeLog.gcc43
==============================================================================
--- head/contrib/gcc/ChangeLog.gcc43 Wed Nov 13 03:50:31 2013
(r258080)
+++ head/contrib/gcc/ChangeLog.gcc43 Wed Nov 13 04:31:27 2013
(r258081)
@@ -232,6 +232,17 @@
* config.gcc: Support core2 processor.
+2006-12-13 Ian Lance Taylor <i...@google.com> (r119855)
+
+ PR c++/19564
+ PR c++/19756
+ * c-typeck.c (parser_build_binary_op): Move parentheses warnings
+ to warn_about_parentheses in c-common.c.
+ * c-common.c (warn_about_parentheses): New function.
+ * c-common.h (warn_about_parentheses): Declare.
+ * doc/invoke.texi (Warning Options): Update -Wparentheses
+ description.
+
2006-12-02 H.J. Lu <hongjiu...@intel.com> (r119454 - partial)
PR target/30040
Modified: head/contrib/gcc/c-common.c
==============================================================================
--- head/contrib/gcc/c-common.c Wed Nov 13 03:50:31 2013 (r258080)
+++ head/contrib/gcc/c-common.c Wed Nov 13 04:31:27 2013 (r258081)
@@ -2585,9 +2585,13 @@ c_common_truthvalue_conversion (tree exp
break;
case MODIFY_EXPR:
- if (!TREE_NO_WARNING (expr))
- warning (OPT_Wparentheses,
- "suggest parentheses around assignment used as truth value");
+ if (!TREE_NO_WARNING (expr)
+ && warn_parentheses)
+ {
+ warning (OPT_Wparentheses,
+ "suggest parentheses around assignment used as truth value");
+ TREE_NO_WARNING (expr) = 1;
+ }
break;
default:
@@ -6471,5 +6475,87 @@ warn_array_subscript_with_type_char (tre
warning (OPT_Wchar_subscripts, "array subscript has type %<char%>");
}
+/* Implement -Wparentheses for the unexpected C precedence rules, to
+ cover cases like x + y << z which readers are likely to
+ misinterpret. We have seen an expression in which CODE is a binary
+ operator used to combine expressions headed by CODE_LEFT and
+ CODE_RIGHT. CODE_LEFT and CODE_RIGHT may be ERROR_MARK, which
+ means that that side of the expression was not formed using a
+ binary operator, or it was enclosed in parentheses. */
+
+void
+warn_about_parentheses (enum tree_code code, enum tree_code code_left,
+ enum tree_code code_right)
+{
+ if (!warn_parentheses)
+ return;
+
+ if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
+ {
+ if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
+ || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
+ warning (OPT_Wparentheses,
+ "suggest parentheses around + or - inside shift");
+ }
+
+ if (code == TRUTH_ORIF_EXPR)
+ {
+ if (code_left == TRUTH_ANDIF_EXPR
+ || code_right == TRUTH_ANDIF_EXPR)
+ warning (OPT_Wparentheses,
+ "suggest parentheses around && within ||");
+ }
+
+ if (code == BIT_IOR_EXPR)
+ {
+ if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR
+ || code_left == PLUS_EXPR || code_left == MINUS_EXPR
+ || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR
+ || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
+ warning (OPT_Wparentheses,
+ "suggest parentheses around arithmetic in operand of |");
+ /* Check cases like x|y==z */
+ if (TREE_CODE_CLASS (code_left) == tcc_comparison
+ || TREE_CODE_CLASS (code_right) == tcc_comparison)
+ warning (OPT_Wparentheses,
+ "suggest parentheses around comparison in operand of |");
+ }
+
+ if (code == BIT_XOR_EXPR)
+ {
+ if (code_left == BIT_AND_EXPR
+ || code_left == PLUS_EXPR || code_left == MINUS_EXPR
+ || code_right == BIT_AND_EXPR
+ || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
+ warning (OPT_Wparentheses,
+ "suggest parentheses around arithmetic in operand of ^");
+ /* Check cases like x^y==z */
+ if (TREE_CODE_CLASS (code_left) == tcc_comparison
+ || TREE_CODE_CLASS (code_right) == tcc_comparison)
+ warning (OPT_Wparentheses,
+ "suggest parentheses around comparison in operand of ^");
+ }
+
+ if (code == BIT_AND_EXPR)
+ {
+ if (code_left == PLUS_EXPR || code_left == MINUS_EXPR
+ || code_right == PLUS_EXPR || code_right == MINUS_EXPR)
+ warning (OPT_Wparentheses,
+ "suggest parentheses around + or - in operand of &");
+ /* Check cases like x&y==z */
+ if (TREE_CODE_CLASS (code_left) == tcc_comparison
+ || TREE_CODE_CLASS (code_right) == tcc_comparison)
+ warning (OPT_Wparentheses,
+ "suggest parentheses around comparison in operand of &");
+ }
+
+ /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
+ if (TREE_CODE_CLASS (code) == tcc_comparison
+ && (TREE_CODE_CLASS (code_left) == tcc_comparison
+ || TREE_CODE_CLASS (code_right) == tcc_comparison))
+ warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not "
+ "have their mathematical meaning");
+}
+
#include "gt-c-common.h"
Modified: head/contrib/gcc/c-common.h
==============================================================================
--- head/contrib/gcc/c-common.h Wed Nov 13 03:50:31 2013 (r258080)
+++ head/contrib/gcc/c-common.h Wed Nov 13 04:31:27 2013 (r258081)
@@ -850,6 +850,9 @@ extern int complete_array_type (tree *,
extern tree builtin_type_for_size (int, bool);
extern void warn_array_subscript_with_type_char (tree);
+extern void warn_about_parentheses (enum tree_code, enum tree_code,
+ enum tree_code);
+
/* In c-gimplify.c */
extern void c_genericize (tree);
Modified: head/contrib/gcc/c-typeck.c
==============================================================================
--- head/contrib/gcc/c-typeck.c Wed Nov 13 03:50:31 2013 (r258080)
+++ head/contrib/gcc/c-typeck.c Wed Nov 13 04:31:27 2013 (r258081)
@@ -2631,73 +2631,7 @@ parser_build_binary_op (enum tree_code c
/* Check for cases such as x+y<<z which users are likely
to misinterpret. */
if (warn_parentheses)
- {
- if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
- {
- if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
- || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
- warning (OPT_Wparentheses,
- "suggest parentheses around + or - inside shift");
- }
-
- if (code == TRUTH_ORIF_EXPR)
- {
- if (code1 == TRUTH_ANDIF_EXPR
- || code2 == TRUTH_ANDIF_EXPR)
- warning (OPT_Wparentheses,
- "suggest parentheses around && within ||");
- }
-
- if (code == BIT_IOR_EXPR)
- {
- if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR
- || code1 == PLUS_EXPR || code1 == MINUS_EXPR
- || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR
- || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
- warning (OPT_Wparentheses,
- "suggest parentheses around arithmetic in operand of |");
- /* Check cases like x|y==z */
- if (TREE_CODE_CLASS (code1) == tcc_comparison
- || TREE_CODE_CLASS (code2) == tcc_comparison)
- warning (OPT_Wparentheses,
- "suggest parentheses around comparison in operand of |");
- }
-
- if (code == BIT_XOR_EXPR)
- {
- if (code1 == BIT_AND_EXPR
- || code1 == PLUS_EXPR || code1 == MINUS_EXPR
- || code2 == BIT_AND_EXPR
- || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
- warning (OPT_Wparentheses,
- "suggest parentheses around arithmetic in operand of ^");
- /* Check cases like x^y==z */
- if (TREE_CODE_CLASS (code1) == tcc_comparison
- || TREE_CODE_CLASS (code2) == tcc_comparison)
- warning (OPT_Wparentheses,
- "suggest parentheses around comparison in operand of ^");
- }
-
- if (code == BIT_AND_EXPR)
- {
- if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
- || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
- warning (OPT_Wparentheses,
- "suggest parentheses around + or - in operand of &");
- /* Check cases like x&y==z */
- if (TREE_CODE_CLASS (code1) == tcc_comparison
- || TREE_CODE_CLASS (code2) == tcc_comparison)
- warning (OPT_Wparentheses,
- "suggest parentheses around comparison in operand of &");
- }
- /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
- if (TREE_CODE_CLASS (code) == tcc_comparison
- && (TREE_CODE_CLASS (code1) == tcc_comparison
- || TREE_CODE_CLASS (code2) == tcc_comparison))
- warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not "
- "have their mathematical meaning");
-
- }
+ warn_about_parentheses (code, code1, code2);
/* Warn about comparisons against string literals, with the exception
of testing for equality or inequality of a string literal with NULL. */
Modified: head/contrib/gcc/cp/cp-tree.h
==============================================================================
--- head/contrib/gcc/cp/cp-tree.h Wed Nov 13 03:50:31 2013
(r258080)
+++ head/contrib/gcc/cp/cp-tree.h Wed Nov 13 04:31:27 2013
(r258081)
@@ -4460,8 +4460,9 @@ extern tree build_x_indirect_ref (tree,
extern tree build_indirect_ref (tree, const char *);
extern tree build_array_ref (tree, tree);
extern tree get_member_function_from_ptrfunc (tree *, tree);
-extern tree build_x_binary_op (enum tree_code, tree, tree,
- bool *);
+extern tree build_x_binary_op (enum tree_code, tree,
+ enum tree_code, tree,
+ enum tree_code, bool *);
extern tree build_x_unary_op (enum tree_code, tree);
extern tree unary_complex_lvalue (enum tree_code, tree);
extern tree build_x_conditional_expr (tree, tree, tree);
Modified: head/contrib/gcc/cp/parser.c
==============================================================================
--- head/contrib/gcc/cp/parser.c Wed Nov 13 03:50:31 2013
(r258080)
+++ head/contrib/gcc/cp/parser.c Wed Nov 13 04:31:27 2013
(r258081)
@@ -1177,8 +1177,15 @@ typedef enum cp_parser_status_kind
typedef struct cp_parser_expression_stack_entry
{
+ /* Left hand side of the binary operation we are currently
+ parsing. */
tree lhs;
+ /* Original tree code for left hand side, if it was a binary
+ expression itself (used for -Wparentheses). */
+ enum tree_code lhs_type;
+ /* Tree code for the binary operation we are parsing. */
enum tree_code tree_type;
+ /* Precedence of the binary operation we are parsing. */
int prec;
} cp_parser_expression_stack_entry;
@@ -1536,7 +1543,7 @@ static tree cp_parser_builtin_offsetof
/* Statements [gram.stmt.stmt] */
static void cp_parser_statement
- (cp_parser *, tree, bool);
+ (cp_parser *, tree, bool, bool *);
static void cp_parser_label_for_labeled_statement
(cp_parser *);
static tree cp_parser_expression_statement
@@ -1546,7 +1553,7 @@ static tree cp_parser_compound_statement
static void cp_parser_statement_seq_opt
(cp_parser *, tree);
static tree cp_parser_selection_statement
- (cp_parser *);
+ (cp_parser *, bool *);
static tree cp_parser_condition
(cp_parser *);
static tree cp_parser_iteration_statement
@@ -1559,7 +1566,7 @@ static void cp_parser_declaration_statem
(cp_parser *);
static tree cp_parser_implicitly_scoped_statement
- (cp_parser *);
+ (cp_parser *, bool *);
static void cp_parser_already_scoped_statement
(cp_parser *);
@@ -5730,12 +5737,13 @@ cp_parser_binary_expression (cp_parser*
cp_parser_expression_stack_entry *sp = &stack[0];
tree lhs, rhs;
cp_token *token;
- enum tree_code tree_type;
+ enum tree_code tree_type, lhs_type, rhs_type;
enum cp_parser_prec prec = PREC_NOT_OPERATOR, new_prec, lookahead_prec;
bool overloaded_p;
/* Parse the first expression. */
lhs = cp_parser_cast_expression (parser, /*address_p=*/false, cast_p);
+ lhs_type = ERROR_MARK;
for (;;)
{
@@ -5768,6 +5776,7 @@ cp_parser_binary_expression (cp_parser*
/* Extract another operand. It may be the RHS of this expression
or the LHS of a new, higher priority expression. */
rhs = cp_parser_simple_cast_expression (parser);
+ rhs_type = ERROR_MARK;
/* Get another operator token. Look up its precedence to avoid
building a useless (immediately popped) stack entry for common
@@ -5783,8 +5792,10 @@ cp_parser_binary_expression (cp_parser*
sp->prec = prec;
sp->tree_type = tree_type;
sp->lhs = lhs;
+ sp->lhs_type = lhs_type;
sp++;
lhs = rhs;
+ lhs_type = rhs_type;
prec = new_prec;
new_prec = lookahead_prec;
goto get_rhs;
@@ -5801,11 +5812,15 @@ cp_parser_binary_expression (cp_parser*
prec = sp->prec;
tree_type = sp->tree_type;
rhs = lhs;
+ rhs_type = lhs_type;
lhs = sp->lhs;
+ lhs_type = sp->lhs_type;
}
overloaded_p = false;
- lhs = build_x_binary_op (tree_type, lhs, rhs, &overloaded_p);
+ lhs = build_x_binary_op (tree_type, lhs, lhs_type, rhs, rhs_type,
+ &overloaded_p);
+ lhs_type = tree_type;
/* If the binary operator required the use of an overloaded operator,
then this expression cannot be an integral constant-expression.
@@ -6222,17 +6237,23 @@ cp_parser_builtin_offsetof (cp_parser *p
try-block
IN_COMPOUND is true when the statement is nested inside a
- cp_parser_compound_statement; this matters for certain pragmas. */
+ cp_parser_compound_statement; this matters for certain pragmas.
+
+ If IF_P is not NULL, *IF_P is set to indicate whether the statement
+ is a (possibly labeled) if statement which is not enclosed in braces
+ and has an else clause. This is used to implement -Wparentheses. */
static void
cp_parser_statement (cp_parser* parser, tree in_statement_expr,
- bool in_compound)
+ bool in_compound, bool *if_p)
{
tree statement;
cp_token *token;
location_t statement_location;
restart:
+ if (if_p != NULL)
+ *if_p = false;
/* There is no statement yet. */
statement = NULL_TREE;
/* Peek at the next token. */
@@ -6257,7 +6278,7 @@ cp_parser_statement (cp_parser* parser,
case RID_IF:
case RID_SWITCH:
- statement = cp_parser_selection_statement (parser);
+ statement = cp_parser_selection_statement (parser, if_p);
break;
case RID_WHILE:
@@ -6522,7 +6543,7 @@ cp_parser_statement_seq_opt (cp_parser*
break;
/* Parse the statement. */
- cp_parser_statement (parser, in_statement_expr, true);
+ cp_parser_statement (parser, in_statement_expr, true, NULL);
}
}
@@ -6533,14 +6554,22 @@ cp_parser_statement_seq_opt (cp_parser*
if ( condition ) statement else statement
switch ( condition ) statement
- Returns the new IF_STMT or SWITCH_STMT. */
+ Returns the new IF_STMT or SWITCH_STMT.
+
+ If IF_P is not NULL, *IF_P is set to indicate whether the statement
+ is a (possibly labeled) if statement which is not enclosed in
+ braces and has an else clause. This is used to implement
+ -Wparentheses. */
static tree
-cp_parser_selection_statement (cp_parser* parser)
+cp_parser_selection_statement (cp_parser* parser, bool *if_p)
{
cp_token *token;
enum rid keyword;
+ if (if_p != NULL)
+ *if_p = false;
+
/* Peek at the next token. */
token = cp_parser_require (parser, CPP_KEYWORD, "selection-statement");
@@ -6576,11 +6605,13 @@ cp_parser_selection_statement (cp_parser
if (keyword == RID_IF)
{
+ bool nested_if;
+
/* Add the condition. */
finish_if_stmt_cond (condition, statement);
/* Parse the then-clause. */
- cp_parser_implicitly_scoped_statement (parser);
+ cp_parser_implicitly_scoped_statement (parser, &nested_if);
finish_then_clause (statement);
/* If the next token is `else', parse the else-clause. */
@@ -6591,8 +6622,28 @@ cp_parser_selection_statement (cp_parser
cp_lexer_consume_token (parser->lexer);
begin_else_clause (statement);
/* Parse the else-clause. */
- cp_parser_implicitly_scoped_statement (parser);
+ cp_parser_implicitly_scoped_statement (parser, NULL);
finish_else_clause (statement);
+
+ /* If we are currently parsing a then-clause, then
+ IF_P will not be NULL. We set it to true to
+ indicate that this if statement has an else clause.
+ This may trigger the Wparentheses warning below
+ when we get back up to the parent if statement. */
+ if (if_p != NULL)
+ *if_p = true;
+ }
+ else
+ {
+ /* This if statement does not have an else clause. If
+ NESTED_IF is true, then the then-clause is an if
+ statement which does have an else clause. We warn
+ about the potential ambiguity. */
+ if (nested_if)
+ warning (OPT_Wparentheses,
+ ("%Hsuggest explicit braces "
+ "to avoid ambiguous %<else%>"),
+ EXPR_LOCUS (statement));
}
/* Now we're all done with the if-statement. */
@@ -6611,7 +6662,7 @@ cp_parser_selection_statement (cp_parser
in_statement = parser->in_statement;
parser->in_switch_statement_p = true;
parser->in_statement |= IN_SWITCH_STMT;
- cp_parser_implicitly_scoped_statement (parser);
+ cp_parser_implicitly_scoped_statement (parser, NULL);
parser->in_switch_statement_p = in_switch_statement_p;
parser->in_statement = in_statement;
@@ -6789,7 +6840,7 @@ cp_parser_iteration_statement (cp_parser
statement = begin_do_stmt ();
/* Parse the body of the do-statement. */
parser->in_statement = IN_ITERATION_STMT;
- cp_parser_implicitly_scoped_statement (parser);
+ cp_parser_implicitly_scoped_statement (parser, NULL);
parser->in_statement = in_statement;
finish_do_body (statement);
/* Look for the `while' keyword. */
@@ -7031,13 +7082,21 @@ cp_parser_declaration_statement (cp_pars
but ensures that is in its own scope, even if it is not a
compound-statement.
+ If IF_P is not NULL, *IF_P is set to indicate whether the statement
+ is a (possibly labeled) if statement which is not enclosed in
+ braces and has an else clause. This is used to implement
+ -Wparentheses.
+
Returns the new statement. */
static tree
-cp_parser_implicitly_scoped_statement (cp_parser* parser)
+cp_parser_implicitly_scoped_statement (cp_parser* parser, bool *if_p)
{
tree statement;
+ if (if_p != NULL)
+ *if_p = false;
+
/* Mark if () ; with a special NOP_EXPR. */
if (cp_lexer_next_token_is (parser->lexer, CPP_SEMICOLON))
{
@@ -7053,7 +7112,7 @@ cp_parser_implicitly_scoped_statement (c
/* Create a compound-statement. */
statement = begin_compound_stmt (0);
/* Parse the dependent-statement. */
- cp_parser_statement (parser, NULL_TREE, false);
+ cp_parser_statement (parser, NULL_TREE, false, if_p);
/* Finish the dummy compound-statement. */
finish_compound_stmt (statement);
}
@@ -7072,7 +7131,7 @@ cp_parser_already_scoped_statement (cp_p
{
/* If the token is a `{', then we must take special action. */
if (cp_lexer_next_token_is_not (parser->lexer, CPP_OPEN_BRACE))
- cp_parser_statement (parser, NULL_TREE, false);
+ cp_parser_statement (parser, NULL_TREE, false, NULL);
else
{
/* Avoid calling cp_parser_compound_statement, so that we
@@ -18645,7 +18704,7 @@ cp_parser_omp_structured_block (cp_parse
tree stmt = begin_omp_structured_block ();
unsigned int save = cp_parser_begin_omp_structured_block (parser);
- cp_parser_statement (parser, NULL_TREE, false);
+ cp_parser_statement (parser, NULL_TREE, false, NULL);
cp_parser_end_omp_structured_block (parser, save);
return finish_omp_structured_block (stmt);
@@ -18890,7 +18949,7 @@ cp_parser_omp_for_loop (cp_parser *parse
/* Note that the grammar doesn't call for a structured block here,
though the loop as a whole is a structured block. */
body = push_stmt_list ();
- cp_parser_statement (parser, NULL_TREE, false);
+ cp_parser_statement (parser, NULL_TREE, false, NULL);
body = pop_stmt_list (body);
return finish_omp_for (loc, decl, init, cond, incr, body, pre_body);
@@ -18983,7 +19042,7 @@ cp_parser_omp_sections_scope (cp_parser
while (1)
{
- cp_parser_statement (parser, NULL_TREE, false);
+ cp_parser_statement (parser, NULL_TREE, false, NULL);
tok = cp_lexer_peek_token (parser->lexer);
if (tok->pragma_kind == PRAGMA_OMP_SECTION)
Modified: head/contrib/gcc/cp/pt.c
==============================================================================
--- head/contrib/gcc/cp/pt.c Wed Nov 13 03:50:31 2013 (r258080)
+++ head/contrib/gcc/cp/pt.c Wed Nov 13 04:31:27 2013 (r258081)
@@ -9078,7 +9078,13 @@ tsubst_copy_and_build (tree t,
return build_x_binary_op
(TREE_CODE (t),
RECUR (TREE_OPERAND (t, 0)),
+ (TREE_NO_WARNING (TREE_OPERAND (t, 0))
+ ? ERROR_MARK
+ : TREE_CODE (TREE_OPERAND (t, 0))),
RECUR (TREE_OPERAND (t, 1)),
+ (TREE_NO_WARNING (TREE_OPERAND (t, 1))
+ ? ERROR_MARK
+ : TREE_CODE (TREE_OPERAND (t, 1))),
/*overloaded_p=*/NULL);
case SCOPE_REF:
@@ -9087,7 +9093,14 @@ tsubst_copy_and_build (tree t,
case ARRAY_REF:
op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
args, complain, in_decl);
- return build_x_binary_op (ARRAY_REF, op1, RECUR (TREE_OPERAND (t, 1)),
+ return build_x_binary_op (ARRAY_REF, op1,
+ (TREE_NO_WARNING (TREE_OPERAND (t, 0))
+ ? ERROR_MARK
+ : TREE_CODE (TREE_OPERAND (t, 0))),
+ RECUR (TREE_OPERAND (t, 1)),
+ (TREE_NO_WARNING (TREE_OPERAND (t, 1))
+ ? ERROR_MARK
+ : TREE_CODE (TREE_OPERAND (t, 1))),
/*overloaded_p=*/NULL);
case SIZEOF_EXPR:
Modified: head/contrib/gcc/cp/semantics.c
==============================================================================
--- head/contrib/gcc/cp/semantics.c Wed Nov 13 03:50:31 2013
(r258080)
+++ head/contrib/gcc/cp/semantics.c Wed Nov 13 04:31:27 2013
(r258081)
@@ -587,6 +587,16 @@ maybe_convert_cond (tree cond)
/* Do the conversion. */
cond = convert_from_reference (cond);
+
+ if (TREE_CODE (cond) == MODIFY_EXPR
+ && !TREE_NO_WARNING (cond)
+ && warn_parentheses)
+ {
+ warning (OPT_Wparentheses,
+ "suggest parentheses around assignment used as truth value");
+ TREE_NO_WARNING (cond) = 1;
+ }
+
return condition_conversion (cond);
}
Modified: head/contrib/gcc/cp/typeck.c
==============================================================================
--- head/contrib/gcc/cp/typeck.c Wed Nov 13 03:50:31 2013
(r258080)
+++ head/contrib/gcc/cp/typeck.c Wed Nov 13 04:31:27 2013
(r258081)
@@ -1690,17 +1690,20 @@ rationalize_conditional_expr (enum tree_
are equal, so we know what conditional expression this used to be. */
if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
{
+ tree op0 = TREE_OPERAND (t, 0);
+ tree op1 = TREE_OPERAND (t, 1);
+
/* The following code is incorrect if either operand side-effects. */
- gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
- && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
+ gcc_assert (!TREE_SIDE_EFFECTS (op0)
+ && !TREE_SIDE_EFFECTS (op1));
return
build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
? LE_EXPR : GE_EXPR),
- TREE_OPERAND (t, 0),
- TREE_OPERAND (t, 1),
+ op0, TREE_CODE (op0),
+ op1, TREE_CODE (op1),
/*overloaded_p=*/NULL),
- build_unary_op (code, TREE_OPERAND (t, 0), 0),
- build_unary_op (code, TREE_OPERAND (t, 1), 0));
+ build_unary_op (code, op0, 0),
+ build_unary_op (code, op1, 0));
}
return
@@ -2908,8 +2911,8 @@ convert_arguments (tree typelist, tree v
conversions on the operands. CODE is the kind of expression to build. */
tree
-build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
- bool *overloaded_p)
+build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
+ tree arg2, enum tree_code arg2_code, bool *overloaded_p)
{
tree orig_arg1;
tree orig_arg2;
@@ -2933,6 +2936,17 @@ build_x_binary_op (enum tree_code code,
expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
overloaded_p);
+ /* Check for cases such as x+y<<z which users are likely to
+ misinterpret. But don't warn about obj << x + y, since that is a
+ common idiom for I/O. */
+ if (warn_parentheses
+ && !processing_template_decl
+ && !error_operand_p (arg1)
+ && !error_operand_p (arg2)
+ && (code != LSHIFT_EXPR
+ || !IS_AGGR_TYPE (TREE_TYPE (arg1))))
+ warn_about_parentheses (code, arg1_code, arg2_code);
+
if (processing_template_decl && expr != error_mark_node)
return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
@@ -6280,6 +6294,19 @@ convert_for_assignment (tree type, tree
errtype);
}
+ /* If -Wparentheses, warn about a = b = c when a has type bool and b
+ does not. */
+ if (warn_parentheses
+ && type == boolean_type_node
+ && TREE_CODE (rhs) == MODIFY_EXPR
+ && !TREE_NO_WARNING (rhs)
+ && TREE_TYPE (rhs) != boolean_type_node)
+ {
+ warning (OPT_Wparentheses,
+ "suggest parentheses around assignment used as truth value");
+ TREE_NO_WARNING (rhs) = 1;
+ }
+
return perform_implicit_conversion (strip_top_quals (type), rhs);
}
Modified: head/contrib/gcc/doc/invoke.texi
==============================================================================
--- head/contrib/gcc/doc/invoke.texi Wed Nov 13 03:50:31 2013
(r258080)
+++ head/contrib/gcc/doc/invoke.texi Wed Nov 13 04:31:27 2013
(r258081)
@@ -2212,9 +2212,7 @@ Warn if a user-supplied include director
Warn if parentheses are omitted in certain contexts, such
as when there is an assignment in a context where a truth value
is expected, or when operators are nested whose precedence people
-often get confused about. Only the warning for an assignment used as
-a truth value is supported when compiling C++; the other warnings are
-only supported when compiling C@.
+often get confused about.
Also warn if a comparison like @samp{x<=y<=z} appears; this is
equivalent to @samp{(x<=y ? 1 : 0) <= z}, which is a different
@@ -2236,14 +2234,15 @@ such a case:
@end group
@end smallexample
-In C, every @code{else} branch belongs to the innermost possible @code{if}
-statement, which in this example is @code{if (b)}. This is often not
-what the programmer expected, as illustrated in the above example by
-indentation the programmer chose. When there is the potential for this
-confusion, GCC will issue a warning when this flag is specified.
-To eliminate the warning, add explicit braces around the innermost
-@code{if} statement so there is no way the @code{else} could belong to
-the enclosing @code{if}. The resulting code would look like this:
+In C/C++, every @code{else} branch belongs to the innermost possible
+@code{if} statement, which in this example is @code{if (b)}. This is
+often not what the programmer expected, as illustrated in the above
+example by indentation the programmer chose. When there is the
+potential for this confusion, GCC will issue a warning when this flag
+is specified. To eliminate the warning, add explicit braces around
+the innermost @code{if} statement so there is no way the @code{else}
+could belong to the enclosing @code{if}. The resulting code would
+look like this:
@smallexample
@group
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