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Re: C/C++ PATCH to implement -Wmultiline-expansion (PR c/80116)
- From: Marek Polacek <polacek at redhat dot com>
- To: Martin Sebor <msebor at gmail dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, Joseph Myers <joseph at codesourcery dot com>, Jason Merrill <jason at redhat dot com>, David Malcolm <dmalcolm at redhat dot com>
- Date: Wed, 7 Jun 2017 20:44:30 +0200
- Subject: Re: C/C++ PATCH to implement -Wmultiline-expansion (PR c/80116)
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- References: <20170601164517.GB3413@redhat.com> <42bf969a-7768-08c2-9427-ebceb860cd67@gmail.com> <20170602165257.GG3413@redhat.com> <21b41803-2898-43c5-401f-2eda88b93503@gmail.com>
On Fri, Jun 02, 2017 at 03:50:12PM -0600, Martin Sebor wrote:
> On 06/02/2017 10:52 AM, Marek Polacek wrote:
> > On Thu, Jun 01, 2017 at 04:17:24PM -0600, Martin Sebor wrote:
> > > Very nice. I think David already suggested handling other statements
> > > besides if (do/while), so let me just add for and switch (as in:
> > > 'switch (1) case SWAP (i, j);')
> >
> > How's that one problematic, though?
>
> The same way as 'if (1) SWAP (i, j);' because it expands to
>
> switch (1) case 1: tmp = i;
> i = j;
> j = tmp;
>
> (I had a typo there so maybe that obscured the problem.)
Ah, ok, I can see now. Actually the C++ FE would already warn with my patch,
but the C FE needed small changes to warn.
> >
> > > The location in the warning look like it could be improved to extend
> > > from just the first column to the whole macro argument but I don't
> > > suppose that's under the direct control of your patch.
> >
> > Well, for e.g. the "in expasion" message we have a good location range:
> > SWAP
> > ^~~~
> > so do you mean this?
> > tmp = x;
> > ^
>
> Yes.
>
> > ? But yea, it's outside the scope of this patch.
> >
> > > Besides the statements already mentioned above, here are a couple
> > > of corner cases I noticed are not handled while playing with the
> > > patch:
> > >
> > > define M(x) x
> > >
> > > int f (int i)
> > > {
> > > if (i)
> > > M (--i; --i); // can this be handled?
> > >
> > > return i;
> > > }
> > >
> > > and
> > >
> > > define M(x) x; x
> > >
> > > int f (int i)
> > > {
> > > if (i)
> > > M (--i; --i); // seems like this should be handled
> > >
> > > return i;
> > > }
> >
> > Hmm, I was hoping my patch would warn for both examples, but it doesn't. I'll
> > have to get back to this a ponder more.
I still haven't looked into this. Might not be easy so I think let's not
block the patch on this.
> > > As an aside since it's outside the subset of the bigger problem
> > > you chose to solve, there is a related issue with macros that
> > > expand to an unparenthesized binary (and even some unary)
> > > expression:
> > >
> > > #define sum(x, y) x + y
> > >
> > > int n = 2 * sum (3, 5);
> > >
> > > I'm not very familiar with this area of the parser but I would
> > > expect it to be relatively straightforward to extend your solution
> > > to handle this problem as well.
> >
> > It'd certainly be useful to warn here. But it doesn't seem to be an
> > easy warning to implement, to me. E.g. warning for
> >
> > int n = 2 + sum (3, 5);
> >
> > would be annoying, I suspect.
>
> Yes, it would be if the warning was only meant to trigger for
> uses that change the meaning. If it was meant to warn on unsafe
> macro definitions instead it should be less so. But that would
> make it a different warning, and mean implementing it in the
> preprocessor. Hmm, I guess it's not as straightforward as it
> seemed.
Nothing ever is ;).
All right, here's the third version of this patch which also warns about
the switch case Martin pointed out above.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2017-06-07 Marek Polacek <polacek@redhat.com>
PR c/80116
* c-common.h (warn_for_multiline_expansion): Declare.
* c-warn.c (warn_for_multiline_expansion): New function.
* c.opt (Wmultiline-expansion): New option.
* c-parser.c (c_parser_if_body): Set the location of the
body of the conditional after parsing all the labels. Call
warn_for_multiline_expansion.
(c_parser_else_body): Likewise.
(c_parser_switch_statement): Likewise.
(c_parser_while_statement): Likewise.
(c_parser_for_statement): Likewise.
(c_parser_statement): Add a default argument. Save the location
after labels have been parsed.
(c_parser_c99_block_statement): Likewise.
* parser.c (cp_parser_statement): Add a default argument. Save the
location of the expression-statement after labels have been parsed.
(cp_parser_implicitly_scoped_statement): Set the location of the
body of the conditional after parsing all the labels. Call
warn_for_multiline_expansion.
(cp_parser_already_scoped_statement): Likewise.
* doc/invoke.texi: Document -Wmultiline-expansion.
* c-c++-common/Wmultiline-expansion-1.c: New test.
* c-c++-common/Wmultiline-expansion-2.c: New test.
* c-c++-common/Wmultiline-expansion-3.c: New test.
* c-c++-common/Wmultiline-expansion-4.c: New test.
* c-c++-common/Wmultiline-expansion-5.c: New test.
* c-c++-common/Wmultiline-expansion-6.c: New test.
* c-c++-common/Wmultiline-expansion-7.c: New test.
* c-c++-common/Wmultiline-expansion-8.c: New test.
* c-c++-common/Wmultiline-expansion-9.c: New test.
* c-c++-common/Wmultiline-expansion-10.c: New test.
diff --git gcc/c-family/c-common.h gcc/c-family/c-common.h
index 79072e6..6efbebc 100644
--- gcc/c-family/c-common.h
+++ gcc/c-family/c-common.h
@@ -1539,6 +1539,7 @@ extern bool maybe_warn_shift_overflow (location_t, tree, tree);
extern void warn_duplicated_cond_add_or_warn (location_t, tree, vec<tree> **);
extern bool diagnose_mismatched_attributes (tree, tree);
extern tree do_warn_duplicated_branches_r (tree *, int *, void *);
+extern void warn_for_multiline_expansion (location_t, location_t, location_t);
/* In c-attribs.c. */
extern bool attribute_takes_identifier_p (const_tree);
diff --git gcc/c-family/c-warn.c gcc/c-family/c-warn.c
index 35321a6..84e1552 100644
--- gcc/c-family/c-warn.c
+++ gcc/c-family/c-warn.c
@@ -2401,3 +2401,91 @@ do_warn_duplicated_branches_r (tree *tp, int *, void *)
do_warn_duplicated_branches (*tp);
return NULL_TREE;
}
+
+/* Implementation of -Wmultiline-expansion. This warning warns about
+ cases when a macro expands to multiple statements not wrapped in
+ do {} while (0) or ({ }) and is used as a body of if/else/for/while
+ conditionals. For example,
+
+ #define DOIT x++; y++
+
+ if (c)
+ DOIT;
+
+ will increment y unconditionally.
+
+ BODY_LOC is the location of the first token in the body after labels
+ have been parsed, NEXT_LOC is the location of the next token after the
+ body of the conditional has been parsed, and GUARD_LOC is the location
+ of the conditional. */
+
+void
+warn_for_multiline_expansion (location_t body_loc, location_t next_loc,
+ location_t guard_loc)
+{
+ if (!warn_multiline_expansion)
+ return;
+
+ /* Ain't got time to waste. We only care about macros here. */
+ if (!from_macro_expansion_at (body_loc)
+ || !from_macro_expansion_at (next_loc))
+ return;
+
+ /* Let's skip macros defined in system headers. */
+ if (in_system_header_at (body_loc)
+ || in_system_header_at (next_loc))
+ return;
+
+ /* Find the actual tokens in the macro definition. BODY_LOC and
+ NEXT_LOC have to come from the same spelling location, but they
+ will resolve to different locations in the context of the macro
+ definition. */
+ location_t body_loc_exp
+ = linemap_resolve_location (line_table, body_loc,
+ LRK_MACRO_DEFINITION_LOCATION, NULL);
+ location_t next_loc_exp
+ = linemap_resolve_location (line_table, next_loc,
+ LRK_MACRO_DEFINITION_LOCATION, NULL);
+ location_t guard_loc_exp
+ = linemap_resolve_location (line_table, guard_loc,
+ LRK_MACRO_DEFINITION_LOCATION, NULL);
+
+ /* These are some funky cases we don't want to warn about. */
+ if (body_loc_exp == guard_loc_exp
+ || next_loc_exp == guard_loc_exp
+ || body_loc_exp == next_loc_exp)
+ return;
+
+ /* Find the macro map for the macro expansion BODY_LOC. */
+ const line_map *map = linemap_lookup (line_table, body_loc);
+ const line_map_macro *macro_map = linemap_check_macro (map);
+
+ /* Now see if the following token is coming from the same macro
+ expansion. If it is, it's a problem, because it should've been
+ parsed at this point. We only look at odd-numbered indexes
+ within the MACRO_MAP_LOCATIONS array, i.e. the spelling locations
+ of the tokens. */
+ bool found_guard = false;
+ bool found_next = false;
+ for (unsigned int i = 1;
+ i < 2 * MACRO_MAP_NUM_MACRO_TOKENS (macro_map);
+ i += 2)
+ {
+ if (MACRO_MAP_LOCATIONS (macro_map)[i] == next_loc_exp)
+ found_next = true;
+ if (MACRO_MAP_LOCATIONS (macro_map)[i] == guard_loc_exp)
+ found_guard = true;
+ }
+
+ /* The conditional itself must not come from the same expansion, because
+ we don't want to warn about
+ #define IF if (x) x++; y++
+ and similar. */
+ if (!found_next || found_guard)
+ return;
+
+ if (warning_at (body_loc, OPT_Wmultiline_expansion,
+ "macro expands to multiple statements"))
+ inform (guard_loc, "some parts of macro expansion are not guarded by "
+ "this conditional");
+}
diff --git gcc/c-family/c.opt gcc/c-family/c.opt
index 37bb236..1043615 100644
--- gcc/c-family/c.opt
+++ gcc/c-family/c.opt
@@ -698,6 +698,10 @@ Wmissing-field-initializers
C ObjC C++ ObjC++ Var(warn_missing_field_initializers) Warning EnabledBy(Wextra)
Warn about missing fields in struct initializers.
+Wmultiline-expansion
+C ObjC C++ ObjC++ Var(warn_multiline_expansion) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall)
+Warn about macros expanding to multiple statements in a body of a conditional such as if, else, while, or for.
+
Wmultiple-inheritance
C++ ObjC++ Var(warn_multiple_inheritance) Warning
Warn on direct multiple inheritance.
diff --git gcc/c/c-parser.c gcc/c/c-parser.c
index 6f954f2..d46f81c 100644
--- gcc/c/c-parser.c
+++ gcc/c/c-parser.c
@@ -1218,9 +1218,11 @@ static void c_parser_initval (c_parser *, struct c_expr *,
static tree c_parser_compound_statement (c_parser *);
static void c_parser_compound_statement_nostart (c_parser *);
static void c_parser_label (c_parser *);
-static void c_parser_statement (c_parser *, bool *);
+static void c_parser_statement (c_parser *, bool *, location_t * = NULL);
static void c_parser_statement_after_labels (c_parser *, bool *,
vec<tree> * = NULL);
+static tree c_parser_c99_block_statement (c_parser *, bool *,
+ location_t * = NULL);
static void c_parser_if_statement (c_parser *, bool *, vec<tree> *);
static void c_parser_switch_statement (c_parser *, bool *);
static void c_parser_while_statement (c_parser *, bool, bool *);
@@ -5204,9 +5206,11 @@ c_parser_label (c_parser *parser)
implement -Wparentheses. */
static void
-c_parser_statement (c_parser *parser, bool *if_p)
+c_parser_statement (c_parser *parser, bool *if_p, location_t *loc_after_labels)
{
c_parser_all_labels (parser);
+ if (loc_after_labels)
+ *loc_after_labels = c_parser_peek_token (parser)->location;
c_parser_statement_after_labels (parser, if_p, NULL);
}
@@ -5466,11 +5470,12 @@ c_parser_paren_condition (c_parser *parser)
implement -Wparentheses. */
static tree
-c_parser_c99_block_statement (c_parser *parser, bool *if_p)
+c_parser_c99_block_statement (c_parser *parser, bool *if_p,
+ location_t *loc_after_labels)
{
tree block = c_begin_compound_stmt (flag_isoc99);
location_t loc = c_parser_peek_token (parser)->location;
- c_parser_statement (parser, if_p);
+ c_parser_statement (parser, if_p, loc_after_labels);
return c_end_compound_stmt (loc, block, flag_isoc99);
}
@@ -5492,6 +5497,7 @@ c_parser_if_body (c_parser *parser, bool *if_p,
{
tree block = c_begin_compound_stmt (flag_isoc99);
location_t body_loc = c_parser_peek_token (parser)->location;
+ location_t body_loc_after_labels = UNKNOWN_LOCATION;
token_indent_info body_tinfo
= get_token_indent_info (c_parser_peek_token (parser));
@@ -5508,11 +5514,18 @@ c_parser_if_body (c_parser *parser, bool *if_p,
else if (c_parser_next_token_is (parser, CPP_OPEN_BRACE))
add_stmt (c_parser_compound_statement (parser));
else
- c_parser_statement_after_labels (parser, if_p);
+ {
+ body_loc_after_labels = c_parser_peek_token (parser)->location;
+ c_parser_statement_after_labels (parser, if_p);
+ }
token_indent_info next_tinfo
= get_token_indent_info (c_parser_peek_token (parser));
warn_for_misleading_indentation (if_tinfo, body_tinfo, next_tinfo);
+ if (body_loc_after_labels != UNKNOWN_LOCATION
+ && next_tinfo.type != CPP_SEMICOLON)
+ warn_for_multiline_expansion (body_loc_after_labels, next_tinfo.location,
+ if_tinfo.location);
return c_end_compound_stmt (body_loc, block, flag_isoc99);
}
@@ -5530,6 +5543,7 @@ c_parser_else_body (c_parser *parser, const token_indent_info &else_tinfo,
tree block = c_begin_compound_stmt (flag_isoc99);
token_indent_info body_tinfo
= get_token_indent_info (c_parser_peek_token (parser));
+ location_t body_loc_after_labels = UNKNOWN_LOCATION;
c_parser_all_labels (parser);
if (c_parser_next_token_is (parser, CPP_SEMICOLON))
@@ -5542,11 +5556,18 @@ c_parser_else_body (c_parser *parser, const token_indent_info &else_tinfo,
c_parser_consume_token (parser);
}
else
- c_parser_statement_after_labels (parser, NULL, chain);
+ {
+ body_loc_after_labels = c_parser_peek_token (parser)->location;
+ c_parser_statement_after_labels (parser, NULL, chain);
+ }
token_indent_info next_tinfo
= get_token_indent_info (c_parser_peek_token (parser));
warn_for_misleading_indentation (else_tinfo, body_tinfo, next_tinfo);
+ if (body_loc_after_labels != UNKNOWN_LOCATION
+ && next_tinfo.type != CPP_SEMICOLON)
+ warn_for_multiline_expansion (body_loc_after_labels, next_tinfo.location,
+ else_tinfo.location);
return c_end_compound_stmt (body_loc, block, flag_isoc99);
}
@@ -5732,7 +5753,12 @@ c_parser_switch_statement (c_parser *parser, bool *if_p)
c_start_case (switch_loc, switch_cond_loc, expr, explicit_cast_p);
save_break = c_break_label;
c_break_label = NULL_TREE;
- body = c_parser_c99_block_statement (parser, if_p);
+ location_t loc_after_labels;
+ bool open_brace_p = c_parser_peek_token (parser)->type == CPP_OPEN_BRACE;
+ body = c_parser_c99_block_statement (parser, if_p, &loc_after_labels);
+ location_t next_loc = c_parser_peek_token (parser)->location;
+ if (!open_brace_p && c_parser_peek_token (parser)->type != CPP_SEMICOLON)
+ warn_for_multiline_expansion (loc_after_labels, next_loc, switch_loc);
c_finish_case (body, ce.original_type);
if (c_break_label)
{
@@ -5783,7 +5809,8 @@ c_parser_while_statement (c_parser *parser, bool ivdep, bool *if_p)
token_indent_info body_tinfo
= get_token_indent_info (c_parser_peek_token (parser));
- body = c_parser_c99_block_statement (parser, if_p);
+ location_t loc_after_labels;
+ body = c_parser_c99_block_statement (parser, if_p, &loc_after_labels);
c_finish_loop (loc, cond, NULL, body, c_break_label, c_cont_label, true);
add_stmt (c_end_compound_stmt (loc, block, flag_isoc99));
c_parser_maybe_reclassify_token (parser);
@@ -5792,6 +5819,10 @@ c_parser_while_statement (c_parser *parser, bool ivdep, bool *if_p)
= get_token_indent_info (c_parser_peek_token (parser));
warn_for_misleading_indentation (while_tinfo, body_tinfo, next_tinfo);
+ if (next_tinfo.type != CPP_SEMICOLON)
+ warn_for_multiline_expansion (loc_after_labels, next_tinfo.location,
+ while_tinfo.location);
+
c_break_label = save_break;
c_cont_label = save_cont;
}
@@ -6076,7 +6107,8 @@ c_parser_for_statement (c_parser *parser, bool ivdep, bool *if_p)
token_indent_info body_tinfo
= get_token_indent_info (c_parser_peek_token (parser));
- body = c_parser_c99_block_statement (parser, if_p);
+ location_t loc_after_labels;
+ body = c_parser_c99_block_statement (parser, if_p, &loc_after_labels);
if (is_foreach_statement)
objc_finish_foreach_loop (loc, object_expression, collection_expression, body, c_break_label, c_cont_label);
@@ -6089,6 +6121,10 @@ c_parser_for_statement (c_parser *parser, bool ivdep, bool *if_p)
= get_token_indent_info (c_parser_peek_token (parser));
warn_for_misleading_indentation (for_tinfo, body_tinfo, next_tinfo);
+ if (next_tinfo.type != CPP_SEMICOLON)
+ warn_for_multiline_expansion (loc_after_labels, next_tinfo.location,
+ for_tinfo.location);
+
c_break_label = save_break;
c_cont_label = save_cont;
}
diff --git gcc/cp/parser.c gcc/cp/parser.c
index 891341d..e2a69ce 100644
--- gcc/cp/parser.c
+++ gcc/cp/parser.c
@@ -2102,7 +2102,7 @@ static void cp_parser_lambda_body
/* Statements [gram.stmt.stmt] */
static void cp_parser_statement
- (cp_parser *, tree, bool, bool *, vec<tree> * = NULL);
+ (cp_parser *, tree, bool, bool *, vec<tree> * = NULL, location_t * = NULL);
static void cp_parser_label_for_labeled_statement
(cp_parser *, tree);
static tree cp_parser_expression_statement
@@ -10531,7 +10531,8 @@ cp_parser_lambda_body (cp_parser* parser, tree lambda_expr)
static void
cp_parser_statement (cp_parser* parser, tree in_statement_expr,
- bool in_compound, bool *if_p, vec<tree> *chain)
+ bool in_compound, bool *if_p, vec<tree> *chain,
+ location_t *loc_after_labels)
{
tree statement, std_attrs = NULL_TREE;
cp_token *token;
@@ -10724,6 +10725,10 @@ cp_parser_statement (cp_parser* parser, tree in_statement_expr,
if (cp_parser_parse_definitely (parser))
return;
}
+ /* All preceding labels have been parsed at this point. */
+ if (loc_after_labels != NULL)
+ *loc_after_labels = statement_location;
+
/* Look for an expression-statement instead. */
statement = cp_parser_expression_statement (parser, in_statement_expr);
@@ -12264,6 +12269,7 @@ cp_parser_implicitly_scoped_statement (cp_parser* parser, bool *if_p,
{
tree statement;
location_t body_loc = cp_lexer_peek_token (parser->lexer)->location;
+ location_t body_loc_after_labels = UNKNOWN_LOCATION;
token_indent_info body_tinfo
= get_token_indent_info (cp_lexer_peek_token (parser->lexer));
@@ -12293,7 +12299,8 @@ cp_parser_implicitly_scoped_statement (cp_parser* parser, bool *if_p,
/* Create a compound-statement. */
statement = begin_compound_stmt (0);
/* Parse the dependent-statement. */
- cp_parser_statement (parser, NULL_TREE, false, if_p, chain);
+ cp_parser_statement (parser, NULL_TREE, false, if_p, chain,
+ &body_loc_after_labels);
/* Finish the dummy compound-statement. */
finish_compound_stmt (statement);
}
@@ -12302,6 +12309,11 @@ cp_parser_implicitly_scoped_statement (cp_parser* parser, bool *if_p,
= get_token_indent_info (cp_lexer_peek_token (parser->lexer));
warn_for_misleading_indentation (guard_tinfo, body_tinfo, next_tinfo);
+ if (body_loc_after_labels != UNKNOWN_LOCATION
+ && next_tinfo.type != CPP_SEMICOLON)
+ warn_for_multiline_expansion (body_loc_after_labels, next_tinfo.location,
+ guard_tinfo.location);
+
/* Return the statement. */
return statement;
}
@@ -12320,11 +12332,17 @@ cp_parser_already_scoped_statement (cp_parser* parser, bool *if_p,
{
token_indent_info body_tinfo
= get_token_indent_info (cp_lexer_peek_token (parser->lexer));
+ location_t loc_after_labels;
- cp_parser_statement (parser, NULL_TREE, false, if_p);
+ cp_parser_statement (parser, NULL_TREE, false, if_p, NULL,
+ &loc_after_labels);
token_indent_info next_tinfo
= get_token_indent_info (cp_lexer_peek_token (parser->lexer));
warn_for_misleading_indentation (guard_tinfo, body_tinfo, next_tinfo);
+
+ if (next_tinfo.type != CPP_SEMICOLON)
+ warn_for_multiline_expansion (loc_after_labels, next_tinfo.location,
+ guard_tinfo.location);
}
else
{
diff --git gcc/doc/invoke.texi gcc/doc/invoke.texi
index 456fa85..445fdb0 100644
--- gcc/doc/invoke.texi
+++ gcc/doc/invoke.texi
@@ -293,7 +293,7 @@ Objective-C and Objective-C++ Dialects}.
-Wmain -Wmaybe-uninitialized -Wmemset-elt-size -Wmemset-transposed-args @gol
-Wmisleading-indentation -Wmissing-braces @gol
-Wmissing-field-initializers -Wmissing-include-dirs @gol
--Wno-multichar -Wnonnull -Wnonnull-compare @gol
+-Wno-multichar -Wmultiline-expansion -Wnonnull -Wnonnull-compare @gol
-Wnormalized=@r{[}none@r{|}id@r{|}nfc@r{|}nfkc@r{]} @gol
-Wnull-dereference -Wodr -Wno-overflow -Wopenmp-simd @gol
-Woverride-init-side-effects -Woverlength-strings @gol
@@ -3824,6 +3824,7 @@ Options} and @ref{Objective-C and Objective-C++ Dialect Options}.
-Wmemset-transposed-args @gol
-Wmisleading-indentation @r{(only for C/C++)} @gol
-Wmissing-braces @r{(only for C/ObjC)} @gol
+-Wmultiline-expansion @gol
-Wnarrowing @r{(only for C++)} @gol
-Wnonnull @gol
-Wnonnull-compare @gol
@@ -4496,6 +4497,29 @@ This warning is enabled by @option{-Wall}.
@opindex Wno-missing-include-dirs
Warn if a user-supplied include directory does not exist.
+@item -Wmultiline-expansion
+@opindex Wmultiline-expansion
+@opindex Wno-multiline-expansion
+Warn about macros expanding to multiple statements in a body of a conditional,
+such as @code{if}, @code{else}, @code{for}, or @code{while}.
+For example:
+
+@smallexample
+#define DOIT x++; y++
+if (c)
+ DOIT;
+@end smallexample
+
+will increment @code{y} unconditionally, not just when @code{c} holds.
+The can usually be fixed by wrapping the macro in a do-while loop:
+@smallexample
+#define DOIT do @{ x++; y++; @} while (0)
+if (c)
+ DOIT;
+@end smallexample
+
+This warning is enabled by @option{-Wall} in C and C++.
+
@item -Wparentheses
@opindex Wparentheses
@opindex Wno-parentheses
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-1.c gcc/testsuite/c-c++-common/Wmultiline-expansion-1.c
index e69de29..119d119 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-1.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-1.c
@@ -0,0 +1,118 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define SWAP(X, Y) \
+ tmp = X; /* { dg-warning "macro expands to multiple statements" } */ \
+ X = Y; \
+ Y = tmp
+
+#define STUFF \
+ if (0) x = y
+
+#define STUFF2 \
+ if (0) x = y; x++
+
+#define STUFF3 \
+ if (x) /* { dg-message "not guarded" } */ \
+ SWAP(x, y) /* { dg-message "in expansion of macro .SWAP." } */
+
+#define SET(X, Y) \
+ (X) = (Y)
+
+#define STUFF4 \
+ if (x) \
+ SET(x, y); \
+ SET(x, y)
+
+#define STUFF5 \
+ { tmp = x; x = y; }
+
+#define STUFF6 \
+ x++;;
+
+int x, y, tmp;
+
+void
+fn1 (void)
+{
+ if (x) /* { dg-message "not guarded" } */
+ SWAP(x, y); /* { dg-message "in expansion of macro .SWAP." } */
+}
+
+void
+fn2 (void)
+{
+ SWAP(x, y);
+}
+
+void
+fn3 (void)
+{
+ if (x)
+ {
+ SWAP(x, y);
+ }
+}
+
+void
+fn4 (void)
+{
+ if (x)
+ ({ x = 10; x++; });
+}
+
+void
+fn5 (void)
+{
+ if (x) /* { dg-message "not guarded" } */
+L1:
+ SWAP (x, y); /* { dg-message "in expansion of macro .SWAP." } */
+ goto L1;
+}
+
+void
+fn6 (void)
+{
+ if (x)
+ SET (x, y);
+ SET (tmp, x);
+}
+
+void
+fn7 (void)
+{
+ STUFF;
+}
+
+void
+fn8 (void)
+{
+ STUFF2;
+}
+
+void
+fn9 (void)
+{
+ STUFF3; /* { dg-message "in expansion of macro .STUFF3." } */
+}
+
+void
+fn10 (void)
+{
+ STUFF4;
+}
+
+void
+fn11 (void)
+{
+ if (x)
+ STUFF5;
+}
+
+void
+fn12 (void)
+{
+ if (x)
+ STUFF6;
+}
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-10.c gcc/testsuite/c-c++-common/Wmultiline-expansion-10.c
index e69de29..3e68fcb 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-10.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-10.c
@@ -0,0 +1,82 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define SWAP(x, y) \
+ tmp = x; /* { dg-warning "macro expands to multiple statements" } */ \
+ x = y; \
+ y = tmp
+
+#define M1 \
+ switch (x) /* { dg-message "not guarded" } */ \
+ case 1: \
+ SWAP (x, y) /* { dg-message "in expansion of macro .SWAP." } */
+
+#define M2 \
+ switch (x) \
+ case 1: \
+ x++
+
+#define M3 \
+ switch (x) \
+ case 1: \
+ x++;;
+
+#define M4 \
+ switch (x) /* { dg-message "not guarded" } */ \
+L1: \
+ case 1: \
+ SWAP (x, y) /* { dg-message "in expansion of macro .SWAP." } */
+
+#define INC \
+ x++;;
+
+int x, y, tmp;
+
+void
+fn0 (void)
+{
+ switch (x) /* { dg-message "not guarded" } */
+ case 1:
+ SWAP (x, y); /* { dg-message "in expansion of macro .SWAP." } */
+
+ switch (x) /* { dg-message "not guarded" } */
+ case 1:
+ case 2:
+ case 3:
+ case 4:
+ case 5:
+ SWAP (x, y); /* { dg-message "in expansion of macro .SWAP." } */
+}
+
+void
+fn1 (void)
+{
+ M1; /* { dg-message "in expansion of macro .M1." } */
+ M2;
+ M3;
+ M4; /* { dg-message "in expansion of macro .M4." } */
+ goto L1;
+}
+
+void
+fn2 (void)
+{
+ switch (x)
+ case 1:
+ INC
+
+ switch (x)
+ case 1:
+ ({ x = 10; x++; });
+}
+
+void
+fn3 (void)
+{
+ switch (x)
+ {
+ case 1:
+ SWAP (x, y);
+ }
+}
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-2.c gcc/testsuite/c-c++-common/Wmultiline-expansion-2.c
index e69de29..b39d253 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-2.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-2.c
@@ -0,0 +1,137 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define SWAP(X, Y) \
+ tmp = X; /* { dg-warning "macro expands to multiple statements" } */ \
+ X = Y; \
+ Y = tmp
+
+#define STUFF \
+ if (0) {} else x = y
+
+#define STUFF2 \
+ if (0) {} else x = y; x++
+
+#define STUFF3 \
+ if (x) \
+ {} \
+ else /* { dg-message "not guarded" } */ \
+ SWAP(x, y) /* { dg-message "in expansion of macro .SWAP." } */
+
+#define SET(X, Y) \
+ (X) = (Y)
+
+#define STUFF4 \
+ if (x) \
+ {} \
+ else \
+ SET(x, y); \
+ SET(x, y)
+
+#define STUFF5 \
+ { tmp = x; x = y; }
+
+#define STUFF6 \
+ x++;;
+
+int x, y, tmp;
+
+void
+fn1 (void)
+{
+ if (x)
+ {
+ }
+ else /* { dg-message "not guarded" } */
+ SWAP(x, y); /* { dg-message "in expansion of macro .SWAP." } */
+}
+
+void
+fn2 (void)
+{
+ SWAP(x, y);
+}
+
+void
+fn3 (void)
+{
+ if (x)
+ {
+ }
+ else
+ {
+ SWAP(x, y);
+ }
+}
+
+void
+fn4 (void)
+{
+ if (x)
+ {
+ }
+ else
+ ({ x = 10; x++; });
+}
+
+void
+fn5 (void)
+{
+ if (x)
+ {
+ }
+ else /* { dg-message "not guarded" } */
+L1:
+ SWAP (x, y); /* { dg-message "in expansion of macro .SWAP." } */
+ goto L1;
+}
+
+void
+fn6 (void)
+{
+ if (x)
+ {
+ }
+ else
+ SET (x, y);
+ SET (tmp, x);
+}
+
+void
+fn7 (void)
+{
+ STUFF;
+}
+
+void
+fn8 (void)
+{
+ STUFF2;
+}
+
+void
+fn9 (void)
+{
+ STUFF3; /* { dg-message "in expansion of macro .STUFF3." } */
+}
+
+void
+fn10 (void)
+{
+ STUFF4;
+}
+
+void
+fn11 (void)
+{
+ if (x)
+ STUFF5;
+}
+
+void
+fn12 (void)
+{
+ if (x)
+ STUFF6;
+}
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-3.c gcc/testsuite/c-c++-common/Wmultiline-expansion-3.c
index e69de29..c2e83af 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-3.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-3.c
@@ -0,0 +1,12 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define CHECK(X) if (!(X)) __builtin_abort ()
+
+void
+fn (int i)
+{
+ CHECK (i == 1);
+ CHECK (i == 2);
+}
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-4.c gcc/testsuite/c-c++-common/Wmultiline-expansion-4.c
index e69de29..3ab76a7 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-4.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-4.c
@@ -0,0 +1,14 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define FN(C) \
+ void \
+ fn (void) \
+ { \
+ C; \
+ }
+
+int i;
+
+FN (if (i) ++i)
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-5.c gcc/testsuite/c-c++-common/Wmultiline-expansion-5.c
index e69de29..01ba0de 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-5.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-5.c
@@ -0,0 +1,18 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define M(N) \
+L ## N: \
+ x++; x++ /* { dg-warning "macro expands to multiple statements" } */
+
+int x, y, tmp;
+
+void
+fn1 (void)
+{
+ if (x) /* { dg-message "not guarded" } */
+ M (0); /* { dg-message "in expansion of macro .M." } */
+ if (x) /* { dg-message "not guarded" } */
+ M (1); /* { dg-message "in expansion of macro .M." } */
+}
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-6.c gcc/testsuite/c-c++-common/Wmultiline-expansion-6.c
index e69de29..9f799e1 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-6.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-6.c
@@ -0,0 +1,22 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define M \
+ if (x) x++; x++
+
+void
+f (int x)
+{
+ M;
+ M;
+ M;
+ M;
+ M;
+ M;
+ M;
+ M;
+ M;
+ M;
+ M;
+}
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-7.c gcc/testsuite/c-c++-common/Wmultiline-expansion-7.c
index e69de29..b561d43 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-7.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-7.c
@@ -0,0 +1,18 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define SWAP(X, Y) \
+ tmp = X; /* { dg-warning "macro expands to multiple statements" } */ \
+ X = Y; \
+ Y = tmp
+
+#define BODY_AND_IF(COND, X, Y) \
+ if (COND) SWAP (X, Y) /* { dg-message "in expansion of macro .SWAP." } */
+
+void
+fn (int x, int y)
+{
+ int tmp;
+ BODY_AND_IF (1, x, y); /* { dg-message "in expansion of macro .BODY_AND_IF." } */
+}
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-8.c gcc/testsuite/c-c++-common/Wmultiline-expansion-8.c
index e69de29..c5d8205 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-8.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-8.c
@@ -0,0 +1,64 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define SWAP(x, y) \
+ tmp = x; /* { dg-warning "macro expands to multiple statements" } */ \
+ x = y; \
+ y = tmp
+
+#define M1 \
+ for (i = 0; i < 1; ++i) /* { dg-message "not guarded" } */ \
+ SWAP (x, y) /* { dg-message "in expansion of macro .SWAP." } */
+
+#define M2 \
+ for (i = 0; i < 1; ++i) \
+ x++
+
+#define M3 \
+ for (i = 0; i < 1; ++i) \
+ x++;;
+
+#define M4 \
+ for (i = 0; i < 1; ++i) /* { dg-message "not guarded" } */ \
+L1: \
+ SWAP (x, y) /* { dg-message "in expansion of macro .SWAP." } */
+
+#define INC \
+ x++;;
+
+int x, y, tmp;
+
+void
+fn0 (void)
+{
+ int i;
+ for (i = 0; i < 1; ++i) /* { dg-message "not guarded" } */
+ SWAP (x, y); /* { dg-message "in expansion of macro .SWAP." } */
+
+ for (i = 0; i < 1; ++i) /* { dg-message "not guarded" } */
+L:
+ SWAP (x, y); /* { dg-message "in expansion of macro .SWAP." } */
+ goto L;
+}
+
+void
+fn1 (void)
+{
+ int i;
+ M1; /* { dg-message "in expansion of macro .M1." } */
+ M2;
+ M3;
+ M4; /* { dg-message "in expansion of macro .M4." } */
+ goto L1;
+}
+
+void
+fn2 (void)
+{
+ for (int i = 0; i < 1; ++i)
+ INC
+
+ for (int i = 0; i < 1; ++i)
+ ({ x = 10; x++; });
+}
diff --git gcc/testsuite/c-c++-common/Wmultiline-expansion-9.c gcc/testsuite/c-c++-common/Wmultiline-expansion-9.c
index e69de29..c503ade 100644
--- gcc/testsuite/c-c++-common/Wmultiline-expansion-9.c
+++ gcc/testsuite/c-c++-common/Wmultiline-expansion-9.c
@@ -0,0 +1,62 @@
+/* PR c/80116 */
+/* { dg-options "-Wmultiline-expansion" } */
+/* { dg-do compile } */
+
+#define SWAP(x, y) \
+ tmp = x; /* { dg-warning "macro expands to multiple statements" } */ \
+ x = y; \
+ y = tmp
+
+#define M1 \
+ while (x) /* { dg-message "not guarded" } */ \
+ SWAP (x, y) /* { dg-message "in expansion of macro .SWAP." } */
+
+#define M2 \
+ while (x) \
+ x++
+
+#define M3 \
+ while (x) \
+ x++;;
+
+#define M4 \
+ while (x) /* { dg-message "not guarded" } */ \
+L1: \
+ SWAP (x, y) /* { dg-message "in expansion of macro .SWAP." } */
+
+#define INC \
+ x++;;
+
+int x, y, tmp;
+
+void
+fn0 (void)
+{
+ while (x) /* { dg-message "not guarded" } */
+ SWAP (x, y); /* { dg-message "in expansion of macro .SWAP." } */
+
+ while (x) /* { dg-message "not guarded" } */
+L:
+ SWAP (x, y); /* { dg-message "in expansion of macro .SWAP." } */
+ goto L;
+}
+
+void
+fn1 (void)
+{
+ M1; /* { dg-message "in expansion of macro .M1." } */
+ M2;
+ M3;
+ M4; /* { dg-message "in expansion of macro .M4." } */
+ goto L1;
+}
+
+void
+fn2 (void)
+{
+ while (x)
+ INC
+
+ while (x)
+ ({ x = 10; x++; });
+}
Marek