[PATCH][4.6] detect C++ errors to fix 2288 and 18770
Nathan Froyd
froydnj@codesourcery.com
Wed May 25 19:57:00 GMT 2011
On Sun, May 22, 2011 at 03:25:41PM -0700, H.J. Lu wrote:
> FWIW, I tried Janis's patch on 4.6 branch and I got
>
> /export/gnu/import/git/gcc/gcc/testsuite/g++.dg/parse/pr18770.C: In
> function 'void e1()':^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.dg/parse/pr18770.C:29:11:
> error: redeclaration of 'int k'^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.dg/parse/pr18770.C:27:12:
> error: 'int k' previously declared here^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.dg/parse/pr18770.C: In
> function 'void e4()':^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.dg/parse/pr18770.C:63:11:
> error: redeclaration of 'int i'^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.dg/parse/pr18770.C:61:14:
> error: 'int i' previously declared here^M
>
> FAIL: g++.dg/parse/pr18770.C prev (test for errors, line 14)
> FAIL: g++.dg/parse/pr18770.C redecl (test for errors, line 17)
> PASS: g++.dg/parse/pr18770.C prev (test for errors, line 27)
> PASS: g++.dg/parse/pr18770.C redecl (test for errors, line 29)
> FAIL: g++.dg/parse/pr18770.C prev (test for errors, line 37)
> FAIL: g++.dg/parse/pr18770.C redecl (test for errors, line 39)
> FAIL: g++.dg/parse/pr18770.C prev (test for errors, line 47)
> FAIL: g++.dg/parse/pr18770.C redecl (test for errors, line 53)
> PASS: g++.dg/parse/pr18770.C prev (test for errors, line 61)
> PASS: g++.dg/parse/pr18770.C redecl (test for errors, line 63)
> FAIL: g++.dg/parse/pr18770.C prev (test for errors, line 71)
> FAIL: g++.dg/parse/pr18770.C redecl (test for errors, line 73)
> PASS: g++.dg/parse/pr18770.C (test for excess errors)
>
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:
> In function 'int main()':^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:22:11:
> error: redeclaration of 'int i'^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:20:14:
> error: 'int i' previously declared here^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:27:11:
> error: redeclaration of 'int i'^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:25:14:
> error: 'int i' previously declared here^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:36:16:
> error: types may not be defined in conditions^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:39:3:
> error: 'A' was not declared in this scope^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:39:5:
> error: expected ';' before 'bar'^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:42:12:
> error: types may not be defined in conditions^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:42:40:
> error: 'one' was not declared in this scope^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:51:14:
> warning: declaration of 'int f()' has 'extern' and is initialized
> [enabled by default]^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:51:18:
> error: function 'int f()' is initialized like a variable^M
> /export/gnu/import/git/gcc/gcc/testsuite/g++.old-deja/g++.jason/cond.C:55:23:
> error: extended initializer lists only available with -std=c++0x or
> -std=gnu++0x^M
>
> FAIL: g++.old-deja/g++.jason/cond.C (test for errors, line 9)
> FAIL: g++.old-deja/g++.jason/cond.C (test for errors, line 11)
> FAIL: g++.old-deja/g++.jason/cond.C (test for errors, line 16)
> PASS: g++.old-deja/g++.jason/cond.C (test for errors, line 20)
> PASS: g++.old-deja/g++.jason/cond.C (test for errors, line 22)
> PASS: g++.old-deja/g++.jason/cond.C (test for errors, line 25)
> PASS: g++.old-deja/g++.jason/cond.C (test for errors, line 27)
> FAIL: g++.old-deja/g++.jason/cond.C (test for errors, line 30)
> FAIL: g++.old-deja/g++.jason/cond.C (test for errors, line 33)
> PASS: g++.old-deja/g++.jason/cond.C (test for errors, line 36)
> PASS: g++.old-deja/g++.jason/cond.C decl (test for errors, line 39)
> PASS: g++.old-deja/g++.jason/cond.C exp (test for errors, line 39)
> PASS: g++.old-deja/g++.jason/cond.C def (test for errors, line 42)
> PASS: g++.old-deja/g++.jason/cond.C expected (test for errors, line 42)
> PASS: g++.old-deja/g++.jason/cond.C extern (test for warnings, line 51)
>
> The patch no longer catches all problems.
The patch just requires some shuffling of logic to catch issues now;
below is a version that works for me on the trunk.
This new checking does require modifying g++.dg/cpp0x/range-for5.C. The
new logic of the patch claims that:
int i;
for (int i : a)
{
int i;
}
is incorrect (the innermost `i' is an erroneous redeclaration). If you
apply the expansion of range-based for loops from [stmt.ranged]p1, you'd
get something like:
for (...; ...; ...)
{
int i = ...;
int i;
}
which is bad. I believe [basic.scope.local]p4 says much the same thing.
Tested with g++ testsuite on x86_64-unknown-linux-gnu; tests in progress
for libstdc++. OK to commit?
-Nathan
gcc/cp/
2011-xx-xx Janis Johnson <janisjo@codesourcery.com>
Nathan Froyd <froydnj@codesourcery.com>
PR c++/2288
PR c++/18770
* name-lookup.h (enum scope_kind): Add sk_cond.
* name-lookup.c (pushdecl_maybe_friend): Get scope of shadowed local.
Detect and report error for redeclaration from for-init or if
or switch condition.
(begin_scope): Handle sk_cond.
* semantics.c (begin_if_stmt): Use sk_cond.
(begin switch_stmt): Ditto.
gcc/testsuite/
2011-xx-xx Janis Johnson <janisjo@codesourcery.com>
Nathan Froyd <froydnj@codesourcery.com>
PR c++/2288
PR c++/18770
* g++.old-deja/g++.jason/cond.C: Remove xfails.
* g++.dg/parse/pr18770.C: New test.
* g++.dg/cpp0x/range-for5.C: Add dg-error marker.
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index bb6d4b9..723f36f 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -957,8 +957,15 @@ pushdecl_maybe_friend_1 (tree x, bool is_friend)
else
{
/* Here to install a non-global value. */
- tree oldlocal = innermost_non_namespace_value (name);
tree oldglobal = IDENTIFIER_NAMESPACE_VALUE (name);
+ tree oldlocal = NULL_TREE;
+ cxx_scope *oldscope = NULL;
+ cxx_binding *oldbinding = outer_binding (name, NULL, true);
+ if (oldbinding)
+ {
+ oldlocal = oldbinding->value;
+ oldscope = oldbinding->scope;
+ }
if (need_new_binding)
{
@@ -1087,6 +1094,20 @@ pushdecl_maybe_friend_1 (tree x, bool is_friend)
}
}
}
+ /* Error if redeclaring a local declared in a
+ for-init-statement or in the condition of an if or
+ switch statement when the new declaration is in the
+ outermost block of the controlled statement.
+ Redeclaring a variable from a for or while condition is
+ detected elsewhere. */
+ else if (TREE_CODE (oldlocal) == VAR_DECL
+ && oldscope == current_binding_level->level_chain
+ && (oldscope->kind == sk_cond
+ || oldscope->kind == sk_for))
+ {
+ error ("redeclaration of %q#D", x);
+ error ("%q+#D previously declared here", oldlocal);
+ }
if (warn_shadow && !nowarn)
{
@@ -1446,6 +1467,7 @@ begin_scope (scope_kind kind, tree entity)
case sk_try:
case sk_catch:
case sk_for:
+ case sk_cond:
case sk_class:
case sk_scoped_enum:
case sk_function_parms:
diff --git a/gcc/cp/name-lookup.h b/gcc/cp/name-lookup.h
index 4bf253f..90b56e4 100644
--- a/gcc/cp/name-lookup.h
+++ b/gcc/cp/name-lookup.h
@@ -109,6 +109,8 @@ typedef enum scope_kind {
sk_catch, /* A catch-block. */
sk_for, /* The scope of the variable declared in a
for-init-statement. */
+ sk_cond, /* The scope of the variable declared in the condition
+ of an if or switch statement. */
sk_function_parms, /* The scope containing function parameters. */
sk_class, /* The scope containing the members of a class. */
sk_scoped_enum, /* The scope containing the enumertors of a C++0x
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 55ad117..7833d76 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -656,7 +656,7 @@ tree
begin_if_stmt (void)
{
tree r, scope;
- scope = do_pushlevel (sk_block);
+ scope = do_pushlevel (sk_cond);
r = build_stmt (input_location, IF_STMT, NULL_TREE,
NULL_TREE, NULL_TREE, scope);
begin_cond (&IF_COND (r));
@@ -1013,7 +1013,7 @@ begin_switch_stmt (void)
{
tree r, scope;
- scope = do_pushlevel (sk_block);
+ scope = do_pushlevel (sk_cond);
r = build_stmt (input_location, SWITCH_STMT, NULL_TREE, NULL_TREE, NULL_TREE, scope);
begin_cond (&SWITCH_STMT_COND (r));
diff --git a/gcc/testsuite/g++.dg/cpp0x/range-for5.C b/gcc/testsuite/g++.dg/cpp0x/range-for5.C
index 9c97ad5..2fe4702 100644
--- a/gcc/testsuite/g++.dg/cpp0x/range-for5.C
+++ b/gcc/testsuite/g++.dg/cpp0x/range-for5.C
@@ -49,6 +49,6 @@ void test1()
int i;
for (int i : a)
{
- int i;
+ int i; // { dg-error "redeclaration" }
}
}
diff --git a/gcc/testsuite/g++.dg/parse/pr18770.C b/gcc/testsuite/g++.dg/parse/pr18770.C
new file mode 100644
index 0000000..df57be4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/pr18770.C
@@ -0,0 +1,175 @@
+/* { dg-do compile } */
+
+/* The ISO C++ standard says, in Section 3.3.2 sentence 4, that a name
+ declared in the for-init-statement or in the condition of an if, for
+ while, or switch statement can't be redeclared in the outermost block
+ of the controlled statement. (Note, this is not an error in C.) */
+
+extern void foo (int);
+extern int j;
+
+void
+e0 (void)
+{
+ for (int i = 0; // { dg-error "previously declared here" "prev" }
+ i < 10; ++i)
+ {
+ int i = 2; // { dg-error "redeclaration" "redecl" }
+ foo (i);
+ }
+}
+
+void
+e1 (void)
+{
+ int i;
+ for (i = 0;
+ int k = j; i++) // { dg-error "previously declared here" "prev" }
+ {
+ int k = 2; // { dg-error "redeclaration" "redecl" }
+ foo (k);
+ }
+}
+
+void
+e2 (void)
+{
+ if (int i = 1) // { dg-error "previously declared here" "prev" }
+ {
+ int i = 2; // { dg-error "redeclaration" "redecl" }
+ foo (i);
+ }
+}
+
+void
+e3 (void)
+{
+ if (int i = 1) // { dg-error "previously declared here" "prev" }
+ {
+ foo (i);
+ }
+ else
+ {
+ int i = 2; // { dg-error "redeclaration" "redecl" }
+ foo (i);
+ }
+}
+
+void
+e4 (void)
+{
+ while (int i = 1) // { dg-error "previously declared here" "prev" }
+ {
+ int i = 2; // { dg-error "redeclaration" "redecl" }
+ foo (i);
+ }
+}
+
+void
+e5 (void)
+{
+ switch (int i = j) // { dg-error "previously declared here" "prev" }
+ {
+ int i; // { dg-error "redeclaration" "redecl" }
+ default:
+ {
+ i = 2;
+ foo (i);
+ }
+ }
+}
+
+void
+f0 (void)
+{
+ for (int i = 0; i < 10; ++i)
+ {
+ foo (i);
+ {
+ int i = 2; // OK, not outermost block.
+ foo (i);
+ }
+ }
+}
+
+void
+f1 (void)
+{
+ int i;
+ for (i = 0; int k = j; i++)
+ {
+ foo (k);
+ {
+ int k = 2; // OK, not outermost block.
+ foo (k);
+ }
+ }
+}
+
+void
+f2 (void)
+{
+ if (int i = 1)
+ {
+ foo (i);
+ {
+ int i = 2; // OK, not outermost block.
+ foo (i);
+ }
+ }
+}
+
+void
+f3 (void)
+{
+ if (int i = 1)
+ {
+ foo (i);
+ }
+ else
+ {
+ foo (i+2);
+ {
+ int i = 2; // OK, not outermost block.
+ foo (i);
+ }
+ }
+}
+
+void
+f4 (void)
+{
+ while (int i = 1)
+ {
+ foo (i);
+ {
+ int i = 2; // OK, not outermost block.
+ foo (i);
+ }
+ }
+}
+
+void
+f5 (void)
+{
+ switch (int i = j)
+ {
+ default:
+ {
+ int i = 2; // OK, not outermost block.
+ foo (i);
+ }
+ }
+}
+
+void
+f6 (void)
+{
+ int i = 1;
+
+ for (int j = 0; j < 10; j++)
+ {
+ int i = 2; // OK, not variable from for-init.
+ foo (i);
+ }
+}
diff --git a/gcc/testsuite/g++.old-deja/g++.jason/cond.C b/gcc/testsuite/g++.old-deja/g++.jason/cond.C
index d0616e4..a6e5ba0 100644
--- a/gcc/testsuite/g++.old-deja/g++.jason/cond.C
+++ b/gcc/testsuite/g++.old-deja/g++.jason/cond.C
@@ -6,14 +6,14 @@ int main()
{
float i;
- if (int i = 1) // { dg-error "" "" { xfail *-*-* } } ,
+ if (int i = 1) // { dg-error "previously" }
{
- char i; // { dg-error "" "" { xfail *-*-* } } ,
+ char i; // { dg-error "redeclaration" }
char j;
}
else
{
- short i; // { dg-error "" "" { xfail *-*-* } } ,
+ short i; // { dg-error "redeclaration" }
char j;
}
@@ -27,10 +27,10 @@ int main()
int i; // { dg-error "redeclaration" }
}
- switch (int i = 0) // { dg-error "" "" { xfail *-*-* } }
+ switch (int i = 0) // { dg-error "previously" }
{
default:
- int i; // { dg-error "" "" { xfail *-*-* } }
+ int i; // { dg-error "redeclaration" }
}
if (struct A { operator int () { return 1; } } *foo = new A) // { dg-error "defined" }
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