C++ PATCH for c++/91845 - ICE with invalid pointer-to-member.

Message ID 20190924020615.GC14737@redhat.com
State New
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  • C++ PATCH for c++/91845 - ICE with invalid pointer-to-member.
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Commit Message

Marek Polacek Sept. 24, 2019, 2:06 a.m.
build_m_component_ref checks if either datum/component it got are erroneous but
they can be turned into the error_mark_node by mark_use as in this case: datum
is "a" before the call to mark_lvalue_use, but that emits an error and returns
the error_mark_node, which then crashes.

We can just move the checks after calling mark_[lr]value_use; those just
return when they get the error_mark_node.  But I tweaked mark_use to also
handle the case when the type is erroneous.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2019-09-23  Marek Polacek  <polacek@redhat.com>

	PR c++/91845 - ICE with invalid pointer-to-member.
	* expr.c (mark_use): Use error_operand_p.
	* typeck2.c (build_m_component_ref): Check error_operand_p after
	calling mark_[lr]value_use.

	* g++.dg/cpp1y/pr91845.C: New test.

Comments

Jason Merrill Sept. 24, 2019, 2:34 p.m. | #1
OK.

On Mon, Sep 23, 2019 at 10:06 PM Marek Polacek <polacek@redhat.com> wrote:
>

> build_m_component_ref checks if either datum/component it got are erroneous but

> they can be turned into the error_mark_node by mark_use as in this case: datum

> is "a" before the call to mark_lvalue_use, but that emits an error and returns

> the error_mark_node, which then crashes.

>

> We can just move the checks after calling mark_[lr]value_use; those just

> return when they get the error_mark_node.  But I tweaked mark_use to also

> handle the case when the type is erroneous.

>

> Bootstrapped/regtested on x86_64-linux, ok for trunk?

>

> 2019-09-23  Marek Polacek  <polacek@redhat.com>

>

>         PR c++/91845 - ICE with invalid pointer-to-member.

>         * expr.c (mark_use): Use error_operand_p.

>         * typeck2.c (build_m_component_ref): Check error_operand_p after

>         calling mark_[lr]value_use.

>

>         * g++.dg/cpp1y/pr91845.C: New test.

>

> diff --git gcc/cp/expr.c gcc/cp/expr.c

> index 212a7f93c5a..d488912d5db 100644

> --- gcc/cp/expr.c

> +++ gcc/cp/expr.c

> @@ -96,7 +96,7 @@ mark_use (tree expr, bool rvalue_p, bool read_p,

>  {

>  #define RECUR(t) mark_use ((t), rvalue_p, read_p, loc, reject_builtin)

>

> -  if (expr == NULL_TREE || expr == error_mark_node)

> +  if (expr == NULL_TREE || error_operand_p (expr))

>      return expr;

>

>    if (reject_builtin && reject_gcc_builtin (expr, loc))

> diff --git gcc/cp/typeck2.c gcc/cp/typeck2.c

> index d5098fa24bb..58fa54f40af 100644

> --- gcc/cp/typeck2.c

> +++ gcc/cp/typeck2.c

> @@ -2068,12 +2068,12 @@ build_m_component_ref (tree datum, tree component, tsubst_flags_t complain)

>    tree binfo;

>    tree ctype;

>

> -  if (error_operand_p (datum) || error_operand_p (component))

> -    return error_mark_node;

> -

>    datum = mark_lvalue_use (datum);

>    component = mark_rvalue_use (component);

>

> +  if (error_operand_p (datum) || error_operand_p (component))

> +    return error_mark_node;

> +

>    ptrmem_type = TREE_TYPE (component);

>    if (!TYPE_PTRMEM_P (ptrmem_type))

>      {

> diff --git gcc/testsuite/g++.dg/cpp1y/pr91845.C gcc/testsuite/g++.dg/cpp1y/pr91845.C

> new file mode 100644

> index 00000000000..cb80dd7a8a7

> --- /dev/null

> +++ gcc/testsuite/g++.dg/cpp1y/pr91845.C

> @@ -0,0 +1,14 @@

> +// PR c++/91845 - ICE with invalid pointer-to-member.

> +// { dg-do compile { target c++14 } }

> +

> +void non_const_mem_ptr() {

> +  struct A {

> +  };

> +  constexpr A a = {1, 2}; // { dg-error "too many initializers" }

> +  struct B {

> +    int A::*p;

> +    constexpr int g() const {

> +      return a.*p; // { dg-error "use of local variable" }

> +    };

> +  };

> +}

Patch

diff --git gcc/cp/expr.c gcc/cp/expr.c
index 212a7f93c5a..d488912d5db 100644
--- gcc/cp/expr.c
+++ gcc/cp/expr.c
@@ -96,7 +96,7 @@  mark_use (tree expr, bool rvalue_p, bool read_p,
 {
 #define RECUR(t) mark_use ((t), rvalue_p, read_p, loc, reject_builtin)
 
-  if (expr == NULL_TREE || expr == error_mark_node)
+  if (expr == NULL_TREE || error_operand_p (expr))
     return expr;
 
   if (reject_builtin && reject_gcc_builtin (expr, loc))
diff --git gcc/cp/typeck2.c gcc/cp/typeck2.c
index d5098fa24bb..58fa54f40af 100644
--- gcc/cp/typeck2.c
+++ gcc/cp/typeck2.c
@@ -2068,12 +2068,12 @@  build_m_component_ref (tree datum, tree component, tsubst_flags_t complain)
   tree binfo;
   tree ctype;
 
-  if (error_operand_p (datum) || error_operand_p (component))
-    return error_mark_node;
-
   datum = mark_lvalue_use (datum);
   component = mark_rvalue_use (component);
 
+  if (error_operand_p (datum) || error_operand_p (component))
+    return error_mark_node;
+
   ptrmem_type = TREE_TYPE (component);
   if (!TYPE_PTRMEM_P (ptrmem_type))
     {
diff --git gcc/testsuite/g++.dg/cpp1y/pr91845.C gcc/testsuite/g++.dg/cpp1y/pr91845.C
new file mode 100644
index 00000000000..cb80dd7a8a7
--- /dev/null
+++ gcc/testsuite/g++.dg/cpp1y/pr91845.C
@@ -0,0 +1,14 @@ 
+// PR c++/91845 - ICE with invalid pointer-to-member.
+// { dg-do compile { target c++14 } }
+
+void non_const_mem_ptr() {
+  struct A {
+  };
+  constexpr A a = {1, 2}; // { dg-error "too many initializers" }
+  struct B {
+    int A::*p;
+    constexpr int g() const {
+      return a.*p; // { dg-error "use of local variable" }
+    };
+  };
+}