Re: [PATCH] c++: Fix thinko in auto return type checking [PR98441]

[Jason Merrill via Gcc-patches]

On 1/5/21 7:31 PM, Marek Polacek wrote:

This fixes a thinko in my r11-2085 patch: when I said "But only give the
!late_return_type errors when funcdecl_p, to accept e.g. auto (*fp)() = f;
in C++11" I should've done this, otherwise we give bogus errors mentioning
"function with trailing return type" when there is none.

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


OK.


gcc/cp/ChangeLog:

PR c++/98441
* decl.c (grokdeclarator): Move the !funcdecl_p check inside the
!late_return_type block.

gcc/testsuite/ChangeLog:

PR c++/98441
* g++.dg/cpp0x/auto55.C: New test.
---
  gcc/cp/decl.c   |  8 +---
  gcc/testsuite/g++.dg/cpp0x/auto55.C | 13 +
  2 files changed, 18 insertions(+), 3 deletions(-)
  create mode 100644 gcc/testsuite/g++.dg/cpp0x/auto55.C

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index bf6f12c26a0..1a114a2e2d0 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -12241,10 +12241,12 @@ grokdeclarator (const cp_declarator *declarator,
tree late_return_type = declarator->u.function.late_return_type;
if (tree auto_node = type_uses_auto (type))
  {
-   if (!late_return_type && funcdecl_p)
+   if (!late_return_type)
  {
-   if (current_class_type
-   && LAMBDA_TYPE_P (current_class_type))
+   if (!funcdecl_p)
+ /* auto (*fp)() = f; is OK.  */;
+   else if (current_class_type
+&& LAMBDA_TYPE_P (current_class_type))
  /* OK for C++11 lambdas.  */;
else if (cxx_dialect < cxx14)
  {
diff --git a/gcc/testsuite/g++.dg/cpp0x/auto55.C 
b/gcc/testsuite/g++.dg/cpp0x/auto55.C
new file mode 100644
index 000..5bd32ac890d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/auto55.C
@@ -0,0 +1,13 @@
+// PR c++/98441
+// { dg-do compile { target c++11 } }
+
+struct a {
+int& mfn();
+};
+
+void fn()
+{
+int&  (a::*myvar1)(void) = ::mfn;
+auto& (a::*myvar2)(void) = ::mfn;
+auto  (a::*myvar3)(void) = ::mfn;
+}

base-commit: ad92bf4b165935b58195825dc8f089f53fd2710b

[PATCH] c++: Fix thinko in auto return type checking [PR98441]

[Marek Polacek via Gcc-patches]

This fixes a thinko in my r11-2085 patch: when I said "But only give the
!late_return_type errors when funcdecl_p, to accept e.g. auto (*fp)() = f;
in C++11" I should've done this, otherwise we give bogus errors mentioning
"function with trailing return type" when there is none.

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

gcc/cp/ChangeLog:

PR c++/98441
* decl.c (grokdeclarator): Move the !funcdecl_p check inside the
!late_return_type block.

gcc/testsuite/ChangeLog:

PR c++/98441
* g++.dg/cpp0x/auto55.C: New test.
---
 gcc/cp/decl.c   |  8 +---
 gcc/testsuite/g++.dg/cpp0x/auto55.C | 13 +
 2 files changed, 18 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/auto55.C

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index bf6f12c26a0..1a114a2e2d0 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -12241,10 +12241,12 @@ grokdeclarator (const cp_declarator *declarator,
tree late_return_type = declarator->u.function.late_return_type;
if (tree auto_node = type_uses_auto (type))
  {
-   if (!late_return_type && funcdecl_p)
+   if (!late_return_type)
  {
-   if (current_class_type
-   && LAMBDA_TYPE_P (current_class_type))
+   if (!funcdecl_p)
+ /* auto (*fp)() = f; is OK.  */;
+   else if (current_class_type
+&& LAMBDA_TYPE_P (current_class_type))
  /* OK for C++11 lambdas.  */;
else if (cxx_dialect < cxx14)
  {
diff --git a/gcc/testsuite/g++.dg/cpp0x/auto55.C 
b/gcc/testsuite/g++.dg/cpp0x/auto55.C
new file mode 100644
index 000..5bd32ac890d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/auto55.C
@@ -0,0 +1,13 @@
+// PR c++/98441
+// { dg-do compile { target c++11 } }
+
+struct a {
+int& mfn();
+};
+
+void fn()
+{
+int&  (a::*myvar1)(void) = ::mfn;
+auto& (a::*myvar2)(void) = ::mfn;
+auto  (a::*myvar3)(void) = ::mfn;
+}

base-commit: ad92bf4b165935b58195825dc8f089f53fd2710b
-- 
2.29.2