On Fri, 19 May 2023, Patrick Palka wrote:
> This implements noexcept-expr mangling (and demangling) as per the
> Itanium ABI.
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this
> look OK for trunk?
>
> PR c++/70790
>
> gcc/cp/ChangeLog:
>
> * mangle.cc (write_expression): Handle NOEXCEPT_EXPR.
>
> libiberty/ChangeLog:
>
> * cp-demangle.c (cplus_demangle_operators): Add the noexcept
> operator.
Oops, we should also make sure we print parens around the operand of
noexcept. Otherwise we'd demangle the mangling of e.g.
void f<int>(A<noexcept(int{})>)
instead as
void f<int>(A<noexceptint{}>)
Fixed in the following patch:
-- >8 --
Subject: [PATCH] c++: mangle noexcept-expr [PR70790]
This implements noexcept-expr mangling (and demangling) as per the
Itanium ABI.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this
look OK for trunk?
PR c++/70790
gcc/cp/ChangeLog:
* mangle.cc (write_expression): Handle NOEXCEPT_EXPR.
libiberty/ChangeLog:
* cp-demangle.c (cplus_demangle_operators): Add the noexcept
operator.
(d_print_comp_inner) <case DEMANGLE_COMPONENT_UNARY>: Always
print parens around the operand of noexcept too.
* testsuite/demangle-expected: Test noexcept operator
demangling.
gcc/testsuite/ChangeLog:
* g++.dg/abi/mangle78.C: New test.
---
gcc/cp/mangle.cc | 5 +++++
gcc/testsuite/g++.dg/abi/mangle78.C | 14 ++++++++++++++
libiberty/cp-demangle.c | 5 +++--
libiberty/testsuite/demangle-expected | 3 +++
4 files changed, 25 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/abi/mangle78.C
diff --git a/gcc/cp/mangle.cc b/gcc/cp/mangle.cc
index 826c5e76c1d..7dab4e62bc9 100644
--- a/gcc/cp/mangle.cc
+++ b/gcc/cp/mangle.cc
@@ -3402,6 +3402,11 @@ write_expression (tree expr)
else
write_string ("tr");
}
+ else if (code == NOEXCEPT_EXPR)
+ {
+ write_string ("nx");
+ write_expression (TREE_OPERAND (expr, 0));
+ }
else if (code == CONSTRUCTOR)
{
bool braced_init = BRACE_ENCLOSED_INITIALIZER_P (expr);
diff --git a/gcc/testsuite/g++.dg/abi/mangle78.C
b/gcc/testsuite/g++.dg/abi/mangle78.C
new file mode 100644
index 00000000000..63c4d779e9f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/mangle78.C
@@ -0,0 +1,14 @@
+// PR c++/70790
+// { dg-do compile { target c++11 } }
+
+template<bool B>
+struct A { };
+
+template<class T>
+void f(A<noexcept(T{})>);
+
+int main() {
+ f<int>({});
+}
+
+// { dg-final { scan-assembler "_Z1fIiEv1AIXnxtlT_EEE" } }
diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c
index f2b36bcad68..efada1c322b 100644
--- a/libiberty/cp-demangle.c
+++ b/libiberty/cp-demangle.c
@@ -1947,6 +1947,7 @@ const struct demangle_operator_info
cplus_demangle_operators[] =
{ "ng", NL ("-"), 1 },
{ "nt", NL ("!"), 1 },
{ "nw", NL ("new"), 3 },
+ { "nx", NL ("noexcept"), 1 },
{ "oR", NL ("|="), 2 },
{ "oo", NL ("||"), 2 },
{ "or", NL ("|"), 2 },
@@ -5836,8 +5837,8 @@ d_print_comp_inner (struct d_print_info *dpi, int options,
if (code && !strcmp (code, "gs"))
/* Avoid parens after '::'. */
d_print_comp (dpi, options, operand);
- else if (code && !strcmp (code, "st"))
- /* Always print parens for sizeof (type). */
+ else if (code && (!strcmp (code, "st") || !strcmp (code, "nx")))
+ /* Always print parens for sizeof (type) or noexcept(expr). */
{
d_append_char (dpi, '(');
d_print_comp (dpi, options, operand);
diff --git a/libiberty/testsuite/demangle-expected
b/libiberty/testsuite/demangle-expected
index d9bc7ed4b1f..52dff883a18 100644
--- a/libiberty/testsuite/demangle-expected
+++ b/libiberty/testsuite/demangle-expected
@@ -1659,3 +1659,6 @@ auto f()::{lambda<typename $T0>(X<$T0>*,
X<int>*)#1}::operator()<char>(X<char>*,
_ZZN1XIiE1FEvENKUliE_clEi
X<int>::F()::{lambda(int)#1}::operator()(int) const
+
+_Z1fIiEv1AIXnxtlT_EEE
+void f<int>(A<noexcept(int{})>)
--
2.41.0.rc0.4.g004e0f790f
> * testsuite/demangle-expected: Test noexcept operator
> demangling.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/abi/mangle78.C: New test.
> ---
> gcc/cp/mangle.cc | 5 +++++
> gcc/testsuite/g++.dg/abi/mangle78.C | 14 ++++++++++++++
> libiberty/cp-demangle.c | 1 +
> libiberty/testsuite/demangle-expected | 3 +++
> 4 files changed, 23 insertions(+)
> create mode 100644 gcc/testsuite/g++.dg/abi/mangle78.C
>
> diff --git a/gcc/cp/mangle.cc b/gcc/cp/mangle.cc
> index 826c5e76c1d..7dab4e62bc9 100644
> --- a/gcc/cp/mangle.cc
> +++ b/gcc/cp/mangle.cc
> @@ -3402,6 +3402,11 @@ write_expression (tree expr)
> else
> write_string ("tr");
> }
> + else if (code == NOEXCEPT_EXPR)
> + {
> + write_string ("nx");
> + write_expression (TREE_OPERAND (expr, 0));
> + }
> else if (code == CONSTRUCTOR)
> {
> bool braced_init = BRACE_ENCLOSED_INITIALIZER_P (expr);
> diff --git a/gcc/testsuite/g++.dg/abi/mangle78.C
> b/gcc/testsuite/g++.dg/abi/mangle78.C
> new file mode 100644
> index 00000000000..a3647711604
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/abi/mangle78.C
> @@ -0,0 +1,14 @@
> +// PR c++/70790
> +// { dg-do compile { target c++11 } }
> +
> +template<bool B>
> +struct A { };
> +
> +template<class T>
> +void f(A<noexcept(T())>);
> +
> +int main() {
> + f<int>({});
> +}
> +
> +// { dg-final { scan-assembler "_Z1fIiEv1AIXnxcvT__EEE" } }
> diff --git a/libiberty/cp-demangle.c b/libiberty/cp-demangle.c
> index f2b36bcad68..341c66db919 100644
> --- a/libiberty/cp-demangle.c
> +++ b/libiberty/cp-demangle.c
> @@ -1947,6 +1947,7 @@ const struct demangle_operator_info
> cplus_demangle_operators[] =
> { "ng", NL ("-"), 1 },
> { "nt", NL ("!"), 1 },
> { "nw", NL ("new"), 3 },
> + { "nx", NL ("noexcept"), 1 },
> { "oR", NL ("|="), 2 },
> { "oo", NL ("||"), 2 },
> { "or", NL ("|"), 2 },
> diff --git a/libiberty/testsuite/demangle-expected
> b/libiberty/testsuite/demangle-expected
> index d9bc7ed4b1f..7195cc39c19 100644
> --- a/libiberty/testsuite/demangle-expected
> +++ b/libiberty/testsuite/demangle-expected
> @@ -1659,3 +1659,6 @@ auto f()::{lambda<typename $T0>(X<$T0>*,
> X<int>*)#1}::operator()<char>(X<char>*,
>
> _ZZN1XIiE1FEvENKUliE_clEi
> X<int>::F()::{lambda(int)#1}::operator()(int) const
> +
> +_Z1fIiEv1AIXnxcvT__EEE
> +void f<int>(A<noexcept((int)())>)
> --
> 2.41.0.rc0.4.g004e0f790f
>
>
