[gcc r13-2222] libstdc++: Add nonnull to starts_with/ends_with/contains string members
Jonathan Wakely
redi@gcc.gnu.org
Fri Aug 26 15:20:36 GMT 2022
https://gcc.gnu.org/g:1b0b969df794d0401ccb9279d44302d1e4729f15
commit r13-2222-g1b0b969df794d0401ccb9279d44302d1e4729f15
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Fri Aug 26 09:43:32 2022 +0100
libstdc++: Add nonnull to starts_with/ends_with/contains string members
Ideally this wouldn't be needed, because eventually these pointers all
get passed to either the basic_string_view(const CharT*) constructor, or
to basic_string_view::find(const CharT*), both of which already have the
attribute. But for that to work requires optimization, so that the null
value gets propagated through the call chain.
Adding it explicitly to each member that requires a non-null pointer
makes the diagnostics more reliable even without optimization. It's
better to give a diagnostic earlier anyway, at the actual problematic
call in the user's code.
libstdc++-v3/ChangeLog:
* include/bits/basic_string.h (starts_with, ends_with, contains):
Add nonnull attribute.
* include/bits/cow_string.h (starts_with, ends_with, contains):
Likewise.
* include/std/string_view (starts_with, ends_with, contains):
Likewise.
* testsuite/21_strings/basic_string/operations/contains/nonnull.cc
* testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc
* testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc
* testsuite/21_strings/basic_string_view/operations/contains/nonnull.cc
* testsuite/21_strings/basic_string_view/operations/ends_with/nonnull.cc
* testsuite/21_strings/basic_string_view/operations/starts_with/nonnull.cc
Diff:
---
libstdc++-v3/include/bits/basic_string.h | 3 +++
libstdc++-v3/include/bits/cow_string.h | 3 +++
libstdc++-v3/include/std/string_view | 3 +++
.../21_strings/basic_string/operations/contains/nonnull.cc | 12 ++++++++++++
.../21_strings/basic_string/operations/ends_with/nonnull.cc | 12 ++++++++++++
.../basic_string/operations/starts_with/nonnull.cc | 12 ++++++++++++
.../basic_string_view/operations/contains/nonnull.cc | 12 ++++++++++++
.../basic_string_view/operations/ends_with/nonnull.cc | 12 ++++++++++++
.../basic_string_view/operations/starts_with/nonnull.cc | 12 ++++++++++++
9 files changed, 81 insertions(+)
diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index b04fba95678..9d8b415302b 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -3400,6 +3400,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
starts_with(_CharT __x) const noexcept
{ return __sv_type(this->data(), this->size()).starts_with(__x); }
+ [[__gnu__::__nonnull__]]
constexpr bool
starts_with(const _CharT* __x) const noexcept
{ return __sv_type(this->data(), this->size()).starts_with(__x); }
@@ -3412,6 +3413,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
ends_with(_CharT __x) const noexcept
{ return __sv_type(this->data(), this->size()).ends_with(__x); }
+ [[__gnu__::__nonnull__]]
constexpr bool
ends_with(const _CharT* __x) const noexcept
{ return __sv_type(this->data(), this->size()).ends_with(__x); }
@@ -3426,6 +3428,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
contains(_CharT __x) const noexcept
{ return __sv_type(this->data(), this->size()).contains(__x); }
+ [[__gnu__::__nonnull__]]
constexpr bool
contains(const _CharT* __x) const noexcept
{ return __sv_type(this->data(), this->size()).contains(__x); }
diff --git a/libstdc++-v3/include/bits/cow_string.h b/libstdc++-v3/include/bits/cow_string.h
index f16e33ac1ef..f5f03338eec 100644
--- a/libstdc++-v3/include/bits/cow_string.h
+++ b/libstdc++-v3/include/bits/cow_string.h
@@ -3012,6 +3012,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
starts_with(_CharT __x) const noexcept
{ return __sv_type(this->data(), this->size()).starts_with(__x); }
+ [[__gnu__::__nonnull__]]
bool
starts_with(const _CharT* __x) const noexcept
{ return __sv_type(this->data(), this->size()).starts_with(__x); }
@@ -3024,6 +3025,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
ends_with(_CharT __x) const noexcept
{ return __sv_type(this->data(), this->size()).ends_with(__x); }
+ [[__gnu__::__nonnull__]]
bool
ends_with(const _CharT* __x) const noexcept
{ return __sv_type(this->data(), this->size()).ends_with(__x); }
@@ -3038,6 +3040,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
contains(_CharT __x) const noexcept
{ return __sv_type(this->data(), this->size()).contains(__x); }
+ [[__gnu__::__nonnull__]]
bool
contains(const _CharT* __x) const noexcept
{ return __sv_type(this->data(), this->size()).contains(__x); }
diff --git a/libstdc++-v3/include/std/string_view b/libstdc++-v3/include/std/string_view
index 30ff136b1cb..5b96ffeecd6 100644
--- a/libstdc++-v3/include/std/string_view
+++ b/libstdc++-v3/include/std/string_view
@@ -360,6 +360,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
starts_with(_CharT __x) const noexcept
{ return !this->empty() && traits_type::eq(this->front(), __x); }
+ [[__gnu__::__nonnull__]]
constexpr bool
starts_with(const _CharT* __x) const noexcept
{ return this->starts_with(basic_string_view(__x)); }
@@ -377,6 +378,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
ends_with(_CharT __x) const noexcept
{ return !this->empty() && traits_type::eq(this->back(), __x); }
+ [[__gnu__::__nonnull__]]
constexpr bool
ends_with(const _CharT* __x) const noexcept
{ return this->ends_with(basic_string_view(__x)); }
@@ -392,6 +394,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
contains(_CharT __x) const noexcept
{ return this->find(__x) != npos; }
+ [[__gnu__::__nonnull__]]
constexpr bool
contains(const _CharT* __x) const noexcept
{ return this->find(__x) != npos; }
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/contains/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/contains/nonnull.cc
new file mode 100644
index 00000000000..e987cb7d297
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/contains/nonnull.cc
@@ -0,0 +1,12 @@
+// { dg-options "-std=gnu++23 -Wnonnull -O0" }
+// { dg-do compile { target c++23 } }
+
+#include <string>
+
+void
+test01(const std::string& s)
+{
+ s.contains((const char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.contains((char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.contains(nullptr); // { dg-warning "\\\[-Wnonnull" }
+}
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc
new file mode 100644
index 00000000000..1f2a156bace
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc
@@ -0,0 +1,12 @@
+// { dg-options "-std=gnu++20 -Wnonnull -O0" }
+// { dg-do compile { target c++20 } }
+
+#include <string>
+
+void
+test01(const std::string& s)
+{
+ s.ends_with((const char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.ends_with((char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.ends_with(nullptr); // { dg-warning "\\\[-Wnonnull" }
+}
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc
new file mode 100644
index 00000000000..8514359c877
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc
@@ -0,0 +1,12 @@
+// { dg-options "-std=gnu++20 -Wnonnull -O0" }
+// { dg-do compile { target c++20 } }
+
+#include <string>
+
+void
+test01(const std::string& s)
+{
+ s.starts_with((const char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.starts_with((char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.starts_with(nullptr); // { dg-warning "\\\[-Wnonnull" }
+}
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/contains/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/contains/nonnull.cc
new file mode 100644
index 00000000000..c0d274f095b
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/contains/nonnull.cc
@@ -0,0 +1,12 @@
+// { dg-options "-std=gnu++23 -Wnonnull -O0" }
+// { dg-do compile { target c++23 } }
+
+#include <string_view>
+
+void
+test01(std::string_view s)
+{
+ s.contains((const char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.contains((char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.contains(nullptr); // { dg-warning "\\\[-Wnonnull" }
+}
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/ends_with/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/ends_with/nonnull.cc
new file mode 100644
index 00000000000..09a99978a37
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/ends_with/nonnull.cc
@@ -0,0 +1,12 @@
+// { dg-options "-std=gnu++20 -Wnonnull -O0" }
+// { dg-do compile { target c++20 } }
+
+#include <string_view>
+
+void
+test01(std::string_view s)
+{
+ s.ends_with((const char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.ends_with((char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.ends_with(nullptr); // { dg-warning "\\\[-Wnonnull" }
+}
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/starts_with/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/starts_with/nonnull.cc
new file mode 100644
index 00000000000..c47f1dae832
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/starts_with/nonnull.cc
@@ -0,0 +1,12 @@
+// { dg-options "-std=gnu++20 -Wnonnull -O0" }
+// { dg-do compile { target c++20 } }
+
+#include <string_view>
+
+void
+test01(std::string_view s)
+{
+ s.starts_with((const char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.starts_with((char*)nullptr); // { dg-warning "\\\[-Wnonnull" }
+ s.starts_with(nullptr); // { dg-warning "\\\[-Wnonnull" }
+}
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