[clang] 2176c5e - [Clang][Sema] Fix display of characters on static assertion failure
Takuya Shimizu via cfe-commits
cfe-commits at lists.llvm.org
Tue Oct 3 22:10:53 PDT 2023
Author: Takuya Shimizu
Date: 2023-10-04T14:09:06+09:00
New Revision: 2176c5e510e3bfcbc75afb13e78d287141f239a7
URL: https://github.com/llvm/llvm-project/commit/2176c5e510e3bfcbc75afb13e78d287141f239a7
DIFF: https://github.com/llvm/llvm-project/commit/2176c5e510e3bfcbc75afb13e78d287141f239a7.diff
LOG: [Clang][Sema] Fix display of characters on static assertion failure
This patch fixes the display of characters appearing in LHS or RHS of == expression in notes to static assertion failure.
This applies C-style escape if the printed character is a special character. This also adds a numerical value displayed next to the character representation.
This also tries to print multi-byte characters if the user-provided expression is multi-byte char type.
Reviewed By: cor3ntin
Differential Revision: https://reviews.llvm.org/D155610
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/include/clang/Basic/Diagnostic.h
clang/lib/Basic/Diagnostic.cpp
clang/lib/Sema/SemaDeclCXX.cpp
clang/test/Lexer/cxx1z-trigraphs.cpp
clang/test/SemaCXX/static-assert-cxx26.cpp
clang/test/SemaCXX/static-assert.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 3dce7f6a8f9d56e..4c8b85fc29755c1 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -222,6 +222,41 @@ Improvements to Clang's diagnostics
- ``-Wfixed-enum-extension`` and ``-Wmicrosoft-fixed-enum`` diagnostics are no longer
emitted when building as C23, since C23 standardizes support for enums with a
fixed underlying type.
+- When describing the failure of static assertion of `==` expression, clang prints the integer
+ representation of the value as well as its character representation when
+ the user-provided expression is of character type. If the character is
+ non-printable, clang now shows the escpaed character.
+ Clang also prints multi-byte characters if the user-provided expression
+ is of multi-byte character type.
+
+ *Example Code*:
+
+ .. code-block:: c++
+
+ static_assert("A\n"[1] == U'🌍');
+
+ *BEFORE*:
+
+ .. code-block:: text
+
+ source:1:15: error: static assertion failed due to requirement '"A\n"[1] == U'\U0001f30d''
+ 1 | static_assert("A\n"[1] == U'🌍');
+ | ^~~~~~~~~~~~~~~~~
+ source:1:24: note: expression evaluates to ''
+ ' == 127757'
+ 1 | static_assert("A\n"[1] == U'🌍');
+ | ~~~~~~~~~^~~~~~~~
+
+ *AFTER*:
+
+ .. code-block:: text
+
+ source:1:15: error: static assertion failed due to requirement '"A\n"[1] == U'\U0001f30d''
+ 1 | static_assert("A\n"[1] == U'🌍');
+ | ^~~~~~~~~~~~~~~~~
+ source:1:24: note: expression evaluates to ''\n' (0x0A, 10) == U'🌍' (0x1F30D, 127757)'
+ 1 | static_assert("A\n"[1] == U'🌍');
+ | ~~~~~~~~~^~~~~~~~
Bug Fixes in This Version
-------------------------
diff --git a/clang/include/clang/Basic/Diagnostic.h b/clang/include/clang/Basic/Diagnostic.h
index 5606a22fe9d68b4..3df037b793b3946 100644
--- a/clang/include/clang/Basic/Diagnostic.h
+++ b/clang/include/clang/Basic/Diagnostic.h
@@ -1840,7 +1840,7 @@ const char ToggleHighlight = 127;
void ProcessWarningOptions(DiagnosticsEngine &Diags,
const DiagnosticOptions &Opts,
bool ReportDiags = true);
-
+void EscapeStringForDiagnostic(StringRef Str, SmallVectorImpl<char> &OutStr);
} // namespace clang
#endif // LLVM_CLANG_BASIC_DIAGNOSTIC_H
diff --git a/clang/lib/Basic/Diagnostic.cpp b/clang/lib/Basic/Diagnostic.cpp
index 7a54d27ef9d8ee2..0208ccc31bd7fc0 100644
--- a/clang/lib/Basic/Diagnostic.cpp
+++ b/clang/lib/Basic/Diagnostic.cpp
@@ -800,9 +800,10 @@ FormatDiagnostic(SmallVectorImpl<char> &OutStr) const {
FormatDiagnostic(Diag.begin(), Diag.end(), OutStr);
}
-/// pushEscapedString - Append Str to the diagnostic buffer,
+/// EscapeStringForDiagnostic - Append Str to the diagnostic buffer,
/// escaping non-printable characters and ill-formed code unit sequences.
-static void pushEscapedString(StringRef Str, SmallVectorImpl<char> &OutStr) {
+void clang::EscapeStringForDiagnostic(StringRef Str,
+ SmallVectorImpl<char> &OutStr) {
OutStr.reserve(OutStr.size() + Str.size());
auto *Begin = reinterpret_cast<const unsigned char *>(Str.data());
llvm::raw_svector_ostream OutStream(OutStr);
@@ -854,7 +855,7 @@ FormatDiagnostic(const char *DiagStr, const char *DiagEnd,
StringRef(DiagStr, DiagEnd - DiagStr).equals("%0") &&
getArgKind(0) == DiagnosticsEngine::ak_std_string) {
const std::string &S = getArgStdStr(0);
- pushEscapedString(S, OutStr);
+ EscapeStringForDiagnostic(S, OutStr);
return;
}
@@ -961,7 +962,7 @@ FormatDiagnostic(const char *DiagStr, const char *DiagEnd,
case DiagnosticsEngine::ak_std_string: {
const std::string &S = getArgStdStr(ArgNo);
assert(ModifierLen == 0 && "No modifiers for strings yet");
- pushEscapedString(S, OutStr);
+ EscapeStringForDiagnostic(S, OutStr);
break;
}
case DiagnosticsEngine::ak_c_string: {
@@ -971,7 +972,7 @@ FormatDiagnostic(const char *DiagStr, const char *DiagEnd,
// Don't crash if get passed a null pointer by accident.
if (!S)
S = "(null)";
- pushEscapedString(S, OutStr);
+ EscapeStringForDiagnostic(S, OutStr);
break;
}
// ---- INTEGERS ----
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 7ebb38ec2ec0c49..f9c010b1a002488 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -49,6 +49,7 @@
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/SaveAndRestore.h"
#include <map>
#include <optional>
@@ -17026,10 +17027,74 @@ Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
AssertMessageExpr, RParenLoc, false);
}
+static void WriteCharTypePrefix(BuiltinType::Kind BTK, llvm::raw_ostream &OS) {
+ switch (BTK) {
+ case BuiltinType::Char_S:
+ case BuiltinType::Char_U:
+ break;
+ case BuiltinType::Char8:
+ OS << "u8";
+ break;
+ case BuiltinType::Char16:
+ OS << 'u';
+ break;
+ case BuiltinType::Char32:
+ OS << 'U';
+ break;
+ case BuiltinType::WChar_S:
+ case BuiltinType::WChar_U:
+ OS << 'L';
+ break;
+ default:
+ llvm_unreachable("Non-character type");
+ }
+}
+
+/// Convert character's value, interpreted as a code unit, to a string.
+/// The value needs to be zero-extended to 32-bits.
+/// FIXME: This assumes Unicode literal encodings
+static void WriteCharValueForDiagnostic(uint32_t Value, const BuiltinType *BTy,
+ unsigned TyWidth,
+ SmallVectorImpl<char> &Str) {
+ char Arr[UNI_MAX_UTF8_BYTES_PER_CODE_POINT];
+ char *Ptr = Arr;
+ BuiltinType::Kind K = BTy->getKind();
+ llvm::raw_svector_ostream OS(Str);
+
+ // This should catch Char_S, Char_U, Char8, and use of escaped characters in
+ // other types.
+ if (K == BuiltinType::Char_S || K == BuiltinType::Char_U ||
+ K == BuiltinType::Char8 || Value <= 0x7F) {
+ StringRef Escaped = escapeCStyle<EscapeChar::Single>(Value);
+ if (!Escaped.empty())
+ EscapeStringForDiagnostic(Escaped, Str);
+ else
+ OS << static_cast<char>(Value);
+ return;
+ }
+
+ switch (K) {
+ case BuiltinType::Char16:
+ case BuiltinType::Char32:
+ case BuiltinType::WChar_S:
+ case BuiltinType::WChar_U: {
+ if (llvm::ConvertCodePointToUTF8(Value, Ptr))
+ EscapeStringForDiagnostic(StringRef(Arr, Ptr - Arr), Str);
+ else
+ OS << "\\x"
+ << llvm::format_hex_no_prefix(Value, TyWidth / 4, /*Upper=*/true);
+ break;
+ }
+ default:
+ llvm_unreachable("Non-character type is passed");
+ }
+}
+
/// Convert \V to a string we can present to the user in a diagnostic
/// \T is the type of the expression that has been evaluated into \V
static bool ConvertAPValueToString(const APValue &V, QualType T,
- SmallVectorImpl<char> &Str) {
+ SmallVectorImpl<char> &Str,
+ ASTContext &Context) {
if (!V.hasValue())
return false;
@@ -17044,13 +17109,38 @@ static bool ConvertAPValueToString(const APValue &V, QualType T,
"Bool type, but value is not 0 or 1");
llvm::raw_svector_ostream OS(Str);
OS << (BoolValue ? "true" : "false");
- } else if (T->isCharType()) {
+ } else {
+ llvm::raw_svector_ostream OS(Str);
// Same is true for chars.
- Str.push_back('\'');
- Str.push_back(V.getInt().getExtValue());
- Str.push_back('\'');
- } else
+ // We want to print the character representation for textual types
+ const auto *BTy = T->getAs<BuiltinType>();
+ if (BTy) {
+ switch (BTy->getKind()) {
+ case BuiltinType::Char_S:
+ case BuiltinType::Char_U:
+ case BuiltinType::Char8:
+ case BuiltinType::Char16:
+ case BuiltinType::Char32:
+ case BuiltinType::WChar_S:
+ case BuiltinType::WChar_U: {
+ unsigned TyWidth = Context.getIntWidth(T);
+ assert(8 <= TyWidth && TyWidth <= 32 && "Unexpected integer width");
+ uint32_t CodeUnit = static_cast<uint32_t>(V.getInt().getZExtValue());
+ WriteCharTypePrefix(BTy->getKind(), OS);
+ OS << '\'';
+ WriteCharValueForDiagnostic(CodeUnit, BTy, TyWidth, Str);
+ OS << "' (0x"
+ << llvm::format_hex_no_prefix(CodeUnit, /*Width=*/2,
+ /*Upper=*/true)
+ << ", " << V.getInt() << ')';
+ return true;
+ }
+ default:
+ break;
+ }
+ }
V.getInt().toString(Str);
+ }
break;
@@ -17147,8 +17237,9 @@ void Sema::DiagnoseStaticAssertDetails(const Expr *E) {
Side->EvaluateAsRValue(DiagSide[I].Result, Context, true);
- DiagSide[I].Print = ConvertAPValueToString(
- DiagSide[I].Result.Val, Side->getType(), DiagSide[I].ValueString);
+ DiagSide[I].Print =
+ ConvertAPValueToString(DiagSide[I].Result.Val, Side->getType(),
+ DiagSide[I].ValueString, Context);
}
if (DiagSide[0].Print && DiagSide[1].Print) {
Diag(Op->getExprLoc(), diag::note_expr_evaluates_to)
diff --git a/clang/test/Lexer/cxx1z-trigraphs.cpp b/clang/test/Lexer/cxx1z-trigraphs.cpp
index 2e47c05e9bd33b8..6b39ff6716605bf 100644
--- a/clang/test/Lexer/cxx1z-trigraphs.cpp
+++ b/clang/test/Lexer/cxx1z-trigraphs.cpp
@@ -21,7 +21,7 @@ error here;
#if !ENABLED_TRIGRAPHS
// expected-error at 11 {{}} expected-warning at 11 {{trigraph ignored}}
-// expected-error at 13 {{failed}} expected-warning at 13 {{trigraph ignored}} expected-note at 13 {{evaluates to ''?' == '#''}}
+// expected-error at 13 {{failed}} expected-warning at 13 {{trigraph ignored}} expected-note at 13 {{evaluates to ''?' (0x3F, 63) == '#' (0x23, 35)'}}
// expected-error at 16 {{}}
// expected-error at 20 {{}}
#else
diff --git a/clang/test/SemaCXX/static-assert-cxx26.cpp b/clang/test/SemaCXX/static-assert-cxx26.cpp
index c2bb2d2ebc6ffb2..b19aac6cabd1324 100644
--- a/clang/test/SemaCXX/static-assert-cxx26.cpp
+++ b/clang/test/SemaCXX/static-assert-cxx26.cpp
@@ -298,3 +298,12 @@ Good<Frobble> a; // expected-note {{in instantiation}}
Bad<int> b; // expected-note {{in instantiation}}
}
+
+namespace EscapeInDiagnostic {
+static_assert('\u{9}' == (char)1, ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to ''\t' (0x09, 9) == '<U+0001>' (0x01, 1)'}}
+static_assert((char8_t)-128 == (char8_t)-123, ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to 'u8'<80>' (0x80, 128) == u8'<85>' (0x85, 133)'}}
+static_assert((char16_t)0xFEFF == (char16_t)0xDB93, ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to 'u'' (0xFEFF, 65279) == u'\xDB93' (0xDB93, 56211)'}}
+}
diff --git a/clang/test/SemaCXX/static-assert.cpp b/clang/test/SemaCXX/static-assert.cpp
index 5d64ff682a20e5e..4200d821339edeb 100644
--- a/clang/test/SemaCXX/static-assert.cpp
+++ b/clang/test/SemaCXX/static-assert.cpp
@@ -268,7 +268,31 @@ namespace Diagnostics {
return 'c';
}
static_assert(getChar() == 'a', ""); // expected-error {{failed}} \
- // expected-note {{evaluates to ''c' == 'a''}}
+ // expected-note {{evaluates to ''c' (0x63, 99) == 'a' (0x61, 97)'}}
+ static_assert((char)9 == '\x61', ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to ''\t' (0x09, 9) == 'a' (0x61, 97)'}}
+ static_assert((char)10 == '\0', ""); // expected-error {{failed}} \
+ // expected-note {{n' (0x0A, 10) == '<U+0000>' (0x00, 0)'}}
+ // The note above is intended to match "evaluates to '\n' (0x0A, 10) == '<U+0000>' (0x00, 0)'", but if we write it as it is,
+ // the "\n" cannot be consumed by the diagnostic consumer.
+ static_assert((signed char)10 == (char)-123, ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to '10 == '<85>' (0x85, -123)'}}
+ static_assert((char)-4 == (unsigned char)-8, ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to ''<FC>' (0xFC, -4) == 248'}}
+ static_assert((char)-128 == (char)-123, ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to ''<80>' (0x80, -128) == '<85>' (0x85, -123)'}}
+ static_assert('\xA0' == (char)'\x20', ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to ''<A0>' (0xA0, -96) == ' ' (0x20, 32)'}}
+ static_assert((char16_t)L'ゆ' == L"C̵̭̯̠̎͌ͅť̺"[1], ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to 'u'ゆ' (0x3086, 12422) == L'̵' (0x335, 821)'}}
+ static_assert(L"＼／"[1] == u'\xFFFD', ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to 'L'／' (0xFF0F, 65295) == u'�' (0xFFFD, 65533)'}}
+ static_assert(L"⚾"[0] == U'🌍', ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to 'L'⚾' (0x26BE, 9918) == U'🌍' (0x1F30D, 127757)'}}
+ static_assert(U"\a"[0] == (wchar_t)9, ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to 'U'\a' (0x07, 7) == L'\t' (0x09, 9)'}}
+ static_assert(L"§"[0] == U'Ö', ""); // expected-error {{failed}} \
+ // expected-note {{evaluates to 'L'§' (0xA7, 167) == U'Ö' (0xD6, 214)'}}
/// Bools are printed as bools.
constexpr bool invert(bool b) {
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