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Address a handful of C4146 compiler warnings where literals can be replaced with std::numeric_limits #147623

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Merged
merged 7 commits into from
Jul 9, 2025
+25 −15
Merged

Address a handful of C4146 compiler warnings where literals can be replaced with std::numeric_limits #147623

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7e1c62f
Numeric limits in ExprConstant.cpp
alsepkow Jul 8, 2025
98197ad
Numeric limits in Format.cpp
alsepkow Jul 8, 2025
a073761
Numeric limits in Lexer.cpp
alsepkow Jul 8, 2025
2a479e1
Numeric limits in SemaExpr.cpp
alsepkow Jul 8, 2025
46d1485
Clang-format previous changes
alsepkow Jul 8, 2025
9aa8125
Update clang/lib/Format/Format.cpp
alsepkow Jul 9, 2025
013a5aa
Update to use numeric_limits across Format.cpp instead of UINT_MAX
alsepkow Jul 9, 2025
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4 changes: 2 additions & 2 deletions clang/lib/AST/ExprConstant.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1428,11 +1428,11 @@ namespace {
}
bool destroy(bool RunDestructors = true) {
bool OK = cleanup(Info, RunDestructors, OldStackSize);
OldStackSize = -1U;
OldStackSize = std::numeric_limits<unsigned>::max();
return OK;
}
~ScopeRAII() {
if (OldStackSize != -1U)
if (OldStackSize != std::numeric_limits<unsigned>::max())
destroy(false);
// Body moved to a static method to encourage the compiler to inline away
// instances of this class.
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7 changes: 5 additions & 2 deletions clang/lib/Format/Format.cpp
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Expand Up @@ -22,7 +22,9 @@
#include "UnwrappedLineFormatter.h"
#include "UsingDeclarationsSorter.h"
#include "clang/Tooling/Inclusions/HeaderIncludes.h"

#include "llvm/ADT/Sequence.h"
#include <limits>

#define DEBUG_TYPE "format-formatter"

Expand Down Expand Up @@ -777,7 +779,7 @@ template <> struct MappingTraits<FormatStyle::SpacesInLineComment> {
IO.mapOptional("Maximum", signedMaximum);
Space.Maximum = static_cast<unsigned>(signedMaximum);

if (Space.Maximum != -1u)
if (Space.Maximum != std::numeric_limits<unsigned>::max())
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Suggested change
if (Space.Maximum != std::numeric_limits<unsigned>::max())
if (Space.Maximum < UINT_MAX)

as that's what's used elsewhere in the file.

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On further consideration, I think it would be cleaner to stay consistent with using numeric_limits for all of the updates. And given that there are only a handful of UINT_MAX cases in this file I've swapped them to use numeric_limits for consistency. That would be the preferred choice if this were new code anyways.

Space.Minimum = std::min(Space.Minimum, Space.Maximum);
}
};
Expand Down Expand Up @@ -1672,7 +1674,8 @@ FormatStyle getLLVMStyle(FormatStyle::LanguageKind Language) {
LLVMStyle.SpacesBeforeTrailingComments = 1;
LLVMStyle.SpacesInAngles = FormatStyle::SIAS_Never;
LLVMStyle.SpacesInContainerLiterals = true;
LLVMStyle.SpacesInLineCommentPrefix = {/*Minimum=*/1, /*Maximum=*/-1u};
LLVMStyle.SpacesInLineCommentPrefix = {
/*Minimum=*/1, /*Maximum=*/std::numeric_limits<unsigned>::max()};
LLVMStyle.SpacesInParens = FormatStyle::SIPO_Never;
LLVMStyle.SpacesInSquareBrackets = false;
LLVMStyle.Standard = FormatStyle::LS_Latest;
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3 changes: 2 additions & 1 deletion clang/lib/Lex/Lexer.cpp
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Expand Up @@ -41,6 +41,7 @@
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <limits>
#include <optional>
#include <string>
#include <tuple>
Expand Down Expand Up @@ -3456,7 +3457,7 @@ std::optional<uint32_t> Lexer::tryReadNumericUCN(const char *&StartPtr,
}

unsigned Value = llvm::hexDigitValue(C);
if (Value == -1U) {
if (Value == std::numeric_limits<unsigned>::max()) {
if (!Delimited)
break;
if (Diagnose)
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6 changes: 4 additions & 2 deletions clang/lib/Sema/SemaExpr.cpp
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Expand Up @@ -65,6 +65,7 @@
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/TimeProfiler.h"
#include "llvm/Support/TypeSize.h"
#include <limits>
#include <optional>

using namespace clang;
Expand Down Expand Up @@ -1906,7 +1907,7 @@ ExprResult Sema::CreateGenericSelectionExpr(
}

SmallVector<unsigned, 1> CompatIndices;
unsigned DefaultIndex = -1U;
unsigned DefaultIndex = std::numeric_limits<unsigned>::max();
// Look at the canonical type of the controlling expression in case it was a
// deduced type like __auto_type. However, when issuing diagnostics, use the
// type the user wrote in source rather than the canonical one.
Expand Down Expand Up @@ -1961,7 +1962,8 @@ ExprResult Sema::CreateGenericSelectionExpr(
// C11 6.5.1.1p2 "If a generic selection has no default generic association,
// its controlling expression shall have type compatible with exactly one of
// the types named in its generic association list."
if (DefaultIndex == -1U && CompatIndices.size() == 0) {
if (DefaultIndex == std::numeric_limits<unsigned>::max() &&
CompatIndices.size() == 0) {
auto P = GetControllingRangeAndType(ControllingExpr, ControllingType);
SourceRange SR = P.first;
Diag(SR.getBegin(), diag::err_generic_sel_no_match) << SR << P.second;
Expand Down