[clang] Address a handful of C4146 compiler warnings where literals can be replaced with std::numeric_limits (PR #147623)
Alex Sepkowski via cfe-commits
cfe-commits at lists.llvm.org
Wed Jul 9 11:00:57 PDT 2025
https://github.com/alsepkow updated https://github.com/llvm/llvm-project/pull/147623
>From 7e1c62fce3741b8182db2428c29136524b27b98c Mon Sep 17 00:00:00 2001
From: Alex Sepkowski <5620315+alsepkow at users.noreply.github.com>
Date: Tue, 8 Jul 2025 16:17:56 -0700
Subject: [PATCH 1/7] Numeric limits in ExprConstant.cpp
---
clang/lib/AST/ExprConstant.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 60c658a8d8f99..5d399a3c75ca8 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -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.
>From 98197ad801b0647e9b755212fe8b6f7648784ac4 Mon Sep 17 00:00:00 2001
From: Alex Sepkowski <5620315+alsepkow at users.noreply.github.com>
Date: Tue, 8 Jul 2025 16:44:39 -0700
Subject: [PATCH 2/7] Numeric limits in Format.cpp
---
clang/lib/Format/Format.cpp | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index f0412cddc6f19..a8c88c6412805 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -22,6 +22,8 @@
#include "UnwrappedLineFormatter.h"
#include "UsingDeclarationsSorter.h"
#include "clang/Tooling/Inclusions/HeaderIncludes.h"
+
+#include <limits>
#include "llvm/ADT/Sequence.h"
#define DEBUG_TYPE "format-formatter"
@@ -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())
Space.Minimum = std::min(Space.Minimum, Space.Maximum);
}
};
@@ -1672,7 +1674,7 @@ 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;
>From a07376154afed4967c652469de3a4ec8ba2be980 Mon Sep 17 00:00:00 2001
From: Alex Sepkowski <5620315+alsepkow at users.noreply.github.com>
Date: Tue, 8 Jul 2025 16:46:54 -0700
Subject: [PATCH 3/7] Numeric limits in Lexer.cpp
---
clang/lib/Lex/Lexer.cpp | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp
index 78988e928a689..1f695b4a8676c 100644
--- a/clang/lib/Lex/Lexer.cpp
+++ b/clang/lib/Lex/Lexer.cpp
@@ -41,6 +41,7 @@
#include <cstddef>
#include <cstdint>
#include <cstring>
+#include <limits>
#include <optional>
#include <string>
#include <tuple>
@@ -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)
>From 2a479e17aced19aecdb9e0e8085857d060b7fbb2 Mon Sep 17 00:00:00 2001
From: Alex Sepkowski <5620315+alsepkow at users.noreply.github.com>
Date: Tue, 8 Jul 2025 16:56:16 -0700
Subject: [PATCH 4/7] Numeric limits in SemaExpr.cpp
---
clang/lib/Sema/SemaExpr.cpp | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 3c3d29c415249..2c721e9cf1bd7 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -18,6 +18,7 @@
#include "clang/AST/ASTDiagnostic.h"
#include "clang/AST/ASTLambda.h"
#include "clang/AST/ASTMutationListener.h"
+#include <limits>
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
@@ -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.
@@ -1961,7 +1962,7 @@ 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;
>From 46d148524cad5699fea71e9522469fac0e7603f5 Mon Sep 17 00:00:00 2001
From: Alex Sepkowski <5620315+alsepkow at users.noreply.github.com>
Date: Tue, 8 Jul 2025 16:57:10 -0700
Subject: [PATCH 5/7] Clang-format previous changes
---
clang/lib/Format/Format.cpp | 5 +++--
clang/lib/Sema/SemaExpr.cpp | 5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index a8c88c6412805..5f5a5d9d8a571 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -23,8 +23,8 @@
#include "UsingDeclarationsSorter.h"
#include "clang/Tooling/Inclusions/HeaderIncludes.h"
-#include <limits>
#include "llvm/ADT/Sequence.h"
+#include <limits>
#define DEBUG_TYPE "format-formatter"
@@ -1674,7 +1674,8 @@ FormatStyle getLLVMStyle(FormatStyle::LanguageKind Language) {
LLVMStyle.SpacesBeforeTrailingComments = 1;
LLVMStyle.SpacesInAngles = FormatStyle::SIAS_Never;
LLVMStyle.SpacesInContainerLiterals = true;
- LLVMStyle.SpacesInLineCommentPrefix = {/*Minimum=*/1, /*Maximum=*/std::numeric_limits<unsigned>::max()};
+ LLVMStyle.SpacesInLineCommentPrefix = {
+ /*Minimum=*/1, /*Maximum=*/std::numeric_limits<unsigned>::max()};
LLVMStyle.SpacesInParens = FormatStyle::SIPO_Never;
LLVMStyle.SpacesInSquareBrackets = false;
LLVMStyle.Standard = FormatStyle::LS_Latest;
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 2c721e9cf1bd7..fcc015be1d5f4 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -18,7 +18,6 @@
#include "clang/AST/ASTDiagnostic.h"
#include "clang/AST/ASTLambda.h"
#include "clang/AST/ASTMutationListener.h"
-#include <limits>
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
@@ -66,6 +65,7 @@
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/TimeProfiler.h"
#include "llvm/Support/TypeSize.h"
+#include <limits>
#include <optional>
using namespace clang;
@@ -1962,7 +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 == std::numeric_limits<unsigned>::max() && 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;
>From 9aa8125a9f044a89902c16f95b318298738a934c Mon Sep 17 00:00:00 2001
From: Alex Sepkowski <alexsepkowski at gmail.com>
Date: Wed, 9 Jul 2025 10:28:20 -0700
Subject: [PATCH 6/7] Update clang/lib/Format/Format.cpp
Swap to UINT_MAX to match formatting of the rest of the file.
Co-authored-by: Owen Pan <owenpiano at gmail.com>
---
clang/lib/Format/Format.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 5f5a5d9d8a571..42b0d25dea145 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -779,7 +779,7 @@ template <> struct MappingTraits<FormatStyle::SpacesInLineComment> {
IO.mapOptional("Maximum", signedMaximum);
Space.Maximum = static_cast<unsigned>(signedMaximum);
- if (Space.Maximum != std::numeric_limits<unsigned>::max())
+ if (Space.Maximum < UINT_MAX)
Space.Minimum = std::min(Space.Minimum, Space.Maximum);
}
};
>From 013a5aa6772fd0c3edb26a61754fe719a4bacfd3 Mon Sep 17 00:00:00 2001
From: Alex Sepkowski <5620315+alsepkow at users.noreply.github.com>
Date: Wed, 9 Jul 2025 10:58:20 -0700
Subject: [PATCH 7/7] Update to use numeric_limits across Format.cpp instead of
UINT_MAX
---
clang/lib/Format/Format.cpp | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 42b0d25dea145..8b217bcbeece6 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -779,7 +779,7 @@ template <> struct MappingTraits<FormatStyle::SpacesInLineComment> {
IO.mapOptional("Maximum", signedMaximum);
Space.Maximum = static_cast<unsigned>(signedMaximum);
- if (Space.Maximum < UINT_MAX)
+ if (Space.Maximum < std::numeric_limits<unsigned>::max())
Space.Minimum = std::min(Space.Minimum, Space.Maximum);
}
};
@@ -3171,11 +3171,12 @@ static bool affectsRange(ArrayRef<tooling::Range> Ranges, unsigned Start,
// the index of the first of the duplicates as the others are going to be
// removed. OffsetToEOL describes the cursor's position relative to the end of
// its current line.
-// If `Cursor` is not on any #include, `Index` will be UINT_MAX.
+// If `Cursor` is not on any #include, `Index` will be
+// std::numeric_limits<unsigned>::max().
static std::pair<unsigned, unsigned>
FindCursorIndex(const ArrayRef<IncludeDirective> &Includes,
const ArrayRef<unsigned> &Indices, unsigned Cursor) {
- unsigned CursorIndex = UINT_MAX;
+ unsigned CursorIndex = std::numeric_limits<unsigned>::max();
unsigned OffsetToEOL = 0;
for (int i = 0, e = Includes.size(); i != e; ++i) {
unsigned Start = Includes[Indices[i]].Offset;
@@ -3443,11 +3444,12 @@ tooling::Replacements sortCppIncludes(const FormatStyle &Style, StringRef Code,
return Replaces;
}
-// Returns group number to use as a first order sort on imports. Gives UINT_MAX
-// if the import does not match any given groups.
+// Returns group number to use as a first order sort on imports. Gives
+// std::numeric_limits<unsigned>::max() if the import does not match any given
+// groups.
static unsigned findJavaImportGroup(const FormatStyle &Style,
StringRef ImportIdentifier) {
- unsigned LongestMatchIndex = UINT_MAX;
+ unsigned LongestMatchIndex = std::numeric_limits<unsigned>::max();
unsigned LongestMatchLength = 0;
for (unsigned I = 0; I < Style.JavaImportGroups.size(); I++) {
const std::string &GroupPrefix = Style.JavaImportGroups[I];
@@ -3676,13 +3678,15 @@ formatReplacements(StringRef Code, const tooling::Replacements &Replaces,
namespace {
inline bool isHeaderInsertion(const tooling::Replacement &Replace) {
- return Replace.getOffset() == UINT_MAX && Replace.getLength() == 0 &&
+ return Replace.getOffset() == std::numeric_limits<unsigned>::max() &&
+ Replace.getLength() == 0 &&
tooling::HeaderIncludes::IncludeRegex.match(
Replace.getReplacementText());
}
inline bool isHeaderDeletion(const tooling::Replacement &Replace) {
- return Replace.getOffset() == UINT_MAX && Replace.getLength() == 1;
+ return Replace.getOffset() == std::numeric_limits<unsigned>::max() &&
+ Replace.getLength() == 1;
}
// FIXME: insert empty lines between newly created blocks.
@@ -3702,7 +3706,7 @@ fixCppIncludeInsertions(StringRef Code, const tooling::Replacements &Replaces,
consumeError(HeaderInsertions.add(R));
} else if (isHeaderDeletion(R)) {
HeadersToDelete.insert(R.getReplacementText());
- } else if (R.getOffset() == UINT_MAX) {
+ } else if (R.getOffset() == std::numeric_limits<unsigned>::max()) {
llvm::errs() << "Insertions other than header #include insertion are "
"not supported! "
<< R.getReplacementText() << "\n";
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