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[StaticAnalyzer] Fix non decimal macro values in tryExpandAsInteger #168632

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[StaticAnalyzer] Fix non decimal macro values in tryExpandAsInteger #168632

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14 changes: 10 additions & 4 deletions clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -142,19 +142,25 @@ std::optional<int> tryExpandAsInteger(StringRef Macro, const Preprocessor &PP) {
if (InvalidSpelling)
return std::nullopt;

llvm::APInt IntValue;
llvm::APSInt IntValue(0, true);
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@steakhal steakhal Nov 19, 2025

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Suggested change
llvm::APSInt IntValue(0, true);
llvm::APSInt IntValue(/*BitWidth=*/0, /*isUnsigned=*/true);

constexpr unsigned AutoSenseRadix = 0;
if (ValueStr.getAsInteger(AutoSenseRadix, IntValue))
if (ValueStr.getAsInteger(AutoSenseRadix,
static_cast<llvm::APInt &>(IntValue)))
Comment on lines +147 to +148
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@steakhal steakhal Nov 19, 2025

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Do we need this static cast? It doesn't seem to be the case. Implicit conversion should just achieve this, no?

return std::nullopt;

// Parse an optional minus sign.
size_t Size = FilteredTokens.size();
if (Size >= 2) {
if (FilteredTokens[Size - 2].is(tok::minus))
if (FilteredTokens[Size - 2].is(tok::minus)) {
// Make sure there's space for a sign bit
if (IntValue.isSignBitSet())
IntValue = IntValue.extend(IntValue.getBitWidth() + 1);
IntValue.setIsUnsigned(false);
IntValue = -IntValue;
}
}

return IntValue.getSExtValue();
return IntValue.getExtValue();
}

OperatorKind operationKindFromOverloadedOperator(OverloadedOperatorKind OOK,
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16 changes: 16 additions & 0 deletions clang/test/Analysis/std-c-library-functions-eof-2-rad.c
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@@ -0,0 +1,16 @@
// RUN: %clang_analyze_cc1 -std=c23 -analyzer-checker=core,unix.StdCLibraryFunctions,debug.ExprInspection -verify -analyzer-config eagerly-assume=false %s

void clang_analyzer_eval(int);

typedef struct FILE FILE;
/// Test that the static analyzer doesn't interpret the most significant bit as the sign bit.
// Unorthodox EOF value with a power of 2 radix
#define EOF (-0b11)

int getc(FILE *);
void test_getc(FILE *fp) {
int y = getc(fp);
if (y < 0) {
clang_analyzer_eval(y == EOF); // expected-warning{{TRUE}}
}
}