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Hookup checking for invalid length modifiers in scanf format strings. 

llvm-svn: 108907
This commit is contained in:
Ted Kremenek 2010-07-20 20:04:47 +00:00
parent ea28f83a5f
commit 4407ea4948
3 changed files with 42 additions and 24 deletions
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44
clang/lib/Analysis/ScanfFormatString.cpp
View File

@ -19,6 +19,7 @@ using clang::analyze_format_string::ArgTypeResult;
using clang::analyze_format_string::FormatStringHandler;
using clang::analyze_format_string::LengthModifier;
using clang::analyze_format_string::OptionalAmount;
using clang::analyze_format_string::ConversionSpecifier;
using clang::analyze_scanf::ScanfConversionSpecifier;
using clang::analyze_scanf::ScanfSpecifier;
@ -146,27 +147,28 @@ static ScanfSpecifierResult ParseScanfSpecifier(FormatStringHandler &H,
switch (*conversionPosition) {
default:
break;
case '%': k = ScanfConversionSpecifier::PercentArg; break;
case 'A': k = ScanfConversionSpecifier::AArg; break;
case 'E': k = ScanfConversionSpecifier::EArg; break;
case 'F': k = ScanfConversionSpecifier::FArg; break;
case 'G': k = ScanfConversionSpecifier::GArg; break;
case 'X': k = ScanfConversionSpecifier::XArg; break;
case 'a': k = ScanfConversionSpecifier::aArg; break;
case 'd': k = ScanfConversionSpecifier::dArg; break;
case 'e': k = ScanfConversionSpecifier::eArg; break;
case 'f': k = ScanfConversionSpecifier::fArg; break;
case 'g': k = ScanfConversionSpecifier::gArg; break;
case 'i': k = ScanfConversionSpecifier::iArg; break;
case 'n': k = ScanfConversionSpecifier::nArg; break;
case 'c': k = ScanfConversionSpecifier::cArg; break;
case 'C': k = ScanfConversionSpecifier::CArg; break;
case 'S': k = ScanfConversionSpecifier::SArg; break;
case '[': k = ScanfConversionSpecifier::ScanListArg; break;
case 'u': k = ScanfConversionSpecifier::uArg; break;
case 'x': k = ScanfConversionSpecifier::xArg; break;
case 'o': k = ScanfConversionSpecifier::oArg; break;
case 's': k = ScanfConversionSpecifier::sArg; break;
case '%': k = ConversionSpecifier::PercentArg; break;
case 'A': k = ConversionSpecifier::AArg; break;
case 'E': k = ConversionSpecifier::EArg; break;
case 'F': k = ConversionSpecifier::FArg; break;
case 'G': k = ConversionSpecifier::GArg; break;
case 'X': k = ConversionSpecifier::XArg; break;
case 'a': k = ConversionSpecifier::aArg; break;
case 'd': k = ConversionSpecifier::dArg; break;
case 'e': k = ConversionSpecifier::eArg; break;
case 'f': k = ConversionSpecifier::fArg; break;
case 'g': k = ConversionSpecifier::gArg; break;
case 'i': k = ConversionSpecifier::iArg; break;
case 'n': k = ConversionSpecifier::nArg; break;
case 'c': k = ConversionSpecifier::cArg; break;
case 'C': k = ConversionSpecifier::CArg; break;
case 'S': k = ConversionSpecifier::SArg; break;
case '[': k = ConversionSpecifier::ScanListArg; break;
case 'u': k = ConversionSpecifier::uArg; break;
case 'x': k = ConversionSpecifier::xArg; break;
case 'o': k = ConversionSpecifier::oArg; break;
case 's': k = ConversionSpecifier::sArg; break;
case 'p': k = ConversionSpecifier::pArg; break;
}
ScanfConversionSpecifier CS(conversionPosition, k);
if (k == ScanfConversionSpecifier::ScanListArg) {

14
clang/lib/Sema/SemaChecking.cpp
View File

@ -1701,9 +1701,17 @@ bool CheckScanfHandler::HandleScanfSpecifier(
CoveredArgs.set(argIndex);
}
// FIXME: Check that the length modifier is valid with the given
// conversion specifier.
// Check the length modifier is valid with the given conversion specifier.
const LengthModifier &LM = FS.getLengthModifier();
if (!FS.hasValidLengthModifier()) {
S.Diag(getLocationOfByte(LM.getStart()),
diag::warn_format_nonsensical_length)
<< LM.toString() << CS.toString()
<< getSpecifierRange(startSpecifier, specifierLen)
<< FixItHint::CreateRemoval(getSpecifierRange(LM.getStart(),
LM.getLength()));
}
// The remaining checks depend on the data arguments.
if (HasVAListArg)
return true;

8
clang/test/Sema/format-strings-scanf.c
View File

@ -2,6 +2,7 @@
typedef __typeof(sizeof(int)) size_t;
typedef struct _FILE FILE;
typedef __WCHAR_TYPE__ wchar_t;
int fscanf(FILE * restrict, const char * restrict, ...) ;
int scanf(const char * restrict, ...) ;
@ -24,3 +25,10 @@ void test(const char *s, int *i) {
scanf("%*d", i); // // expected-warning{{data argument not used by format string}}
scanf("%*d%1$d", i); // no-warning
}
void bad_length_modifiers(char *s, void *p, wchar_t *ws, long double *ld) {
scanf("%hhs", "foo"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}}
scanf("%1$zp", p); // expected-warning{{length modifier 'z' results in undefined behavior or no effect with 'p' conversion specifier}}
scanf("%ls", ws); // no-warning
scanf("%#.2Lf", ld); // expected-warning{{invalid conversion specifier '#'}}
}