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Bug 7377: printf checking fails to flag some undefined behavior 

http://llvm.org/bugs/show_bug.cgi?id=7377

Updated format string highlighting and fixits to take advantage of the new CharSourceRange class.
- Change HighlightRange to allow highlighting whitespace only in a CharSourceRange (for warnings about the ' ' (space) flag)
- Change format specifier range helper function to allow for half-open ranges (+1 to end)
- Enabled previously failing tests (FIXMEs/XFAILs removed)
- Small fixes and additions to format string test cases

M       test/Sema/format-strings.c
M       test/Sema/format-strings-fixit.c
M       lib/Frontend/TextDiagnosticPrinter.cpp
M       lib/Sema/SemaChecking.cpp

llvm-svn: 106480
This commit is contained in:
Tom Care 2010-06-21 21:21:01 +00:00
parent 24757ff75e
commit 3f272b853f
4 changed files with 37 additions and 37 deletions
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29
clang/lib/Frontend/TextDiagnosticPrinter.cpp
View File

@ -123,21 +123,24 @@ void TextDiagnosticPrinter::HighlightRange(const CharSourceRange &R,
assert(StartColNo <= EndColNo && "Invalid range!");
// Pick the first non-whitespace column.
while (StartColNo < SourceLine.size() &&
(SourceLine[StartColNo] == ' ' || SourceLine[StartColNo] == '\t'))
++StartColNo;
// Check that a token range does not highlight only whitespace.
if (R.isTokenRange()) {
// Pick the first non-whitespace column.
while (StartColNo < SourceLine.size() &&
(SourceLine[StartColNo] == ' ' || SourceLine[StartColNo] == '\t'))
++StartColNo;
// Pick the last non-whitespace column.
if (EndColNo > SourceLine.size())
EndColNo = SourceLine.size();
while (EndColNo-1 &&
(SourceLine[EndColNo-1] == ' ' || SourceLine[EndColNo-1] == '\t'))
--EndColNo;
// Pick the last non-whitespace column.
if (EndColNo > SourceLine.size())
EndColNo = SourceLine.size();
while (EndColNo-1 &&
(SourceLine[EndColNo-1] == ' ' || SourceLine[EndColNo-1] == '\t'))
--EndColNo;
// If the start/end passed each other, then we are trying to highlight a range
// that just exists in whitespace, which must be some sort of other bug.
assert(StartColNo <= EndColNo && "Trying to highlight whitespace??");
// If the start/end passed each other, then we are trying to highlight a range
// that just exists in whitespace, which must be some sort of other bug.
assert(StartColNo <= EndColNo && "Trying to highlight whitespace??");
}
// Fill the range with ~'s.
for (unsigned i = StartColNo; i < EndColNo; ++i)

31
clang/lib/Sema/SemaChecking.cpp
View File

@ -1194,8 +1194,8 @@ public:
unsigned specifierLen);
private:
SourceRange getFormatStringRange();
SourceRange getFormatSpecifierRange(const char *startSpecifier,
unsigned specifierLen);
CharSourceRange getFormatSpecifierRange(const char *startSpecifier,
unsigned specifierLen);
SourceLocation getLocationOfByte(const char *x);
bool HandleAmount(const analyze_printf::OptionalAmount &Amt, unsigned k,
@ -1220,10 +1220,15 @@ SourceRange CheckPrintfHandler::getFormatStringRange() {
return OrigFormatExpr->getSourceRange();
}
SourceRange CheckPrintfHandler::
CharSourceRange CheckPrintfHandler::
getFormatSpecifierRange(const char *startSpecifier, unsigned specifierLen) {
return SourceRange(getLocationOfByte(startSpecifier),
getLocationOfByte(startSpecifier+specifierLen-1));
SourceLocation Start = getLocationOfByte(startSpecifier);
SourceLocation End = getLocationOfByte(startSpecifier + specifierLen - 1);
// Advance the end SourceLocation by one due to half-open ranges.
End = End.getFileLocWithOffset(1);
return CharSourceRange::getCharRange(Start, End);
}
SourceLocation CheckPrintfHandler::getLocationOfByte(const char *x) {
@ -1451,7 +1456,7 @@ CheckPrintfHandler::HandleFormatSpecifier(const analyze_printf::FormatSpecifier
// Check for invalid use of field width
if (!FS.hasValidFieldWidth()) {
HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 1,
HandleInvalidAmount(FS, FS.getFieldWidth(), /* field width */ 0,
startSpecifier, specifierLen);
}
@ -1466,21 +1471,17 @@ CheckPrintfHandler::HandleFormatSpecifier(const analyze_printf::FormatSpecifier
HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen);
if (!FS.hasValidPlusPrefix())
HandleFlag(FS, FS.hasPlusPrefix(), startSpecifier, specifierLen);
// FIXME: the following lines are disabled due to clang assertions on
// highlights containing spaces.
// if (!FS.hasValidSpacePrefix())
// HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen);
if (!FS.hasValidSpacePrefix())
HandleFlag(FS, FS.hasSpacePrefix(), startSpecifier, specifierLen);
if (!FS.hasValidAlternativeForm())
HandleFlag(FS, FS.hasAlternativeForm(), startSpecifier, specifierLen);
if (!FS.hasValidLeftJustified())
HandleFlag(FS, FS.isLeftJustified(), startSpecifier, specifierLen);
// Check that flags are not ignored by another flag
// FIXME: the following lines are disabled due to clang assertions on
// highlights containing spaces.
//if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+'
// HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(),
// startSpecifier, specifierLen);
if (FS.hasSpacePrefix() && FS.hasPlusPrefix()) // ' ' ignored by '+'
HandleIgnoredFlag(FS, FS.hasSpacePrefix(), FS.hasPlusPrefix(),
startSpecifier, specifierLen);
if (FS.hasLeadingZeros() && FS.isLeftJustified()) // '0' ignored by '-'
HandleIgnoredFlag(FS, FS.hasLeadingZeros(), FS.isLeftJustified(),
startSpecifier, specifierLen);

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

@ -1,9 +1,6 @@
// RUN: cp %s %t
// RUN: %clang_cc1 -pedantic -Wall -fixit %t || true
// RUN: %clang_cc1 -fsyntax-only -pedantic -Wall -Werror %t
// XFAIL: *
// FIXME: Some of these tests currently fail due to a bug in the HighlightRange
// function in lib/Frontend/TextDiagnosticPrinter.cpp.
/* This is a test of the various code modification hints that are
provided as part of warning or extension diagnostics. All of the
@ -26,9 +23,10 @@ void test() {
printf("%1d", (long double) 1.23);
// Flag handling
printf("%0+s", (unsigned) 31337); // flags should stay
printf("%0f", "test"); // flag should be removed
printf("%0+s", (unsigned) 31337); // 0 flag should stay
printf("%#p", (void *) 0);
printf("% +f", 1.23); // + flag should stay
printf("%0-f", 1.23); // - flag should stay
// Positional arguments
printf("%1$f:%2$.*3$f:%4$.*3$f\n", 1, 2, 3, 4);

6
clang/test/Sema/format-strings.c
View File

@ -1,7 +1,4 @@
// RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral %s
// XFAIL: *
// FIXME: temporarily marking as expected fail until whitespace highlighting
// is fixed.
#include <stdarg.h>
typedef __typeof(sizeof(int)) size_t;
@ -277,7 +274,8 @@ void bug7377_bad_length_mod_usage() {
// Bad optional amount use
printf("%.2c", 'a'); // expected-warning{{precision used with 'c' conversion specifier, resulting in undefined behavior}}
printf("%1n", (void *) 0); // expected-warning{{precision used with 'n' conversion specifier, resulting in undefined behavior}} expected-warning{{use of '%n' in format string discouraged (potentially insecure)}}
printf("%1n", (void *) 0); // expected-warning{{field width used with 'n' conversion specifier, resulting in undefined behavior}} expected-warning{{use of '%n' in format string discouraged (potentially insecure)}}
printf("%.9n", (void *) 0); // expected-warning{{precision used with 'n' conversion specifier, resulting in undefined behavior}} expected-warning{{use of '%n' in format string discouraged (potentially insecure)}}
// Ignored flags
printf("% +f", 1.23); // expected-warning{{flag ' ' is ignored when flag '+' is present}}