[cfe-commits] r48011 - in /cfe/trunk: Sema/SemaDecl.cpp include/clang/Basic/DiagnosticKinds.def test/Sema/format-attribute.c
Ted Kremenek
kremenek at apple.com
Fri Mar 7 10:43:49 PST 2008
Author: kremenek
Date: Fri Mar 7 12:43:49 2008
New Revision: 48011
URL: http://llvm.org/viewvc/llvm-project?rev=48011&view=rev
Log:
Patch by Nuno Lopes:
Added more comments for code processing attribute "format".
Added more checks for corner cases, test cases, and warnings.
Added:
cfe/trunk/test/Sema/format-attribute.c
Modified:
cfe/trunk/Sema/SemaDecl.cpp
cfe/trunk/include/clang/Basic/DiagnosticKinds.def
Modified: cfe/trunk/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/Sema/SemaDecl.cpp?rev=48011&r1=48010&r2=48011&view=diff
==============================================================================
--- cfe/trunk/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/Sema/SemaDecl.cpp Fri Mar 7 12:43:49 2008
@@ -2084,6 +2084,8 @@
d->addAttr(new NoThrowAttr());
}
+/// Handle __attribute__((format(type,idx,firstarg))) attributes
+/// based on http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
void Sema::HandleFormatAttribute(Decl *d, AttributeList *rawAttr) {
if (!rawAttr->getParameterName()) {
@@ -2105,9 +2107,16 @@
return;
}
+ const FunctionTypeProto *proto =
+ dyn_cast<FunctionTypeProto>(Fn->getType()->getAsFunctionType());
+ if (!proto)
+ return;
+
// FIXME: in C++ the implicit 'this' function parameter also counts.
+ // this is needed in order to be compatible with GCC
// the index must start in 1 and the limit is numargs+1
- unsigned NumArgs = Fn->getNumParams()+1; // +1 for ...
+ unsigned NumArgs = Fn->getNumParams();
+ unsigned FirstIdx = 1;
const char *Format = rawAttr->getParameterName()->getName();
unsigned FormatLen = rawAttr->getParameterName()->getLength();
@@ -2128,35 +2137,60 @@
return;
}
+ // checks for the 2nd argument
Expr *IdxExpr = static_cast<Expr *>(rawAttr->getArg(0));
- llvm::APSInt Idx(32);
+ llvm::APSInt Idx(Context.getTypeSize(IdxExpr->getType()));
if (!IdxExpr->isIntegerConstantExpr(Idx, Context)) {
Diag(rawAttr->getLoc(), diag::err_attribute_argument_n_not_int,
"format", std::string("2"), IdxExpr->getSourceRange());
return;
}
- if (Idx.getZExtValue() < 1 || Idx.getZExtValue() > NumArgs) {
+ if (Idx.getZExtValue() < FirstIdx || Idx.getZExtValue() > NumArgs) {
Diag(rawAttr->getLoc(), diag::err_attribute_argument_out_of_bounds,
"format", std::string("2"), IdxExpr->getSourceRange());
return;
}
+ // make sure the format string is really a string
+ QualType Ty = proto->getArgType(Idx.getZExtValue()-1);
+ if (!Ty->isPointerType() ||
+ !Ty->getAsPointerType()->getPointeeType()->isCharType()) {
+ Diag(rawAttr->getLoc(), diag::err_format_attribute_not_string,
+ IdxExpr->getSourceRange());
+ return;
+ }
+
+
+ // check the 3rd argument
Expr *FirstArgExpr = static_cast<Expr *>(rawAttr->getArg(1));
- llvm::APSInt FirstArg(32);
+ llvm::APSInt FirstArg(Context.getTypeSize(FirstArgExpr->getType()));
if (!FirstArgExpr->isIntegerConstantExpr(FirstArg, Context)) {
Diag(rawAttr->getLoc(), diag::err_attribute_argument_n_not_int,
"format", std::string("3"), FirstArgExpr->getSourceRange());
return;
}
+ // check if the function is variadic if the 3rd argument non-zero
+ if (FirstArg != 0) {
+ if (proto->isVariadic()) {
+ ++NumArgs; // +1 for ...
+ } else {
+ Diag(d->getLocation(), diag::err_format_attribute_requires_variadic);
+ return;
+ }
+ }
+
+ // strftime requires FirstArg to be 0 because it doesn't read from any variable
+ // the input is just the current time + the format string
if (FormatLen == 8 && !memcmp(Format, "strftime", 8)) {
- if (FirstArg.getZExtValue() != 0) {
+ if (FirstArg != 0) {
Diag(rawAttr->getLoc(), diag::err_format_strftime_third_parameter,
FirstArgExpr->getSourceRange());
return;
}
- } else if (FirstArg.getZExtValue() > NumArgs) {
+ // if 0 it disables parameter checking (to use with e.g. va_list)
+ } else if (FirstArg != 0 && FirstArg != NumArgs) {
Diag(rawAttr->getLoc(), diag::err_attribute_argument_out_of_bounds,
"format", std::string("3"), FirstArgExpr->getSourceRange());
return;
Modified: cfe/trunk/include/clang/Basic/DiagnosticKinds.def
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticKinds.def?rev=48011&r1=48010&r2=48011&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticKinds.def (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticKinds.def Fri Mar 7 12:43:49 2008
@@ -562,6 +562,10 @@
"'%0' attribute parameter %1 is out of bounds")
DIAG(err_format_strftime_third_parameter, ERROR,
"strftime format attribute requires 3rd parameter to be 0")
+DIAG(err_format_attribute_requires_variadic, ERROR,
+ "format attribute requires variadic function")
+DIAG(err_format_attribute_not_string, ERROR,
+ "format argument not a string type")
DIAG(err_attribute_invalid_size, ERROR,
"vector size not an integral multiple of component size")
DIAG(err_attribute_zero_size, ERROR,
Added: cfe/trunk/test/Sema/format-attribute.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/format-attribute.c?rev=48011&view=auto
==============================================================================
--- cfe/trunk/test/Sema/format-attribute.c (added)
+++ cfe/trunk/test/Sema/format-attribute.c Fri Mar 7 12:43:49 2008
@@ -0,0 +1,16 @@
+//RUN: clang -fsyntax-only -verify %s
+
+#include <stdarg.h>
+
+void a(const char *a, ...) __attribute__((format(printf, 1,2))); // no-error
+void b(const char *a, ...) __attribute__((format(printf, 1,1))); // expected-error {{'format' attribute parameter 3 is out of bounds}}
+void c(const char *a, ...) __attribute__((format(printf, 0,2))); // expected-error {{'format' attribute parameter 2 is out of bounds}}
+void d(const char *a, int c) __attribute__((format(printf, 1,2))); // expected-error {{format attribute requires variadic function}}
+void e(char *str, int c, ...) __attribute__((format(printf, 2,3))); // expected-error {{format argument not a string type}}
+
+typedef const char* xpto;
+void f(xpto c, va_list list) __attribute__((format(printf, 1, 0))); // no-error
+void g(xpto c) __attribute__((format(printf, 1, 0))); // no-error
+
+void y(char *str) __attribute__((format(strftime, 1,0))); // no-error
+void z(char *str, int c, ...) __attribute__((format(strftime, 1,2))); // expected-error {{strftime format attribute requires 3rd parameter to be 0}}
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