[cfe-commits] r126290 - in /cfe/trunk: include/clang/Basic/PartialDiagnostic.h include/clang/Sema/ScopeInfo.h lib/Sema/AnalysisBasedWarnings.cpp lib/Sema/Sema.cpp lib/Sema/SemaExpr.cpp lib/Sema/SemaStmt.cpp test/Sema/i-c-e.c test/SemaCXX/array-bounds.cpp
Ted Kremenek
kremenek at apple.com
Tue Feb 22 17:52:04 PST 2011
Author: kremenek
Date: Tue Feb 22 19:52:04 2011
New Revision: 126290
URL: http://llvm.org/viewvc/llvm-project?rev=126290&view=rev
Log:
Enhance Sema::DiagRuntimeBehavior() to delay some diagnostics to see if the related code is reachable. This suppresses some
diagnostics that occur in unreachable code (e.g., -Warray-bound).
We only pay the cost of doing the reachability analysis when we issue one of these diagnostics.
Modified:
cfe/trunk/include/clang/Basic/PartialDiagnostic.h
cfe/trunk/include/clang/Sema/ScopeInfo.h
cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp
cfe/trunk/lib/Sema/Sema.cpp
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/lib/Sema/SemaStmt.cpp
cfe/trunk/test/Sema/i-c-e.c
cfe/trunk/test/SemaCXX/array-bounds.cpp
Modified: cfe/trunk/include/clang/Basic/PartialDiagnostic.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/PartialDiagnostic.h?rev=126290&r1=126289&r2=126290&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/PartialDiagnostic.h (original)
+++ cfe/trunk/include/clang/Basic/PartialDiagnostic.h Tue Feb 22 19:52:04 2011
@@ -75,7 +75,7 @@
/// \brief An allocator for Storage objects, which uses a small cache to
/// objects, used to reduce malloc()/free() traffic for partial diagnostics.
class StorageAllocator {
- static const unsigned NumCached = 4;
+ static const unsigned NumCached = 16;
Storage Cached[NumCached];
Storage *FreeList[NumCached];
unsigned NumFreeListEntries;
Modified: cfe/trunk/include/clang/Sema/ScopeInfo.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/ScopeInfo.h?rev=126290&r1=126289&r2=126290&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/ScopeInfo.h (original)
+++ cfe/trunk/include/clang/Sema/ScopeInfo.h Tue Feb 22 19:52:04 2011
@@ -15,6 +15,7 @@
#define LLVM_CLANG_SEMA_SCOPE_INFO_H
#include "clang/AST/Type.h"
+#include "clang/Basic/PartialDiagnostic.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/SetVector.h"
@@ -30,6 +31,17 @@
namespace sema {
+class PossiblyUnreachableDiag {
+public:
+ PartialDiagnostic PD;
+ SourceLocation Loc;
+ const Stmt *stmt;
+
+ PossiblyUnreachableDiag(const PartialDiagnostic &PD, SourceLocation Loc,
+ const Stmt *stmt)
+ : PD(PD), Loc(Loc), stmt(stmt) {}
+};
+
/// \brief Retains information about a function, method, or block that is
/// currently being parsed.
class FunctionScopeInfo {
@@ -60,6 +72,11 @@
/// block, if there is any chance of applying the named return value
/// optimization.
llvm::SmallVector<ReturnStmt*, 4> Returns;
+
+ /// \brief A list of PartialDiagnostics created but delayed within the
+ /// current function scope. These diagnostics are vetted for reachability
+ /// prior to being emitted.
+ llvm::SmallVector<PossiblyUnreachableDiag, 4> PossiblyUnreachableDiags;
void setHasBranchIntoScope() {
HasBranchIntoScope = true;
Modified: cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp?rev=126290&r1=126289&r2=126290&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp (original)
+++ cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp Tue Feb 22 19:52:04 2011
@@ -15,6 +15,7 @@
#include "clang/Sema/AnalysisBasedWarnings.h"
#include "clang/Sema/SemaInternal.h"
+#include "clang/Sema/ScopeInfo.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/AST/DeclObjC.h"
@@ -26,6 +27,8 @@
#include "clang/Analysis/AnalysisContext.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/Analyses/ReachableCode.h"
+#include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
+#include "clang/Analysis/CFGStmtMap.h"
#include "clang/Analysis/Analyses/UninitializedValuesV2.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/Support/Casting.h"
@@ -478,6 +481,16 @@
Diagnostic::Ignored);
}
+static void flushDiagnostics(Sema &S, sema::FunctionScopeInfo *fscope) {
+ for (llvm::SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator
+ i = fscope->PossiblyUnreachableDiags.begin(),
+ e = fscope->PossiblyUnreachableDiags.end();
+ i != e; ++i) {
+ const sema::PossiblyUnreachableDiag &D = *i;
+ S.Diag(D.Loc, D.PD);
+ }
+}
+
void clang::sema::
AnalysisBasedWarnings::IssueWarnings(sema::AnalysisBasedWarnings::Policy P,
sema::FunctionScopeInfo *fscope,
@@ -491,9 +504,6 @@
// time.
Diagnostic &Diags = S.getDiagnostics();
- if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred())
- return;
-
// Do not do any analysis for declarations in system headers if we are
// going to just ignore them.
if (Diags.getSuppressSystemWarnings() &&
@@ -504,6 +514,12 @@
if (cast<DeclContext>(D)->isDependentContext())
return;
+ if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred()) {
+ // Flush out any possibly unreachable diagnostics.
+ flushDiagnostics(S, fscope);
+ return;
+ }
+
const Stmt *Body = D->getBody();
assert(Body);
@@ -512,6 +528,34 @@
AnalysisContext AC(D, 0, /*useUnoptimizedCFG=*/false, /*addehedges=*/false,
/*addImplicitDtors=*/true, /*addInitializers=*/true);
+ // Emit delayed diagnostics.
+ if (!fscope->PossiblyUnreachableDiags.empty()) {
+ bool analyzed = false;
+ if (CFGReachabilityAnalysis *cra = AC.getCFGReachablityAnalysis())
+ if (CFGStmtMap *csm = AC.getCFGStmtMap()) {
+ analyzed = true;
+ for (llvm::SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator
+ i = fscope->PossiblyUnreachableDiags.begin(),
+ e = fscope->PossiblyUnreachableDiags.end();
+ i != e; ++i) {
+ const sema::PossiblyUnreachableDiag &D = *i;
+ if (const CFGBlock *blk = csm->getBlock(D.stmt)) {
+ // Can this block be reached from the entrance?
+ if (cra->isReachable(&AC.getCFG()->getEntry(), blk))
+ S.Diag(D.Loc, D.PD);
+ }
+ else {
+ // Emit the warning anyway if we cannot map to a basic block.
+ S.Diag(D.Loc, D.PD);
+ }
+ }
+ }
+
+ if (!analyzed)
+ flushDiagnostics(S, fscope);
+ }
+
+
// Warning: check missing 'return'
if (P.enableCheckFallThrough) {
const CheckFallThroughDiagnostics &CD =
Modified: cfe/trunk/lib/Sema/Sema.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.cpp?rev=126290&r1=126289&r2=126290&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/Sema.cpp (original)
+++ cfe/trunk/lib/Sema/Sema.cpp Tue Feb 22 19:52:04 2011
@@ -48,6 +48,7 @@
SwitchStack.clear();
Returns.clear();
ErrorTrap.reset();
+ PossiblyUnreachableDiags.clear();
}
BlockScopeInfo::~BlockScopeInfo() { }
@@ -639,9 +640,19 @@
// Issue any analysis-based warnings.
if (WP && D)
AnalysisWarnings.IssueWarnings(*WP, Scope, D, blkExpr);
+ else {
+ for (llvm::SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator
+ i = Scope->PossiblyUnreachableDiags.begin(),
+ e = Scope->PossiblyUnreachableDiags.end();
+ i != e; ++i) {
+ const sema::PossiblyUnreachableDiag &D = *i;
+ Diag(D.Loc, D.PD);
+ }
+ }
- if (FunctionScopes.back() != Scope)
+ if (FunctionScopes.back() != Scope) {
delete Scope;
+ }
}
/// \brief Determine whether any errors occurred within this function/method/
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=126290&r1=126289&r2=126290&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Tue Feb 22 19:52:04 2011
@@ -387,13 +387,13 @@
return false;
if (Expr->getType()->isObjCObjectType() &&
- DiagRuntimeBehavior(Expr->getLocStart(), Expr,
+ DiagRuntimeBehavior(Expr->getLocStart(), 0,
PDiag(diag::err_cannot_pass_objc_interface_to_vararg)
<< Expr->getType() << CT))
return true;
if (!Expr->getType()->isPODType() &&
- DiagRuntimeBehavior(Expr->getLocStart(), Expr,
+ DiagRuntimeBehavior(Expr->getLocStart(), 0,
PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg)
<< Expr->getType() << CT))
return true;
@@ -6721,7 +6721,7 @@
if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) {
if (DRL->getDecl() == DRR->getDecl() &&
!IsWithinTemplateSpecialization(DRL->getDecl())) {
- DiagRuntimeBehavior(Loc, lex, PDiag(diag::warn_comparison_always)
+ DiagRuntimeBehavior(Loc, 0, PDiag(diag::warn_comparison_always)
<< 0 // self-
<< (Opc == BO_EQ
|| Opc == BO_LE
@@ -6743,7 +6743,7 @@
always_evals_to = 2; // e.g. array1 <= array2
break;
}
- DiagRuntimeBehavior(Loc, lex, PDiag(diag::warn_comparison_always)
+ DiagRuntimeBehavior(Loc, 0, PDiag(diag::warn_comparison_always)
<< 1 // array
<< always_evals_to);
}
@@ -6784,7 +6784,7 @@
default: assert(false && "Invalid comparison operator");
}
- DiagRuntimeBehavior(Loc, literalString,
+ DiagRuntimeBehavior(Loc, 0,
PDiag(diag::warn_stringcompare)
<< isa<ObjCEncodeExpr>(literalStringStripped)
<< literalString->getSourceRange());
@@ -7094,7 +7094,7 @@
if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex->IgnoreParens()))
if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex->IgnoreParens()))
if (DRL->getDecl() == DRR->getDecl())
- DiagRuntimeBehavior(Loc, rex,
+ DiagRuntimeBehavior(Loc, 0,
PDiag(diag::warn_comparison_always)
<< 0 // self-
<< 2 // "a constant"
@@ -7355,9 +7355,11 @@
UO->getSubExpr()->IgnoreParenCasts()->
isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) &&
!UO->getType().isVolatileQualified()) {
- Diag(UO->getOperatorLoc(), diag::warn_indirection_through_null)
- << UO->getSubExpr()->getSourceRange();
- Diag(UO->getOperatorLoc(), diag::note_indirection_through_null);
+ DiagRuntimeBehavior(UO->getOperatorLoc(), UO,
+ PDiag(diag::warn_indirection_through_null)
+ << UO->getSubExpr()->getSourceRange());
+ DiagRuntimeBehavior(UO->getOperatorLoc(), UO,
+ PDiag(diag::note_indirection_through_null));
}
// Check for trivial buffer overflows.
@@ -9475,7 +9477,13 @@
case PotentiallyEvaluated:
case PotentiallyEvaluatedIfUsed:
- Diag(Loc, PD);
+ if (stmt && getCurFunctionOrMethodDecl()) {
+ FunctionScopes.back()->PossiblyUnreachableDiags.
+ push_back(sema::PossiblyUnreachableDiag(PD, Loc, stmt));
+ }
+ else
+ Diag(Loc, PD);
+
return true;
case PotentiallyPotentiallyEvaluated:
Modified: cfe/trunk/lib/Sema/SemaStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmt.cpp?rev=126290&r1=126289&r2=126290&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaStmt.cpp (original)
+++ cfe/trunk/lib/Sema/SemaStmt.cpp Tue Feb 22 19:52:04 2011
@@ -146,7 +146,7 @@
}
}
- DiagRuntimeBehavior(Loc, S, PDiag(DiagID) << R1 << R2);
+ DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2);
}
StmtResult
Modified: cfe/trunk/test/Sema/i-c-e.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/i-c-e.c?rev=126290&r1=126289&r2=126290&view=diff
==============================================================================
--- cfe/trunk/test/Sema/i-c-e.c (original)
+++ cfe/trunk/test/Sema/i-c-e.c Tue Feb 22 19:52:04 2011
@@ -60,7 +60,9 @@
// Pointer + __builtin_constant_p
char pbcp[__builtin_constant_p(4) ? (intptr_t)&expr : 0]; // expected-error {{variable length array declaration not allowed at file scope}}
-int illegaldiv1[1 || 1/0]; // expected-warning {{division by zero is undefined}}
+int illegaldiv1a[1 || 1/0]; // expected-warning {{division by zero is undefined}}
+int illegaldiv1b[1 && 1/0]; // expected-warning {{division by zero is undefined}} expected-error{{variable length array declaration not allowed at file scope}}
+
int illegaldiv2[1/0]; // expected-error {{variable length array declaration not allowed at file scope}} \
// expected-warning {{division by zero is undefined}}
int illegaldiv3[INT_MIN / -1]; // expected-error {{variable length array declaration not allowed at file scope}}
Modified: cfe/trunk/test/SemaCXX/array-bounds.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/array-bounds.cpp?rev=126290&r1=126289&r2=126290&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/array-bounds.cpp (original)
+++ cfe/trunk/test/SemaCXX/array-bounds.cpp Tue Feb 22 19:52:04 2011
@@ -63,11 +63,11 @@
}
template <int I> struct S {
- char arr[I]; // expected-note 3 {{declared here}}
+ char arr[I]; // expected-note 2 {{declared here}}
};
template <int I> void f() {
S<3> s;
- s.arr[4] = 0; // expected-warning 2 {{array index of '4' indexes past the end of an array (that contains 3 elements)}}
+ s.arr[4] = 0; // expected-warning {{array index of '4' indexes past the end of an array (that contains 3 elements)}}
s.arr[I] = 0; // expected-warning {{array index of '5' indexes past the end of an array (that contains 3 elements)}}
}
@@ -79,9 +79,8 @@
#define ARR_IN_MACRO(flag, arr, idx) flag ? arr[idx] : 1
int test_no_warn_macro_unreachable() {
- int arr[SIZE]; // expected-note 2 {{array 'arr' declared here}}
- // FIXME: We don't want to warn for the first case.
- return ARR_IN_MACRO(0, arr, SIZE) + // expected-warning{{array index of '10' indexes past the end of an array (that contains 10 elements)}}
+ int arr[SIZE]; // expected-note {{array 'arr' declared here}}
+ return ARR_IN_MACRO(0, arr, SIZE) + // no-warning
ARR_IN_MACRO(1, arr, SIZE); // expected-warning{{array index of '10' indexes past the end of an array (that contains 10 elements)}}
}
@@ -91,3 +90,15 @@
return array[(unsigned long long) 100]; // expected-warning {{array index of '100' indexes past the end of an array (that contains 100 elements)}}
}
+template <bool extendArray>
+void myFunc() {
+ int arr[3 + (extendArray ? 1 : 0)];
+
+ if (extendArray)
+ arr[3] = 42;
+}
+
+void f() {
+ myFunc<false>();
+}
+
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