This revision was automatically updated to reflect the committed changes.
Closed by commit rL344864: [AST, analyzer] Transform rvalue cast outputs to
lvalues (fheinous-gnu… (authored by a.sidorin, committed by ).
Herald added subscribers: llvm-commits, dkrupp, donat.nagy.
Changed prior to commit:
https://reviews.llvm.org/D45416?vs=144998&id=170322#toc
Repository:
rL LLVM
https://reviews.llvm.org/D45416
Files:
cfe/trunk/lib/Sema/SemaStmtAsm.cpp
cfe/trunk/test/Analysis/asm.cpp
cfe/trunk/test/Analysis/cfg.cpp
Index: cfe/trunk/test/Analysis/cfg.cpp
===================================================================
--- cfe/trunk/test/Analysis/cfg.cpp
+++ cfe/trunk/test/Analysis/cfg.cpp
@@ -1,6 +1,6 @@
-// RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++11 -analyzer-config cfg-rich-constructors=false %s > %t 2>&1
+// RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -fheinous-gnu-extensions -std=c++11 -analyzer-config cfg-rich-constructors=false %s > %t 2>&1
// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,WARNINGS %s
-// RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -std=c++11 -analyzer-config cfg-rich-constructors=true %s > %t 2>&1
+// RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG -triple x86_64-apple-darwin12 -fheinous-gnu-extensions -std=c++11 -analyzer-config cfg-rich-constructors=true %s > %t 2>&1
// RUN: FileCheck --input-file=%t -check-prefixes=CHECK,ANALYZER %s
// This file tests how we construct two different flavors of the Clang CFG -
@@ -84,6 +84,24 @@
static_assert(1, "abc");
}
+
+// CHECK-LABEL: void checkGCCAsmRValueOutput()
+// CHECK: [B2 (ENTRY)]
+// CHECK-NEXT: Succs (1): B1
+// CHECK: [B1]
+// CHECK-NEXT: 1: int arg
+// CHECK-NEXT: 2: arg
+// CHECK-NEXT: 3: (int)[B1.2] (CStyleCastExpr, NoOp, int)
+// CHECK-NEXT: 4: asm ("" : "=r" ([B1.3]));
+// CHECK-NEXT: 5: arg
+// CHECK-NEXT: 6: asm ("" : "=r" ([B1.5]));
+void checkGCCAsmRValueOutput() {
+ int arg;
+ __asm__("" : "=r"((int)arg)); // rvalue output operand
+ __asm__("" : "=r"(arg)); // lvalue output operand
+}
+
+
// CHECK-LABEL: void F(EmptyE e)
// CHECK: ENTRY
// CHECK-NEXT: Succs (1): B1
Index: cfe/trunk/test/Analysis/asm.cpp
===================================================================
--- cfe/trunk/test/Analysis/asm.cpp
+++ cfe/trunk/test/Analysis/asm.cpp
@@ -0,0 +1,12 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker debug.ExprInspection -fheinous-gnu-extensions -w %s -verify
+
+int clang_analyzer_eval(int);
+
+int global;
+void testRValueOutput() {
+ int &ref = global;
+ ref = 1;
+ __asm__("" : "=r"(((int)(global)))); // don't crash on rvalue output operand
+ clang_analyzer_eval(global == 1); // expected-warning{{UNKNOWN}}
+ clang_analyzer_eval(ref == 1); // expected-warning{{UNKNOWN}}
+}
Index: cfe/trunk/lib/Sema/SemaStmtAsm.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaStmtAsm.cpp
+++ cfe/trunk/lib/Sema/SemaStmtAsm.cpp
@@ -27,14 +27,66 @@
using namespace clang;
using namespace sema;
+/// Remove the upper-level LValueToRValue cast from an expression.
+static void removeLValueToRValueCast(Expr *E) {
+ Expr *Parent = E;
+ Expr *ExprUnderCast = nullptr;
+ SmallVector<Expr *, 8> ParentsToUpdate;
+
+ while (true) {
+ ParentsToUpdate.push_back(Parent);
+ if (auto *ParenE = dyn_cast<ParenExpr>(Parent)) {
+ Parent = ParenE->getSubExpr();
+ continue;
+ }
+
+ Expr *Child = nullptr;
+ CastExpr *ParentCast = dyn_cast<CastExpr>(Parent);
+ if (ParentCast)
+ Child = ParentCast->getSubExpr();
+ else
+ return;
+
+ if (auto *CastE = dyn_cast<CastExpr>(Child))
+ if (CastE->getCastKind() == CK_LValueToRValue) {
+ ExprUnderCast = CastE->getSubExpr();
+ // LValueToRValue cast inside GCCAsmStmt requires an explicit cast.
+ ParentCast->setSubExpr(ExprUnderCast);
+ break;
+ }
+ Parent = Child;
+ }
+
+ // Update parent expressions to have same ValueType as the underlying.
+ assert(ExprUnderCast &&
+ "Should be reachable only if LValueToRValue cast was found!");
+ auto ValueKind = ExprUnderCast->getValueKind();
+ for (Expr *E : ParentsToUpdate)
+ E->setValueKind(ValueKind);
+}
+
+/// Emit a warning about usage of "noop"-like casts for lvalues (GNU extension)
+/// and fix the argument with removing LValueToRValue cast from the expression.
+static void emitAndFixInvalidAsmCastLValue(const Expr *LVal, Expr *BadArgument,
+ Sema &S) {
+ if (!S.getLangOpts().HeinousExtensions) {
+ S.Diag(LVal->getBeginLoc(), diag::err_invalid_asm_cast_lvalue)
+ << BadArgument->getSourceRange();
+ } else {
+ S.Diag(LVal->getBeginLoc(), diag::warn_invalid_asm_cast_lvalue)
+ << BadArgument->getSourceRange();
+ }
+ removeLValueToRValueCast(BadArgument);
+}
+
/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently
/// ignore "noop" casts in places where an lvalue is required by an inline asm.
/// We emulate this behavior when -fheinous-gnu-extensions is specified, but
/// provide a strong guidance to not use it.
///
/// This method checks to see if the argument is an acceptable l-value and
/// returns false if it is a case we can handle.
-static bool CheckAsmLValue(const Expr *E, Sema &S) {
+static bool CheckAsmLValue(Expr *E, Sema &S) {
// Type dependent expressions will be checked during instantiation.
if (E->isTypeDependent())
return false;
@@ -46,12 +98,7 @@
// are supposed to allow.
const Expr *E2 = E->IgnoreParenNoopCasts(S.Context);
if (E != E2 && E2->isLValue()) {
- if (!S.getLangOpts().HeinousExtensions)
- S.Diag(E2->getBeginLoc(), diag::err_invalid_asm_cast_lvalue)
- << E->getSourceRange();
- else
- S.Diag(E2->getBeginLoc(), diag::warn_invalid_asm_cast_lvalue)
- << E->getSourceRange();
+ emitAndFixInvalidAsmCastLValue(E2, E, S);
// Accept, even if we emitted an error diagnostic.
return false;
}
@@ -264,13 +311,7 @@
break;
case Expr::MLV_LValueCast: {
const Expr *LVal = OutputExpr->IgnoreParenNoopCasts(Context);
- if (!getLangOpts().HeinousExtensions) {
- Diag(LVal->getBeginLoc(), diag::err_invalid_asm_cast_lvalue)
- << OutputExpr->getSourceRange();
- } else {
- Diag(LVal->getBeginLoc(), diag::warn_invalid_asm_cast_lvalue)
- << OutputExpr->getSourceRange();
- }
+ emitAndFixInvalidAsmCastLValue(LVal, OutputExpr, *this);
// Accept, even if we emitted an error diagnostic.
break;
}
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