PTAL
Hi rsmith,
http://llvm-reviews.chandlerc.com/D380
CHANGE SINCE LAST DIFF
http://llvm-reviews.chandlerc.com/D380?vs=919&id=1101#toc
Files:
lib/Sema/SemaStmt.cpp
test/Sema/unused-expr.c
Index: lib/Sema/SemaStmt.cpp
===================================================================
--- lib/Sema/SemaStmt.cpp
+++ lib/Sema/SemaStmt.cpp
@@ -158,9 +158,14 @@
if (!E)
return;
SourceLocation ExprLoc = E->IgnoreParens()->getExprLoc();
- if (SourceMgr.isInSystemMacro(ExprLoc) ||
- SourceMgr.isMacroBodyExpansion(ExprLoc))
- return;
+ // In most cases, we don't want to warn if the expression is written in a
+ // macro body, or if the macro comes from a system header. If the offending
+ // expression is a call to a function with the warn_unused_result attribute,
+ // we warn no matter the location. Because of the order in which the various
+ // checks need to happen, we factor out the macro-related test here.
+ bool ShouldSuppress =
+ SourceMgr.isMacroBodyExpansion(ExprLoc) ||
+ SourceMgr.isInSystemMacro(ExprLoc);
const Expr *WarnExpr;
SourceLocation Loc;
@@ -193,12 +198,16 @@
return;
// If the callee has attribute pure, const, or warn_unused_result, warn
with
- // a more specific message to make it clear what is happening.
+ // a more specific message to make it clear what is happening. If the call
+ // is written in a macro body, only warn if it has the warn_unused_result
+ // attribute.
if (const Decl *FD = CE->getCalleeDecl()) {
if (FD->getAttr<WarnUnusedResultAttr>()) {
Diag(Loc, diag::warn_unused_result) << R1 << R2;
return;
}
+ if (ShouldSuppress)
+ return;
if (FD->getAttr<PureAttr>()) {
Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure";
return;
@@ -208,7 +217,10 @@
return;
}
}
- } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
+ } else if (ShouldSuppress)
+ return;
+
+ if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) {
Diag(Loc, diag::err_arc_unused_init_message) << R1;
return;
Index: test/Sema/unused-expr.c
===================================================================
--- test/Sema/unused-expr.c
+++ test/Sema/unused-expr.c
@@ -132,6 +132,8 @@
#define M3(a) (t3(a), fn2())
#define M4(a, b) (foo((a), (b)) ? 0 : t3(a), 1)
#define M5(a, b) (foo((a), (b)), 1)
+#define M6() fn1()
+#define M7() fn2()
void t11(int i, int j) {
M1(i, j); // no warning
NOP((long)foo(i, j)); // expected-warning {{expression result unused}}
@@ -143,10 +145,14 @@
NOP((foo(i, j) ? 0 : t3(i), 1)); // expected-warning {{expression result
unused}}
M5(i, j); // no warning
NOP((foo(i, j), 1)); // expected-warning {{expression result unused}}
+ M6(); // expected-warning {{ignoring return value}}
+ M7(); // no warning
}
#undef NOP
#undef M1
#undef M2
#undef M3
#undef M4
#undef M5
+#undef M6
+#undef M7
Index: lib/Sema/SemaStmt.cpp
===================================================================
--- lib/Sema/SemaStmt.cpp
+++ lib/Sema/SemaStmt.cpp
@@ -158,9 +158,14 @@
if (!E)
return;
SourceLocation ExprLoc = E->IgnoreParens()->getExprLoc();
- if (SourceMgr.isInSystemMacro(ExprLoc) ||
- SourceMgr.isMacroBodyExpansion(ExprLoc))
- return;
+ // In most cases, we don't want to warn if the expression is written in a
+ // macro body, or if the macro comes from a system header. If the offending
+ // expression is a call to a function with the warn_unused_result attribute,
+ // we warn no matter the location. Because of the order in which the various
+ // checks need to happen, we factor out the macro-related test here.
+ bool ShouldSuppress =
+ SourceMgr.isMacroBodyExpansion(ExprLoc) ||
+ SourceMgr.isInSystemMacro(ExprLoc);
const Expr *WarnExpr;
SourceLocation Loc;
@@ -193,12 +198,16 @@
return;
// If the callee has attribute pure, const, or warn_unused_result, warn with
- // a more specific message to make it clear what is happening.
+ // a more specific message to make it clear what is happening. If the call
+ // is written in a macro body, only warn if it has the warn_unused_result
+ // attribute.
if (const Decl *FD = CE->getCalleeDecl()) {
if (FD->getAttr<WarnUnusedResultAttr>()) {
Diag(Loc, diag::warn_unused_result) << R1 << R2;
return;
}
+ if (ShouldSuppress)
+ return;
if (FD->getAttr<PureAttr>()) {
Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure";
return;
@@ -208,7 +217,10 @@
return;
}
}
- } else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
+ } else if (ShouldSuppress)
+ return;
+
+ if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) {
Diag(Loc, diag::err_arc_unused_init_message) << R1;
return;
Index: test/Sema/unused-expr.c
===================================================================
--- test/Sema/unused-expr.c
+++ test/Sema/unused-expr.c
@@ -132,6 +132,8 @@
#define M3(a) (t3(a), fn2())
#define M4(a, b) (foo((a), (b)) ? 0 : t3(a), 1)
#define M5(a, b) (foo((a), (b)), 1)
+#define M6() fn1()
+#define M7() fn2()
void t11(int i, int j) {
M1(i, j); // no warning
NOP((long)foo(i, j)); // expected-warning {{expression result unused}}
@@ -143,10 +145,14 @@
NOP((foo(i, j) ? 0 : t3(i), 1)); // expected-warning {{expression result unused}}
M5(i, j); // no warning
NOP((foo(i, j), 1)); // expected-warning {{expression result unused}}
+ M6(); // expected-warning {{ignoring return value}}
+ M7(); // no warning
}
#undef NOP
#undef M1
#undef M2
#undef M3
#undef M4
#undef M5
+#undef M6
+#undef M7
_______________________________________________
cfe-commits mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
