r337148 - [Sema] Add fixit for unused lambda captures
Alexander Shaposhnikov via cfe-commits
cfe-commits at lists.llvm.org
Mon Jul 16 00:23:47 PDT 2018
Author: alexshap
Date: Mon Jul 16 00:23:47 2018
New Revision: 337148
URL: http://llvm.org/viewvc/llvm-project?rev=337148&view=rev
Log:
[Sema] Add fixit for unused lambda captures
This diff adds a fixit to suggest removing unused lambda captures
in the appropriate diagnostic.
Patch by Andrew Comminos!
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D48845
Added:
cfe/trunk/test/FixIt/fixit-unused-lambda-capture.cpp
Modified:
cfe/trunk/include/clang/Sema/DeclSpec.h
cfe/trunk/include/clang/Sema/ScopeInfo.h
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Parse/ParseExprCXX.cpp
cfe/trunk/lib/Sema/SemaLambda.cpp
Modified: cfe/trunk/include/clang/Sema/DeclSpec.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/DeclSpec.h?rev=337148&r1=337147&r2=337148&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/DeclSpec.h (original)
+++ cfe/trunk/include/clang/Sema/DeclSpec.h Mon Jul 16 00:23:47 2018
@@ -2540,12 +2540,16 @@ struct LambdaIntroducer {
LambdaCaptureInitKind InitKind;
ExprResult Init;
ParsedType InitCaptureType;
+ SourceRange ExplicitRange;
+
LambdaCapture(LambdaCaptureKind Kind, SourceLocation Loc,
IdentifierInfo *Id, SourceLocation EllipsisLoc,
LambdaCaptureInitKind InitKind, ExprResult Init,
- ParsedType InitCaptureType)
+ ParsedType InitCaptureType,
+ SourceRange ExplicitRange)
: Kind(Kind), Loc(Loc), Id(Id), EllipsisLoc(EllipsisLoc),
- InitKind(InitKind), Init(Init), InitCaptureType(InitCaptureType) {}
+ InitKind(InitKind), Init(Init), InitCaptureType(InitCaptureType),
+ ExplicitRange(ExplicitRange) {}
};
SourceRange Range;
@@ -2563,9 +2567,10 @@ struct LambdaIntroducer {
SourceLocation EllipsisLoc,
LambdaCaptureInitKind InitKind,
ExprResult Init,
- ParsedType InitCaptureType) {
+ ParsedType InitCaptureType,
+ SourceRange ExplicitRange) {
Captures.push_back(LambdaCapture(Kind, Loc, Id, EllipsisLoc, InitKind, Init,
- InitCaptureType));
+ InitCaptureType, ExplicitRange));
}
};
Modified: cfe/trunk/include/clang/Sema/ScopeInfo.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/ScopeInfo.h?rev=337148&r1=337147&r2=337148&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/ScopeInfo.h (original)
+++ cfe/trunk/include/clang/Sema/ScopeInfo.h Mon Jul 16 00:23:47 2018
@@ -829,6 +829,9 @@ public:
/// if the enclosing full-expression is instantiation dependent).
llvm::SmallSet<Expr *, 8> NonODRUsedCapturingExprs;
+ /// A map of explicit capture indices to their introducer source ranges.
+ llvm::DenseMap<unsigned, SourceRange> ExplicitCaptureRanges;
+
/// Contains all of the variables defined in this lambda that shadow variables
/// that were defined in parent contexts. Used to avoid warnings when the
/// shadowed variables are uncaptured by this lambda.
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=337148&r1=337147&r2=337148&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Mon Jul 16 00:23:47 2018
@@ -5602,8 +5602,10 @@ public:
/// Does copying/destroying the captured variable have side effects?
bool CaptureHasSideEffects(const sema::Capture &From);
- /// Diagnose if an explicit lambda capture is unused.
- void DiagnoseUnusedLambdaCapture(const sema::Capture &From);
+ /// Diagnose if an explicit lambda capture is unused. Returns true if a
+ /// diagnostic is emitted.
+ bool DiagnoseUnusedLambdaCapture(SourceRange CaptureRange,
+ const sema::Capture &From);
/// Complete a lambda-expression having processed and attached the
/// lambda body.
Modified: cfe/trunk/lib/Parse/ParseExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseExprCXX.cpp?rev=337148&r1=337147&r2=337148&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseExprCXX.cpp (original)
+++ cfe/trunk/lib/Parse/ParseExprCXX.cpp Mon Jul 16 00:23:47 2018
@@ -808,6 +808,7 @@ Optional<unsigned> Parser::ParseLambdaIn
IdentifierInfo *Id = nullptr;
SourceLocation EllipsisLoc;
ExprResult Init;
+ SourceLocation LocStart = Tok.getLocation();
if (Tok.is(tok::star)) {
Loc = ConsumeToken();
@@ -981,8 +982,11 @@ Optional<unsigned> Parser::ParseLambdaIn
Loc, Kind == LCK_ByRef, Id, InitKind, InitExpr);
Init = InitExpr;
}
+
+ SourceLocation LocEnd = PrevTokLocation;
+
Intro.addCapture(Kind, Loc, Id, EllipsisLoc, InitKind, Init,
- InitCaptureType);
+ InitCaptureType, SourceRange(LocStart, LocEnd));
}
T.consumeClose();
Modified: cfe/trunk/lib/Sema/SemaLambda.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLambda.cpp?rev=337148&r1=337147&r2=337148&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaLambda.cpp (original)
+++ cfe/trunk/lib/Sema/SemaLambda.cpp Mon Jul 16 00:23:47 2018
@@ -993,6 +993,8 @@ void Sema::ActOnStartOfLambdaDefinition(
CheckCXXThisCapture(C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true,
/*FunctionScopeIndexToStopAtPtr*/ nullptr,
C->Kind == LCK_StarThis);
+ if (!LSI->Captures.empty())
+ LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
continue;
}
@@ -1139,6 +1141,8 @@ void Sema::ActOnStartOfLambdaDefinition(
TryCapture_ExplicitByVal;
tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc);
}
+ if (!LSI->Captures.empty())
+ LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
}
finishLambdaExplicitCaptures(LSI);
@@ -1478,12 +1482,13 @@ bool Sema::CaptureHasSideEffects(const C
return false;
}
-void Sema::DiagnoseUnusedLambdaCapture(const Capture &From) {
+bool Sema::DiagnoseUnusedLambdaCapture(SourceRange CaptureRange,
+ const Capture &From) {
if (CaptureHasSideEffects(From))
- return;
+ return false;
if (From.isVLATypeCapture())
- return;
+ return false;
auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture);
if (From.isThisCapture())
@@ -1491,6 +1496,8 @@ void Sema::DiagnoseUnusedLambdaCapture(c
else
diag << From.getVariable();
diag << From.isNonODRUsed();
+ diag << FixItHint::CreateRemoval(CaptureRange);
+ return true;
}
ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
@@ -1532,18 +1539,49 @@ ExprResult Sema::BuildLambdaExpr(SourceL
// Translate captures.
auto CurField = Class->field_begin();
+ // True if the current capture has a used capture or default before it.
+ bool CurHasPreviousCapture = CaptureDefault != LCD_None;
+ SourceLocation PrevCaptureLoc = CurHasPreviousCapture ?
+ CaptureDefaultLoc : IntroducerRange.getBegin();
+
for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I, ++CurField) {
const Capture &From = LSI->Captures[I];
+
assert(!From.isBlockCapture() && "Cannot capture __block variables");
bool IsImplicit = I >= LSI->NumExplicitCaptures;
+ // Use source ranges of explicit captures for fixits where available.
+ SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I];
+
// Warn about unused explicit captures.
+ bool IsCaptureUsed = true;
if (!CurContext->isDependentContext() && !IsImplicit && !From.isODRUsed()) {
// Initialized captures that are non-ODR used may not be eliminated.
bool NonODRUsedInitCapture =
IsGenericLambda && From.isNonODRUsed() && From.getInitExpr();
- if (!NonODRUsedInitCapture)
- DiagnoseUnusedLambdaCapture(From);
+ if (!NonODRUsedInitCapture) {
+ bool IsLast = (I + 1) == LSI->NumExplicitCaptures;
+ SourceRange FixItRange;
+ if (CaptureRange.isValid()) {
+ if (!CurHasPreviousCapture && !IsLast) {
+ // If there are no captures preceding this capture, remove the
+ // following comma.
+ FixItRange = SourceRange(CaptureRange.getBegin(),
+ getLocForEndOfToken(CaptureRange.getEnd()));
+ } else {
+ // Otherwise, remove the comma since the last used capture.
+ FixItRange = SourceRange(getLocForEndOfToken(PrevCaptureLoc),
+ CaptureRange.getEnd());
+ }
+ }
+
+ IsCaptureUsed = !DiagnoseUnusedLambdaCapture(FixItRange, From);
+ }
+ }
+
+ if (CaptureRange.isValid()) {
+ CurHasPreviousCapture |= IsCaptureUsed;
+ PrevCaptureLoc = CaptureRange.getEnd();
}
// Handle 'this' capture.
Added: cfe/trunk/test/FixIt/fixit-unused-lambda-capture.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/FixIt/fixit-unused-lambda-capture.cpp?rev=337148&view=auto
==============================================================================
--- cfe/trunk/test/FixIt/fixit-unused-lambda-capture.cpp (added)
+++ cfe/trunk/test/FixIt/fixit-unused-lambda-capture.cpp Mon Jul 16 00:23:47 2018
@@ -0,0 +1,94 @@
+// RUN: cp %s %t
+// RUN: %clang_cc1 -x c++ -fsyntax-only -Wunused-lambda-capture -Wno-unused-value -std=c++1z -fixit %t
+// RUN: grep -v CHECK %t | FileCheck %s
+
+void test() {
+ int i = 0;
+ int j = 0;
+ int k = 0;
+ int c = 10;
+ int a[c];
+
+ [i,j] { return i; };
+ // CHECK: [i] { return i; };
+ [i,j] { return j; };
+ // CHECK: [j] { return j; };
+ [&i,j] { return j; };
+ // CHECK: [j] { return j; };
+ [j,&i] { return j; };
+ // CHECK: [j] { return j; };
+ [i,j,k] {};
+ // CHECK: [] {};
+ [i,j,k] { return i + j; };
+ // CHECK: [i,j] { return i + j; };
+ [i,j,k] { return j + k; };
+ // CHECK: [j,k] { return j + k; };
+ [i,j,k] { return i + k; };
+ // CHECK: [i,k] { return i + k; };
+ [i,j,k] { return i + j + k; };
+ // CHECK: [i,j,k] { return i + j + k; };
+ [&,i] { return k; };
+ // CHECK: [&] { return k; };
+ [=,&i] { return k; };
+ // CHECK: [=] { return k; };
+ [=,&i,&j] { return j; };
+ // CHECK: [=,&j] { return j; };
+ [=,&i,&j] { return i; };
+ // CHECK: [=,&i] { return i; };
+ [z = i] {};
+ // CHECK: [] {};
+ [i,z = i] { return z; };
+ // CHECK: [z = i] { return z; };
+ [z = i,i] { return z; };
+ // CHECK: [z = i] { return z; };
+ [&a] {};
+ // CHECK: [] {};
+ [i,&a] { return i; };
+ // CHECK: [i] { return i; };
+ [&a,i] { return i; };
+ // CHECK: [i] { return i; };
+
+ #define I_MACRO() i
+ #define I_REF_MACRO() &i
+ [I_MACRO()] {};
+ // CHECK: [] {};
+ [I_MACRO(),j] { return j; };
+ // CHECK: [j] { return j; };
+ [j,I_MACRO()] { return j; };
+ // CHECK: [j] { return j; };
+ [I_REF_MACRO(),j] { return j; };
+ // CHECK: [j] { return j; };
+ [j,I_REF_MACRO()] { return j; };
+ // CHECK: [j] { return j; };
+
+ int n = 0;
+ [z = (n = i),j] {};
+ // CHECK: [z = (n = i)] {};
+ [j,z = (n = i)] {};
+ // CHECK: [z = (n = i)] {};
+}
+
+class ThisTest {
+ void test() {
+ int i = 0;
+
+ [this] {};
+ // CHECK: [] {};
+ [i,this] { return i; };
+ // CHECK: [i] { return i; };
+ [this,i] { return i; };
+ // CHECK: [i] { return i; };
+ [*this] {};
+ // CHECK: [] {};
+ [*this,i] { return i; };
+ // CHECK: [i] { return i; };
+ [i,*this] { return i; };
+ // CHECK: [i] { return i; };
+ [*this] { return this; };
+ // CHECK: [*this] { return this; };
+ [*this,i] { return this; };
+ // CHECK: [*this] { return this; };
+ [i,*this] { return this; };
+ // CHECK: [*this] { return this; };
+ }
+};
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