mbenfield updated this revision to Diff 346904.
mbenfield added a comment.
Herald added subscribers: llvm-commits, lldb-commits, kbarton, hiraditya,
nemanjai.
Herald added projects: LLDB, LLVM.
Don't warn for reference or dependent types (fixing false positives).
Also fix a few places where this warning is correctly triggered. In a couple
places I did that by adding __attribute__((unused)) rather than removing the
unused variable.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D100581/new/
https://reviews.llvm.org/D100581
Files:
clang/include/clang/Basic/DiagnosticGroups.td
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/include/clang/Sema/Sema.h
clang/lib/Sema/SemaDecl.cpp
clang/lib/Sema/SemaExpr.cpp
clang/lib/Sema/SemaExprCXX.cpp
clang/test/CXX/expr/expr.prim/expr.prim.lambda/p12.cpp
clang/test/CodeGen/2007-10-30-Volatile.c
clang/test/CodeGen/X86/x86_32-xsave.c
clang/test/CodeGen/X86/x86_64-xsave.c
clang/test/CodeGen/builtins-arm.c
clang/test/CodeGen/builtins-riscv.c
clang/test/FixIt/fixit.cpp
clang/test/Misc/warning-wall.c
clang/test/Sema/shift.c
clang/test/Sema/vector-gcc-compat.c
clang/test/Sema/vector-gcc-compat.cpp
clang/test/Sema/warn-unused-but-set-parameters.c
clang/test/Sema/warn-unused-but-set-variables.c
clang/test/SemaCXX/goto.cpp
clang/test/SemaCXX/shift.cpp
clang/test/SemaCXX/sizeless-1.cpp
clang/test/SemaCXX/warn-unused-but-set-parameters-cpp.cpp
clang/test/SemaCXX/warn-unused-but-set-variables-cpp.cpp
clang/test/SemaObjC/foreach.m
lldb/source/Interpreter/CommandInterpreter.cpp
lldb/source/Plugins/ABI/PowerPC/ABISysV_ppc.cpp
lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
llvm/lib/Target/AArch64/GISel/AArch64PostSelectOptimize.cpp
llvm/lib/Target/ARM/ARMISelLowering.cpp
llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
llvm/lib/Target/PowerPC/PPCBranchSelector.cpp
llvm/lib/Target/X86/X86FloatingPoint.cpp
llvm/utils/benchmark/src/complexity.cc
Index: llvm/utils/benchmark/src/complexity.cc
===================================================================
--- llvm/utils/benchmark/src/complexity.cc
+++ llvm/utils/benchmark/src/complexity.cc
@@ -76,7 +76,6 @@
LeastSq MinimalLeastSq(const std::vector<int64_t>& n,
const std::vector<double>& time,
BigOFunc* fitting_curve) {
- double sigma_gn = 0.0;
double sigma_gn_squared = 0.0;
double sigma_time = 0.0;
double sigma_time_gn = 0.0;
@@ -84,7 +83,6 @@
// Calculate least square fitting parameter
for (size_t i = 0; i < n.size(); ++i) {
double gn_i = fitting_curve(n[i]);
- sigma_gn += gn_i;
sigma_gn_squared += gn_i * gn_i;
sigma_time += time[i];
sigma_time_gn += time[i] * gn_i;
Index: llvm/lib/Target/X86/X86FloatingPoint.cpp
===================================================================
--- llvm/lib/Target/X86/X86FloatingPoint.cpp
+++ llvm/lib/Target/X86/X86FloatingPoint.cpp
@@ -1526,7 +1526,7 @@
// Scan the assembly for ST registers used, defined and clobbered. We can
// only tell clobbers from defs by looking at the asm descriptor.
- unsigned STUses = 0, STDefs = 0, STClobbers = 0, STDeadDefs = 0;
+ unsigned STUses = 0, STDefs = 0, STClobbers = 0;
unsigned NumOps = 0;
SmallSet<unsigned, 1> FRegIdx;
unsigned RCID;
@@ -1559,8 +1559,6 @@
case InlineAsm::Kind_RegDef:
case InlineAsm::Kind_RegDefEarlyClobber:
STDefs |= (1u << STReg);
- if (MO.isDead())
- STDeadDefs |= (1u << STReg);
break;
case InlineAsm::Kind_Clobber:
STClobbers |= (1u << STReg);
Index: llvm/lib/Target/PowerPC/PPCBranchSelector.cpp
===================================================================
--- llvm/lib/Target/PowerPC/PPCBranchSelector.cpp
+++ llvm/lib/Target/PowerPC/PPCBranchSelector.cpp
@@ -415,5 +415,5 @@
}
BlockSizes.clear();
- return true;
+ return EverMadeChange;
}
Index: llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
===================================================================
--- llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
+++ llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
@@ -1247,7 +1247,7 @@
if (LoLoop.Preheader)
LoLoop.Start = SearchForStart(LoLoop.Preheader);
else
- return false;
+ return Changed;
// Find the low-overhead loop components and decide whether or not to fall
// back to a normal loop. Also look for a vctp instructions and decide
@@ -1281,7 +1281,7 @@
LLVM_DEBUG(LoLoop.dump());
if (!LoLoop.FoundAllComponents()) {
LLVM_DEBUG(dbgs() << "ARM Loops: Didn't find loop start, update, end\n");
- return false;
+ return Changed;
}
assert(LoLoop.Start->getOpcode() != ARM::t2WhileLoopStart &&
Index: llvm/lib/Target/ARM/ARMISelLowering.cpp
===================================================================
--- llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -6746,12 +6746,10 @@
return SDValue();
// NEON has a 64-bit VMOV splat where each byte is either 0 or 0xff.
uint64_t BitMask = 0xff;
- uint64_t Val = 0;
unsigned ImmMask = 1;
Imm = 0;
for (int ByteNum = 0; ByteNum < 8; ++ByteNum) {
if (((SplatBits | SplatUndef) & BitMask) == BitMask) {
- Val |= BitMask;
Imm |= ImmMask;
} else if ((SplatBits & BitMask) != 0) {
return SDValue();
Index: llvm/lib/Target/AArch64/GISel/AArch64PostSelectOptimize.cpp
===================================================================
--- llvm/lib/Target/AArch64/GISel/AArch64PostSelectOptimize.cpp
+++ llvm/lib/Target/AArch64/GISel/AArch64PostSelectOptimize.cpp
@@ -180,7 +180,7 @@
bool Changed = false;
for (auto &BB : MF)
Changed |= optimizeNZCVDefs(BB);
- return true;
+ return Changed;
}
char AArch64PostSelectOptimize::ID = 0;
Index: lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
===================================================================
--- lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
+++ lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV1.cpp
@@ -339,8 +339,6 @@
if (!objc_module_sp)
return;
- uint32_t isa_count = 0;
-
lldb::addr_t hash_table_ptr = GetISAHashTablePointer();
if (hash_table_ptr != LLDB_INVALID_ADDRESS) {
// Read the NXHashTable struct:
@@ -383,8 +381,6 @@
if (bucket_isa_count == 0)
continue;
- isa_count += bucket_isa_count;
-
ObjCISA isa;
if (bucket_isa_count == 1) {
// When we only have one entry in the bucket, the bucket data
Index: lldb/source/Plugins/ABI/PowerPC/ABISysV_ppc.cpp
===================================================================
--- lldb/source/Plugins/ABI/PowerPC/ABISysV_ppc.cpp
+++ lldb/source/Plugins/ABI/PowerPC/ABISysV_ppc.cpp
@@ -683,7 +683,7 @@
r3_value.GetData(r3_data);
rdx_value.GetData(rdx_data);
- uint32_t fp_bytes =
+ uint32_t fp_bytes __attribute__((unused)) =
0; // Tracks how much of the xmm registers we've consumed so far
uint32_t integer_bytes =
0; // Tracks how much of the r3/rds registers we've consumed so far
Index: lldb/source/Interpreter/CommandInterpreter.cpp
===================================================================
--- lldb/source/Interpreter/CommandInterpreter.cpp
+++ lldb/source/Interpreter/CommandInterpreter.cpp
@@ -3101,7 +3101,7 @@
CommandObject *cmd_obj = nullptr;
StreamString revised_command_line;
bool wants_raw_input = false;
- size_t actual_cmd_name_len = 0;
+ size_t actual_cmd_name_len __attribute__((unused)) = 0;
std::string next_word;
StringList matches;
bool done = false;
Index: clang/test/SemaObjC/foreach.m
===================================================================
--- clang/test/SemaObjC/foreach.m
+++ clang/test/SemaObjC/foreach.m
@@ -1,4 +1,4 @@
-/* RUN: %clang_cc1 -Wall -fsyntax-only -verify -std=c89 -pedantic %s
+/* RUN: %clang_cc1 -Wall -Wno-unused-but-set-variable -fsyntax-only -verify -std=c89 -pedantic %s
*/
@class NSArray;
Index: clang/test/SemaCXX/warn-unused-but-set-variables-cpp.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/warn-unused-but-set-variables-cpp.cpp
@@ -0,0 +1,50 @@
+// RUN: %clang_cc1 -fblocks -fsyntax-only -Wunused-but-set-variable -verify %s
+
+struct S {
+ int i;
+};
+
+struct __attribute__((warn_unused)) SWarnUnused {
+ int j;
+};
+
+int f0() {
+ int y; // expected-warning{{variable 'y' set but not used}}
+ y = 0;
+
+ int z __attribute__((unused));
+ z = 0;
+
+ // In C++, don't warn for structs. (following gcc's behavior)
+ struct S s;
+ struct S t;
+ s = t;
+
+ // Unless it's marked with the warn_unused attribute.
+ struct SWarnUnused swu; // expected-warning{{variable 'swu' set but not used}}
+ struct SWarnUnused swu2;
+ swu = swu2;
+
+ int x;
+ x = 0;
+ return x + 5;
+}
+
+void f1(void) {
+ (void)^() {
+ int y; // expected-warning{{variable 'y' set but not used}}
+ y = 0;
+
+ int x;
+ x = 0;
+ return x;
+ };
+}
+
+void f2() {
+ // Don't warn for either of these cases.
+ constexpr int x = 2;
+ const int y = 1;
+ char a[x];
+ char b[y];
+}
Index: clang/test/SemaCXX/warn-unused-but-set-parameters-cpp.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/warn-unused-but-set-parameters-cpp.cpp
@@ -0,0 +1,38 @@
+// RUN: %clang_cc1 -fblocks -fsyntax-only -Wunused-but-set-parameter -verify %s
+
+int f0(int x,
+ int y, // expected-warning{{parameter 'y' set but not used}}
+ int z __attribute__((unused))) {
+ y = 0;
+ return x;
+}
+
+void f1(void) {
+ (void)^(int x,
+ int y, // expected-warning{{parameter 'y' set but not used}}
+ int z __attribute__((unused))) {
+ y = 0;
+ return x;
+ };
+}
+
+struct S {
+ int i;
+};
+
+// In C++, don't warn for a struct (following gcc).
+void f3(struct S s) {
+ struct S t;
+ s = t;
+}
+
+// Also don't warn for a reference.
+void f4(int &x) {
+ x = 0;
+}
+
+// Make sure this doesn't warn.
+struct A {
+ int i;
+ A(int j) : i(j) {}
+};
Index: clang/test/SemaCXX/sizeless-1.cpp
===================================================================
--- clang/test/SemaCXX/sizeless-1.cpp
+++ clang/test/SemaCXX/sizeless-1.cpp
@@ -1,7 +1,7 @@
-// RUN: %clang_cc1 -fcxx-exceptions -fsyntax-only -verify -W -Wall -Wrange-loop-analysis -triple arm64-linux-gnu -target-feature +sve -std=c++98 %s
-// RUN: %clang_cc1 -fcxx-exceptions -fsyntax-only -verify -W -Wall -Wrange-loop-analysis -triple arm64-linux-gnu -target-feature +sve -std=c++11 %s
-// RUN: %clang_cc1 -fcxx-exceptions -fsyntax-only -verify -W -Wall -Wrange-loop-analysis -triple arm64-linux-gnu -target-feature +sve -std=c++17 %s
-// RUN: %clang_cc1 -fcxx-exceptions -fsyntax-only -verify -W -Wall -Wrange-loop-analysis -triple arm64-linux-gnu -target-feature +sve -std=gnu++17 %s
+// RUN: %clang_cc1 -fcxx-exceptions -fsyntax-only -verify -W -Wall -Wno-unused-but-set-variable -Wrange-loop-analysis -triple arm64-linux-gnu -target-feature +sve -std=c++98 %s
+// RUN: %clang_cc1 -fcxx-exceptions -fsyntax-only -verify -W -Wall -Wno-unused-but-set-variable -Wrange-loop-analysis -triple arm64-linux-gnu -target-feature +sve -std=c++11 %s
+// RUN: %clang_cc1 -fcxx-exceptions -fsyntax-only -verify -W -Wall -Wno-unused-but-set-variable -Wrange-loop-analysis -triple arm64-linux-gnu -target-feature +sve -std=c++17 %s
+// RUN: %clang_cc1 -fcxx-exceptions -fsyntax-only -verify -W -Wall -Wno-unused-but-set-variable -Wrange-loop-analysis -triple arm64-linux-gnu -target-feature +sve -std=gnu++17 %s
namespace std {
struct type_info;
Index: clang/test/SemaCXX/shift.cpp
===================================================================
--- clang/test/SemaCXX/shift.cpp
+++ clang/test/SemaCXX/shift.cpp
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -Wall -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify=expected,cxx17 -std=c++17 %s
-// RUN: %clang_cc1 -Wall -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify=expected,cxx2a -std=c++2a %s
+// RUN: %clang_cc1 -Wall -Wno-unused-but-set-variable -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify=expected,cxx17 -std=c++17 %s
+// RUN: %clang_cc1 -Wall -Wno-unused-but-set-variable -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify=expected,cxx2a -std=c++2a %s
#include <limits.h>
Index: clang/test/SemaCXX/goto.cpp
===================================================================
--- clang/test/SemaCXX/goto.cpp
+++ clang/test/SemaCXX/goto.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -Wall -fblocks %s
+// RUN: %clang_cc1 -fsyntax-only -verify -Wall -Wno-unused-but-set-variable -fblocks %s
// PR9463
double *end;
Index: clang/test/Sema/warn-unused-but-set-variables.c
===================================================================
--- /dev/null
+++ clang/test/Sema/warn-unused-but-set-variables.c
@@ -0,0 +1,47 @@
+// RUN: %clang_cc1 -fblocks -fsyntax-only -Wunused-but-set-variable -verify %s
+
+struct S {
+ int i;
+};
+
+int f0() {
+ int y; // expected-warning{{variable 'y' set but not used}}
+ y = 0;
+
+ int z __attribute__((unused));
+ z = 0;
+
+ struct S s; // expected-warning{{variable 's' set but not used}}
+ struct S t;
+ s = t;
+
+ // Don't warn for an extern variable.
+ extern int w;
+ w = 0;
+
+ // Following gcc, this should not warn.
+ int a;
+ w = (a = 0);
+
+ int x;
+ x = 0;
+ return x;
+}
+
+void f1(void) {
+ (void)^() {
+ int y; // expected-warning{{variable 'y' set but not used}}
+ y = 0;
+
+ int x;
+ x = 0;
+ return x;
+ };
+}
+
+void f2 (void) {
+ // Don't warn, even if it's only used in a non-ODR context.
+ int x;
+ x = 0;
+ (void) sizeof(x);
+}
Index: clang/test/Sema/warn-unused-but-set-parameters.c
===================================================================
--- /dev/null
+++ clang/test/Sema/warn-unused-but-set-parameters.c
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -fblocks -fsyntax-only -Wunused-but-set-parameter -verify %s
+
+int f0(int x,
+ int y, // expected-warning{{parameter 'y' set but not used}}
+ int z __attribute__((unused))) {
+ y = 0;
+ return x;
+}
+
+void f1(void) {
+ (void)^(int x,
+ int y, // expected-warning{{parameter 'y' set but not used}}
+ int z __attribute__((unused))) {
+ y = 0;
+ return x;
+ };
+}
+
+struct S {
+ int i;
+};
+
+void f3(struct S s) { // expected-warning{{parameter 's' set but not used}}
+ struct S t;
+ s = t;
+}
Index: clang/test/Sema/vector-gcc-compat.cpp
===================================================================
--- clang/test/Sema/vector-gcc-compat.cpp
+++ clang/test/Sema/vector-gcc-compat.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -verify -fsyntax-only -Weverything -std=c++11 -triple x86_64-apple-darwin10
+// RUN: %clang_cc1 %s -verify -fsyntax-only -Weverything -Wno-unused-but-set-variable -std=c++11 -triple x86_64-apple-darwin10
// Test the compatibility of clang++'s vector extensions with g++'s vector
// extensions. In comparison to the extensions available in C, the !, ?:, && and
Index: clang/test/Sema/vector-gcc-compat.c
===================================================================
--- clang/test/Sema/vector-gcc-compat.c
+++ clang/test/Sema/vector-gcc-compat.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -verify -fsyntax-only -Weverything -triple x86_64-apple-darwin10
+// RUN: %clang_cc1 %s -verify -fsyntax-only -Weverything -Wno-unused-but-set-variable -triple x86_64-apple-darwin10
// Test the compatibility of clang's vector extensions with gcc's vector
// extensions for C. Notably &&, ||, ?: and ! are not available.
Index: clang/test/Sema/shift.c
===================================================================
--- clang/test/Sema/shift.c
+++ clang/test/Sema/shift.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -Wall -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify %s
+// RUN: %clang_cc1 -Wall -Wno-unused-but-set-variable -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify %s
#include <limits.h>
Index: clang/test/Misc/warning-wall.c
===================================================================
--- clang/test/Misc/warning-wall.c
+++ clang/test/Misc/warning-wall.c
@@ -73,6 +73,7 @@
CHECK-NEXT: -Wpotentially-evaluated-expression
CHECK-NEXT: -Wunused-variable
CHECK-NEXT: -Wunused-const-variable
+CHECK-NEXT: -Wunused-but-set-variable
CHECK-NEXT: -Wunused-property-ivar
CHECK-NEXT: -Wvolatile-register-var
CHECK-NEXT: -Wobjc-missing-super-calls
Index: clang/test/FixIt/fixit.cpp
===================================================================
--- clang/test/FixIt/fixit.cpp
+++ clang/test/FixIt/fixit.cpp
@@ -1,12 +1,12 @@
-// RUN: %clang_cc1 -pedantic -Wall -Wno-comment -verify -fcxx-exceptions -x c++ -std=c++98 %s
+// RUN: %clang_cc1 -pedantic -Wall -Wno-unused-but-set-variable -Wno-comment -verify -fcxx-exceptions -x c++ -std=c++98 %s
// RUN: cp %s %t-98
-// RUN: not %clang_cc1 -pedantic -Wall -Wno-comment -fcxx-exceptions -fixit -x c++ -std=c++98 %t-98
-// RUN: %clang_cc1 -fsyntax-only -pedantic -Wall -Werror -Wno-comment -fcxx-exceptions -x c++ -std=c++98 %t-98
+// RUN: not %clang_cc1 -pedantic -Wall -Wno-unused-but-set-variable -Wno-comment -fcxx-exceptions -fixit -x c++ -std=c++98 %t-98
+// RUN: %clang_cc1 -fsyntax-only -pedantic -Wall -Wno-unused-but-set-variable -Werror -Wno-comment -fcxx-exceptions -x c++ -std=c++98 %t-98
// RUN: not %clang_cc1 -fsyntax-only -pedantic -fdiagnostics-parseable-fixits -x c++ -std=c++11 %s 2>&1 | FileCheck %s
-// RUN: %clang_cc1 -pedantic -Wall -Wno-comment -verify -fcxx-exceptions -x c++ -std=c++11 %s
+// RUN: %clang_cc1 -pedantic -Wall -Wno-unused-but-set-variable -Wno-comment -verify -fcxx-exceptions -x c++ -std=c++11 %s
// RUN: cp %s %t-11
-// RUN: not %clang_cc1 -pedantic -Wall -Wno-comment -fcxx-exceptions -fixit -x c++ -std=c++11 %t-11
-// RUN: %clang_cc1 -fsyntax-only -pedantic -Wall -Werror -Wno-comment -fcxx-exceptions -x c++ -std=c++11 %t-11
+// RUN: not %clang_cc1 -pedantic -Wall -Wno-unused-but-set-variable -Wno-comment -fcxx-exceptions -fixit -x c++ -std=c++11 %t-11
+// RUN: %clang_cc1 -fsyntax-only -pedantic -Wall -Wno-unused-but-set-variable -Werror -Wno-comment -fcxx-exceptions -x c++ -std=c++11 %t-11
/* This is a test of the various code modification hints that are
provided as part of warning or extension diagnostics. All of the
Index: clang/test/CodeGen/builtins-riscv.c
===================================================================
--- clang/test/CodeGen/builtins-riscv.c
+++ clang/test/CodeGen/builtins-riscv.c
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -Wall -Werror -triple riscv32 -disable-O0-optnone -emit-llvm -o - %s | opt -S -mem2reg | FileCheck %s
-// RUN: %clang_cc1 -Wall -Werror -triple riscv64 -disable-O0-optnone -emit-llvm -o - %s | opt -S -mem2reg | FileCheck %s
+// RUN: %clang_cc1 -Wall -Wno-unused-but-set-variable -Werror -triple riscv32 -disable-O0-optnone -emit-llvm -o - %s | opt -S -mem2reg | FileCheck %s
+// RUN: %clang_cc1 -Wall -Wno-unused-but-set-variable -Werror -triple riscv64 -disable-O0-optnone -emit-llvm -o - %s | opt -S -mem2reg | FileCheck %s
void test_eh_return_data_regno() {
// CHECK: store volatile i32 10
Index: clang/test/CodeGen/builtins-arm.c
===================================================================
--- clang/test/CodeGen/builtins-arm.c
+++ clang/test/CodeGen/builtins-arm.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -Wall -Werror -triple thumbv7-eabi -target-cpu cortex-a8 -disable-O0-optnone -emit-llvm -o - %s | opt -S -mem2reg | FileCheck %s
+// RUN: %clang_cc1 -Wall -Wno-unused-but-set-variable -Werror -triple thumbv7-eabi -target-cpu cortex-a8 -disable-O0-optnone -emit-llvm -o - %s | opt -S -mem2reg | FileCheck %s
#include <stdint.h>
Index: clang/test/CodeGen/X86/x86_64-xsave.c
===================================================================
--- clang/test/CodeGen/X86/x86_64-xsave.c
+++ clang/test/CodeGen/X86/x86_64-xsave.c
@@ -1,17 +1,17 @@
-// RUN: %clang_cc1 %s -DTEST_XSAVE -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVE
-// RUN: %clang_cc1 %s -DTEST_XSAVE -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -fno-signed-char -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVE
+// RUN: %clang_cc1 %s -DTEST_XSAVE -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVE
+// RUN: %clang_cc1 %s -DTEST_XSAVE -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -fno-signed-char -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVE
-// RUN: %clang_cc1 %s -DTEST_XGETBV -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XGETBV
-// RUN: %clang_cc1 %s -DTEST_XSETBV -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -fno-signed-char -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSETBV
+// RUN: %clang_cc1 %s -DTEST_XGETBV -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XGETBV
+// RUN: %clang_cc1 %s -DTEST_XSETBV -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -fno-signed-char -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSETBV
-// RUN: %clang_cc1 %s -DTEST_XSAVEOPT -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsaveopt -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVEOPT
-// RUN: %clang_cc1 %s -DTEST_XSAVEOPT -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsaveopt -fno-signed-char -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVEOPT
+// RUN: %clang_cc1 %s -DTEST_XSAVEOPT -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsaveopt -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVEOPT
+// RUN: %clang_cc1 %s -DTEST_XSAVEOPT -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsaveopt -fno-signed-char -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVEOPT
-// RUN: %clang_cc1 %s -DTEST_XSAVEC -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsavec -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVEC
-// RUN: %clang_cc1 %s -DTEST_XSAVEC -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsavec -fno-signed-char -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVEC
+// RUN: %clang_cc1 %s -DTEST_XSAVEC -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsavec -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVEC
+// RUN: %clang_cc1 %s -DTEST_XSAVEC -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsavec -fno-signed-char -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVEC
-// RUN: %clang_cc1 %s -DTEST_XSAVES -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsaves -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVES
-// RUN: %clang_cc1 %s -DTEST_XSAVES -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsaves -fno-signed-char -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVES
+// RUN: %clang_cc1 %s -DTEST_XSAVES -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsaves -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVES
+// RUN: %clang_cc1 %s -DTEST_XSAVES -O0 -triple=x86_64-unknown-unknown -target-feature +xsave -target-feature +xsaves -fno-signed-char -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVES
// Don't include mm_malloc.h, it's system specific.
#define __MM_MALLOC_H
Index: clang/test/CodeGen/X86/x86_32-xsave.c
===================================================================
--- clang/test/CodeGen/X86/x86_32-xsave.c
+++ clang/test/CodeGen/X86/x86_32-xsave.c
@@ -1,17 +1,17 @@
-// RUN: %clang_cc1 %s -DTEST_XSAVE -O0 -triple=i686-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVE
-// RUN: %clang_cc1 %s -DTEST_XSAVE -O0 -triple=i686-unknown-unknown -target-feature +xsave -fno-signed-char -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVE
+// RUN: %clang_cc1 %s -DTEST_XSAVE -O0 -triple=i686-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVE
+// RUN: %clang_cc1 %s -DTEST_XSAVE -O0 -triple=i686-unknown-unknown -target-feature +xsave -fno-signed-char -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVE
-// RUN: %clang_cc1 %s -DTEST_XGETBV -O0 -triple=i686-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XGETBV
-// RUN: %clang_cc1 %s -DTEST_XSETBV -O0 -triple=i686-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSETBV
+// RUN: %clang_cc1 %s -DTEST_XGETBV -O0 -triple=i686-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XGETBV
+// RUN: %clang_cc1 %s -DTEST_XSETBV -O0 -triple=i686-unknown-unknown -target-feature +xsave -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSETBV
-// RUN: %clang_cc1 %s -DTEST_XSAVEOPT -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsaveopt -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVEOPT
-// RUN: %clang_cc1 %s -DTEST_XSAVEOPT -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsaveopt -fno-signed-char -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVEOPT
+// RUN: %clang_cc1 %s -DTEST_XSAVEOPT -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsaveopt -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVEOPT
+// RUN: %clang_cc1 %s -DTEST_XSAVEOPT -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsaveopt -fno-signed-char -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVEOPT
-// RUN: %clang_cc1 %s -DTEST_XSAVEC -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsavec -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVEC
-// RUN: %clang_cc1 %s -DTEST_XSAVEC -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsavec -fno-signed-char -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVEC
+// RUN: %clang_cc1 %s -DTEST_XSAVEC -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsavec -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVEC
+// RUN: %clang_cc1 %s -DTEST_XSAVEC -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsavec -fno-signed-char -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVEC
-// RUN: %clang_cc1 %s -DTEST_XSAVES -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsaves -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVES
-// RUN: %clang_cc1 %s -DTEST_XSAVES -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsaves -fno-signed-char -emit-llvm -o - -Wall -Werror | FileCheck %s --check-prefix=XSAVES
+// RUN: %clang_cc1 %s -DTEST_XSAVES -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsaves -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVES
+// RUN: %clang_cc1 %s -DTEST_XSAVES -O0 -triple=i686-unknown-unknown -target-feature +xsave -target-feature +xsaves -fno-signed-char -emit-llvm -o - -Wall -Wno-unused-but-set-variable -Werror | FileCheck %s --check-prefix=XSAVES
// Don't include mm_malloc.h, it's system specific.
#define __MM_MALLOC_H
Index: clang/test/CodeGen/2007-10-30-Volatile.c
===================================================================
--- clang/test/CodeGen/2007-10-30-Volatile.c
+++ clang/test/CodeGen/2007-10-30-Volatile.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -emit-llvm %s -o /dev/null -Wall -Werror
+// RUN: %clang_cc1 -emit-llvm %s -o /dev/null -Wall -Wno-unused-but-set-variable -Werror
void bork() {
char * volatile p = 0;
volatile int cc = 0;
Index: clang/test/CXX/expr/expr.prim/expr.prim.lambda/p12.cpp
===================================================================
--- clang/test/CXX/expr/expr.prim/expr.prim.lambda/p12.cpp
+++ clang/test/CXX/expr/expr.prim/expr.prim.lambda/p12.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -std=c++11 %s -Wunused -Wno-unused-lambda-capture -verify
+// RUN: %clang_cc1 -std=c++11 %s -Wunused -Wno-unused-but-set-variable -Wno-unused-lambda-capture -verify
void odr_used() {
int i = 17;
Index: clang/lib/Sema/SemaExprCXX.cpp
===================================================================
--- clang/lib/Sema/SemaExprCXX.cpp
+++ clang/lib/Sema/SemaExprCXX.cpp
@@ -7782,9 +7782,34 @@
return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen);
}
+static void MaybeDecrementCount(
+ Expr *E, llvm::DenseMap<const VarDecl *, int> &RefsMinusAssignments) {
+ DeclRefExpr *LHS = nullptr;
+ if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
+ if (!BO->isAssignmentOp())
+ return;
+ LHS = dyn_cast<DeclRefExpr>(BO->getLHS());
+ } else if (CXXOperatorCallExpr *COCE = dyn_cast<CXXOperatorCallExpr>(E)) {
+ if (!COCE->isAssignmentOp())
+ return;
+ LHS = dyn_cast<DeclRefExpr>(COCE->getArg(0));
+ }
+ if (!LHS)
+ return;
+ VarDecl *VD = dyn_cast<VarDecl>(LHS->getDecl());
+ if (!VD)
+ return;
+ auto iter = RefsMinusAssignments.find(VD);
+ if (iter == RefsMinusAssignments.end())
+ return;
+ iter->getSecond()--;
+}
+
/// Perform the conversions required for an expression used in a
/// context that ignores the result.
ExprResult Sema::IgnoredValueConversions(Expr *E) {
+ MaybeDecrementCount(E, RefsMinusAssignments);
+
if (E->hasPlaceholderType()) {
ExprResult result = CheckPlaceholderExpr(E);
if (result.isInvalid()) return E;
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -18327,8 +18327,9 @@
"MarkVarDeclODRUsed failed to cleanup MaybeODRUseExprs?");
}
-static void DoMarkVarDeclReferenced(Sema &SemaRef, SourceLocation Loc,
- VarDecl *Var, Expr *E) {
+static void DoMarkVarDeclReferenced(
+ Sema &SemaRef, SourceLocation Loc, VarDecl *Var, Expr *E,
+ llvm::DenseMap<const VarDecl *, int> &RefsMinusAssignments) {
assert((!E || isa<DeclRefExpr>(E) || isa<MemberExpr>(E) ||
isa<FunctionParmPackExpr>(E)) &&
"Invalid Expr argument to DoMarkVarDeclReferenced");
@@ -18345,6 +18346,10 @@
bool UsableInConstantExpr =
Var->mightBeUsableInConstantExpressions(SemaRef.Context);
+ if (Var->isLocalVarDeclOrParm() && !Var->hasExternalStorage()) {
+ RefsMinusAssignments.insert({Var, 0}).first->getSecond()++;
+ }
+
// C++20 [expr.const]p12:
// A variable [...] is needed for constant evaluation if it is [...] a
// variable whose name appears as a potentially constant evaluated
@@ -18500,16 +18505,18 @@
/// (C++ [basic.def.odr]p2, C99 6.9p3). Note that this should not be
/// used directly for normal expressions referring to VarDecl.
void Sema::MarkVariableReferenced(SourceLocation Loc, VarDecl *Var) {
- DoMarkVarDeclReferenced(*this, Loc, Var, nullptr);
+ DoMarkVarDeclReferenced(*this, Loc, Var, nullptr, RefsMinusAssignments);
}
-static void MarkExprReferenced(Sema &SemaRef, SourceLocation Loc,
- Decl *D, Expr *E, bool MightBeOdrUse) {
+static void
+MarkExprReferenced(Sema &SemaRef, SourceLocation Loc, Decl *D, Expr *E,
+ bool MightBeOdrUse,
+ llvm::DenseMap<const VarDecl *, int> &RefsMinusAssignments) {
if (SemaRef.isInOpenMPDeclareTargetContext())
SemaRef.checkDeclIsAllowedInOpenMPTarget(E, D);
if (VarDecl *Var = dyn_cast<VarDecl>(D)) {
- DoMarkVarDeclReferenced(SemaRef, Loc, Var, E);
+ DoMarkVarDeclReferenced(SemaRef, Loc, Var, E, RefsMinusAssignments);
return;
}
@@ -18555,7 +18562,8 @@
if (!isConstantEvaluated() && FD->isConsteval() &&
!RebuildingImmediateInvocation)
ExprEvalContexts.back().ReferenceToConsteval.insert(E);
- MarkExprReferenced(*this, E->getLocation(), E->getDecl(), E, OdrUse);
+ MarkExprReferenced(*this, E->getLocation(), E->getDecl(), E, OdrUse,
+ RefsMinusAssignments);
}
/// Perform reference-marking and odr-use handling for a MemberExpr.
@@ -18574,13 +18582,15 @@
}
SourceLocation Loc =
E->getMemberLoc().isValid() ? E->getMemberLoc() : E->getBeginLoc();
- MarkExprReferenced(*this, Loc, E->getMemberDecl(), E, MightBeOdrUse);
+ MarkExprReferenced(*this, Loc, E->getMemberDecl(), E, MightBeOdrUse,
+ RefsMinusAssignments);
}
/// Perform reference-marking and odr-use handling for a FunctionParmPackExpr.
void Sema::MarkFunctionParmPackReferenced(FunctionParmPackExpr *E) {
for (VarDecl *VD : *E)
- MarkExprReferenced(*this, E->getParameterPackLocation(), VD, E, true);
+ MarkExprReferenced(*this, E->getParameterPackLocation(), VD, E, true,
+ RefsMinusAssignments);
}
/// Perform marking for a reference to an arbitrary declaration. It
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -1906,6 +1906,41 @@
Diag(D->getLocation(), DiagID) << D << Hint;
}
+void Sema::DiagnoseUnusedButSetDecl(const VarDecl *VD) {
+ // If it's not referenced, it can't be set.
+ if (!VD->isReferenced() || !VD->getDeclName() || VD->hasAttr<UnusedAttr>())
+ return;
+
+ const auto *Ty = VD->getType().getTypePtr()->getBaseElementTypeUnsafe();
+
+ if (Ty->isReferenceType() || Ty->isDependentType())
+ return;
+
+ if (const TagType *TT = Ty->getAs<TagType>()) {
+ const TagDecl *Tag = TT->getDecl();
+ if (Tag->hasAttr<UnusedAttr>())
+ return;
+ // In C++, don't warn for record types that don't have WarnUnusedAttr, to
+ // mimic gcc's behavior.
+ if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Tag)) {
+ if (!RD->hasAttr<WarnUnusedAttr>())
+ return;
+ }
+ }
+
+ auto iter = RefsMinusAssignments.find(VD);
+ if (iter == RefsMinusAssignments.end())
+ return;
+
+ assert(iter->getSecond() >= 0 &&
+ "Found a negative number of references to a VarDecl");
+ if (iter->getSecond() != 0)
+ return;
+ unsigned DiagID = isa<ParmVarDecl>(VD) ? diag::warn_unused_but_set_parameter
+ : diag::warn_unused_but_set_variable;
+ Diag(VD->getLocation(), DiagID) << VD;
+}
+
static void CheckPoppedLabel(LabelDecl *L, Sema &S) {
// Verify that we have no forward references left. If so, there was a goto
// or address of a label taken, but no definition of it. Label fwd
@@ -1938,6 +1973,10 @@
DiagnoseUnusedDecl(D);
if (const auto *RD = dyn_cast<RecordDecl>(D))
DiagnoseUnusedNestedTypedefs(RD);
+ if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
+ DiagnoseUnusedButSetDecl(VD);
+ RefsMinusAssignments.erase(VD);
+ }
}
if (!D->getDeclName()) continue;
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -1514,6 +1514,11 @@
bool WarnedStackExhausted = false;
+ /// Increment when we find a reference; decrement when we find an ignored
+ /// assignment. Ultimately the value is 0 if every reference is an ignored
+ /// assignment.
+ llvm::DenseMap<const VarDecl *, int> RefsMinusAssignments;
+
public:
Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
TranslationUnitKind TUKind = TU_Complete,
@@ -4861,6 +4866,10 @@
void DiagnoseUnusedNestedTypedefs(const RecordDecl *D);
void DiagnoseUnusedDecl(const NamedDecl *ND);
+ /// If VD is set but not otherwise used, diagnose, for a parameter or a
+ /// variable.
+ void DiagnoseUnusedButSetDecl(const VarDecl *VD);
+
/// Emit \p DiagID if statement located on \p StmtLoc has a suspicious null
/// statement as a \p Body, and it is located on the same line.
///
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -310,8 +310,12 @@
"repeated RISC-V 'interrupt' attribute is here">;
def warn_unused_parameter : Warning<"unused parameter %0">,
InGroup<UnusedParameter>, DefaultIgnore;
+def warn_unused_but_set_parameter : Warning<"parameter %0 set but not used">,
+ InGroup<UnusedButSetParameter>, DefaultIgnore;
def warn_unused_variable : Warning<"unused variable %0">,
InGroup<UnusedVariable>, DefaultIgnore;
+def warn_unused_but_set_variable : Warning<"variable %0 set but not used">,
+ InGroup<UnusedButSetVariable>, DefaultIgnore;
def warn_unused_local_typedef : Warning<
"unused %select{typedef|type alias}0 %1">,
InGroup<UnusedLocalTypedef>, DefaultIgnore;
Index: clang/include/clang/Basic/DiagnosticGroups.td
===================================================================
--- clang/include/clang/Basic/DiagnosticGroups.td
+++ clang/include/clang/Basic/DiagnosticGroups.td
@@ -725,6 +725,7 @@
def UnusedLabel : DiagGroup<"unused-label">;
def UnusedLambdaCapture : DiagGroup<"unused-lambda-capture">;
def UnusedParameter : DiagGroup<"unused-parameter">;
+def UnusedButSetParameter : DiagGroup<"unused-but-set-parameter">;
def UnusedResult : DiagGroup<"unused-result">;
def PotentiallyEvaluatedExpression : DiagGroup<"potentially-evaluated-expression">;
def UnevaluatedExpression : DiagGroup<"unevaluated-expression",
@@ -734,6 +735,7 @@
def UnusedConstVariable : DiagGroup<"unused-const-variable">;
def UnusedVariable : DiagGroup<"unused-variable",
[UnusedConstVariable]>;
+def UnusedButSetVariable : DiagGroup<"unused-but-set-variable">;
def UnusedLocalTypedef : DiagGroup<"unused-local-typedef">;
def UnusedPropertyIvar : DiagGroup<"unused-property-ivar">;
def UnusedGetterReturnValue : DiagGroup<"unused-getter-return-value">;
@@ -875,7 +877,7 @@
// UnusedMemberFunction, (clean-up llvm before enabling)
UnusedPrivateField, UnusedLambdaCapture,
UnusedLocalTypedef, UnusedValue, UnusedVariable,
- UnusedPropertyIvar]>,
+ UnusedButSetVariable, UnusedPropertyIvar]>,
DiagCategory<"Unused Entity Issue">;
// Format settings.
@@ -927,6 +929,7 @@
MissingMethodReturnType,
SignCompare,
UnusedParameter,
+ UnusedButSetParameter,
NullPointerArithmetic,
EmptyInitStatement,
StringConcatation,
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