manojgupta updated this revision to Diff 155891.
manojgupta added a comment.
Added helper text, updated tests.
Repository:
rC Clang
https://reviews.llvm.org/D47894
Files:
docs/ClangCommandLineReference.rst
include/clang/Driver/Options.td
include/clang/Frontend/CodeGenOptions.def
lib/CodeGen/CGCall.cpp
lib/Driver/ToolChains/Clang.cpp
lib/Frontend/CompilerInvocation.cpp
test/CodeGen/delete-null-pointer-checks.c
test/CodeGen/nonnull.c
test/CodeGen/vla.c
test/CodeGenCXX/address-space-ref.cpp
test/CodeGenCXX/constructors.cpp
test/CodeGenCXX/temporaries.cpp
test/Driver/clang_f_opts.c
test/Sema/nonnull.c
Index: test/Sema/nonnull.c
===================================================================
--- test/Sema/nonnull.c
+++ test/Sema/nonnull.c
@@ -1,5 +1,9 @@
// RUN: %clang_cc1 -fsyntax-only -verify %s
// rdar://9584012
+//
+// Verify All warnings are still issued with the option -fno-delete-null-pointer-checks
+// if nullptr is passed to function with nonnull attribute.
+// RUN: %clang_cc1 -fsyntax-only -fno-delete-null-pointer-checks -verify %s
typedef struct {
char *str;
Index: test/Driver/clang_f_opts.c
===================================================================
--- test/Driver/clang_f_opts.c
+++ test/Driver/clang_f_opts.c
@@ -348,7 +348,6 @@
// RUN: -fwhole-program \
// RUN: -fcaller-saves \
// RUN: -freorder-blocks \
-// RUN: -fdelete-null-pointer-checks \
// RUN: -ffat-lto-objects \
// RUN: -fmerge-constants \
// RUN: -finline-small-functions \
@@ -414,7 +413,6 @@
// CHECK-WARNING-DAG: optimization flag '-fwhole-program' is not supported
// CHECK-WARNING-DAG: optimization flag '-fcaller-saves' is not supported
// CHECK-WARNING-DAG: optimization flag '-freorder-blocks' is not supported
-// CHECK-WARNING-DAG: optimization flag '-fdelete-null-pointer-checks' is not supported
// CHECK-WARNING-DAG: optimization flag '-ffat-lto-objects' is not supported
// CHECK-WARNING-DAG: optimization flag '-fmerge-constants' is not supported
// CHECK-WARNING-DAG: optimization flag '-finline-small-functions' is not supported
@@ -526,3 +524,10 @@
// RUN: %clang -### -S -fno-merge-all-constants -fmerge-all-constants %s 2>&1 | FileCheck -check-prefix=CHECK-MERGE-ALL-CONSTANTS %s
// CHECK-NO-MERGE-ALL-CONSTANTS-NOT: "-fmerge-all-constants"
// CHECK-MERGE-ALL-CONSTANTS: "-fmerge-all-constants"
+
+// RUN: %clang -### -S -fdelete-null-pointer-checks %s 2>&1 | FileCheck -check-prefix=CHECK-NULL-POINTER-CHECKS %s
+// RUN: %clang -### -S -fno-delete-null-pointer-checks %s 2>&1 | FileCheck -check-prefix=CHECK-NO-NULL-POINTER-CHECKS %s
+// RUN: %clang -### -S -fdelete-null-pointer-checks -fno-delete-null-pointer-checks %s 2>&1 | FileCheck -check-prefix=CHECK-NO-NULL-POINTER-CHECKS %s
+// RUN: %clang -### -S -fno-delete-null-pointer-checks -fdelete-null-pointer-checks %s 2>&1 | FileCheck -check-prefix=CHECK-NULL-POINTER-CHECKS %s
+// CHECK-NO-NULL-POINTER-CHECKS: "-fno-delete-null-pointer-checks"
+// CHECK-NULL-POINTER-CHECKS-NOT: "-fno-delete-null-pointer-checks"
Index: test/CodeGenCXX/temporaries.cpp
===================================================================
--- test/CodeGenCXX/temporaries.cpp
+++ test/CodeGenCXX/temporaries.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-apple-darwin9 -std=c++11 | FileCheck %s
+// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-apple-darwin9 -std=c++11 | FileCheck %s -check-prefixes=CHECK,NULL-INVALID
+// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-apple-darwin9 -std=c++11 -fno-delete-null-pointer-checks | FileCheck %s -check-prefixes=CHECK,NULL-VALID
namespace PR16263 {
const unsigned int n = 1234;
@@ -347,7 +348,8 @@
struct D;
D& zed(B);
void foobar() {
- // CHECK: call nonnull %"struct.PR6648::D"* @_ZN6PR66483zedENS_1BE
+ // NULL-INVALID: call nonnull %"struct.PR6648::D"* @_ZN6PR66483zedENS_1BE
+ // NULL-VALID: call %"struct.PR6648::D"* @_ZN6PR66483zedENS_1BE
zed(foo);
}
}
Index: test/CodeGenCXX/constructors.cpp
===================================================================
--- test/CodeGenCXX/constructors.cpp
+++ test/CodeGenCXX/constructors.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -emit-llvm -o - | FileCheck %s --implicit-check-not=should_not_appear_in_output
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -emit-llvm -o - | FileCheck %s --implicit-check-not=should_not_appear_in_output --check-prefixes=CHECK,NULL-INVALID
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -emit-llvm -fno-delete-null-pointer-checks -o - | FileCheck %s --implicit-check-not=should_not_appear_in_output --check-prefixes=CHECK,NULL-VALID
struct Member { int x; Member(); Member(int); Member(const Member &); };
struct VBase { int x; VBase(); VBase(int); VBase(const VBase &); };
@@ -21,10 +22,12 @@
A::A(struct Undeclared &ref) : mem(0) {}
// Check that delegation works.
-// CHECK-LABEL: define void @_ZN1AC2ER10Undeclared(%struct.A* %this, %struct.Undeclared* nonnull %ref) unnamed_addr
+// NULL-INVALID-LABEL: define void @_ZN1AC2ER10Undeclared(%struct.A* %this, %struct.Undeclared* nonnull %ref) unnamed_addr
+// NULL-VALID-LABEL: define void @_ZN1AC2ER10Undeclared(%struct.A* %this, %struct.Undeclared* %ref) unnamed_addr
// CHECK: call void @_ZN6MemberC1Ei(
-// CHECK-LABEL: define void @_ZN1AC1ER10Undeclared(%struct.A* %this, %struct.Undeclared* nonnull %ref) unnamed_addr
+// NULL-INVALID-LABEL: define void @_ZN1AC1ER10Undeclared(%struct.A* %this, %struct.Undeclared* nonnull %ref) unnamed_addr
+// NULL-VALID-LABEL: define void @_ZN1AC1ER10Undeclared(%struct.A* %this, %struct.Undeclared* %ref) unnamed_addr
// CHECK: call void @_ZN1AC2ER10Undeclared(
A::A(ValueClass v) : mem(v.y - v.x) {}
@@ -43,11 +46,13 @@
B::B(struct Undeclared &ref) : A(ref), mem(1) {}
-// CHECK-LABEL: define void @_ZN1BC2ER10Undeclared(%struct.B* %this, %struct.Undeclared* nonnull %ref) unnamed_addr
+// NULL-INVALID-LABEL: define void @_ZN1BC2ER10Undeclared(%struct.B* %this, %struct.Undeclared* nonnull %ref) unnamed_addr
+// NULL-VALID-LABEL: define void @_ZN1BC2ER10Undeclared(%struct.B* %this, %struct.Undeclared* %ref) unnamed_addr
// CHECK: call void @_ZN1AC2ER10Undeclared(
// CHECK: call void @_ZN6MemberC1Ei(
-// CHECK-LABEL: define void @_ZN1BC1ER10Undeclared(%struct.B* %this, %struct.Undeclared* nonnull %ref) unnamed_addr
+// NULL-INVALID-LABEL: define void @_ZN1BC1ER10Undeclared(%struct.B* %this, %struct.Undeclared* nonnull %ref) unnamed_addr
+// NULL-VALID-LABEL: define void @_ZN1BC1ER10Undeclared(%struct.B* %this, %struct.Undeclared* %ref) unnamed_addr
// CHECK: call void @_ZN1BC2ER10Undeclared(
Index: test/CodeGenCXX/address-space-ref.cpp
===================================================================
--- test/CodeGenCXX/address-space-ref.cpp
+++ test/CodeGenCXX/address-space-ref.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 %s -std=c++11 -triple=x86_64-apple-darwin10 -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 %s -std=c++11 -triple=x86_64-apple-darwin10 -emit-llvm -o - | FileCheck %s -check-prefixes=CHECK,NULL-INVALID
+// RUN: %clang_cc1 %s -std=c++11 -triple=x86_64-apple-darwin10 -fno-delete-null-pointer-checks -emit-llvm -o - | FileCheck %s -check-prefixes=CHECK,NULL-VALID
// For a reference to a complete type, output the dereferenceable attribute (in
// any address space).
@@ -29,6 +30,7 @@
return x;
}
-// CHECK: define nonnull %class.bc* @_Z4bar2R2bcS0_(%class.bc* nonnull %x, %class.bc* nonnull %y)
+// NULL-INVALID: define nonnull %class.bc* @_Z4bar2R2bcS0_(%class.bc* nonnull %x, %class.bc* nonnull %y)
+// NULL-VALID: define %class.bc* @_Z4bar2R2bcS0_(%class.bc* %x, %class.bc* %y)
Index: test/CodeGen/vla.c
===================================================================
--- test/CodeGen/vla.c
+++ test/CodeGen/vla.c
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 -triple i386-unknown-unknown %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -triple i386-unknown-unknown %s -emit-llvm -o - | FileCheck %s -check-prefixes=CHECK,NULL-INVALID
+// RUN: %clang_cc1 -triple i386-unknown-unknown %s -emit-llvm -fno-delete-null-pointer-checks -o - | FileCheck %s -check-prefixes=CHECK,NULL-VALID
int b(char* x);
@@ -202,5 +203,6 @@
// CHECK: define void @test8(i32* dereferenceable(12) %a)
void test9(int n, int a[static n]) { }
-// CHECK: define void @test9(i32 %n, i32* nonnull %a)
+// NULL-INVALID: define void @test9(i32 %n, i32* nonnull %a)
+// NULL-VALID: define void @test9(i32 %n, i32* %a)
Index: test/CodeGen/nonnull.c
===================================================================
--- test/CodeGen/nonnull.c
+++ test/CodeGen/nonnull.c
@@ -1,32 +1,39 @@
-// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm < %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm < %s | FileCheck -check-prefix=NULL-INVALID %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm -fno-delete-null-pointer-checks < %s | FileCheck -check-prefix=NULL-VALID %s
-// CHECK: define void @foo(i32* nonnull %x)
+// NULL-INVALID: define void @foo(i32* nonnull %x)
+// NULL-VALID: define void @foo(i32* %x)
void foo(int * __attribute__((nonnull)) x) {
*x = 0;
}
-// CHECK: define void @bar(i32* nonnull %x)
+// NULL-INVALID: define void @bar(i32* nonnull %x)
+// NULL-VALID: define void @bar(i32* %x)
void bar(int * x) __attribute__((nonnull(1))) {
*x = 0;
}
-// CHECK: define void @bar2(i32* %x, i32* nonnull %y)
+// NULL-INVALID: define void @bar2(i32* %x, i32* nonnull %y)
+// NULL-VALID: define void @bar2(i32* %x, i32* %y)
void bar2(int * x, int * y) __attribute__((nonnull(2))) {
*x = 0;
}
static int a;
-// CHECK: define nonnull i32* @bar3()
+// NULL-INVALID: define nonnull i32* @bar3()
+// NULL-VALID: define i32* @bar3()
int * bar3() __attribute__((returns_nonnull)) {
return &a;
}
-// CHECK: define i32 @bar4(i32 %n, i32* nonnull %p)
+// NULL-INVALID: define i32 @bar4(i32 %n, i32* nonnull %p)
+// NULL-VALID: define i32 @bar4(i32 %n, i32* %p)
int bar4(int n, int *p) __attribute__((nonnull)) {
return n + *p;
}
-// CHECK: define i32 @bar5(i32 %n, i32* nonnull %p)
+// NULL-INVALID: define i32 @bar5(i32 %n, i32* nonnull %p)
+// NULL-VALID: define i32 @bar5(i32 %n, i32* %p)
int bar5(int n, int *p) __attribute__((nonnull(1, 2))) {
return n + *p;
}
@@ -37,15 +44,18 @@
double d;
} TransparentUnion __attribute__((transparent_union));
-// CHECK: define i32 @bar6(i64 %
+// NULL-INVALID: define i32 @bar6(i64 %
+// NULL-VALID: define i32 @bar6(i64 %
int bar6(TransparentUnion tu) __attribute__((nonnull(1))) {
return *tu.p;
}
-// CHECK: define void @bar7(i32* nonnull %a, i32* nonnull %b)
+// NULL-INVALID: define void @bar7(i32* nonnull %a, i32* nonnull %b)
+// NULL-VALID: define void @bar7(i32* %a, i32* %b)
void bar7(int *a, int *b) __attribute__((nonnull(1)))
__attribute__((nonnull(2))) {}
-// CHECK: define void @bar8(i32* nonnull %a, i32* nonnull %b)
+// NULL-INVALID: define void @bar8(i32* nonnull %a, i32* nonnull %b)
+// NULL-VALID: define void @bar8(i32* %a, i32* %b)
void bar8(int *a, int *b) __attribute__((nonnull))
__attribute__((nonnull(1))) {}
Index: test/CodeGen/delete-null-pointer-checks.c
===================================================================
--- /dev/null
+++ test/CodeGen/delete-null-pointer-checks.c
@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -emit-llvm -triple x86_64-unknown-linux-gnu -O2 -o - %s | FileCheck -check-prefix=NULL-POINTER-INVALID %s
+// RUN: %clang_cc1 -emit-llvm -triple x86_64-unknown-linux-gnu -O2 -o - %s -fno-delete-null-pointer-checks | FileCheck -check-prefix=NULL-POINTER-VALID %s
+
+// Test that clang does not remove the null pointer check with
+// -fno-delete-null-pointer-checks.
+int null_check(int *P) {
+// NULL-POINTER-VALID: %[[TOBOOL:.*]] = icmp eq i32* %P, null
+// NULL-POINTER-INVALID-NOT: icmp eq
+// NULL-POINTER-VALID: %[[SEL:.*]] = select i1 %[[TOBOOL:.*]], i32* null, i32*
+// NULL-POINTER-INVALID-NOT: select i1
+// NULL-POINTER-VALID: load i32, i32* %[[SEL:.*]]
+ int *Q = P;
+ if (P) {
+ Q = P + 2;
+ }
+ return *Q;
+}
+
+// NULL-POINTER-INVALID-NOT: attributes #0 = {{.*}} "null-pointer-is-valid"="true"
+// NULL-POINTER-VALID: attributes #0 = {{.*}} "null-pointer-is-valid"="true"
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -746,6 +746,8 @@
Opts.NoUseJumpTables = Args.hasArg(OPT_fno_jump_tables);
+ Opts.NullPointerIsValid = Args.hasArg(OPT_fno_delete_null_pointer_checks);
+
Opts.ProfileSampleAccurate = Args.hasArg(OPT_fprofile_sample_accurate);
Opts.PrepareForLTO = Args.hasArg(OPT_flto, OPT_flto_EQ);
Index: lib/Driver/ToolChains/Clang.cpp
===================================================================
--- lib/Driver/ToolChains/Clang.cpp
+++ lib/Driver/ToolChains/Clang.cpp
@@ -3344,6 +3344,10 @@
options::OPT_fno_merge_all_constants, false))
CmdArgs.push_back("-fmerge-all-constants");
+ if (Args.hasFlag(options::OPT_fno_delete_null_pointer_checks,
+ options::OPT_fdelete_null_pointer_checks, false))
+ CmdArgs.push_back("-fno-delete-null-pointer-checks");
+
// LLVM Code Generator Options.
if (Args.hasArg(options::OPT_frewrite_map_file) ||
Index: lib/CodeGen/CGCall.cpp
===================================================================
--- lib/CodeGen/CGCall.cpp
+++ lib/CodeGen/CGCall.cpp
@@ -1734,6 +1734,8 @@
FuncAttrs.addAttribute("less-precise-fpmad",
llvm::toStringRef(CodeGenOpts.LessPreciseFPMAD));
+ if (CodeGenOpts.NullPointerIsValid)
+ FuncAttrs.addAttribute("null-pointer-is-valid", "true");
if (!CodeGenOpts.FPDenormalMode.empty())
FuncAttrs.addAttribute("denormal-fp-math", CodeGenOpts.FPDenormalMode);
@@ -1867,7 +1869,8 @@
}
if (TargetDecl->hasAttr<RestrictAttr>())
RetAttrs.addAttribute(llvm::Attribute::NoAlias);
- if (TargetDecl->hasAttr<ReturnsNonNullAttr>())
+ if (TargetDecl->hasAttr<ReturnsNonNullAttr>() &&
+ !CodeGenOpts.NullPointerIsValid)
RetAttrs.addAttribute(llvm::Attribute::NonNull);
if (TargetDecl->hasAttr<AnyX86NoCallerSavedRegistersAttr>())
FuncAttrs.addAttribute("no_caller_saved_registers");
@@ -1974,7 +1977,8 @@
if (!PTy->isIncompleteType() && PTy->isConstantSizeType())
RetAttrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy)
.getQuantity());
- else if (getContext().getTargetAddressSpace(PTy) == 0)
+ else if (getContext().getTargetAddressSpace(PTy) == 0 &&
+ !CodeGenOpts.NullPointerIsValid)
RetAttrs.addAttribute(llvm::Attribute::NonNull);
}
@@ -2083,7 +2087,8 @@
if (!PTy->isIncompleteType() && PTy->isConstantSizeType())
Attrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy)
.getQuantity());
- else if (getContext().getTargetAddressSpace(PTy) == 0)
+ else if (getContext().getTargetAddressSpace(PTy) == 0 &&
+ !CodeGenOpts.NullPointerIsValid)
Attrs.addAttribute(llvm::Attribute::NonNull);
}
@@ -2343,7 +2348,8 @@
if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(Arg)) {
if (getNonNullAttr(CurCodeDecl, PVD, PVD->getType(),
- PVD->getFunctionScopeIndex()))
+ PVD->getFunctionScopeIndex()) &&
+ !CGM.getCodeGenOpts().NullPointerIsValid)
AI->addAttr(llvm::Attribute::NonNull);
QualType OTy = PVD->getOriginalType();
@@ -2362,7 +2368,8 @@
Attrs.addDereferenceableAttr(
getContext().getTypeSizeInChars(ETy).getQuantity()*ArrSize);
AI->addAttrs(Attrs);
- } else if (getContext().getTargetAddressSpace(ETy) == 0) {
+ } else if (getContext().getTargetAddressSpace(ETy) == 0 &&
+ !CGM.getCodeGenOpts().NullPointerIsValid) {
AI->addAttr(llvm::Attribute::NonNull);
}
}
@@ -2372,7 +2379,8 @@
// we can't use the dereferenceable attribute, but in addrspace(0)
// we know that it must be nonnull.
if (ArrTy->getSizeModifier() == VariableArrayType::Static &&
- !getContext().getTargetAddressSpace(ArrTy->getElementType()))
+ !getContext().getTargetAddressSpace(ArrTy->getElementType()) &&
+ !CGM.getCodeGenOpts().NullPointerIsValid)
AI->addAttr(llvm::Attribute::NonNull);
}
Index: include/clang/Frontend/CodeGenOptions.def
===================================================================
--- include/clang/Frontend/CodeGenOptions.def
+++ include/clang/Frontend/CodeGenOptions.def
@@ -130,6 +130,7 @@
CODEGENOPT(NoImplicitFloat , 1, 0) ///< Set when -mno-implicit-float is enabled.
CODEGENOPT(NoInfsFPMath , 1, 0) ///< Assume FP arguments, results not +-Inf.
CODEGENOPT(NoSignedZeros , 1, 0) ///< Allow ignoring the signedness of FP zero
+CODEGENOPT(NullPointerIsValid , 1, 0) ///< Assume Null pointer deference is defined.
CODEGENOPT(Reassociate , 1, 0) ///< Allow reassociation of FP math ops
CODEGENOPT(ReciprocalMath , 1, 0) ///< Allow FP divisions to be reassociated.
CODEGENOPT(NoTrappingMath , 1, 0) ///< Set when -fno-trapping-math is enabled.
Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -1076,6 +1076,13 @@
Flags<[CC1Option]>;
def fno_rewrite_imports : Flag<["-"], "fno-rewrite-imports">, Group<f_Group>;
+def fdelete_null_pointer_checks : Flag<["-"],
+ "fdelete-null-pointer-checks">, Group<f_Group>,
+ HelpText<"Assume that null pointers can not be dereferenced safely, and remove useless null checks">;
+def fno_delete_null_pointer_checks : Flag<["-"],
+ "fno-delete-null-pointer-checks">, Group<f_Group>, Flags<[CC1Option]>,
+ HelpText<"Assume that it may be possible to safely dereference null pointers">;
+
def frewrite_map_file : Separate<["-"], "frewrite-map-file">,
Group<f_Group>,
Flags<[ DriverOption, CC1Option ]>;
@@ -2843,8 +2850,6 @@
defm eliminate_unused_debug_types : BooleanFFlag<"eliminate-unused-debug-types">, Group<clang_ignored_f_Group>;
defm branch_count_reg : BooleanFFlag<"branch-count-reg">, Group<clang_ignored_gcc_optimization_f_Group>;
defm default_inline : BooleanFFlag<"default-inline">, Group<clang_ignored_gcc_optimization_f_Group>;
-defm delete_null_pointer_checks : BooleanFFlag<"delete-null-pointer-checks">,
- Group<clang_ignored_gcc_optimization_f_Group>;
defm fat_lto_objects : BooleanFFlag<"fat-lto-objects">, Group<clang_ignored_gcc_optimization_f_Group>;
defm float_store : BooleanFFlag<"float-store">, Group<clang_ignored_gcc_optimization_f_Group>;
defm friend_injection : BooleanFFlag<"friend-injection">, Group<clang_ignored_f_Group>;
Index: docs/ClangCommandLineReference.rst
===================================================================
--- docs/ClangCommandLineReference.rst
+++ docs/ClangCommandLineReference.rst
@@ -1543,6 +1543,10 @@
Disable implicit builtin knowledge of a specific function
+.. option:: -fdelete-null-pointer-checks, -fno-delete-null-pointer-checks
+
+Assume that null pointers cannot be dereferenced safely and any code/data cannot reside at address zero.
+
.. option:: -fno-elide-type
Do not elide types when printing diagnostics
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