[clang] fc6ec9b - [Sema] Fix for PR50741
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cfe-commits at lists.llvm.org
Thu Jun 17 07:17:05 PDT 2021
Author: eahcmrh
Date: 2021-06-17T16:16:59+02:00
New Revision: fc6ec9b98cf96bca8f68cc65395f861919c06c2f
URL: https://github.com/llvm/llvm-project/commit/fc6ec9b98cf96bca8f68cc65395f861919c06c2f
DIFF: https://github.com/llvm/llvm-project/commit/fc6ec9b98cf96bca8f68cc65395f861919c06c2f.diff
LOG: [Sema] Fix for PR50741
Fixed crash when doing pointer math on a void pointer.
Also, reworked test to use -verify rather than FileCheck.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D104424
Added:
Modified:
clang/lib/Sema/SemaChecking.cpp
clang/test/Sema/unbounded-array-bounds.c
Removed:
################################################################################
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index a9915cb6d720e..32b7861f7f003 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -14567,8 +14567,13 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
EffectiveType->getCanonicalTypeInternal()));
if (index.getBitWidth() < AddrBits)
index = index.zext(AddrBits);
- CharUnits ElemCharUnits = ASTC.getTypeSizeInChars(EffectiveType);
- llvm::APInt ElemBytes(index.getBitWidth(), ElemCharUnits.getQuantity());
+ Optional<CharUnits> ElemCharUnits =
+ ASTC.getTypeSizeInCharsIfKnown(EffectiveType);
+ // PR50741 - If EffectiveType has unknown size (e.g., if it's a void
+ // pointer) bounds-checking isn't meaningful.
+ if (!ElemCharUnits)
+ return;
+ llvm::APInt ElemBytes(index.getBitWidth(), ElemCharUnits->getQuantity());
// If index has more active bits than address space, we already know
// we have a bounds violation to warn about. Otherwise, compute
// address of (index + 1)th element, and warn about bounds violation
@@ -14599,7 +14604,7 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
DiagRuntimeBehavior(BaseExpr->getBeginLoc(), BaseExpr,
PDiag(DiagID)
<< toString(index, 10, true) << AddrBits
- << (unsigned)ASTC.toBits(ElemCharUnits)
+ << (unsigned)ASTC.toBits(*ElemCharUnits)
<< toString(ElemBytes, 10, false)
<< toString(MaxElems, 10, false)
<< (unsigned)MaxElems.getLimitedValue(~0U)
diff --git a/clang/test/Sema/unbounded-array-bounds.c b/clang/test/Sema/unbounded-array-bounds.c
index d47463ff94345..061dfdbd17f25 100644
--- a/clang/test/Sema/unbounded-array-bounds.c
+++ b/clang/test/Sema/unbounded-array-bounds.c
@@ -1,9 +1,6 @@
-// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-X86-ADDR64 %s \
-// RUN: --implicit-check-not 'past the last possible element'
-// RUN: %clang_cc1 -triple i386-pc-linux-gnu -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-I386-ADDR32 %s \
-// RUN: --implicit-check-not 'past the last possible element'
-// RUN: %clang_cc1 -triple avr-pc-linux-gnu -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-AVR-ADDR16 %s \
-// RUN: --implicit-check-not 'past the last possible element'
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only -Wno-unused -verify=addr64,expected %s
+// RUN: %clang_cc1 -triple i386-pc-linux-gnu -fsyntax-only -Wno-unused -verify=addr32,expected %s
+// RUN: %clang_cc1 -triple avr-pc-linux-gnu -fsyntax-only -Wno-unused -verify=addr16,expected %s
struct S {
long long a;
@@ -12,61 +9,61 @@ struct S {
short d;
};
-struct S s[];
+struct S s[]; // expected-warning {{tentative array definition}} expected-note {{declared here}} addr16-note {{declared here}}
void f1() {
++s[3].a;
++s[7073650413200313099].b;
- // CHECK-X86-ADDR64: :[[@LINE-1]]:5: warning: array index 7073650413200313099 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements)
- // CHECK-I386-ADDR32: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 178956970 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-3]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
+ // addr16-warning at -1 {{array index 7073650413200313099 refers past the last possible element for an array in 16-bit address space containing 160-bit (20-byte) elements (max possible 3276 elements)}}
+ // addr32-warning at -2 {{array index 7073650413200313099 refers past the last possible element for an array in 32-bit address space containing 192-bit (24-byte) elements (max possible 178956970 elements)}}
+ // addr64-warning at -3 {{array index 7073650413200313099 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements)}}
++s[7073650].c;
- // CHECK-AVR-ADDR16: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
+ // addr16-warning at -1 {{array index 7073650 refers past the last possible element for an array in 16-bit address space containing 160-bit (20-byte) elements (max possible 3276 elements)}}
}
-long long ll[];
+long long ll[]; // expected-warning {{tentative array definition}} expected-note {{declared here}} addr16-note {{declared here}} addr32-note {{declared here}}
void f2() {
++ll[3];
++ll[2705843009213693952];
- // CHECK-X86-ADDR64: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 64-bit {{.*}} (max possible 2305843009213693952 elements)
- // CHECK-I386-ADDR32: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 536870912 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-3]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 8192 elements)
+ // addr16-warning at -1 {{array index 2705843009213693952 refers past the last possible element for an array in 16-bit address space containing 64-bit (8-byte) elements (max possible 8192 elements)}}
+ // addr32-warning at -2 {{array index 2705843009213693952 refers past the last possible element for an array in 32-bit address space containing 64-bit (8-byte) elements (max possible 536870912 elements)}}
+ // addr64-warning at -3 {{array index 2705843009213693952 refers past the last possible element for an array in 64-bit address space containing 64-bit (8-byte) elements (max possible 2305843009213693952 elements)}}
++ll[847073650];
- // CHECK-I386-ADDR32: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 536870912 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 8192 elements)
+ // addr16-warning at -1 {{array index 847073650 refers past the last possible element for an array in 16-bit address space containing 64-bit (8-byte) elements (max possible 8192 elements)}}
+ // addr32-warning at -2 {{array index 847073650 refers past the last possible element for an array in 32-bit address space containing 64-bit (8-byte) elements (max possible 536870912 elements)}}
}
-void f3(struct S p[]) {
+void f3(struct S p[]) { // expected-note {{declared here}} addr16-note {{declared here}}
++p[3].a;
++p[7073650413200313099].b;
- // CHECK-X86-ADDR64: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 64-bit {{.*}} (max possible 576460752303423488 elements)
- // CHECK-I386-ADDR32: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 178956970 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-3]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
+ // addr16-warning at -1 {{array index 7073650413200313099 refers past the last possible element for an array in 16-bit address space containing 160-bit (20-byte) elements (max possible 3276 elements)}}
+ // addr32-warning at -2 {{array index 7073650413200313099 refers past the last possible element for an array in 32-bit address space containing 192-bit (24-byte) elements (max possible 178956970 elements)}}
+ // addr64-warning at -3 {{array index 7073650413200313099 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements)}}
++p[7073650].c;
- // CHECK-AVR-ADDR16: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
+ // addr16-warning at -1 {{array index 7073650 refers past the last possible element for an array in 16-bit address space containing 160-bit (20-byte) elements (max possible 3276 elements)}}
}
-void f4(struct S *p) {
+void f4(struct S *p) { // expected-note {{declared here}} addr16-note {{declared here}}
p += 3;
p += 7073650413200313099;
- // CHECK-X86-ADDR64: :[[@LINE-1]]:3: warning: the pointer incremented by 7073650413200313099 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements)
- // CHECK-I386-ADDR32: :[[@LINE-2]]:3: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 178956970 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-3]]:3: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
+ // addr16-warning at -1 {{the pointer incremented by 7073650413200313099 refers past the last possible element for an array in 16-bit address space containing 160-bit (20-byte) elements (max possible 3276 elements)}}
+ // addr32-warning at -2 {{the pointer incremented by 7073650413200313099 refers past the last possible element for an array in 32-bit address space containing 192-bit (24-byte) elements (max possible 178956970 elements)}}
+ // addr64-warning at -3 {{the pointer incremented by 7073650413200313099 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements)}}
p += 7073650;
- // CHECK-AVR-ADDR16: :[[@LINE-1]]:3: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
+ // addr16-warning at -1 {{the pointer incremented by 7073650 refers past the last possible element for an array in 16-bit address space containing 160-bit (20-byte) elements (max possible 3276 elements)}}
}
struct BQ {
struct S bigblock[3276];
};
-struct BQ bq[];
+struct BQ bq[]; // expected-warning {{tentative array definition}} addr16-note {{declared here}}
void f5() {
++bq[0].bigblock[0].a;
++bq[1].bigblock[0].a;
- // CHECK-AVR-ADDR16: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 1 element)
+ // addr16-warning at -1 {{array index 1 refers past the last possible element for an array in 16-bit address space containing 524160-bit (65520-byte) elements (max possible 1 element)}}
}
void f6() {
@@ -78,3 +75,8 @@ void f6() {
// Should NOT produce a warning.
*(middle + 5 - N) = 22;
}
+
+void pr50741() {
+ (void *)0 + 0xdead000000000000UL;
+ // no array-bounds warning, and no crash
+}
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