baloghadamsoftware created this revision.
Herald added a subscriber: whisperity.
Users reported some false positives using this check. This patch sets the
default value of the option for checking implicit widening casts to false. We
also suggest renaming the check to something like missing-or-misplaced-widening
cast so the name also covers the implicit case. This patch supersedes
https://reviews.llvm.org/D31097.
https://reviews.llvm.org/D32164
Files:
clang-tidy/misc/MisplacedWideningCastCheck.cpp
test/clang-tidy/misc-misplaced-widening-cast-implicit-enabled.cpp
test/clang-tidy/misc-misplaced-widening-cast.cpp
Index: test/clang-tidy/misc-misplaced-widening-cast.cpp
===================================================================
--- test/clang-tidy/misc-misplaced-widening-cast.cpp
+++ /dev/null
@@ -1,101 +0,0 @@
-// RUN: %check_clang_tidy %s misc-misplaced-widening-cast %t -- -config="{CheckOptions: [{key: misc-misplaced-widening-cast.CheckImplicitCasts, value: 1}]}" --
-
-void func(long arg) {}
-
-void assign(int a, int b) {
- long l;
-
- l = a * b;
- // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long' is ineffective, or there is loss of precision before the conversion [misc-misplaced-widening-cast]
- l = (long)(a * b);
- // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
- l = (long)a * b;
-
- l = a << 8;
- // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
- l = (long)(a << 8);
- // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
- l = (long)b << 8;
-
- l = static_cast<long>(a * b);
- // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
-}
-
-void compare(int a, int b, long c) {
- bool l;
-
- l = a * b == c;
- // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
- l = c == a * b;
- // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
- l = (long)(a * b) == c;
- // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
- l = c == (long)(a * b);
- // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
- l = (long)a * b == c;
- l = c == (long)a * b;
-}
-
-void init(unsigned int n) {
- long l1 = n << 8;
- // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: either cast from 'unsigned int' to 'long'
- long l2 = (long)(n << 8);
- // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: either cast from 'unsigned int' to 'long'
- long l3 = (long)n << 8;
-}
-
-void call(unsigned int n) {
- func(n << 8);
- // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: either cast from 'unsigned int' to 'long'
- func((long)(n << 8));
- // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: either cast from 'unsigned int' to 'long'
- func((long)n << 8);
-}
-
-long ret(int a) {
- if (a < 0) {
- return a * 1000;
- // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
- } else if (a > 0) {
- return (long)(a * 1000);
- // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
- } else {
- return (long)a * 1000;
- }
-}
-
-void dontwarn1(unsigned char a, int i, unsigned char *p) {
- long l;
- // The result is a 9 bit value, there is no truncation in the implicit cast.
- l = (long)(a + 15);
- // The result is a 12 bit value, there is no truncation in the implicit cast.
- l = (long)(a << 4);
- // The result is a 3 bit value, there is no truncation in the implicit cast.
- l = (long)((i % 5) + 1);
- // The result is a 16 bit value, there is no truncation in the implicit cast.
- l = (long)(((*p) << 8) + *(p + 1));
-}
-
-template <class T> struct DontWarn2 {
- void assign(T a, T b) {
- long l;
- l = (long)(a * b);
- }
-};
-DontWarn2<int> DW2;
-
-// Cast is not suspicious when casting macro.
-#define A (X<<2)
-long macro1(int X) {
- return (long)A;
-}
-
-// Don't warn about cast in macro.
-#define B(X,Y) (long)(X*Y)
-long macro2(int x, int y) {
- return B(x,y);
-}
-
-void floatingpoint(float a, float b) {
- double d = (double)(a * b); // Currently we don't warn for this.
-}
Index: test/clang-tidy/misc-misplaced-widening-cast-implicit-enabled.cpp
===================================================================
--- /dev/null
+++ test/clang-tidy/misc-misplaced-widening-cast-implicit-enabled.cpp
@@ -0,0 +1,101 @@
+// RUN: %check_clang_tidy %s misc-misplaced-widening-cast %t -- -config="{CheckOptions: [{key: misc-misplaced-widening-cast.CheckImplicitCasts, value: 1}]}" --
+
+void func(long arg) {}
+
+void assign(int a, int b) {
+ long l;
+
+ l = a * b;
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long' is ineffective, or there is loss of precision before the conversion [misc-misplaced-widening-cast]
+ l = (long)(a * b);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+ l = (long)a * b;
+
+ l = a << 8;
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+ l = (long)(a << 8);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+ l = (long)b << 8;
+
+ l = static_cast<long>(a * b);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+}
+
+void compare(int a, int b, long c) {
+ bool l;
+
+ l = a * b == c;
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+ l = c == a * b;
+ // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
+ l = (long)(a * b) == c;
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+ l = c == (long)(a * b);
+ // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
+ l = (long)a * b == c;
+ l = c == (long)a * b;
+}
+
+void init(unsigned int n) {
+ long l1 = n << 8;
+ // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: either cast from 'unsigned int' to 'long'
+ long l2 = (long)(n << 8);
+ // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: either cast from 'unsigned int' to 'long'
+ long l3 = (long)n << 8;
+}
+
+void call(unsigned int n) {
+ func(n << 8);
+ // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: either cast from 'unsigned int' to 'long'
+ func((long)(n << 8));
+ // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: either cast from 'unsigned int' to 'long'
+ func((long)n << 8);
+}
+
+long ret(int a) {
+ if (a < 0) {
+ return a * 1000;
+ // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
+ } else if (a > 0) {
+ return (long)(a * 1000);
+ // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
+ } else {
+ return (long)a * 1000;
+ }
+}
+
+void dontwarn1(unsigned char a, int i, unsigned char *p) {
+ long l;
+ // The result is a 9 bit value, there is no truncation in the implicit cast.
+ l = (long)(a + 15);
+ // The result is a 12 bit value, there is no truncation in the implicit cast.
+ l = (long)(a << 4);
+ // The result is a 3 bit value, there is no truncation in the implicit cast.
+ l = (long)((i % 5) + 1);
+ // The result is a 16 bit value, there is no truncation in the implicit cast.
+ l = (long)(((*p) << 8) + *(p + 1));
+}
+
+template <class T> struct DontWarn2 {
+ void assign(T a, T b) {
+ long l;
+ l = (long)(a * b);
+ }
+};
+DontWarn2<int> DW2;
+
+// Cast is not suspicious when casting macro.
+#define A (X<<2)
+long macro1(int X) {
+ return (long)A;
+}
+
+// Don't warn about cast in macro.
+#define B(X,Y) (long)(X*Y)
+long macro2(int x, int y) {
+ return B(x,y);
+}
+
+void floatingpoint(float a, float b) {
+ double d = (double)(a * b); // Currently we don't warn for this.
+}
Index: clang-tidy/misc/MisplacedWideningCastCheck.cpp
===================================================================
--- clang-tidy/misc/MisplacedWideningCastCheck.cpp
+++ clang-tidy/misc/MisplacedWideningCastCheck.cpp
@@ -21,7 +21,7 @@
MisplacedWideningCastCheck::MisplacedWideningCastCheck(
StringRef Name, ClangTidyContext *Context)
: ClangTidyCheck(Name, Context),
- CheckImplicitCasts(Options.get("CheckImplicitCasts", true)) {}
+ CheckImplicitCasts(Options.get("CheckImplicitCasts", false)) {}
void MisplacedWideningCastCheck::storeOptions(
ClangTidyOptions::OptionMap &Opts) {
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
