Author: Micah Weston Date: 2022-05-09T10:16:19-04:00 New Revision: 882915df61e33f3a2b7f58e52f572717e1c11499
URL: https://github.com/llvm/llvm-project/commit/882915df61e33f3a2b7f58e52f572717e1c11499 DIFF: https://github.com/llvm/llvm-project/commit/882915df61e33f3a2b7f58e52f572717e1c11499.diff LOG: Enum conversion warning when one signed and other unsigned. Ensures an -Wenum-conversion warning happens when one of the enums is signed and the other is unsigned. Also adds a test file to verify these warnings. This warning would not happen since the -Wsign-conversion would make a diagnostic then return, never allowing the -Wenum-conversion checks. For example: C enum PE { P = -1 }; enum NE { N }; enum NE conv(enum PE E) { return E; } Before this would only create a diagnostic with -Wsign-conversion and never on -Wenum-conversion. Now it will create a diagnostic for both -Wsign-conversion and -Wenum-conversion. I could change it to just warn on -Wenum-conversion as that was what I initially did. Seeing PR35200 (or GitHub Issue 316268), I let both diagnostics check so that the sign conversion could generate a warning. Added: clang/test/Sema/enum-enum-conversion.c Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaChecking.cpp clang/test/Sema/enum-sign-conversion.c Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index a82ae8845e65..d4b38f3551fa 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -207,6 +207,9 @@ Improvements to Clang's diagnostics - ``-Wthread-safety-analysis`` now considers overloaded compound assignment and increment/decrement operators as writing to their first argument, thus requiring an exclusive lock if the argument is guarded. +- ``-Wenum-conversion`` now warns on converting a signed enum of one type to an + unsigned enum of a diff erent type (or vice versa) rather than + ``-Wsign-conversion``. Non-comprehensive list of changes in this release ------------------------------------------------- diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 31459af5033f..0cdceb47b738 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -13858,9 +13858,10 @@ static void CheckImplicitConversion(Sema &S, Expr *E, QualType T, // Fall through for non-constants to give a sign conversion warning. } - if ((TargetRange.NonNegative && !LikelySourceRange.NonNegative) || - (!TargetRange.NonNegative && LikelySourceRange.NonNegative && - LikelySourceRange.Width == TargetRange.Width)) { + if ((!isa<EnumType>(Target) || !isa<EnumType>(Source)) && + ((TargetRange.NonNegative && !LikelySourceRange.NonNegative) || + (!TargetRange.NonNegative && LikelySourceRange.NonNegative && + LikelySourceRange.Width == TargetRange.Width))) { if (S.SourceMgr.isInSystemMacro(CC)) return; diff --git a/clang/test/Sema/enum-enum-conversion.c b/clang/test/Sema/enum-enum-conversion.c new file mode 100644 index 000000000000..b6cfe722f63b --- /dev/null +++ b/clang/test/Sema/enum-enum-conversion.c @@ -0,0 +1,25 @@ +// RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only -Wenum-conversion -verify %s +// RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only -Wconversion -verify %s + +// Signed enums +enum SE1 { N1 = -1 }; +enum SE2 { N2 = -2 }; +// Unsigned unums +enum UE1 { P1 }; +enum UE2 { P2 }; + +enum UE2 f1(enum UE1 E) { + return E; // expected-warning {{implicit conversion from enumeration type 'enum UE1' to diff erent enumeration type 'enum UE2'}} +} + +enum SE1 f2(enum UE1 E) { + return E; // expected-warning {{implicit conversion from enumeration type 'enum UE1' to diff erent enumeration type 'enum SE1'}} +} + +enum UE1 f3(enum SE1 E) { + return E; // expected-warning {{implicit conversion from enumeration type 'enum SE1' to diff erent enumeration type 'enum UE1'}} +} + +enum SE2 f4(enum SE1 E) { + return E; // expected-warning {{implicit conversion from enumeration type 'enum SE1' to diff erent enumeration type 'enum SE2'}} +} diff --git a/clang/test/Sema/enum-sign-conversion.c b/clang/test/Sema/enum-sign-conversion.c index 518fc670d314..ecc7de2da857 100644 --- a/clang/test/Sema/enum-sign-conversion.c +++ b/clang/test/Sema/enum-sign-conversion.c @@ -1,13 +1,45 @@ -// RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only -verify -DUNSIGNED -Wsign-conversion %s -// RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only -verify -Wsign-conversion %s +// RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only -Wsign-conversion -verify=unsigned,both %s +// RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only -Wconversion -verify=unsigned,both %s +// RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only -verify -Wsign-conversion -verify=win32,both %s // PR35200 enum X { A,B,C}; int f(enum X x) { -#ifdef UNSIGNED - return x; // expected-warning {{implicit conversion changes signedness: 'enum X' to 'int'}} -#else - // expected-no-diagnostics - return x; -#endif + return x; // unsigned-warning {{implicit conversion changes signedness: 'enum X' to 'int'}} +} + +enum SE1 { N1 = -1 }; // Always a signed underlying type. +enum E1 { P1 }; // Unsigned underlying type except on Windows. + +// ensure no regression with enum to sign (related to enum-enum-conversion.c) +int f1(enum E1 E) { + return E; // unsigned-warning {{implicit conversion changes signedness: 'enum E1' to 'int'}} +} + +enum E1 f2(int E) { + return E; // unsigned-warning {{implicit conversion changes signedness: 'int' to 'enum E1'}} +} + +int f3(enum SE1 E) { + return E; // shouldn't warn +} + +enum SE1 f4(int E) { + return E; // shouldn't warn +} + +unsigned f5(enum E1 E) { + return E; // win32-warning {{implicit conversion changes signedness: 'enum E1' to 'unsigned int'}} +} + +enum E1 f6(unsigned E) { + return E; // win32-warning {{implicit conversion changes signedness: 'unsigned int' to 'enum E1'}} +} + +unsigned f7(enum SE1 E) { + return E; // both-warning {{implicit conversion changes signedness: 'enum SE1' to 'unsigned int'}} +} + +enum SE1 f8(unsigned E) { + return E; // both-warning {{implicit conversion changes signedness: 'unsigned int' to 'enum SE1'}} } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
