Author: Fangrui Song Date: 2020-04-23T18:26:06-07:00 New Revision: 14aaf4457c641bd5130072ba2a035e254b92fad3
URL: https://github.com/llvm/llvm-project/commit/14aaf4457c641bd5130072ba2a035e254b92fad3 DIFF: https://github.com/llvm/llvm-project/commit/14aaf4457c641bd5130072ba2a035e254b92fad3.diff LOG: [Sema] Split off warn_impcast_integer_float_precision_constant into -Wimplicit-const-int-float-conversion Currently, both `warn_impcast_integer_float_precision_constant` and `warn_impcast_integer_float_precision` are covered by -Wimplicit-int-float-conversion, but only the ..._constant warning is on by default. `warn_impcast_integer_float_precision_constant` likely flags real problems while `warn_impcast_integer_float_precision` may flag legitimate use cases (for example, `int` used with limited range supported by `float`). If -Wno-implicit-int-float-conversion is used, currently there is no way to restore the ..._constant warning. This patch adds -Wimplicit-const-int-float-conversion to address the issue. (Similar to the reasoning in https://reviews.llvm.org/D64666#1598194) Adapted from a patch by Brooks Moses. Reviewed By: nickdesaulniers Differential Revision: https://reviews.llvm.org/D78661 Added: Modified: clang/include/clang/Basic/DiagnosticGroups.td clang/include/clang/Basic/DiagnosticSemaKinds.td clang/test/Sema/implicit-int-float-conversion.c Removed: ################################################################################ diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td index 87444e5b6d98..3db9d5814ba3 100644 --- a/clang/include/clang/Basic/DiagnosticGroups.td +++ b/clang/include/clang/Basic/DiagnosticGroups.td @@ -85,7 +85,9 @@ def ObjCSignedCharBoolImplicitIntConversion : DiagGroup<"objc-signed-char-bool-implicit-int-conversion">; def ImplicitIntConversion : DiagGroup<"implicit-int-conversion", [ObjCSignedCharBoolImplicitIntConversion]>; -def ImplicitIntFloatConversion : DiagGroup<"implicit-int-float-conversion">; +def ImplicitConstIntFloatConversion : DiagGroup<"implicit-const-int-float-conversion">; +def ImplicitIntFloatConversion : DiagGroup<"implicit-int-float-conversion", + [ImplicitConstIntFloatConversion]>; def ObjCSignedCharBoolImplicitFloatConversion : DiagGroup<"objc-signed-char-bool-implicit-float-conversion">; def ImplicitFloatConversion : DiagGroup<"implicit-float-conversion", diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 1101bd5a4bb6..c9aa49a31ed8 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -3549,7 +3549,7 @@ def warn_impcast_integer_float_precision : Warning< InGroup<ImplicitIntFloatConversion>, DefaultIgnore; def warn_impcast_integer_float_precision_constant : Warning< "implicit conversion from %2 to %3 changes value from %0 to %1">, - InGroup<ImplicitIntFloatConversion>; + InGroup<ImplicitConstIntFloatConversion>; def warn_impcast_float_to_integer : Warning< "implicit conversion from %0 to %1 changes value from %2 to %3">, diff --git a/clang/test/Sema/implicit-int-float-conversion.c b/clang/test/Sema/implicit-int-float-conversion.c index b8c29d2d457d..f2a2838b6406 100644 --- a/clang/test/Sema/implicit-int-float-conversion.c +++ b/clang/test/Sema/implicit-int-float-conversion.c @@ -1,8 +1,12 @@ -// RUN: %clang_cc1 %s -verify -Wno-conversion -Wimplicit-int-float-conversion +// RUN: %clang_cc1 %s -verify +// RUN: %clang_cc1 %s -verify -Wno-implicit-int-float-conversion -Wimplicit-const-int-float-conversion +// RUN: %clang_cc1 %s -DNONCONST=1 -verify -Wimplicit-int-float-conversion +#ifdef NONCONST long testReturn(long a, float b) { return a + b; // expected-warning {{implicit conversion from 'long' to 'float' may lose precision}} } +#endif void testAssignment() { float f = 222222; @@ -12,7 +16,9 @@ void testAssignment() { float ffff = 222222222222UL; // expected-warning {{changes value from 222222222222 to 222222221312}} long l = 222222222222L; +#ifdef NONCOST float fff = l; // expected-warning {{implicit conversion from 'long' to 'float' may lose precision}} +#endif } void testExpression() { @@ -24,7 +30,9 @@ void testExpression() { float c = 22222222 + 22222223; // expected-warning {{implicit conversion from 'int' to 'float' changes value from 44444445 to 44444444}} int i = 0; +#ifdef NONCONST float d = i + a; // expected-warning {{implicit conversion from 'int' to 'float' may lose precision}} +#endif double e = 0.0; double f = i + e; @@ -36,5 +44,7 @@ void testCNarrowing() { float a = {222222222222L}; // expected-warning {{changes value from 222222222222 to 222222221312}} long b = 222222222222L; +#ifdef NONCONST float c = {b}; // expected-warning {{implicit conversion from 'long' to 'float' may lose precision}} +#endif } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits