[OpenMP][libomp] Fix fallthrough attribute detection for Intel compilers

icc does not properly detect lack of fallthrough attribute since it defines __GNU__ > 7 and also icc's __has_cpp_attribute/__has_attribute feature detectors do not properly detect the lack of fallthrough attribute. Differential Revision: https://reviews.llvm.org/D126001
llvm · Jul 19, 2022 · 28c8da2 · 28c8da2
1 parent b7d3ba4
commit 28c8da2
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diff --git a/openmp/runtime/src/kmp_os.h b/openmp/runtime/src/kmp_os.h
@@ -345,6 +345,9 @@ extern "C" {
 // Use a function like macro to imply that it must be followed by a semicolon
 #if __cplusplus > 201402L && __has_cpp_attribute(fallthrough)
 #define KMP_FALLTHROUGH() [[fallthrough]]
+// icc cannot properly tell this attribute is absent so force off
+#elif KMP_COMPILER_ICC
+#define KMP_FALLTHROUGH() ((void)0)
 #elif __has_cpp_attribute(clang::fallthrough)
 #define KMP_FALLTHROUGH() [[clang::fallthrough]]
 #elif __has_attribute(fallthrough) || __GNUC__ >= 7

diff --git a/openmp/tools/archer/ompt-tsan.cpp b/openmp/tools/archer/ompt-tsan.cpp
@@ -42,6 +42,9 @@
 // Use a function like macro to imply that it must be followed by a semicolon
 #if __cplusplus > 201402L && __has_cpp_attribute(fallthrough)
 #define KMP_FALLTHROUGH() [[fallthrough]]
+// icc cannot properly tell this attribute is absent so force off
+#elif defined(__INTEL_COMPILER)
+#define KMP_FALLTHROUGH() ((void)0)
 #elif __has_cpp_attribute(clang::fallthrough)
 #define KMP_FALLTHROUGH() [[clang::fallthrough]]
 #elif __has_attribute(fallthrough) || __GNUC__ >= 7