feat: Include I_MPI_CC/I_MPI_CXX in the input hash

The I_MPI_CC and I_MPI_CXX variables affect which underlying compiler
ICC uses. Reference:
<https://www.intel.com/content/www/us/en/develop/documentation/
mpi-developer-reference-windows/top/environment-variable-reference/
compilation-environment-variables.html>.

Closes #1210.

diff --git a/src/ccache.cpp b/src/ccache.cpp
index 9bc5c5f2bb103c558d22e9c81a110c22790a22ae..20ce2e2a72f8a2ef7e32a60c441911deb9650b3c 100644 (file)
--- a/src/ccache.cpp
+++ b/src/ccache.cpp
@@ -1381,6 +1381,12 @@ hash_common_info(const Context& ctx,
     "COMPILER_PATH",
     "GCC_COMPARE_DEBUG",
     "GCC_EXEC_PREFIX",
+    // Variables that affect which underlying compiler ICC uses. Reference:
+    // <https://www.intel.com/content/www/us/en/develop/documentation/
+    // mpi-developer-reference-windows/top/environment-variable-reference/
+    // compilation-environment-variables.html>
+    "I_MPI_CC",
+    "I_MPI_CXX",
 #ifdef __APPLE__
     // On macOS, /usr/bin/clang is a compiler wrapper that switches compiler
     // based on at least these variables: