Ignore -ivfsoverlay parameter (#839)

Co-authored-by: Peter Steinberger <steipete@gmail.com>

8 files changed, 71 insertions, 4 deletions

diff --git a/doc/MANUAL.adoc b/doc/MANUAL.adoc
index 2b6f0012..b74277c5 100644
--- a/doc/MANUAL.adoc
+++ b/doc/MANUAL.adoc
@@ -824,6 +824,10 @@ still has to do _some_ preprocessing (like macros).
     mtime is too new. This sloppiness disables that check. See also
     _<<_handling_of_newly_created_header_files,Handling of newly created header
     files>>_.
+*ivsfsoverlay*::
+    Ignore the Clang compiler option *-ivfsoverlay* and its argument. This is
+    useful if you use Xcode, which uses virtual file system (VFS) for
+    combining Objective-C and Swift code for example.
 *locale*::
     Ccache includes the environment variables *LANG*, *LC_ALL*, *LC_CTYPE* and
     *LC_MESSAGES* in the hash by default since they may affect localization of
diff --git a/src/Config.cpp b/src/Config.cpp
index 68dc3f57..9e709236 100644
--- a/src/Config.cpp
+++ b/src/Config.cpp
@@ -275,6 +275,8 @@ parse_sloppiness(const std::string& value)
       result |= SLOPPY_LOCALE;
     } else if (token == "modules") {
       result |= SLOPPY_MODULES;
+    } else if (token == "ivfsoverlay") {
+      result |= SLOPPY_IVFSOVERLAY;
     } // else: ignore unknown value for forward compatibility
     start = value.find_first_not_of(", ", end);
   }
@@ -315,6 +317,9 @@ format_sloppiness(uint32_t sloppiness)
   if (sloppiness & SLOPPY_MODULES) {
     result += "modules, ";
   }
+  if (sloppiness & SLOPPY_IVFSOVERLAY) {
+    result += "ivfsoverlay, ";
+  }
   if (!result.empty()) {
     // Strip last ", ".
     result.resize(result.size() - 2);
diff --git a/src/Sloppiness.hpp b/src/Sloppiness.hpp
index bd2078e9..62c0508a 100644
--- a/src/Sloppiness.hpp
+++ b/src/Sloppiness.hpp
@@ -38,4 +38,6 @@ enum Sloppiness {
   SLOPPY_LOCALE = 1 << 8,
   // Allow caching even if -fmodules is used.
   SLOPPY_MODULES = 1 << 9,
+  // Ignore virtual file system (VFS) overlay file.
+  SLOPPY_IVFSOVERLAY = 1 << 10,
 };
diff --git a/src/argprocessing.cpp b/src/argprocessing.cpp
index b2ba1e0c..92b929e0 100644
--- a/src/argprocessing.cpp
+++ b/src/argprocessing.cpp
@@ -232,6 +232,15 @@ process_arg(Context& ctx,
     return nullopt;
   }
 
+  // Ignore clang -ivfsoverlay <arg> to not detect multiple input files.
+  if (args[i] == "-ivfsoverlay"
+      && !(config.sloppiness() & SLOPPY_IVFSOVERLAY)) {
+    LOG_RAW(
+      "You have to specify \"ivfsoverlay\" sloppiness when using"
+      " -ivfsoverlay to get hits");
+    return Statistic::unsupported_compiler_option;
+  }
+
   // Special case for -E.
   if (args[i] == "-E") {
     return Statistic::called_for_preprocessing;
diff --git a/src/compopt.cpp b/src/compopt.cpp
index 96cc047c..447f8e99 100644
--- a/src/compopt.cpp
+++ b/src/compopt.cpp
@@ -115,6 +115,7 @@ const CompOpt compopts[] = {
   {"-iquote", AFFECTS_CPP | TAKES_ARG | TAKES_CONCAT_ARG | TAKES_PATH},
   {"-isysroot", AFFECTS_CPP | TAKES_ARG | TAKES_CONCAT_ARG | TAKES_PATH},
   {"-isystem", AFFECTS_CPP | TAKES_ARG | TAKES_CONCAT_ARG | TAKES_PATH},
+  {"-ivfsoverlay", TAKES_ARG},
   {"-iwithprefix", AFFECTS_CPP | TAKES_ARG | TAKES_CONCAT_ARG | TAKES_PATH},
   {"-iwithprefixbefore",
    AFFECTS_CPP | TAKES_ARG | TAKES_CONCAT_ARG | TAKES_PATH},
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index c33befd0..ae0df8e8 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -47,6 +47,7 @@ addtest(fileclone)
 addtest(hardlink)
 addtest(inode_cache)
 addtest(input_charset)
+addtest(ivfsoverlay)
 addtest(masquerading)
 addtest(modules)
 addtest(multi_arch)
diff --git a/test/suites/ivfsoverlay.bash b/test/suites/ivfsoverlay.bash
new file mode 100644
index 00000000..ca882217
--- /dev/null
+++ b/test/suites/ivfsoverlay.bash
@@ -0,0 +1,44 @@
+SUITE_ivfsoverlay_PROBE() {
+    if ! $COMPILER_TYPE_CLANG; then
+        echo "-ivfsoverlay not supported by compiler"
+    else
+        touch test.c
+        cat <<EOF >test.yaml
+{"case-sensitive":"false","roots":[],"version":0}
+EOF
+        $COMPILER -ivfsoverlay test.yaml test.c -S || echo "compiler does not support -ivfsoverlay"
+    fi
+}
+
+SUITE_ivfsoverlay_SETUP() {
+    unset CCACHE_NODIRECT
+
+    cat <<EOF >test.yaml
+{"case-sensitive":"false","roots":[],"version":0}
+EOF
+    cat <<EOF >test.c
+// test.c
+int test;
+EOF
+}
+
+SUITE_ivfsoverlay() {
+    # -------------------------------------------------------------------------
+    TEST "without sloppy ivfsoverlay"
+
+    $CCACHE_COMPILE -ivfsoverlay test.yaml -c test.c
+    expect_stat 'cache hit (direct)' 0
+    expect_stat 'cache miss' 0
+    expect_stat 'unsupported compiler option' 1
+
+    # -------------------------------------------------------------------------
+    TEST "with sloppy ivfsoverlay"
+
+    CCACHE_SLOPPINESS="$DEFAULT_SLOPPINESS ivfsoverlay" $CCACHE_COMPILE -ivfsoverlay test.yaml -c test.c
+    expect_stat 'cache hit (direct)' 0
+    expect_stat 'cache miss' 1
+
+    CCACHE_SLOPPINESS="$DEFAULT_SLOPPINESS ivfsoverlay" $CCACHE_COMPILE -ivfsoverlay test.yaml -c test.c
+    expect_stat 'cache hit (direct)' 1
+    expect_stat 'cache miss' 1
+}
diff --git a/unittest/test_Config.cpp b/unittest/test_Config.cpp
index fad4ff42..e509c9ce 100644
--- a/unittest/test_Config.cpp
+++ b/unittest/test_Config.cpp
@@ -128,7 +128,7 @@ TEST_CASE("Config::update_from_file")
     "run_second_cpp = false\n"
     "sloppiness =     time_macros   ,include_file_mtime"
     "  include_file_ctime,file_stat_matches,file_stat_matches_ctime,pch_defines"
-    " ,  no_system_headers,system_headers,clang_index_store\n"
+    " ,  no_system_headers,system_headers,clang_index_store,ivfsoverlay\n"
     "stats = false\n"
     "temporary_dir = ${USER}_foo\n"
     "umask = 777"); // Note: no newline.
@@ -169,7 +169,8 @@ TEST_CASE("Config::update_from_file")
         == (SLOPPY_INCLUDE_FILE_MTIME | SLOPPY_INCLUDE_FILE_CTIME
             | SLOPPY_TIME_MACROS | SLOPPY_FILE_STAT_MATCHES
             | SLOPPY_FILE_STAT_MATCHES_CTIME | SLOPPY_SYSTEM_HEADERS
-            | SLOPPY_PCH_DEFINES | SLOPPY_CLANG_INDEX_STORE));
+            | SLOPPY_PCH_DEFINES | SLOPPY_CLANG_INDEX_STORE
+            | SLOPPY_IVFSOVERLAY));
   CHECK_FALSE(config.stats());
   CHECK(config.temporary_dir() == FMT("{}_foo", user));
   CHECK(config.umask() == 0777);
@@ -402,7 +403,7 @@ TEST_CASE("Config::visit_items")
     "run_second_cpp = false\n"
     "sloppiness = include_file_mtime, include_file_ctime, time_macros,"
     " file_stat_matches, file_stat_matches_ctime, pch_defines, system_headers,"
-    " clang_index_store\n"
+    " clang_index_store, ivfsoverlay\n"
     "stats = false\n"
     "temporary_dir = td\n"
     "umask = 022\n");
@@ -459,7 +460,7 @@ TEST_CASE("Config::visit_items")
     "(test.conf) run_second_cpp = false",
     "(test.conf) sloppiness = include_file_mtime, include_file_ctime,"
     " time_macros, pch_defines, file_stat_matches, file_stat_matches_ctime,"
-    " system_headers, clang_index_store",
+    " system_headers, clang_index_store, ivfsoverlay",
     "(test.conf) stats = false",
     "(test.conf) temporary_dir = td",
     "(test.conf) umask = 022",