Merge pull request #5336 from modocache/sr-2855-driver-show-incremental-args

[SR-2855] Show args mismatch in -driver-show-incremental

Author: modocache

lib/Driver/Driver.cpp

@@ -342,6 +342,10 @@ static bool populateOutOfDateMap(InputInfoMap &map, StringRef argsHashStr,
   }
 
   if (!optionsMatch) {
+    if (ShowIncrementalBuildDecisions) {
+      llvm::outs() << "Incremental compilation has been disabled, because "
+                   << "different arguments were passed to the compiler.\n";
+    }
     return true;
   }
 

test/Driver/Dependencies/driver-show-incremental-arguments.swift

@@ -0,0 +1,22 @@
+// Test that when:
+//
+// 1. Using -incremental -v -driver-show-incremental, and...
+// 2. ...the arguments passed to the Swift compiler version differ from the ones
+//    used in the original compilation...
+//
+// ...then the driver prints a message indicating that incremental compilation
+// is disabled.
+
+
+// RUN: rm -rf %t && cp -r %S/Inputs/one-way/ %t
+// RUN: %S/Inputs/touch.py 443865900 %t/*
+// RUN: echo '{version: "'$(%swiftc_driver_plain -version | head -n1)'", inputs: {"./main.swift": [443865900, 0], "./other.swift": [443865900, 0]}}' > %t/main~buildrecord.swiftdeps
+
+// RUN: cd %t && %swiftc_driver -driver-use-frontend-path %S/Inputs/update-dependencies.py -c ./main.swift ./other.swift -module-name main -incremental -v -driver-show-incremental -output-file-map %t/output.json | %FileCheck --check-prefix CHECK-INCREMENTAL %s
+// CHECK-INCREMENTAL-NOT: Incremental compilation has been disabled
+// CHECK-INCREMENTAL: Queuing main.swift (initial)
+
+// RUN: cd %t && %swiftc_driver -driver-use-frontend-path %S/Inputs/update-dependencies.py -g -c ./main.swift ./other.swift -module-name main -incremental -v -driver-show-incremental -output-file-map %t/output.json | %FileCheck --check-prefix CHECK-ARGS-MISMATCH %s
+// CHECK-ARGS-MISMATCH: Incremental compilation has been disabled{{.*}}different arguments
+// CHECK-ARGS-MISMATCH-NOT: Queuing main.swift (initial)
+