Setup-integration: improve error message when failing to load gnatcov_rts

Author: leocreuse

testsuite/tests/integrated_instrumentation/168-rts_error_msg/gnatcov_rts.gpr

@@ -0,0 +1 @@
+INVALID PROJECT FILE FOR TEST PURPOSES

testsuite/tests/integrated_instrumentation/168-rts_error_msg/main.c

@@ -0,0 +1,5 @@
+int
+main ()
+{
+  return 0;
+}

testsuite/tests/integrated_instrumentation/168-rts_error_msg/test.py

@@ -0,0 +1,44 @@
+"""
+Test that the error message emitted by the "gnatcov setup-integration" command
+is helpful when failing to load the coverage runtime project.
+"""
+
+import os
+
+from SUITE.cutils import Wdir
+from SUITE.tutils import contents_of, thistest, xcov
+
+# Point gnatcov towards our invalid GNATcov_RTS project
+env = os.environ
+env["GPR_PROJECT_PATH"] = os.getcwd()
+
+tmp = Wdir("tmp_")
+
+# Try to setup for a simple main file
+integration_log = "setup-integration.log"
+p = xcov(
+    [
+        "setup-integration",
+        "-cstmt+mcdc",
+        "--output-dir=.",
+        "--files=../main.c",
+    ],
+    env=env,
+    out=integration_log,
+    register_failure=False
+)
+
+thistest.fail_if(p.status == 0, "gnatcov exit status shouldn't be success")
+
+# Check that the error message correctly reports an issue with the coverage
+# runtime.
+thistest.fail_if_no_match(
+    what="gnatcov error message",
+    regexp=r".*gnatcov(\.exe)?: Failed locating or loading gnatcov_rts\.gpr"
+           r"(\n|.)*Is the project available on the GPR_PROJECT_PATH\?"
+           r"(\n|.)*gprls output was:"
+           r"(\n|.)*",
+    actual=contents_of(integration_log),
+)
+
+thistest.result()

tools/gnatcov/instrument-setup_config.adb

@@ -136,16 +136,28 @@ package body Instrument.Setup_Config is
          Output_Filename : constant String :=
            Output_Dir / "gprls_output";
          Output_File     : File_Type;
+         GPRLS_Success   : Boolean;
       begin
          Args.Append (+"-P");
          Args.Append (+"gnatcov_rts");
          Args.Append (+"-vP1");
-         Run_Command
+         GPRLS_Success := Run_Command
            (Command             => "gprls",
             Arguments           => Args,
             Origin_Command_Name => "gnatcov setup-integration",
-            Output_File         => Output_Filename);
+            Output_File         => Output_Filename,
+            Ignore_Error        => True);
          Open (Output_File, In_File, Output_Filename);
+         if not GPRLS_Success then
+            Outputs.Error ("Failed locating or loading gnatcov_rts.gpr");
+            Warning_Or_Error ("Is the project available on the"
+                              & " GPR_PROJECT_PATH?");
+            Warning_Or_Error ("gprls output was:");
+            while not End_Of_File (Output_File) loop
+               Warning_Or_Error (Get_Line (Output_File));
+            end loop;
+            raise Xcov_Exit_Exc;
+         end if;
          while not End_Of_File (Output_File) loop
             declare
                Line : constant String := Get_Line (Output_File);