Merge branch 'eyraud/109' into 'master'

C/C++ instr: consider other compiler switches for preprocessing

See merge request eng/cov/gnatcoverage!255

Ref: eng/cov/gnatcoverage#109

Author: Jugst3r

testsuite/tests/instr-cov/C++/109-pp-switches/main.cpp

@@ -0,0 +1,7 @@
+#include <typeinfo>
+
+int
+main (int argc, char **argv)
+{
+  return 0;
+}

testsuite/tests/instr-cov/C++/109-pp-switches/test.py

@@ -0,0 +1,33 @@
+"""
+Check that the instrumenter considers the -fno-rtti switch for preprocessing.
+"""
+
+from SCOV.minicheck import build_run_and_coverage, check_xcov_reports
+from SCOV.instr import xcov_instrument
+from SUITE.context import thistest
+from SUITE.cutils import Wdir
+from SUITE.tutils import gprbuild, gprfor
+from SUITE.gprutils import GPRswitches
+
+
+tmp = Wdir("tmp_")
+
+build_run_and_coverage(
+    gprsw=GPRswitches(root_project=gprfor(srcdirs=[".."], mains=["main.cpp"])),
+    covlevel="stmt",
+    mains=["main"],
+    extra_instr_args=["--c++-opts=-fno-rtti"],
+    extra_gprbuild_cargs=["-fno-rtti"],
+    extra_coverage_args=["-axcov", "--output-dir=xcov"],
+    trace_mode="src",
+)
+
+check_xcov_reports(
+    "*.xcov",
+    {
+        "main.cpp.xcov": {"+": {6}},
+    },
+    "xcov",
+)
+
+thistest.result()

tools/gnatcov/compiler_wrappers-gcc.adb

@@ -361,6 +361,7 @@ is
             if Ends_With (Arg, ".c")
               or else Ends_With (Arg, ".cc")
               or else Ends_With (Arg, ".cpp")
+              or else Ends_With (Arg, ".cxx")
             then
                if Length (Result.Filename) = 0 then
                   Result.Filename := +Ada.Directories.Full_Name (+Arg);

tools/gnatcov/instrument-c.adb

@@ -80,15 +80,11 @@ package body Instrument.C is
    type Macro_Set_Cst_Access is access constant Macro_Set;
 
    function Builtin_Macros
-     (Lang, Compiler, Std, Output_Dir : String) return Macro_Set_Cst_Access;
-   --  Return the list of built-in macros for the given compiler, standard and
-   --  language. Output_Dir is used to store a temporary file.
-   --
-   --  Note that we could generate a fully-fledged preprocessor configuration
-   --  (the standard macros + the command-line defined macros with an
-   --  additional argument there), but it is more convenient to cache the
-   --  "light" preprocessor configuration that is determined by the compiler,
-   --  language and standard only.
+     (Lang, Compiler, Output_Dir : String;
+      Compiler_Switches : String_Vectors.Vector) return Macro_Set_Cst_Access;
+   --  Return the list of built-in macros for the given compiler, language and
+   --  according to the compiler switches. Output_Dir is used to store a
+   --  temporary file.
 
    procedure Preprocess_Source
      (Filename      : String;
@@ -2524,16 +2520,15 @@ package body Instrument.C is
    --------------------
 
    function Builtin_Macros
-     (Lang, Compiler, Std, Output_Dir : String) return Macro_Set_Cst_Access
+     (Lang, Compiler, Output_Dir : String;
+      Compiler_Switches : String_Vectors.Vector) return Macro_Set_Cst_Access
    is
       use Ada.Characters.Handling;
 
       PID : constant Unsigned_64 :=
         Unsigned_64 (Pid_To_Integer (Current_Process_Id));
 
       L      : constant String := To_Lower (Lang);
-      Key    : constant Unbounded_String :=
-        +Compiler & " -x " & L & " " & Std;
       Result : constant Macro_Set_Access := new Macro_Set;
 
       Args     : String_Vectors.Vector;
@@ -2549,18 +2544,15 @@ package body Instrument.C is
 
       Args.Append (+"-x");
       Args.Append (+L);
-      if Std'Length /= 0 then
-         Args.Append (+Std);
-      end if;
+      Args.Append (Compiler_Switches);
       Args.Append (+"-E");
       Args.Append (+"-dM");
       Args.Append (+"-");
 
       Run_Command
         (Command             => Compiler,
          Arguments           => Args,
-         Origin_Command_Name =>
-           "getting built-in macros for " & (+Key),
+         Origin_Command_Name => "gnatcov instrument",
          Output_File         => Filename,
          In_To_Null          => True);
 
@@ -4532,8 +4524,8 @@ package body Instrument.C is
         Builtin_Macros
           (Image (C_Family_Language (Instrumenter.Language)),
            +Prj.Compiler_Driver (Instrumenter.Language),
-           +Self.Std,
-           +Prj.Output_Dir).all;
+           +Prj.Output_Dir,
+           Self.Compiler_Switches).all;
    end Import_Options;
 
    ---------------------------

tools/gnatcov/instrument-common.adb

@@ -473,13 +473,13 @@ package body Instrument.Common is
          Add_Macro_Switches (Options.PP_Macros);
       end if;
 
-      --  The -std switch also indicates the C/C++ version used, and
-      --  influences both the configuration of the preprocessor, and the
-      --  parsing of the file.
+      --  Add other compiler switches as they may also influence both the
+      --  configuration of the preprocessor, and the parsing of the file. A
+      --  non-exhaustive list includes undefining macros through -U switches,
+      --  using -std to change the C++ standard in use, -fno-rtti to prevent
+      --  inclusion of runtime type information etc.
 
-      if Length (Options.Std) /= 0 then
-         Args.Append (Options.Std);
-      end if;
+      Args.Append (Options.Compiler_Switches);
 
    end Add_Options;
 
@@ -638,11 +638,21 @@ package body Instrument.Common is
 
             elsif Read_With_Argument (A, 'U', Value) then
                Self.PP_Macros.Include ((Define => False, Name => Value));
+               --  Account for all the switches that can influence the file
+               --  preprocessing.
 
-            elsif Has_Prefix (A, "-std=") then
-               Self.Std := +A;
-            end if;
+            elsif Has_Prefix (A, "-std")
+              or else Has_Prefix (A, "-fno-rtti")
+              or else Has_Prefix (A, "-fno-exceptions")
 
+              --  All the warning switches can influence the preprocessing
+              --  through the use of the __has_warning macro, e.g.
+              --  #if __has_warning("-Wimplicit-fallthrough")
+
+              or else Has_Prefix (A, "-W")
+            then
+               Self.Compiler_Switches.Append (+A);
+            end if;
             I := I + 1;
          end;
       end loop;

tools/gnatcov/instrument-common.ads

@@ -552,9 +552,10 @@ package Instrument.Common is
       PP_Macros : Macro_Set;
       --  Set of macros for the preprocessor
 
-      Std : Unbounded_String;
-      --  -std=X argument to pass to the preprocessor and the parser, or the
-      --  empty string.
+      Compiler_Switches : String_Vectors.Vector;
+      --  List of compiler switches that can influence the file preprocessing.
+      --  The list should be amended alongside our discoveries. It is
+      --  currently: -std, -fno-exceptions, -fno-rtti, -W* switches.
    end record;
    --  Options to analyze (preprocess and/or parse) a compilation unit