goto-cc: support GCC's print-sysroot* options

Hand these over to an underlying native compiler, and do the same for
all dump* options.

Includes clean-up of documentation placement and disable clang-format for the
collection of options.

Author: tautschnig

src/goto-cc/gcc_cmdline.cpp

@@ -18,9 +18,7 @@ Author: CM Wintersteiger, 2006
 
 #include <util/prefix.h>
 
-/// parses the command line options into a cmdlinet
-/// \par parameters: argument count, argument strings
-/// \return none
+// clang-format off
 // non-gcc options
 const char *goto_cc_options_with_separated_argument[]=
 {
@@ -163,6 +161,8 @@ const char *gcc_options_without_argument[]=
   "-print-multi-directory",
   "-print-multi-lib",
   "-print-search-dirs",
+  "-print-sysroot",
+  "-print-sysroot-headers-suffix",
   "-Q",
   "-Qn",
   "-Qy",
@@ -211,7 +211,11 @@ const char *gcc_options_without_argument[]=
   "-fast", // Apple only
   nullptr
 };
+// clang-format on
 
+/// parses the command line options into a cmdlinet
+/// \par parameters: argument count, argument strings
+/// \return none
 bool gcc_cmdlinet::parse(int argc, const char **argv)
 {
   assert(argc>0);

src/goto-cc/gcc_mode.cpp

@@ -380,12 +380,24 @@ int gcc_modet::doit()
     return EX_OK; // Exit!
   }
 
-  if(cmdline.isset("dumpversion"))
+  if(
+    cmdline.isset("dumpmachine") || cmdline.isset("dumpspecs") ||
+    cmdline.isset("dumpversion") || cmdline.isset("print-sysroot") ||
+    cmdline.isset("print-sysroot-headers-suffix"))
   {
     if(produce_hybrid_binary)
       return run_gcc(compiler);
 
-    std::cout << "3.4.4\n";
+    // GCC will only print one of these, even when multiple arguments are
+    // passed, so we do the same
+    if(cmdline.isset("dumpmachine"))
+      std::cout << config.this_architecture() << '\n';
+    else if(cmdline.isset("dumpversion"))
+      std::cout << "3.4.4\n";
+
+    // we don't have any meaningful output for the other options, and GCC
+    // doesn't necessarily produce non-empty output either
+
     return EX_OK;
   }