Show -with-rtsopts options in runtime's --info (#15261)

Add an additional line to the output of +RTS --info.  It shows the value
of the flag -with-rtsopts provided at compile/link time.

Test Plan: make test TESTS="T15261a T15261b"

Reviewers: hvr, erikd, dfeuer, thomie, austin, bgamari, simonmar, osa1,
monoidal

Reviewed By: osa1, monoidal

Subscribers: osa1, rwbarton, carter

GHC Trac Issues: #15261

Differential Revision: https://phabricator.haskell.org/D5053

1 files changed, 4 insertions, 2 deletions

diff --git a/rts/RtsUtils.c b/rts/RtsUtils.c
index 5357dc635e..618815de76 100644
--- a/rts/RtsUtils.c
+++ b/rts/RtsUtils.c
@@ -275,7 +275,7 @@ int genericRaise(int sig) {
 #endif
 }
 
-static void mkRtsInfoPair(char *key, char *val) {
+static void mkRtsInfoPair(const char *key, const char *val) {
     /* XXX should check for "s, \s etc in key and val */
     printf(" ,(\"%s\", \"%s\")\n", key, val);
 }
@@ -285,7 +285,7 @@ static void mkRtsInfoPair(char *key, char *val) {
 #define TOSTRING2(x) #x
 #define TOSTRING(x)  TOSTRING2(x)
 
-void printRtsInfo(void) {
+void printRtsInfo(const RtsConfig rts_config) {
     /* The first entry is just a hack to make it easy to get the
      * commas right */
     printf(" [(\"GHC RTS\", \"YES\")\n");
@@ -306,6 +306,8 @@ void printRtsInfo(void) {
     mkRtsInfoPair("Word size",               TOSTRING(WORD_SIZE_IN_BITS));
     mkRtsInfoPair("Compiler unregisterised", GhcUnregisterised);
     mkRtsInfoPair("Tables next to code",     GhcEnableTablesNextToCode);
+    mkRtsInfoPair("Flag -with-rtsopts",      /* See Trac #15261 */
+        rts_config.rts_opts != NULL ? rts_config.rts_opts : "");
     printf(" ]\n");
 }