From b1faec1dc212f070e56021e43f815c7cb0c0c8de Mon Sep 17 00:00:00 2001
From: Nimrod Gileadi <nimrod@google.com>
Date: Mon, 20 Jun 2022 00:02:31 -0700
Subject: [PATCH] Use _Generic instead of string comparisons for code that
 depends on field type.

This will allow us to add fields that can't be cast to int or double, without breaking print.

PiperOrigin-RevId: 456005913
Change-Id: I1fccfd11466f4745f69172af0ae61be07642927c
---
 src/engine/engine_print.c | 42 ++++++++++++++++++++++++---------------
 1 file changed, 26 insertions(+), 16 deletions(-)

diff --git a/src/engine/engine_print.c b/src/engine/engine_print.c
index 59de9530..92fb1bc2 100644
--- a/src/engine/engine_print.c
+++ b/src/engine/engine_print.c
@@ -306,17 +306,23 @@ void mj_printFormattedModel(const mjModel* m, const char* filename, const char*
   //   note that comparison is based on the integer address, not its value
   const int* object_class;
 
-#define X( type, name, num, sz )                                              \
-  if (&m->num == object_class && (strncmp(#name, "name_", 5)!=0) && sz) {     \
-    fprintf(fp, "  ");                                                        \
-    fprintf(fp, NAME_FORMAT, #name);                                          \
-    for (int j=0; j < sz; j++) {                                              \
-       ((strcmp(#type, "mjtNum") == 0) || (strcmp(#type, "float") == 0)) ?    \
-          (fprintf(fp, float_format, (mjtNum)m->name[sz*i+j]),                \
-           fprintf(fp, " ")) :                                                \
-          fprintf(fp, INT_FORMAT " ", (int)m->name[sz*i+j]);                  \
-    }                                                                         \
-    fprintf(fp, "\n");                                                        \
+#define X(type, name, num, sz)                                              \
+  if (&m->num == object_class && (strncmp(#name, "name_", 5) != 0) && sz) { \
+    const char* format = _Generic(*m->name,                                 \
+                                  double:  float_format,                    \
+                                  float:   float_format,                    \
+                                  int:     INT_FORMAT,                      \
+                                  mjtByte: INT_FORMAT,                      \
+                                  default: NULL);                           \
+    if (format) {                                                           \
+      fprintf(fp, "  ");                                                    \
+      fprintf(fp, NAME_FORMAT, #name);                                      \
+      for (int j = 0; j < sz; j++) {                                        \
+          fprintf(fp, format, m->name[sz * i + j]);                         \
+          fprintf(fp, " ");                                                 \
+      }                                                                     \
+      fprintf(fp, "\n");                                                    \
+    }                                                                       \
   }
 
   // bodies
@@ -714,11 +720,15 @@ void mj_printFormattedData(const mjModel* m, mjData* d, const char* filename,
   // ---------------------------------- print mjData fields
 
   fprintf(fp, "SIZES\n");
-#define X( type, name )                          \
-  if(strcmp(#type, "int")==0) {                  \
-    fprintf(fp, "  ");                           \
-    fprintf(fp, NAME_FORMAT, #name);             \
-    fprintf(fp, INT_FORMAT "\n", (int)d->name);  \
+#define X(type, name)                                                         \
+  {                                                                           \
+    const char* format = _Generic(d->name, int : INT_FORMAT, default : NULL); \
+    if (format) {                                                             \
+      fprintf(fp, "  ");                                                      \
+      fprintf(fp, NAME_FORMAT, #name);                                        \
+      fprintf(fp, format, d->name);                                           \
+      fprintf(fp, "\n");                                                      \
+    }                                                                         \
   }
 
   MJDATA_SCALAR