[cpp] Add RootsFrame to libc bindings (#1411)

oilshell · Nov 14, 2022 · 8d11ad1 · 8d11ad1
1 parent 0ec4805
commit 8d11ad1
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Showing 2 changed files with 28 additions and 1 deletion.
diff --git a/cpp/libc.cc b/cpp/libc.cc
@@ -12,6 +12,7 @@
 namespace libc {
 
 Str* gethostname() {
+  NO_ROOTS_FRAME(FUNC_NAME);  // OverAllocatedStr() does it
   Str* result = OverAllocatedStr(HOST_NAME_MAX);
   int status = ::gethostname(result->data_, HOST_NAME_MAX);
   if (status != 0) {
@@ -23,6 +24,7 @@ Str* gethostname() {
 }
 
 int fnmatch(Str* pat, Str* str) {
+  NO_ROOTS_FRAME(FUNC_NAME);  // No allocaitons here
   int flags = FNM_EXTMATCH;
   int result = ::fnmatch(pat->data_, str->data_, flags);
   switch (result) {
@@ -37,6 +39,7 @@ int fnmatch(Str* pat, Str* str) {
 }
 
 List<Str*>* glob(Str* pat) {
+  RootsFrame _r{FUNC_NAME};
   glob_t results;
   // Hm, it's weird that the first one can't be called with GLOB_APPEND.  You
   // get a segfault.
@@ -75,17 +78,20 @@ List<Str*>* glob(Str* pat) {
   // Print array of results
   size_t i;
   for (i = 0; i < n; i++) {
+    NO_ROOTS_FRAME(LOOP);  // Allocations are retained through `matches`
     const char* m = results.gl_pathv[i];
     matches->append(StrFromC(m));
   }
   globfree(&results);
 
+  gHeap.RootOnReturn(matches);
   return matches;
 }
 
 // Raises RuntimeError if the pattern is invalid.  TODO: Use a different
 // exception?
 List<Str*>* regex_match(Str* pattern, Str* str) {
+  RootsFrame _r{FUNC_NAME};
   List<Str*>* results = NewList<Str*>();
 
   regex_t pat;
@@ -103,6 +109,7 @@ List<Str*>* regex_match(Str* pattern, Str* str) {
   if (match) {
     int i;
     for (i = 0; i < outlen; i++) {
+      NO_ROOTS_FRAME(LOOP);  // Allocations are retained through `results`
       int len = pmatch[i].rm_eo - pmatch[i].rm_so;
       Str* m = StrFromC(s0 + pmatch[i].rm_so, len);
       results->append(m);
@@ -116,6 +123,7 @@ List<Str*>* regex_match(Str* pattern, Str* str) {
     return nullptr;
   }
 
+  gHeap.RootOnReturn(results);
   return results;
 }
 
@@ -128,6 +136,7 @@ const int NMATCH = 2;
 
 // Odd: This a Tuple2* not Tuple2 because it's Optional[Tuple2]!
 Tuple2<int, int>* regex_first_group_match(Str* pattern, Str* str, int pos) {
+  RootsFrame _r{FUNC_NAME};
   regex_t pat;
   regmatch_t m[NMATCH];
 
@@ -158,7 +167,11 @@ Tuple2<int, int>* regex_first_group_match(Str* pattern, Str* str, int pos) {
   // Assume there is a match
   regoff_t start = m[1].rm_so;
   regoff_t end = m[1].rm_eo;
-  return Alloc<Tuple2<int, int>>(pos + start, pos + end);
+  Tuple2<int, int>* tup = Alloc<Tuple2<int, int>>(pos + start, pos + end);
+
+  // Tuple2<...> uses the OBJ_HEADER macro
+  gHeap.RootOnReturn(reinterpret_cast<Obj*>(tup));
+  return tup;
 }
 
 }  // namespace libc
diff --git a/cpp/libc_test.cc b/cpp/libc_test.cc
@@ -1,8 +1,21 @@
 #include "cpp/libc.h"
 
+#include <unistd.h>  // gethostname()
+
 #include "mycpp/runtime.h"
 #include "vendor/greatest.h"
 
+TEST hostname_test() {
+  Str* s0 = libc::gethostname();
+  ASSERT(s0 != nullptr);
+
+  char buf[1024];
+  ASSERT(gethostname(buf, HOST_NAME_MAX) == 0);
+  ASSERT(str_equals(s0, StrFromC(buf)));
+
+  PASS();
+}
+
 TEST libc_test() {
   Str* s1 = (StrFromC("foo.py "))->strip();
   ASSERT(libc::fnmatch(StrFromC("*.py"), s1));
@@ -65,6 +78,7 @@ int main(int argc, char** argv) {
 
   RUN_TEST(libc_test);
   RUN_TEST(libc_glob_test);
+  RUN_TEST(hostname_test);
 
   gHeap.CleanProcessExit();