Fix bugs and make improvements

- Get clone() working on FreeBSD
- Increase some Python build quotas
- Add more atomic builtins to chibicc
- Fix ASAN poisoning of alloca() memory
- Make MODE= mandatory link path tinier
- Improve the examples folder a little bit
- Start working on some more resource limits
- Make the linenoise auto-complete UI as good as GNU readline
- Update compile.com, avoiding AVX codegen on non-AVX systems
- Make sure empty path to syscalls like opendir raises ENOENT
- Correctly polyfill ENOENT vs. ENOTDIR on the New Technology
- Port bestline's paredit features to //third_party/linenoise
- Remove workarounds for RHEL 5.0 bugs that were fixed in 5.1

third_party/chibicc/chibicc.h

@@ -348,6 +348,8 @@ typedef enum {
   ND_LOAD,        // Atomic load
   ND_TESTANDSET,  // Atomic lock test and set
   ND_RELEASE,     // Atomic lock release
+  ND_FETCHADD,    // Atomic fetch and add
+  ND_SUBFETCH,    // Atomic sub and fetch
   ND_FPCLASSIFY,  // floating point classify
   ND_MOVNTDQ,     // Intel MOVNTDQ
   ND_PMOVMSKB,    // Intel PMOVMSKB

third_party/chibicc/codegen.c

@@ -262,6 +262,20 @@ static char *reg_ax(int sz) {
   UNREACHABLE();
 }
 
+static char *reg_di(int sz) {
+  switch (sz) {
+    case 1:
+      return "%dil";
+    case 2:
+      return "%di";
+    case 4:
+      return "%edi";
+    case 8:
+      return "%rdi";
+  }
+  UNREACHABLE();
+}
+
 static const char *gotpcrel(void) {
   if (opt_pic) {
     return "@gotpcrel(%rip)";
@@ -1542,6 +1556,26 @@ void gen_expr(Node *node) {
       println("\tmov\t%s,(%%rdi)", reg_ax(node->ty->size));
       return;
     }
+    case ND_FETCHADD: {
+      gen_expr(node->lhs);
+      push();
+      gen_expr(node->rhs);
+      pop("%rdi");
+      println("\txadd\t%s,(%%rdi)", reg_ax(node->ty->size));
+      return;
+    }
+    case ND_SUBFETCH: {
+      gen_expr(node->lhs);
+      push();
+      gen_expr(node->rhs);
+      pop("%rdi");
+      push();
+      println("\tneg\t%s", reg_ax(node->ty->size));
+      println("\txadd\t%s,(%%rdi)", reg_ax(node->ty->size));
+      pop("%rdi");
+      println("\tsub\t%s,%s", reg_di(node->ty->size), reg_ax(node->ty->size));
+      return;
+    }
     case ND_RELEASE: {
       gen_expr(node->lhs);
       push();

third_party/chibicc/kw.gperf

@@ -119,6 +119,8 @@ __builtin_types_compatible_p,     KW___BUILTIN_TYPES_COMPATIBLE_P
 "->",                             KW_ARROW
 ".",                              KW_DOT
 __atomic_load,                    KW___ATOMIC_LOAD
+__atomic_fetch_add,               KW___ATOMIC_FETCH_ADD
+__atomic_sub_fetch,               KW___ATOMIC_SUB_FETCH
 __sync_lock_test_and_set,         KW___SYNC_LOCK_TEST_AND_SET
 __sync_lock_release,              KW___SYNC_LOCK_RELEASE
 __builtin_ia32_movntdq,           KW___BUILTIN_IA32_MOVNTDQ

third_party/chibicc/kw.h

@@ -110,6 +110,8 @@
 #define KW___SYNC_LOCK_RELEASE          126
 #define KW___BUILTIN_IA32_PMOVMSKB128   127
 #define KW___BUILTIN_IA32_MOVNTDQ       128
+#define KW___ATOMIC_FETCH_ADD           129
+#define KW___ATOMIC_SUB_FETCH           130
 
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_

third_party/chibicc/kw.inc

@@ -37,7 +37,7 @@
 #line 10 "kw.gperf"
 struct thatispacked KwSlot { char *name; unsigned char code; };
 
-#define TOTAL_KEYWORDS 114
+#define TOTAL_KEYWORDS 116
 #define MIN_WORD_LENGTH 1
 #define MAX_WORD_LENGTH 28
 #define MIN_HASH_VALUE 1
@@ -230,7 +230,7 @@ LookupKw (register const char *str, register size_t len)
       {"||",                             KW_LOGOR},
 #line 67 "kw.gperf"
       {"_Alignof",                         KW__ALIGNOF},
-#line 122 "kw.gperf"
+#line 124 "kw.gperf"
       {"__sync_lock_test_and_set",         KW___SYNC_LOCK_TEST_AND_SET},
 #line 49 "kw.gperf"
       {"error",                            KW_ERROR},
@@ -249,7 +249,7 @@ LookupKw (register const char *str, register size_t len)
       {""},
 #line 66 "kw.gperf"
       {"_Alignas",                         KW__ALIGNAS},
-#line 123 "kw.gperf"
+#line 125 "kw.gperf"
       {"__sync_lock_release",              KW___SYNC_LOCK_RELEASE},
       {""},
 #line 39 "kw.gperf"
@@ -340,20 +340,22 @@ LookupKw (register const char *str, register size_t len)
       {""}, {""}, {""},
 #line 100 "kw.gperf"
       {"__builtin_strlen",                 KW___BUILTIN_STRLEN},
-#line 124 "kw.gperf"
+#line 126 "kw.gperf"
       {"__builtin_ia32_movntdq",           KW___BUILTIN_IA32_MOVNTDQ},
       {""}, {""}, {""},
 #line 120 "kw.gperf"
       {".",                              KW_DOT},
 #line 36 "kw.gperf"
       {"include",                          KW_INCLUDE},
-      {""}, {""}, {""},
+#line 122 "kw.gperf"
+      {"__atomic_fetch_add",               KW___ATOMIC_FETCH_ADD},
+      {""}, {""},
 #line 14 "kw.gperf"
       {"return",                           KW_RETURN},
       {""}, {""}, {""},
 #line 26 "kw.gperf"
       {"union",                            KW_UNION},
-#line 125 "kw.gperf"
+#line 127 "kw.gperf"
       {"__builtin_ia32_pmovmskb128",       KW___BUILTIN_IA32_PMOVMSKB128},
       {""}, {""}, {""}, {""}, {""}, {""}, {""}, {""}, {""},
 #line 112 "kw.gperf"
@@ -373,7 +375,10 @@ LookupKw (register const char *str, register size_t len)
       {""}, {""}, {""}, {""},
 #line 53 "kw.gperf"
       {"inline",                           KW_INLINE},
-      {""}, {""}, {""}, {""},
+      {""},
+#line 123 "kw.gperf"
+      {"__atomic_sub_fetch",               KW___ATOMIC_SUB_FETCH},
+      {""}, {""},
 #line 113 "kw.gperf"
       {"!",                              KW_EXCLAIM}
     };

third_party/chibicc/parse.c

@@ -3243,6 +3243,32 @@ static Node *primary(Token **rest, Token *tok) {
       *rest = skip(tok, ')');
       return node;
     }
+    if (kw == KW___ATOMIC_FETCH_ADD) {
+      Node *node = new_node(ND_FETCHADD, tok);
+      tok = skip(tok->next, '(');
+      node->lhs = assign(&tok, tok);
+      add_type(node->lhs);
+      node->ty = node->lhs->ty->base;
+      tok = skip(tok, ',');
+      node->rhs = assign(&tok, tok);
+      tok = skip(tok, ',');
+      const_expr(&tok, tok);
+      *rest = skip(tok, ')');
+      return node;
+    }
+    if (kw == KW___ATOMIC_SUB_FETCH) {
+      Node *node = new_node(ND_SUBFETCH, tok);
+      tok = skip(tok->next, '(');
+      node->lhs = assign(&tok, tok);
+      add_type(node->lhs);
+      node->ty = node->lhs->ty->base;
+      tok = skip(tok, ',');
+      node->rhs = assign(&tok, tok);
+      tok = skip(tok, ',');
+      const_expr(&tok, tok);
+      *rest = skip(tok, ')');
+      return node;
+    }
     if (kw == KW___SYNC_LOCK_TEST_AND_SET) {
       Node *node = new_node(ND_TESTANDSET, tok);
       tok = skip(tok->next, '(');