From dbeb998018ce3a739500f9a29e9b62639de2c49f Mon Sep 17 00:00:00 2001
From: Tyge Løvset <tylo@norceresearch.no>
Date: Mon, 27 Dec 2021 15:47:17 +0100
Subject: Added autocheck.l utility to check for wrong usage of c_auto*.

---
 autocheck.ll        | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 build_autocheck.sh  |   5 +++
 examples/new_smap.c |   8 +++--
 3 files changed, 111 insertions(+), 3 deletions(-)
 create mode 100644 autocheck.ll
 create mode 100644 build_autocheck.sh

diff --git a/autocheck.ll b/autocheck.ll
new file mode 100644
index 00000000..9b090b1c
--- /dev/null
+++ b/autocheck.ll
@@ -0,0 +1,101 @@
+/* Check for illegal return/break/continue usage inside a STC-lib c_auto* block (RAII).
+ * Copyright Tyge Løvset, (c) 2021.
+ */
+%{
+#include <stdbool.h>
+enum { LOOP=1<<0, AUTO=1<<1 };
+enum { NORMAL, BRACES, BRACESDONE };
+static int braces_lev = 0, block_lev = 0;
+static int state = NORMAL;
+static unsigned int block[64] = {0}, block_type = 0;
+const char* fname;
+%}
+
+ID [_a-zA-Z][_a-zA-Z0-9]*
+STR \"([^"\\]|\\.)*\"
+
+%option never-interactive noyymore noyywrap nounistd
+%x cmt
+%x prep
+
+%%
+\/\/.*          ; // line cmt
+\/\*            BEGIN(cmt);
+<cmt>\n         ++yylineno;
+<cmt>\*\/       BEGIN(INITIAL);
+<cmt>.          ;
+^[ \t]*#.*\\\n  { ++yylineno; BEGIN(prep); }
+<prep>.*\\\n    ++yylineno;
+<prep>.*\n      { ++yylineno; BEGIN(INITIAL); }
+^[ \t]*#.*      ;
+{STR}           ;
+'\\?.'          ;
+c_foreach       |
+c_forrange      |
+for             |
+while           |
+switch          { block_type |= LOOP; state = BRACES; }
+do              { block_type |= LOOP; state = BRACESDONE; }
+if              { state = BRACES; }
+c_autovar       |
+c_autoscope     |
+c_autodefer     |
+c_auto          { block_type = AUTO; state = BRACES; }
+\(              { if (state == BRACES) ++braces_lev; }
+\)              { if (state == BRACES && --braces_lev == 0) {
+                    state = BRACESDONE;
+                  }
+                }
+;[ \t]*else     ;
+;               { if (state == BRACESDONE) {
+                    block_type = block[block_lev];
+                    state = NORMAL;
+                  }
+                }
+\{              { if (state != BRACES) { block[++block_lev] = block_type; state = NORMAL; } }
+\}              { if (state != BRACES) block_type = block[--block_lev]; }
+return          { if (block_type == AUTO) {
+                    printf("%s:%d: error: 'return' used inside a c_auto* scope.\n"
+                           "    Use 'c_exitauto' to exit the current c_auto* scope.\n", fname, yylineno);
+                  } else if (block_type & AUTO) {
+                    printf("%s:%d: error: 'return' used in a loop inside a c_auto* scope.\n"
+                           "    Use 'break' to exit loops, then 'c_exitauto' to exit c_auto*.\n", fname, yylineno);
+                  }
+                }
+break           { if (block_type == AUTO)
+                    printf("%s:%d: error: 'break' used inside a c_auto* scope.\n"
+                           "    Use 'c_exitauto' to exit the current c_auto* scope.\n", fname, yylineno);
+                }
+continue        { if (block_type == AUTO)
+                    printf("%s:%d: warning: 'continue' used inside a c_auto* scope.\n"
+                           "    It will only break out of the current c_auto* scope.\n"
+                           "    Use 'c_exitauto' instead to make it explicit.\n", fname, yylineno);
+                }
+c_exitauto      { if (block_type != AUTO)
+                    printf("%s:%d: warning: 'c_exitauto' used outside a c_auto* scope.\n"
+                           "    Did you mean 'continue' instead?", fname, yylineno);
+                }
+{ID}            ;
+\n              ++yylineno;
+.               ;
+
+%%
+
+#include <string.h>
+
+int main(int argc, char **argv)
+{
+    if (argc == 1 || strcmp(argv[1], "--help") == 0) {
+        printf("usage: %s [--help] {C-file | -}\n", argv[0]);
+        return 0;
+    }
+    if (strcmp(argv[1], "-") == 0) {
+        fname = "<stdin>";
+        yyin = stdin;
+    } else {
+        fname = argv[1];
+        yyin = fopen(fname, "r");
+    }
+
+    yylex();
+}
diff --git a/build_autocheck.sh b/build_autocheck.sh
new file mode 100644
index 00000000..96ec7d4d
--- /dev/null
+++ b/build_autocheck.sh
@@ -0,0 +1,5 @@
+if [ "$OS" = "Windows_NT" ]; then EXE=.exe; fi
+flex autocheck.ll
+gcc -O2 lex.yy.c -o autocheck$EXE
+rm lex.yy.c
+strip autocheck$EXE
diff --git a/examples/new_smap.c b/examples/new_smap.c
index 2cb35b99..e1a9b13a 100644
--- a/examples/new_smap.c
+++ b/examples/new_smap.c
@@ -43,9 +43,11 @@ int main()
         csmap_int_insert(&map, 123, 321);
 
     c_auto (csmap_pnt, pmap) {
-        csmap_pnt_insert(&pmap, (Point){42, 14}, 1);
-        csmap_pnt_insert(&pmap, (Point){32, 94}, 2);
-        csmap_pnt_insert(&pmap, (Point){62, 81}, 3);
+        c_apply(v, csmap_pnt_insert(&pmap, c_pair(v)), csmap_pnt_value, {
+            {{42, 14}, 1},
+            {{32, 94}, 2},
+            {{62, 81}, 3},
+        });
         c_foreach (i, csmap_pnt, pmap)
             printf(" (%d,%d: %d)", i.ref->first.x, i.ref->first.y, i.ref->second);
         puts("");
-- 
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