Make exciting improvements

- Add Lua backtraces to redbean!
- Wipe serving keys after redbean forks
- Audit redbean to remove free via exit
- Log SSL client ciphersuite preferences
- Increase ASAN malloc() backtrace depth
- Make GetSslRoots() behave as a singleton
- Move leaks.c from LIBC_TESTLIB to LIBC_LOG
- Add undocumented %n to printf() for newlines
- Fix redbean memory leak reindexing inode change
- Fix redbean memory leak with Fetch() DNS object
- Restore original environ after __cxa_finalize()
- Make backtrace always work after __cxa_finalize()
- Introduce COUNTEXPR() diagnostic / benchmark tool
- Fix a few more instances of errno being clobbered
- Consolidate the ANSI color disabling internal APIs

libc/log/countexpr.h

@@ -0,0 +1,85 @@
+#ifndef COSMOPOLITAN_LIBC_LOG_COUNTEXPR_H_
+#define COSMOPOLITAN_LIBC_LOG_COUNTEXPR_H_
+#include "libc/macros.internal.h"
+#include "libc/nexgen32e/bench.h"
+#include "libc/nexgen32e/bsr.h"
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+/**
+ * Shows nanosecond timings histogram for expr at exit().
+ */
+#define COUNTEXPR(expr)                                                \
+  COUNTEXPR_(expr, #expr, STRINGIFY(__FILE__), __LINE__, rdtsc, rdtsc, \
+             "COUNTEXPR")
+
+/**
+ * Like COUNTEXPR() but can be used on function calls that return void.
+ */
+#define COUNTSTMT(stmt)                                                    \
+  (void)COUNTEXPR_((stmt, 0), #stmt, STRINGIFY(__FILE__), __LINE__, rdtsc, \
+                   rdtsc, "COUNTSTMT")
+
+/**
+ * Same as COUNTEXPR() but uses Intel's expensive measurement technique.
+ */
+#define BENCHEXPR(expr)                                                \
+  COUNTEXPR_(expr, #expr, STRINGIFY(__FILE__), __LINE__, __startbench, \
+             __endbench, "BENCHEXPR")
+
+#define COUNTEXPR_(expr, code, file, line, start, stop, macro) \
+  COUNTEXPR__(expr, STRINGIFY(code), file, line, start, stop, STRINGIFY(macro))
+
+#define COUNTEXPR__(expr, code, file, line, start, stop, macro) \
+  ({                                                            \
+    struct countexpr *InfO;                                     \
+    uint64_t t1_, t2_, TiCkS, NaNoS;                            \
+    t1_ = start();                                              \
+    asm volatile("" ::: "memory");                              \
+    autotype(expr) ReS = (expr);                                \
+    asm volatile("" ::: "memory");                              \
+    t2_ = stop();                                               \
+    TiCkS = t2_ >= t1_ ? t2_ - t1_ : ~t1_ + t2_ + 1;            \
+    asm(".section .rodata.str1.1,\"aMS\",@progbits,1\n\t"       \
+        ".align\t1\n"                                           \
+        "31340:\t.asciz\t" file "\n\t"                          \
+        "31338:\t.asciz\t" code "\n"                            \
+        "31332:\t.asciz\t" macro "\n"                           \
+        ".previous\n\t"                                         \
+        ".section .yoink\n\t"                                   \
+        "nopl\tcountexpr_data(%%rip)\n\t"                       \
+        ".previous\n\t"                                         \
+        ".section .sort.data.countexpr.2,\"a\",@progbits\n\t"   \
+        ".align\t8\n31337:\t"                                   \
+        ".quad\t" #line "\n\t"                                  \
+        ".quad\t31340b\n\t"                                     \
+        ".quad\t31338b\n\t"                                     \
+        ".quad\t31332b\n\t"                                     \
+        ".rept\t65\n\t"                                         \
+        ".quad\t0\n\t"                                          \
+        ".endr\n\t"                                             \
+        ".previous\n\t"                                         \
+        "lea\t31337b(%%rip),%0"                                 \
+        : "=r"(InfO));                                          \
+    /* approximation of round(x*.323018) which is usually */    \
+    /* the ratio, between x86 rdtsc ticks and nanoseconds */    \
+    NaNoS = (TiCkS * 338709) >> 20;                             \
+    ++InfO->logos[NaNoS ? bsrl(NaNoS) + 1 : 0];                 \
+    ReS;                                                        \
+  })
+
+struct countexpr {
+  long line; /* zero for last entry */
+  const char *file;
+  const char *code;
+  const char *macro;
+  long logos[65];
+};
+
+extern struct countexpr countexpr_data[];
+
+void countexpr_report(void);
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_LIBC_LOG_COUNTEXPR_H_ */