Dont use realloc

examples/stm32/nucleo-f746zg-baremetal/Makefile

@@ -8,8 +8,7 @@ CFLAGS  ?=  -W -Wall -Wextra -Werror -Wundef -Wshadow -Wdouble-promotion \
 						-I. -I$(ROOT) -DMG_ARCH=MG_ARCH_NEWLIB -DMIP_DEBUG=1 \
 						-DMG_ENABLE_CUSTOM_MILLIS=1 -DMG_ENABLE_LINES=1 -DMG_ENABLE_MIP=1 \
 						-mcpu=cortex-m7 -mthumb -mfloat-abi=softfp -mfpu=vfpv4 $(EXTRA)
-LDFLAGS ?= -Tlink.ld -nostartfiles -nostdlib --specs nano.specs \
+LDFLAGS ?= -Tlink.ld -nostartfiles -nostdlib --specs nano.specs -lc -lgcc -Wl,--gc-sections -Wl,-Map=$@.map
-					 -lc -lgcc -Wl,--gc-sections -Wl,-Map=$@.map
 SOURCES = boot.c main.c syscalls.c $(ROOT)/mongoose.c
 
 all build example: $(TARGET).bin
@@ -20,6 +19,12 @@ $(TARGET).bin: $(TARGET).elf
 $(TARGET).elf: $(SOURCES) mcu.h
 	$(DOCKER) $(CROSS)-gcc $(SOURCES) $(CFLAGS) $(LDFLAGS) -o $@
 
+# Build on Windows. Download Win32 Zip from ARM GCC downloads, unzip to c:\armgcc
+ARMGCC ?= c:/armgcc
+windows: $(TARGET).bin
+windows: CROSS = $(ARMGCC)/bin/arm-none-eabi
+windows: DOCKER =
+
 # Build an interactive device dashboard
 dash: $(TARGET).elf
 dash: CFLAGS += -DDASH -DMG_ENABLE_PACKED_FS=1

mongoose.c

@@ -552,6 +552,53 @@ void mg_error(struct mg_connection *c, const char *fmt, ...) {
 
 
 
+size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap) {
+  va_list ap_copy;
+  size_t len;
+
+  va_copy(ap_copy, ap);
+  len = mg_vsnprintf(*buf, size, fmt, &ap_copy);
+  va_end(ap_copy);
+
+  if (len >= size) {
+    //  Allocate a buffer that is large enough
+    if ((*buf = (char *) calloc(1, len + 1)) == NULL) {
+      len = 0;
+    } else {
+      va_copy(ap_copy, ap);
+      len = mg_vsnprintf(*buf, len + 1, fmt, &ap_copy);
+      va_end(ap_copy);
+    }
+  }
+
+  return len;
+}
+
+size_t mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
+  size_t ret;
+  va_list ap;
+  va_start(ap, fmt);
+  ret = mg_vasprintf(buf, size, fmt, ap);
+  va_end(ap);
+  return ret;
+}
+
+char *mg_vmprintf(const char *fmt, va_list ap) {
+  char *s = NULL;
+  mg_vasprintf(&s, 0, fmt, ap);
+  return s;
+}
+
+char *mg_mprintf(const char *fmt, ...) {
+  char *s = NULL;
+  va_list ap;
+  va_start(ap, fmt);
+  mg_vasprintf(&s, 0, fmt, ap);
+  va_end(ap);
+  return s;
+}
+
+
 size_t mg_rprintf(void (*out)(char, void *), void *ptr, const char *fmt, ...) {
   size_t len = 0;
   va_list ap;
@@ -561,26 +608,28 @@ size_t mg_rprintf(void (*out)(char, void *), void *ptr, const char *fmt, ...) {
   return len;
 }
 
-static void mg_putchar_iobuf(char ch, void *param) {
+static void mg_putchar_iobuf_static(char ch, void *param) {
   struct mg_iobuf *io = (struct mg_iobuf *) param;
   if (io->len < io->size) io->buf[io->len++] = (uint8_t) ch;
 }
 
+// We don't use realloc() in mongoose, so resort to inefficient calloc
+// Every new character reallocates the whole string
 void mg_putchar_realloc(char ch, void *param) {
   char *s, *buf = *(char **) param;
-  size_t len = buf == NULL ? 0 : strlen(buf), chunksize = 256;
+  size_t len = buf == NULL ? 0 : strlen(buf);
-  size_t new_size = len + 1 + 1 + chunksize;
+  if ((s = (char *) calloc(1, len + 2)) != NULL) {
-  new_size -= new_size % chunksize;
+    if (buf != NULL) memcpy(s, buf, len);
-  if ((s = (char *) realloc(buf, new_size)) != NULL) {
     s[len] = ch;
     s[len + 1] = '\0';
+    free(buf);
     *(char **) param = s;
   }
 }
 
 size_t mg_vsnprintf(char *buf, size_t len, const char *fmt, va_list *ap) {
   struct mg_iobuf io = {(uint8_t *) buf, len, 0};
-  size_t n = mg_vrprintf(mg_putchar_iobuf, &io, fmt, ap);
+  size_t n = mg_vrprintf(mg_putchar_iobuf_static, &io, fmt, ap);
   if (n < len) buf[n] = '\0';
   return n;
 }
@@ -4717,51 +4766,6 @@ void mg_unhex(const char *buf, size_t len, unsigned char *to) {
   }
 }
 
-size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap) {
-  va_list ap_copy;
-  size_t len;
-
-  va_copy(ap_copy, ap);
-  len = mg_vsnprintf(*buf, size, fmt, &ap_copy);
-  va_end(ap_copy);
-
-  if (len >= size) {
-    //  Allocate a buffer that is large enough
-    if ((*buf = (char *) calloc(1, len + 1)) == NULL) {
-      len = 0;
-    } else {
-      va_copy(ap_copy, ap);
-      len = mg_vsnprintf(*buf, len + 1, fmt, &ap_copy);
-      va_end(ap_copy);
-    }
-  }
-
-  return len;
-}
-
-size_t mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
-  size_t ret;
-  va_list ap;
-  va_start(ap, fmt);
-  ret = mg_vasprintf(buf, size, fmt, ap);
-  va_end(ap);
-  return ret;
-}
-
-char *mg_vmprintf(const char *fmt, va_list ap) {
-  char *s = NULL;
-  mg_vasprintf(&s, 0, fmt, ap);
-  return s;
-}
-
-char *mg_mprintf(const char *fmt, ...) {
-  char *s = NULL;
-  va_list ap;
-  va_start(ap, fmt);
-  mg_vasprintf(&s, 0, fmt, ap);
-  va_end(ap);
-  return s;
-}
 
 uint64_t mg_tou64(struct mg_str str) {
   uint64_t result = 0;

src/fmt.c

@@ -1,6 +1,53 @@
 #include "iobuf.h"
 #include "str.h"
 
+size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap) {
+  va_list ap_copy;
+  size_t len;
+
+  va_copy(ap_copy, ap);
+  len = mg_vsnprintf(*buf, size, fmt, &ap_copy);
+  va_end(ap_copy);
+
+  if (len >= size) {
+    //  Allocate a buffer that is large enough
+    if ((*buf = (char *) calloc(1, len + 1)) == NULL) {
+      len = 0;
+    } else {
+      va_copy(ap_copy, ap);
+      len = mg_vsnprintf(*buf, len + 1, fmt, &ap_copy);
+      va_end(ap_copy);
+    }
+  }
+
+  return len;
+}
+
+size_t mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
+  size_t ret;
+  va_list ap;
+  va_start(ap, fmt);
+  ret = mg_vasprintf(buf, size, fmt, ap);
+  va_end(ap);
+  return ret;
+}
+
+char *mg_vmprintf(const char *fmt, va_list ap) {
+  char *s = NULL;
+  mg_vasprintf(&s, 0, fmt, ap);
+  return s;
+}
+
+char *mg_mprintf(const char *fmt, ...) {
+  char *s = NULL;
+  va_list ap;
+  va_start(ap, fmt);
+  mg_vasprintf(&s, 0, fmt, ap);
+  va_end(ap);
+  return s;
+}
+
+
 size_t mg_rprintf(void (*out)(char, void *), void *ptr, const char *fmt, ...) {
   size_t len = 0;
   va_list ap;
@@ -10,26 +57,28 @@ size_t mg_rprintf(void (*out)(char, void *), void *ptr, const char *fmt, ...) {
   return len;
 }
 
-static void mg_putchar_iobuf(char ch, void *param) {
+static void mg_putchar_iobuf_static(char ch, void *param) {
   struct mg_iobuf *io = (struct mg_iobuf *) param;
   if (io->len < io->size) io->buf[io->len++] = (uint8_t) ch;
 }
 
+// We don't use realloc() in mongoose, so resort to inefficient calloc
+// Every new character reallocates the whole string
 void mg_putchar_realloc(char ch, void *param) {
   char *s, *buf = *(char **) param;
-  size_t len = buf == NULL ? 0 : strlen(buf), chunksize = 256;
+  size_t len = buf == NULL ? 0 : strlen(buf);
-  size_t new_size = len + 1 + 1 + chunksize;
+  if ((s = (char *) calloc(1, len + 2)) != NULL) {
-  new_size -= new_size % chunksize;
+    if (buf != NULL) memcpy(s, buf, len);
-  if ((s = (char *) realloc(buf, new_size)) != NULL) {
     s[len] = ch;
     s[len + 1] = '\0';
+    free(buf);
     *(char **) param = s;
   }
 }
 
 size_t mg_vsnprintf(char *buf, size_t len, const char *fmt, va_list *ap) {
   struct mg_iobuf io = {(uint8_t *) buf, len, 0};
-  size_t n = mg_vrprintf(mg_putchar_iobuf, &io, fmt, ap);
+  size_t n = mg_vrprintf(mg_putchar_iobuf_static, &io, fmt, ap);
   if (n < len) buf[n] = '\0';
   return n;
 }

src/str.c

@@ -196,51 +196,6 @@ void mg_unhex(const char *buf, size_t len, unsigned char *to) {
   }
 }
 
-size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap) {
-  va_list ap_copy;
-  size_t len;
-
-  va_copy(ap_copy, ap);
-  len = mg_vsnprintf(*buf, size, fmt, &ap_copy);
-  va_end(ap_copy);
-
-  if (len >= size) {
-    //  Allocate a buffer that is large enough
-    if ((*buf = (char *) calloc(1, len + 1)) == NULL) {
-      len = 0;
-    } else {
-      va_copy(ap_copy, ap);
-      len = mg_vsnprintf(*buf, len + 1, fmt, &ap_copy);
-      va_end(ap_copy);
-    }
-  }
-
-  return len;
-}
-
-size_t mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
-  size_t ret;
-  va_list ap;
-  va_start(ap, fmt);
-  ret = mg_vasprintf(buf, size, fmt, ap);
-  va_end(ap);
-  return ret;
-}
-
-char *mg_vmprintf(const char *fmt, va_list ap) {
-  char *s = NULL;
-  mg_vasprintf(&s, 0, fmt, ap);
-  return s;
-}
-
-char *mg_mprintf(const char *fmt, ...) {
-  char *s = NULL;
-  va_list ap;
-  va_start(ap, fmt);
-  mg_vasprintf(&s, 0, fmt, ap);
-  va_end(ap);
-  return s;
-}
 
 uint64_t mg_tou64(struct mg_str str) {
   uint64_t result = 0;