Code refactoring: extract path prefix handling code

.. into reusable interfaces. No functional change is expected.

llvm-svn: 275807

compiler-rt/lib/profile/GCDAProfiling.c

@@ -20,8 +20,9 @@
 |*
 \*===----------------------------------------------------------------------===*/
 
-#include "InstrProfilingUtil.h"
+#include "InstrProfilingInternal.h"
 #include "InstrProfilingPort.h"
+#include "InstrProfilingUtil.h"
 
 #include <errno.h>
 #include <fcntl.h>
@@ -171,45 +172,16 @@ static uint64_t read_64bit_value() {
 
 static char *mangle_filename(const char *orig_filename) {
   char *new_filename;
-  size_t filename_len, prefix_len;
+  size_t prefix_len;
   int prefix_strip;
-  int level = 0;
-  const char *fname, *ptr;
-  const char *prefix = getenv("GCOV_PREFIX");
-  const char *prefix_strip_str = getenv("GCOV_PREFIX_STRIP");
+  const char *prefix = lprofGetPathPrefix(&prefix_strip, &prefix_len);
 
-  if (prefix == NULL || prefix[0] == '\0')
+  if (prefix == NULL)
     return strdup(orig_filename);
 
-  if (prefix_strip_str) {
-    prefix_strip = atoi(prefix_strip_str);
-
-    /* Negative GCOV_PREFIX_STRIP values are ignored */
-    if (prefix_strip < 0)
-      prefix_strip = 0;
-  } else {
-    prefix_strip = 0;
-  }
-
-  fname = orig_filename;
-  for (level = 0, ptr = fname + 1; level < prefix_strip; ++ptr) {
-    if (*ptr == '\0')
-      break;
-
-    if (!IS_DIR_SEPARATOR(*ptr))
-      continue;
-    fname = ptr;
-    ++level;
-  }
-
-  filename_len = strlen(fname);
-  prefix_len = strlen(prefix);
-  new_filename = malloc(prefix_len + 1 + filename_len + 1);
-  memcpy(new_filename, prefix, prefix_len);
-
-  if (!IS_DIR_SEPARATOR(prefix[prefix_len - 1]))
-    new_filename[prefix_len++] = DIR_SEPARATOR;
-  memcpy(new_filename + prefix_len, fname, filename_len + 1);
+  new_filename = malloc(prefix_len + 1 + strlen(orig_filename) + 1);
+  lprofApplyPathPrefix(new_filename, orig_filename, prefix, prefix_len,
+                       prefix_strip);
 
   return new_filename;
 }

compiler-rt/lib/profile/InstrProfilingInternal.h

@@ -163,6 +163,20 @@ void lprofSetupValueProfiler();
  * to dump merged profile data into its own profile file. */
 uint64_t lprofGetLoadModuleSignature();
 
+/* GCOV_PREFIX and GCOV_PREFIX_STRIP support */
+/* Return the path prefix specified by GCOV_PREFIX environment variable.
+ * If GCOV_PREFIX_STRIP is also specified, the strip level (integer value)
+ * is returned via \c *PrefixStrip. The prefix length is stored in *PrefixLen.
+ */
+const char *lprofGetPathPrefix(int *PrefixStrip, size_t *PrefixLen);
+/* Apply the path prefix specified in \c Prefix to path string in \c PathStr,
+ * and store the result to buffer pointed to by \c Buffer. If \c PrefixStrip
+ * is not zero, path prefixes are stripped from \c PathStr (the level of
+ * stripping is specified by \c PrefixStrip) before \c Prefix is added.
+ */
+void lprofApplyPathPrefix(char *Dest, const char *PathStr, const char *Prefix,
+                          size_t PrefixLen, int PrefixStrip);
+
 COMPILER_RT_VISIBILITY extern char *(*GetEnvHook)(const char *);
 COMPILER_RT_VISIBILITY extern void (*FreeHook)(void *);
 COMPILER_RT_VISIBILITY extern uint8_t *DynamicBufferIOBuffer;

compiler-rt/lib/profile/InstrProfilingUtil.c

@@ -26,6 +26,7 @@
 #include <sys/utsname.h>
 #endif
 
+#include <stdlib.h>
 #include <string.h>
 
 COMPILER_RT_VISIBILITY
@@ -132,3 +133,54 @@ COMPILER_RT_VISIBILITY FILE *lprofOpenFileEx(const char *ProfileName) {
 
   return f;
 }
+
+COMPILER_RT_VISIBILITY const char *lprofGetPathPrefix(int *PrefixStrip,
+                                                      size_t *PrefixLen) {
+  const char *Prefix = getenv("GCOV_PREFIX");
+  const char *PrefixStripStr = getenv("GCOV_PREFIX_STRIP");
+
+  *PrefixLen = 0;
+  *PrefixStrip = 0;
+  if (Prefix == NULL || Prefix[0] == '\0')
+    return NULL;
+
+  if (PrefixStripStr) {
+    *PrefixStrip = atoi(PrefixStripStr);
+
+    /* Negative GCOV_PREFIX_STRIP values are ignored */
+    if (*PrefixStrip < 0)
+      *PrefixStrip = 0;
+  } else {
+    *PrefixStrip = 0;
+  }
+  *PrefixLen = strlen(Prefix);
+
+  return Prefix;
+}
+
+COMPILER_RT_VISIBILITY void
+lprofApplyPathPrefix(char *Dest, const char *PathStr, const char *Prefix,
+                     size_t PrefixLen, int PrefixStrip) {
+
+  const char *Ptr;
+  int Level;
+  const char *StrippedPathStr = PathStr;
+
+  for (Level = 0, Ptr = PathStr + 1; Level < PrefixStrip; ++Ptr) {
+    if (*Ptr == '\0')
+      break;
+
+    if (!IS_DIR_SEPARATOR(*Ptr))
+      continue;
+
+    StrippedPathStr = Ptr;
+    ++Level;
+  }
+
+  memcpy(Dest, Prefix, PrefixLen);
+
+  if (!IS_DIR_SEPARATOR(Prefix[PrefixLen - 1]))
+    Dest[PrefixLen++] = DIR_SEPARATOR;
+
+  memcpy(Dest + PrefixLen, StrippedPathStr, strlen(StrippedPathStr) + 1);
+}