Only read *predecessor once so as to fix a theoretical issue where it changes

between two reads (threading).

Fix an off-by-one in the indirect counter table that I meant to revert after an
earlier experiment. Whoops!

Implement GCOV_PREFIX. Doesn't handle GCOV_PREFIX_STRIP yet.

Fix an off-by-one in string emission. Extra whoops!

Tolerate DISubprograms that have null Function*'s attached to them. I don't yet
understand what this means, but it happens when you have a global static with
a non-trivial constructor/destructor.

Fix a crash on switch statements with a single successor (default-only).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130443 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Instrumentation/GCOVProfiling.cpp

@@ -146,9 +146,9 @@ namespace {
       writeBytes(s.data(), s.size());
 
       // Write 1 to 4 bytes of NUL padding.
-      assert((unsigned)(5 - ((s.size() + 1) % 4)) > 0);
+      assert((unsigned)(4 - (s.size() % 4)) > 0);
-      assert((unsigned)(5 - ((s.size() + 1) % 4)) <= 4);
+      assert((unsigned)(4 - (s.size() % 4)) <= 4);
-      writeBytes("\0\0\0\0", 5 - ((s.size() + 1) % 4));
+      writeBytes("\0\0\0\0", 4 - (s.size() % 4));
     }
 
     raw_ostream *os;
@@ -263,7 +263,7 @@ namespace {
       write(BlockLen);
       uint32_t Ident = reinterpret_cast<intptr_t>((MDNode*)SP);
       write(Ident);
-      write(0); // checksum
+      write(0);  // checksum
       writeGCOVString(SP.getName());
       writeGCOVString(SP.getFilename());
       write(SP.getLineNumber());
@@ -356,8 +356,10 @@ void GCOVProfiler::emitGCNO(DebugInfoFinder &DIF) {
     DISubprogram SP(*SPI);
     raw_fd_ostream *&os = GcnoFiles[SP.getCompileUnit()];
 
-    GCOVFunction Func(SP, os);
     Function *F = SP.getFunction();
+    if (!F) continue;
+    GCOVFunction Func(SP, os);
+
     for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
       GCOVBlock &Block = Func.getBlock(BB);
       TerminatorInst *TI = BB->getTerminator();
@@ -402,6 +404,7 @@ bool GCOVProfiler::emitProfileArcs(DebugInfoFinder &DIF) {
            SPE = DIF.subprogram_end(); SPI != SPE; ++SPI) {
     DISubprogram SP(*SPI);
     Function *F = SP.getFunction();
+    if (!F) continue;
 
     unsigned Edges = 0;
     for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
@@ -471,7 +474,7 @@ bool GCOVProfiler::emitProfileArcs(DebugInfoFinder &DIF) {
       const Type *Int32Ty = Type::getInt32Ty(*Ctx);
       for (int i = 0, e = ComplexEdgePreds.size(); i != e; ++i) {
         IRBuilder<> Builder(ComplexEdgePreds[i+1]->getTerminator());
-        Builder.CreateStore(ConstantInt::get(Int32Ty, i+1), EdgeState);
+        Builder.CreateStore(ConstantInt::get(Int32Ty, i), EdgeState);
       }
       for (int i = 0, e = ComplexEdgeSuccs.size(); i != e; ++i) {
         // call runtime to perform increment
@@ -517,7 +520,7 @@ GlobalVariable *GCOVProfiler::buildEdgeLookupTable(
   for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
     TerminatorInst *TI = BB->getTerminator();
     int Successors = isa<ReturnInst>(TI) ? 1 : TI->getNumSuccessors();
-    if (Successors && !isa<BranchInst>(TI) && !isa<ReturnInst>(TI)) {
+    if (Successors > 1 && !isa<BranchInst>(TI) && !isa<ReturnInst>(TI)) {
       for (int i = 0; i != Successors; ++i) {
         BasicBlock *Succ = TI->getSuccessor(i);
         IRBuilder<> builder(Succ);

runtime/libprofile/GCDAProfiling.c

@@ -46,6 +46,24 @@ static void write_int64(uint64_t i) {
   write_int32(hi);
 }
 
+static char *mangle_filename(const char *orig_filename) {
+  /* TODO: handle GCOV_PREFIX_STRIP */
+  const char *prefix;
+  char *filename = 0;
+
+  prefix = getenv("GCOV_PREFIX");
+
+  if (!prefix)
+    return strdup(filename);
+
+  filename = malloc(strlen(prefix) + 1 + strlen(orig_filename) + 1);
+  strcpy(filename, prefix);
+  strcat(filename, "/");
+  strcat(filename, orig_filename);
+
+  return filename;
+}
+
 /*
  * --- LLVM line counter API ---
  */
@@ -54,15 +72,19 @@ static void write_int64(uint64_t i) {
  * profiling enabled will emit to a different file. Only one file may be
  * started at a time.
  */
-void llvm_gcda_start_file(const char *filename) {
+void llvm_gcda_start_file(const char *orig_filename) {
-  output_file = fopen(filename, "w+");
+  char *filename;
+  filename = mangle_filename(orig_filename);
+  output_file = fopen(filename, "wb");
 
   /* gcda file, version 404*, stamp LLVM. */
   fwrite("adcg*404MVLL", 12, 1, output_file);
 
 #ifdef DEBUG_GCDAPROFILING
-  printf("llvmgcda: [%s]\n", filename);
+  printf("llvmgcda: [%s]\n", orig_filename);
 #endif
+
+  free(filename);
 }
 
 /* Given an array of pointers to counters (counters), increment the n-th one,
@@ -71,12 +93,16 @@ void llvm_gcda_start_file(const char *filename) {
 void llvm_gcda_increment_indirect_counter(uint32_t *predecessor,
                                           uint64_t **counters) {
   uint64_t *counter;
-  if (*predecessor == 0xffffffff)
+  uint32_t pred;
+
+  pred = *predecessor;
+  if (pred == 0xffffffff)
     return;
+  counter = counters[pred];
 
   /* Don't crash if the pred# is out of sync. This can happen due to threads,
      or because of a TODO in GCOVProfiling.cpp buildEdgeLookupTable(). */
-  if ((counter = counters[*predecessor]))
+  if (counter)
     ++*counter;
 #ifdef DEBUG_GCDAPROFILING
   else