Require that the module symbol table can't appear after function.

src/PNaClTranslator.cpp

@@ -3158,6 +3158,12 @@ bool ModuleParser::ParseBlock(unsigned BlockID) {
     if (FoundValuesymtab)
       Fatal("Duplicate valuesymtab in module");
 
+    // If we have already processed a function block (i.e. we have already
+    // installed global names and variable initializers) we can no longer accept
+    // the value symbol table. Names have already been generated.
+    if (GlobalDeclarationNamesAndInitializersInstalled)
+      Fatal("Module valuesymtab not allowed after function blocks");
+
     FoundValuesymtab = true;
     ModuleValuesymtabParser Parser(BlockID, this);
     return Parser.ParseThisBlock();

tests_lit/parse_errs/Inputs/symtab-after-fcn.tbc

+65535,8,2;
+1,1;
+65535,17,2;
+1,2;
+2;
+21,0,0;
+65534;
+8,1,0,0,0;
+65535,19,2;
+5,0;
+65534;
+65535,12,2;
+1,1;
+10;
+65534;
+65535,14,2;
+1,0,102;
+65534;
+65534;

tests_lit/parse_errs/symtab-after-fcn.test

+; Test if we detect if the value symbol table appears after a function block.
+
+; REQUIRES: no_minimal_build
+
+; RUN: not %pnacl_sz -bitcode-as-text %p/Inputs/symtab-after-fcn.tbc \
+; RUN:     -bitcode-format=pnacl -notranslate -build-on-read 2>&1 \
+; RUN:   | FileCheck %s
+
+; CHECK: Module valuesymtab not allowed after function blocks
+
+; RUN: pnacl-bcfuzz -bitcode-as-text %p/Inputs/symtab-after-fcn.tbc \
+; RUN:   -output - | pnacl-bcdis -no-records | FileCheck -check-prefix=ASM %s
+
+; ASM: module {  // BlockID = 8
+; ASM:   function void @f0() {  // BlockID = 12
+; ASM:   }
+; ASM:   valuesymtab {  // BlockID = 14
+; ASM:   }
+; ASM: }