generalize commandline options and add global-base option for s2wasm

3 files changed, 26 insertions, 13 deletions

diff --git a/src/command-line.h b/src/command-line.h
index 63cf09d9f..4b8b12b4c 100644
--- a/src/command-line.h
+++ b/src/command-line.h
@@ -26,9 +26,12 @@
 namespace wasm {
 
 struct Options {
+  // standard options
   bool debug;
   std::string infile;
   std::string outfile;
+  // extra options
+  std::map<std::string, const char*> extra;
   Options() : debug(false) {}
 };
 
@@ -37,17 +40,11 @@ bool optionIs(const char *arg, const char *LongOpt, const char *ShortOpt) {
 }
 
 // TODO(jfb) Make this configurable: callers should pass in option handlers.
-void processCommandLine(int argc, const char *argv[], Options *options) {
+void processCommandLine(int argc, const char *argv[], Options *options, const char *help) {
   assert(argc > 0 && "expect at least program name as an argument");
   for (size_t i = 1, e = argc; i != e; ++i) {
     if (optionIs(argv[i], "--help", "-h")) {
-      std::cerr << "s2wasm INFILE\n\n"
-                   "Link .s file into .wast\n\n"
-                   "Optional arguments:\n"
-                   "  -n, --help    Show this help message and exit\n"
-                   "  -d, --debug   Print debug information to stderr\n"
-                   "  -o, --output  Output file (stdout if not specified)\n"
-                << std::endl;
+      std::cerr << help;
       exit(EXIT_SUCCESS);
     } else if (optionIs(argv[i], "--debug", "-d")) {
       options->debug = true;
@@ -62,6 +59,14 @@ void processCommandLine(int argc, const char *argv[], Options *options) {
         exit(EXIT_FAILURE);
       }
       options->outfile = argv[++i];
+    } else if (argv[i][0] == '-' && argv[i][1] == '-') {
+      size_t j = 2;
+      std::string name;
+      while (argv[i][j] && argv[i][j] != '=') {
+        name += argv[i][j];
+        j++;
+      }
+      options->extra[name] = argv[i][j] == '=' ? &argv[i][j+1] : "(no value)";
     } else {
       if (options->infile.size()) {
         std::cerr << "Expected only one input file, got '" << options->infile
diff --git a/src/s2wasm-main.cpp b/src/s2wasm-main.cpp
index cb60d2a57..86a9737a7 100644
--- a/src/s2wasm-main.cpp
+++ b/src/s2wasm-main.cpp
@@ -26,7 +26,14 @@ using namespace wasm;
 
 int main(int argc, const char *argv[]) {
   Options options;
-  processCommandLine(argc, argv, &options);
+  processCommandLine(argc, argv, &options,
+                     "s2wasm INFILE\n\n"
+                     "Link .s file into .wast\n\n"
+                     "Optional arguments:\n"
+                     "  -n, --help        Show this help message and exit\n"
+                     "  -d, --debug       Print debug information to stderr\n"
+                     "  -o, --output      Output file (stdout if not specified)\n"
+                     "  --global-base=N   Where to start to place globals\n");
 
   std::string input;
   {
@@ -62,7 +69,8 @@ int main(int argc, const char *argv[]) {
 
   if (options.debug) std::cerr << "Parsing and wasming..." << std::endl;
   AllocatingModule wasm;
-  S2WasmBuilder s2wasm(wasm, input.c_str(), options.debug);
+  size_t globalBase = options.extra["global-base"] ? atoi(options.extra["global-base"]) : 1;
+  S2WasmBuilder s2wasm(wasm, input.c_str(), options.debug, globalBase);
 
   if (options.debug) std::cerr << "Emscripten gluing..." << std::endl;
   std::stringstream meta;
diff --git a/src/s2wasm.h b/src/s2wasm.h
index b732464d9..467f912bf 100644
--- a/src/s2wasm.h
+++ b/src/s2wasm.h
@@ -40,8 +40,8 @@ class S2WasmBuilder {
   bool debug;
 
 public:
- S2WasmBuilder(AllocatingModule& wasm, const char* input, bool debug)
-     : wasm(wasm), allocator(wasm.allocator), debug(debug) {
+ S2WasmBuilder(AllocatingModule& wasm, const char* input, bool debug, size_t nextStatic)
+     : wasm(wasm), allocator(wasm.allocator), debug(debug), nextStatic(nextStatic) {
    s = input;
    scan();
    s = input;
@@ -52,7 +52,7 @@ public:
 private:
   // state
 
-  size_t nextStatic = 1; // location of next static allocation, i.e., the data segment
+  size_t nextStatic; // location of next static allocation, i.e., the data segment
   std::map<Name, int32_t> staticAddresses; // name => address
 
   struct Addressing {