refactor applypatch and friends

Change the applypatch function to take meaningful arguments instead of
argc and argv.  Move all the parsing of arguments into main.c (for the
standalone binary) and into install.c (for the updater function).
applypatch() takes patches as Value objects, so we can pass in blobs
extracted from the package without ever writing them to temp files.

The patching code is changed to read the patch from memory instead of
a file.

A bunch of compiler warnings (mostly about signed vs unsigned types)
are fixed.

Support for the IMGDIFF1 format is dropped.  (We've been generating
IMGDIFF2 packages for some time now.)

Change-Id: I217563c500012750f27110db821928a06211323f
diff --git a/applypatch/main.c b/applypatch/main.c
index e08f5c1..3917f86 100644
--- a/applypatch/main.c
+++ b/applypatch/main.c
@@ -15,8 +15,126 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
-extern int applypatch(int argc, char** argv);
+#include "applypatch.h"
+#include "edify/expr.h"
+#include "mincrypt/sha.h"
+
+int CheckMode(int argc, char** argv) {
+    if (argc < 3) {
+        return 2;
+    }
+    return applypatch_check(argv[2], argc-3, argv+3);
+}
+
+int SpaceMode(int argc, char** argv) {
+    if (argc != 3) {
+        return 2;
+    }
+    char* endptr;
+    size_t bytes = strtol(argv[2], &endptr, 10);
+    if (bytes == 0 && endptr == argv[2]) {
+        printf("can't parse \"%s\" as byte count\n\n", argv[2]);
+        return 1;
+    }
+    return CacheSizeCheck(bytes);
+}
+
+// Parse arguments (which should be of the form "<sha1>" or
+// "<sha1>:<filename>" into the new parallel arrays *sha1s and
+// *patches (loading file contents into the patches).  Returns 0 on
+// success.
+static int ParsePatchArgs(int argc, char** argv,
+                          char*** sha1s, Value*** patches, int* num_patches) {
+    *num_patches = argc;
+    *sha1s = malloc(*num_patches * sizeof(char*));
+    *patches = malloc(*num_patches * sizeof(Value*));
+    memset(*patches, 0, *num_patches * sizeof(Value*));
+
+    uint8_t digest[SHA_DIGEST_SIZE];
+
+    int i;
+    for (i = 0; i < *num_patches; ++i) {
+        char* colon = strchr(argv[i], ':');
+        if (colon != NULL) {
+            *colon = '\0';
+            ++colon;
+        }
+
+        if (ParseSha1(argv[i], digest) != 0) {
+            printf("failed to parse sha1 \"%s\"\n", argv[i]);
+            return -1;
+        }
+
+        (*sha1s)[i] = argv[i];
+        if (colon == NULL) {
+            (*patches)[i] = NULL;
+        } else {
+            FileContents fc;
+            if (LoadFileContents(colon, &fc) != 0) {
+                goto abort;
+            }
+            (*patches)[i] = malloc(sizeof(Value));
+            (*patches)[i]->type = VAL_BLOB;
+            (*patches)[i]->size = fc.size;
+            (*patches)[i]->data = (char*)fc.data;
+        }
+    }
+
+    return 0;
+
+  abort:
+    for (i = 0; i < *num_patches; ++i) {
+        Value* p = (*patches)[i];
+        if (p != NULL) {
+            free(p->data);
+            free(p);
+        }
+    }
+    free(*sha1s);
+    free(*patches);
+    return -1;
+}
+
+int PatchMode(int argc, char** argv) {
+    if (argc < 6) {
+        return 2;
+    }
+
+    char* endptr;
+    size_t target_size = strtol(argv[4], &endptr, 10);
+    if (target_size == 0 && endptr == argv[4]) {
+        printf("can't parse \"%s\" as byte count\n\n", argv[4]);
+        return 1;
+    }
+
+    char** sha1s;
+    Value** patches;
+    int num_patches;
+    if (ParsePatchArgs(argc-5, argv+5, &sha1s, &patches, &num_patches) != 0) {
+        printf("failed to parse patch args\n");
+        return 1;
+    }
+
+    int result = applypatch(argv[1], argv[2], argv[3], target_size,
+                            num_patches, sha1s, patches);
+
+    int i;
+    for (i = 0; i < num_patches; ++i) {
+        Value* p = patches[i];
+        if (p != NULL) {
+            free(p->data);
+            free(p);
+        }
+    }
+    free(sha1s);
+    free(patches);
+
+    return result;
+}
 
 // This program applies binary patches to files in a way that is safe
 // (the original file is not touched until we have the desired
@@ -42,9 +160,9 @@
 // LoadMTDContents() function above for the format of such a filename.
 
 int main(int argc, char** argv) {
-  int result = applypatch(argc, argv);
-  if (result == 2) {
-    printf(
+    if (argc < 2) {
+      usage:
+        printf(
             "usage: %s <src-file> <tgt-file> <tgt-sha1> <tgt-size> "
             "[<src-sha1>:<patch> ...]\n"
             "   or  %s -c <file> [<sha1> ...]\n"
@@ -55,6 +173,23 @@
             "  MTD:<partition>:<len_1>:<sha1_1>:<len_2>:<sha1_2>:...\n"
             "to specify reading from or writing to an MTD partition.\n\n",
             argv[0], argv[0], argv[0], argv[0]);
-  }
-  return result;
+        return 2;
+    }
+
+    int result;
+
+    if (strncmp(argv[1], "-l", 3) == 0) {
+        result = ShowLicenses();
+    } else if (strncmp(argv[1], "-c", 3) == 0) {
+        result = CheckMode(argc, argv);
+    } else if (strncmp(argv[1], "-s", 3) == 0) {
+        result = SpaceMode(argc, argv);
+    } else {
+        result = PatchMode(argc, argv);
+    }
+
+    if (result == 2) {
+        goto usage;
+    }
+    return result;
 }