Fix sanity check issue

.gitignore

@@ -95,7 +95,6 @@ DerivedData
 *.pbobjc.*
 *.pbrpc.*
 src/objective-c/**/Build
-src/objective-c/boringssl_prefix_headers
 
 # Cocoapods artifacts
 Pods/

templates/src/objective-c/BoringSSL-GRPC.podspec.template

@@ -223,9 +223,18 @@
       % endfor
       EOF
 
-      # Grab prefix header from Github repo
+      # To avoid symbol conflict with OpenSSL, gRPC needs to rename all the BoringSSL symbols with a 
+      # prefix. This is done with BoringSSL's BORINGSSL_PREFIX mechanism
+      # (https://github.com/google/boringssl/blob/75148d7abf12bdd1797fec3c5da9a21963703516/BUILDING.md#building-with-prefixed-symbols).
+      # The required prefix header file boringssl_prefix_symbols.h is not part of BoringSSL repo at
+      # this moment. It has to be generated by BoringSSL's users and be injected to BoringSSL build.
+      # gRPC generates this file in script /tools/distrib/upgrade_boringssl_objc.sh. This script
+      # outputs a gzip+base64 encoded version of boringssl_prefix_symbols.h because of Cocoapods'
+      # limit on the 'prepare_command' field length. The encoded header is put at
+      # /src/boringssl/boringssl_prefix_symbols.h.gz.b64. Here we decode the content and inject
+      # the header to correcty location in BoringSSL.
       base64 -D <<EOF | gunzip > include/openssl/boringssl_prefix_symbols.h
-      % for line in open("src/objective-c/boringssl_prefix_headers/boringssl_prefix_symbols.h.gz.base64", "r").readlines():
+      % for line in open("src/boringssl/boringssl_prefix_symbols.h.gz.b64", "r").readlines():
         ${line}\
       % endfor
       EOF
@@ -234,7 +243,8 @@
       find . -type f \\( -path '*.h' -or -path '*.cc' -or -path '*.c' \\) -print0 | xargs -0 -L1 sed -E -i'.grpc_back' 's;#include <openssl/;#include <openssl_grpc/;g'
       # BoringSSL include boringssl_prefix_symbols.h without any prefix, which does not match the
 
-      # Xcode import style. We add it here so that Xcode knows where to find it.
+      # Include of boringssl_prefix_symbols.h does not follow Xcode import style. We add the package
+      # name here so that Xcode knows where to find it.
       find . -type f \\( -path '*.h' -or -path '*.cc' -or -path '*.c' \\) -print0 | xargs -0 -L1 sed -E -i'.grpc_back' 's;#include <boringssl_prefix_symbols.h>;#include <openssl_grpc/boringssl_prefix_symbols.h>;g'
     END_OF_COMMAND
   end

tools/distrib/upgrade_boringssl_objc.sh

@@ -22,7 +22,7 @@ cd "$(dirname $0)"
 cd ../../third_party/boringssl
 
 BORINGSSL_COMMIT=$(git rev-parse HEAD)
-BORINGSSL_PREFIX_HEADERS_DIR=src/objective-c/boringssl_prefix_headers
+BORINGSSL_PREFIX_HEADERS_DIR=src/boringssl
 
 # Do the following in grpc root directory
 cd ../..

tools/dockerfile/grpc_objc/generate_boringssl_prefix_header/generate_boringssl_prefix_header.sh

@@ -36,6 +36,6 @@ make boringssl_prefix_symbols
 
 [ -f symbol_prefix_include/boringssl_prefix_symbols.h ] || { echo "Failed to build boringssl_prefix_symbols.sh" ; exit 1 ; }
 
-gzip -c symbol_prefix_include/boringssl_prefix_symbols.h | base64 > /output/boringssl_prefix_symbols.h.gz.base64
+gzip -c symbol_prefix_include/boringssl_prefix_symbols.h | base64 > /output/boringssl_prefix_symbols.h.gz.b64
 
 exit 0