From a recent build log:

% cat -n /home/wetmore/brad | less

   67 /bin/sh: gcc: not found
   68 gnumake[1]: Entering directory /net/shimmer/export/home/otto/nightlies/jdk7/ws/corba/make'

corba/make/common/shared/Compiler-sun.gmk has:

    33 ifeq ($(PLATFORM), solaris)

    45 # But gcc is still needed no matter what on 32bit
    46 ifeq ($(ARCH_DATA_MODEL), 32)
    47 REQUIRED_GCC_VER = 2.95
    48 GCC =$(GCC_COMPILER_PATH)gcc
    49 _GCC_VER :=$(shell $(GCC) -dumpversion 2>&1 )
    50 GCC_VER :=$(call GetVersion,"$(_GCC_VER)")
    51 endif
    52 endif


but the corba build never needs gcc when on Solaris. It uses the Sun cc to compile src/share/native/com/sun/corba/se/internal/io/ioser.c and create libioser12.so

When building on a system with no gcc on PATH, this generates spurious "/bin/sh: gcc: not found" warnings.