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* [glibc/google/grte/v5-2.27/master] Make gen-XX-const scripts work with llvm-as
@ 2021-08-28 0:42 Fangrui Song
0 siblings, 0 replies; 2+ messages in thread
From: Fangrui Song @ 2021-08-28 0:42 UTC (permalink / raw)
To: glibc-cvs
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=ad41eacfb70e98e13cbfda076ded0c77b387ae8b
commit ad41eacfb70e98e13cbfda076ded0c77b387ae8b
Author: Josh Kunz <jkz@google.com>
Date: Wed Aug 7 11:40:50 2019 -0700
Make gen-XX-const scripts work with llvm-as
The gen-as-const and gen-py-const scripts are used to generate integer constant
definitions from a list of constant C-expressions. This is achieved by
generating a C program with inline `asm` statements, that depend on
these constant expressions. During compilation, the constant expressions
are evaluated, and included in the inline asm. The build process
generates only the assembly, and then used `sed` to extract the values
from the assembly text.
This is clever. It allows the build process to extract the value of C
statements built under the target architecture. The implementation is a
bit fragile, but it is not immediately obvious to me how it could be
improved.
This change slightly modifies `gen-as-const` and `gen-py-const` to emit
valid assembly directives instead of invalid directives that were
previously emitted. Since the values are extracted via string parsing,
this has no effect on the values extracted. This is needed because the
LLVM assembler validates all statements before emitting them, whereas it
appears GCC will literally emit any `asm` directives without validation
or recognition.
Diff:
---
Makerules | 5 ++---
scripts/gen-as-const.awk | 2 +-
scripts/gen-py-const.awk | 2 +-
3 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/Makerules b/Makerules
index 652879038c..1bffdcc147 100644
--- a/Makerules
+++ b/Makerules
@@ -260,7 +260,7 @@ $(py-const): $(py-const-dir)%.py: %.pysym $(py-const-script) \
$(common-before-compile)
$(make-target-directory)
$(AWK) -f $(py-const-script) $< \
- | $(CC) -S $(MOARFLAGS) -o $@.tmp $(CFLAGS) $(CPPFLAGS) -x c -
+ | $(CC) -S -o $@.tmp $(CFLAGS) $(CPPFLAGS) -x c -
echo '# GENERATED FILE\n' > $@.tmp2
echo '# Constant definitions for pretty printers.' >> $@.tmp2
echo '# See gen-py-const.awk for details.\n' >> $@.tmp2
@@ -276,11 +276,10 @@ ifdef gen-as-const-headers
# Generating headers for assembly constants.
# We need this defined early to get into before-compile before
# it's used in sysd-rules, below.
-# clang's integrated assembler doesn't like the freaky tokens.
$(common-objpfx)%.h $(common-objpfx)%.h.d: $(..)scripts/gen-as-const.awk \
%.sym $(common-before-compile)
$(AWK) -f $< $(filter %.sym,$^) \
- | $(CC) -S $(MOARFLAGS) -o $(@:.h.d=.h)T3 $(CFLAGS) $(CPPFLAGS) -x c - \
+ | $(CC) -S -o $(@:.h.d=.h)T3 $(CFLAGS) $(CPPFLAGS) -x c - \
-MD -MP -MF $(@:.h=.h.d)T -MT '$(@:.h=.h.d) $(@:.h.d=.h)'
sed -n 's/^.*@@@name@@@\([^@]*\)@@@value@@@[^0-9Xxa-fA-F-]*\([0-9Xxa-fA-F-][0-9Xxa-fA-F-]*\).*@@@end@@@.*$$/#define \1 \2/p' \
$(@:.h.d=.h)T3 > $(@:.h.d=.h)T
diff --git a/scripts/gen-as-const.awk b/scripts/gen-as-const.awk
index 1ffd5f2c1c..36e6de303c 100644
--- a/scripts/gen-as-const.awk
+++ b/scripts/gen-as-const.awk
@@ -49,7 +49,7 @@ NF > 1 {
if (test)
print " TEST (" name ", \"" FILENAME ":" FNR "\", " $0 ")";
else
- printf "asm (\"@@@name@@@%s@@@value@@@%%0@@@end@@@\" : : \"i\" ((long) %s));\n",
+ printf "asm (\".ascii \\\"@@@name@@@%s@@@value@@@%%0@@@end@@@\\\"\" : : \"i\" ((long) %s));\n",
name, $0;
}
diff --git a/scripts/gen-py-const.awk b/scripts/gen-py-const.awk
index 91220281c5..beb41964ee 100644
--- a/scripts/gen-py-const.awk
+++ b/scripts/gen-py-const.awk
@@ -111,7 +111,7 @@ NF > 1 {
# '$0' ends up being everything that appeared after the first field
# separator.
- printf " asm (\"@name@%s@value@%0@\" : : \"i\" (%s));\n", name, $0;
+ printf " asm (\".ascii \\\"@name@%s@value@%0@\\\"\" : : \"i\" (%s));\n", name, $0;
}
# Close the 'dummy' function.
^ permalink raw reply [flat|nested] 2+ messages in thread
* [glibc/google/grte/v5-2.27/master] Make gen-XX-const scripts work with llvm-as
@ 2019-08-12 18:35 Josh Kunz
0 siblings, 0 replies; 2+ messages in thread
From: Josh Kunz @ 2019-08-12 18:35 UTC (permalink / raw)
To: glibc-cvs
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=cf8e3f8757941f0ee2842eb3942273ebc7897e86
commit cf8e3f8757941f0ee2842eb3942273ebc7897e86
Author: Josh Kunz <jkz@google.com>
Date: Wed Aug 7 11:40:50 2019 -0700
Make gen-XX-const scripts work with llvm-as
The gen-as-const and gen-py-const scripts are used to generate integer constant
definitions from a list of constant C-expressions. This is achieved by
generating a C program with inline `asm` statements, that depend on
these constant expressions. During compilation, the constant expressions
are evaluated, and included in the inline asm. The build process
generates only the assembly, and then used `sed` to extract the values
from the assembly text.
This is clever. It allows the build process to extract the value of C
statements built under the target architecture. The implementation is a
bit fragile, but it is not immediately obvious to me how it could be
improved.
This change slightly modifies `gen-as-const` and `gen-py-const` to emit
valid assembly directives instead of invalid directives that were
previously emitted. Since the values are extracted via string parsing,
this has no effect on the values extracted. This is needed because the
LLVM assembler validates all statements before emitting them, whereas it
appears GCC will literally emit any `asm` directives without validation
or recognition.
Diff:
---
Makerules | 10 ++--------
scripts/gen-as-const.awk | 2 +-
scripts/gen-py-const.awk | 2 +-
3 files changed, 4 insertions(+), 10 deletions(-)
diff --git a/Makerules b/Makerules
index e19c3a2..1bffdcc 100644
--- a/Makerules
+++ b/Makerules
@@ -225,11 +225,6 @@ sed-remove-dotdot := -e 's@ *\([^ \/$$][^ \]*\)@ $$(..)\1@g' \
-e 's@^\([^ \/$$][^ \]*\)@$$(..)\1@g'
endif
-MOARFLAGS =
-ifeq ($(with-clang),yes)
-MOARFLAGS = -no-integrated-as -funique-section-names
-endif
-
ifdef gen-py-const-headers
# We'll use a static pattern rule to match .pysym files with their
# corresponding generated .py files.
@@ -265,7 +260,7 @@ $(py-const): $(py-const-dir)%.py: %.pysym $(py-const-script) \
$(common-before-compile)
$(make-target-directory)
$(AWK) -f $(py-const-script) $< \
- | $(CC) -S $(MOARFLAGS) -o $@.tmp $(CFLAGS) $(CPPFLAGS) -x c -
+ | $(CC) -S -o $@.tmp $(CFLAGS) $(CPPFLAGS) -x c -
echo '# GENERATED FILE\n' > $@.tmp2
echo '# Constant definitions for pretty printers.' >> $@.tmp2
echo '# See gen-py-const.awk for details.\n' >> $@.tmp2
@@ -281,11 +276,10 @@ ifdef gen-as-const-headers
# Generating headers for assembly constants.
# We need this defined early to get into before-compile before
# it's used in sysd-rules, below.
-# clang's integrated assembler doesn't like the freaky tokens.
$(common-objpfx)%.h $(common-objpfx)%.h.d: $(..)scripts/gen-as-const.awk \
%.sym $(common-before-compile)
$(AWK) -f $< $(filter %.sym,$^) \
- | $(CC) -S $(MOARFLAGS) -o $(@:.h.d=.h)T3 $(CFLAGS) $(CPPFLAGS) -x c - \
+ | $(CC) -S -o $(@:.h.d=.h)T3 $(CFLAGS) $(CPPFLAGS) -x c - \
-MD -MP -MF $(@:.h=.h.d)T -MT '$(@:.h=.h.d) $(@:.h.d=.h)'
sed -n 's/^.*@@@name@@@\([^@]*\)@@@value@@@[^0-9Xxa-fA-F-]*\([0-9Xxa-fA-F-][0-9Xxa-fA-F-]*\).*@@@end@@@.*$$/#define \1 \2/p' \
$(@:.h.d=.h)T3 > $(@:.h.d=.h)T
diff --git a/scripts/gen-as-const.awk b/scripts/gen-as-const.awk
index 1ffd5f2..36e6de3 100644
--- a/scripts/gen-as-const.awk
+++ b/scripts/gen-as-const.awk
@@ -49,7 +49,7 @@ NF > 1 {
if (test)
print " TEST (" name ", \"" FILENAME ":" FNR "\", " $0 ")";
else
- printf "asm (\"@@@name@@@%s@@@value@@@%%0@@@end@@@\" : : \"i\" ((long) %s));\n",
+ printf "asm (\".ascii \\\"@@@name@@@%s@@@value@@@%%0@@@end@@@\\\"\" : : \"i\" ((long) %s));\n",
name, $0;
}
diff --git a/scripts/gen-py-const.awk b/scripts/gen-py-const.awk
index 9122028..beb4196 100644
--- a/scripts/gen-py-const.awk
+++ b/scripts/gen-py-const.awk
@@ -111,7 +111,7 @@ NF > 1 {
# '$0' ends up being everything that appeared after the first field
# separator.
- printf " asm (\"@name@%s@value@%0@\" : : \"i\" (%s));\n", name, $0;
+ printf " asm (\".ascii \\\"@name@%s@value@%0@\\\"\" : : \"i\" (%s));\n", name, $0;
}
# Close the 'dummy' function.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2019-08-12 18:35 Josh Kunz
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